Friday, March 31, 2023

Tornado Outbreak Is, Sadly Very Bad, And It Isn't Over

Image from television station KATV shows a large,
destructive tornado today in the Little Rock, Arkansas area.
Just a quick evening update on the tornado situation in the Midwest and South. 

We're probably not even halfway done with this tornado outbreak as of 6 p.m. eastern time and already the news is bad. And it will get worse. 

So far, the worse news is from the Little Rock, Arkansas, area. The west and north side of the metro area was hit hard by a large tornado this afternoon.

Details are still sketchy, but there are reports of at least 600 injuries, and not enough ambulances to transport victims.  in Local hospitals declared a mass casualty event. Video emerging from Little Rock show badly damaged or destroyed houses and cars tossed about on highways. Commercial buildings appear to have also suffered a lot of damage.

More tornadoes remain across much of Arkansas. Little Rock might be hit again, as supercells with possible tornadoes look like they might be headed toward the southeastern side of Little Rock. 

Meanwhile, at least one large, long lasting tornado was marauding through Iowa. Video from Iowa shows a massive tornado chugging through farm country. At last report, the huge tornado was just west of Iowa City.  It appeared that Cedar Rapids could be endangered by this twister a little later on. 

Tornadoes, some violent and long-lasting, are forecast to last well into the evening in a broad area of the Midwest and South. 

Meanwhile, back here in Vermont, it snowed today. But they have increased the threat of severe thunderstorms. As of this morning, only a low, low marginal risk of severe storms was up for southern Vermont. It was level one on a five point alert scale.

Now, southern Vermont is  under a "slight" risk of severe storms, which is level 2 on the five point scale. The marginal risk has been extended north to just south of the Canadian border. There's also now a very, very low, but not zero chance of a tornado in a narrow band, from the Vermont/New Hampshire border near Brattleboro, through southwestern New England, the New York City area and on into New Jersey.

I'll have a much bigger update tomorrow.


After A (Mostly) Steady State March, Vermont Is In For Dug Nap-Style Weather Roller Coaster

The scene in one of my perennial gardens today fits the
highly changeable weather we'll have the next couple
of days. Note the snowbanks AND the tender
green spring shoots coming up.
 We in Vermont are now in a weather pattern in which pretty much anything could happen, and probably will. So buckle up! 

On the very bright side, there's nothing super destructive or dangerous in our forecast, in contrast to the tornadoes, severe weather, winter storms and floods forecast for much of the nation's midsection today.

We'll still need to stay on our toes, though..

Those snow squalls Wednesday night pretty much behaved as expected. They were spotty, but where they hit, you had these brief blizzards of zero visibility and strong gusty winds. 

When it came through St. Albans, we didn't really get much snow, but the roar of the wind in the darkness was pretty impressive.  We also saw a couple lightning flashes to our west, and later, more lightning was reported near Jay Peak. 

After a chilly but bright Thursday, more changes are coming along, fast and furiously. 

Today will cloud up pretty fast, if it isn't already overcast where you are. An approaching warm front today will ironically not cause warm weather. 

Instead, rain or snow will break out. Even in the valleys, any initial rain will change to snow as the precipitation helps cool the atmosphere, at least temporarily. The snow, maybe mixed with rain in the warmer valleys will continue into the evening. 

Most places should only get a slushy coating to maybe an inch or two in the high spots.  The peak of this will hit during the evening commute, but main roads should stay in pretty good shape. Some back roads, especially in higher elevations, might get a little iffy.

Overnight we'll have drizzle and fog and maybe a little freezing drizzle in the cold spots. Again, annoying, but not the end of the world. 

SATURDAY SURPRISES?

Saturday - April Fool's Day - will fittingly bring us pretty much all kinds of possible weather. It'll pretty much be like that Dug Nap artwork with a forecast of some pretty wild weather changes. 

It won't turn out to be as extreme as in Dug Nap's imagination, but the weather on Saturday will seem to change every hour. 

 A burst of rain should come through Saturday mornin amid raw temperatures in the low 40s.

 Then the sun might actually peek through the clouds for awhile, and temperatures should rocket upward. Warmer valleys, especially west of the Green Mountains, should make it into the low 60s. If that happens, it'll be the warmest since mid-November.  A sign of spring, finally. 

There's actually a marginal risk of
severe storms in parts of Vermont
tomorrow. Sign of spring?

The "problem" with the warm temperatures is that will help make the air unstable. This could set off some showers and thunderstorms. Again springlike.   Another sign of spring is that for the first time this year, NOAA's Storm Prediction Center has parts of Vermont in a risk zone for severe thunderstorms. 

Before you panic, it's the lowest level one risk out of five risk categories. That means there might - maybe - be one or two instances of damaging wind gusts in the most vigorous thunderstorms. This would be mostly south of Route 2. Although there might be a rumble or two of thunder further north. 

Then we get a sharp cold front. Temperatures will tumble down to within a few degrees of 20 late Saturday night as rain showers change to snow showers. Fortunately, we won't have much accumulation. 

But during Saturday night and Sunday morning, after all those bursts of rain and the mild weather on Saturday afternoon, we'll probably have some minor flooding. 

 Luckily, this storm won't be powerful for us, anyway, to touch off anything major. But you'll see fields under water, probably. And the low lying roads that usually get flooded in the spring probably will in this go around, too.

The yo-yo weather continues into next week, at least. It'll be a very chilly day for early April on Sunday, with highs barely making into the 30s.  But we'll have a nice rebound to 50 or above next week. But there's a lot of questions as to how warm it will get and how long it will last. Plus, we'll have other fitful bursts of rain to contend with, too. 

 

Rare High Risk Tornado Alert In Midwest as Wild Weather Hits Much Of Nation

The map on the home page of the National Weather Service
is getting colorful again, which means there's a wide
variety of weather hazards in the nation today. 
 UPDATE 1:15 PM

NOAA's Storm Prediction Center has issued a rare high risk alert for two areas in the nation's middle, as fears grow of violent, exceedingly dangerous and long lasting tornadoes.

The high risk zones center in one area near the Iowa/Illinois border and another one in northern Mississippi, southwestern Tennessee and eastern Arkansas 

High risk alerts like this are rare and basically a hair on fire alarm that powerful, deadly tornadoes are likely,

This is the first high risk tornado alert NOAA has issued since March, 2021. On average, a high risk alert is issued  two or three times a year, but some years  have none and a few years can have as many as six. 

A "Particularly Dangerous Tornado Watch has been issued for parts of Iowa, Illinois and Missouri, and one will probably be issues soon further south. Numerous supercells were poised to erupt in Iowa as of this writing. 

Also, the moderate risk area, the second highest severe weather alert, has been greatly expanded to include a broad area centered on the mid-Mississippi Valley. 
Pink areas are high risk areas today for violent, long-lasting
tornadoes. It's the first high risk alert since March 2021.
The red area is moderate risk for dangerous tornadoes and
severe weather, level four out of five levels of risk.
That's an unusually large area to be under moderate risk 

It's going to be a dangerous, potentially deadly afternoon and evening across the nation's middle.  We can only hope the strongest tornadoes stay in very rural areas and avoid cities and towns. 


PREVIOUS DISCUSSION

A classic spring storm is bringing a huge variety of sometimes dangerous weather to much of the United States today. 

The biggest threat continues to be the possibility of some large, long lasting and intense tornadoes. The most likely targets for this are Iowa, western Illinois, and a big circle centered just about on Memphis, Tennessee.

There could be other tornadoes between these two higher danger areas, too.  I would say anybody who lives in the highest tornado danger area today and live in mobile homes or other comparatively weak structures should just move out today and hang out in someplace safer until the threat passes tonight. 

Large hail and destructive straight line winds in this region will get at some people who are fortunate to miss any tornadoes. I'm hoping we don't have a death toll like we had in Mississippi last Friday. 

Elsewhere, it's not quite as dangerous but still hair-raising. Outside the tornado risk zone, I'd give South Dakota the nod for the worst place to be today. 

This was the earlier severe weather outlook from this morning
showing only two patches of moderate risk, which is level
four out of five. Compared to the new map, you can see
how much worse things have gotten. 
The eastern half of South Dakota, except for the far southeastern corner, is under a blizzard warning today into tomorrow morning. Up to a foot of snow with gusts up to 55 mph are expected. 

To make matters worse, parts of the blizzard zone are in an ice storm warning, too.  Freezing rain threatens to pile up on trees and wires enough to make them break just before the blizzard conditions hit with those winds. Power outages and tree damage look to be pretty inevitable. 

Well south of this zone, strong, dry winds threaten to set off grass and rangeland fires in vast areas of Kansas, Oklahoma, Texas and western Missouri. 

Humidity will be in the bone-dry 10 to 20 percent range today as winds gust to over 50 mph. Meanwhile, flooding looks to be a problem in parts of the South today. 

Wind advisories and warnings cover probably a quarter of the nation from New Mexico to Pennsylvania. 

As you'll see in a separate post this morning that here in Vermont, the weather will be wonky as heck for the next couple of days. But at least it won't be super dangerous, so we can count our blessings. 

 

Thursday, March 30, 2023

Wow! Here's A Switch! First Warmer/Drier Than Normal Forecast in California In Many Weeks

Funny how a routine long range forecast can blow a weather geek of their seat.

Here's something not seen in months: Drier than 
normal weather is forecast in California 8 to14
days from now after an incredibly stormy winter. 
Today, I took a gander at the daily updated eight to 14 day United States weather outlook from the National Weather Service Climate Prediction Center. 

This forecast, covering April 7 to 13 is starting lean toward above normal temperatures in northern California and near normal reading in the southern half of the state. This April 7-13 period also has the state in drier than normal conditions.

This is the first time in many, many weeks in which the West Coast forecast did not call for well below normal temperatures and well above normal rain and snowfall. 

This news, welcome by many no doubt, comes after another cold storm dumped another one to two feet of snow on many of California's snow-crushed higher elevations. 

The latest storm brings the snowpack in the Sierra Nevada to the deepest and wettest since at least before 1983, and is probably in the top 5 list dating to the 1950s.  

The snowpack in Utah's mountains has also reached a record high. The snow measuring equipment at the top of Little Cottonwood Canyon in Utah is actually buried. There's 13.5 feet of snow on the ground at this site. 

The eight to 14 day forecast in Utah calls for greater than equal chances of cooler and drier than normal conditions. 

One caveat to note is the eight to 14 day forecasts aren't alway right. A lot can happen in the atmosphere over the course of a week to make the prediction wrong. 

The 8 to 14 day forecast also leans slightly
toward warmer than average conditions in California

A little bit of warm, dry weather in California is no problem, as the snow gradually begins to melt.  They'll have to watch out for sustained very warm to hot weather that could occur later in April and May which could melt the snow too fast, resulting in flooding. 

For what it's worth, the six to 10 day outlook for Vermont calls for a welcome spate of warmer than normal temperatures with possibly somewhat above normal precipitation. 

The eight to 14 day forecast for Vermont calls for near normal temperatures and rainfall.

Normal temperatures in the April 7-13 time frame in Vermont feature highs of around 50 degrees and lows near the freezing point. 

Satellite Photo Shows Vermont Snow Melt Progress

Visible satellite view of Vermont on Wednesday shows
many valley areas have lost their snow. Some interesting
areas in there, too. Click on the photo to make it 
bigger and easier to pick out details. 
 I came across an interesting visible satellite photo on the Burlington National Weather Service office web page yesterday, before the clouds rolled in. 

It gave a very clear view of how the snow has melted out of the Champlain Valley, and some of the lowlands in the Connecticut River Valley. 

The photo is in this post. Click on the image to make it bigger and easier to pick details out. 

One thing I noticed is the sharp line between no snow and snow in eastern Bennington, Rutland and Addison counties. 

The valley floors are virtually free of snow, but go up just a tiny bit in elevation along the western slopes of the Green Mountains, and you encounter solid snowpack. 

I noticed this as I drove through parts of Addison and Rutland counties on Sunday. Often during the spring thaw, the snow cover somewhat gradually goes from bare ground, to patchy to mostly snow to complete snow. On Sunday's trip,  I could see the abrupt change from no snow to complete snow cover,

This probably has a lot to do with the snowstorm on March 14-15. It was highly elevation dependent. The lowest elevations got modest amounts of snow, while elevations from about 900 feet and up got clobbered. That's probably part of what you see along those western slopes. 

If you also look closely, you can see the snow on the Taconic mountains in northwestern Bennington and western Rutland County. Again, you can discern the valleys. The little gap in the snow cover heading southeast to northwest in northern Bennington County and southwestern Rutland County is the Route 30 corridor in the Mettawee Valley.

By the way, that Mettawee Valley area of Route 30 is in my opinion the prettiest stretch of road in Vermont. Definitely worth a trip. 

Along another stretch of Route 30 in southeastern Vermont, you can see the snow free valley it travels heading northwest from Brattleboro, until the road encounters higher elevations and snow cover somewhere near Townshend or Jamaica. 

You can also see a gap in the snow cover in west-central Rutland County, with just a patch of snow to the north. That gap is the valley Route 4 takes toward Whitehall, New York. The small white patch to the north of Route 4 is Grandpa's Knob, and probably one or two higher peaks before the Taconics dwindle to nothing west of Brandon. 

A also think Grandpa's Knob is a wonderful name for a mountain. Or a senior citizen rock band. 

Looking much further north, if you squint your eyes,  you can sort of detect a narrow "crack" in the snow cover from far eastern Chittenden County through much of central Washington County. That's the Winooski River valley. The valley floor has little snow, but just slightly uphill from the river, you encounter a decent snow cover, 

Even further north, that patch of snow in central Franklin County just east of St. Albans is St. Albans Hill, just to the south of where I live.  My house is a third of the way up an adjacent, slightly smaller hill.  

I can attest that yesterday the bottom of the hill was snow free, my  yard still had patches of snow, and the top of the hill was almost totally snow covered. My hill is the tiny white dot north of the patch of white that is St. Albans Hill. 

You can also see that Lake Champlain is largely clear of ice, except the eastern part of the Lake from Malletts Bay in Colchester on up to St. Albans Bay.  The bays in the northern parts of the lake are usually the last to lose their ice in the spring. 

As we go through the next several weeks, on clear days, you'll see satellite images showing the snow cover retreating from both western and eastern Vermont, until only the summits of the Green Mountains. 

A New, Large Tornado Threat Looms Friday In Middle Of Nation. Also, Climate Change Worsening These Storms?

Areas in yellow, orange and red are in danger of severe
thunderstorms and tornadoes Friday. The areas in 
red are in particularly high danger. 
 After Friday's deadly tornadoes in Mississippi last Friday that killed 26 people, and sporadic severe weather daily since, a new, large threat is looming this coming Friday. 

Details are still sparse on the details of  how widespread and how violent the next round or severe weather will become, there's potential for some strong tornadoes.

The danger zone is also very unusually large. At this point a broad area centered on the central Mississippi Valley is under threat. 

Areas that could have severe weather and tornadoes extend from northern Iowa to central Louisiana, and from Missouri to Ohio. 

The culprit will be a strong storm system that will develop in the central Plains and pull a big plume of warm, very humid air northward all the way to the southern Great Lakes. 

The muggy, unstable air, combined with the spin in the atmosphere the large storm will help to provide, will trigger the severe weather.  The predicted storm is a classic set up for a big severe weather outbreak. 

That storm will eventually affect us here in Vermont. We son't have any tornadoes, but we will see rain, possibly starting out mixed with snow, a squirt of warm air, and possibly some downpours and some thunder. This could trigger some flooding if it gets toasty enough to melt a lot of snow and/or if it rains extra hard. 

A sharp cold front will plunge us briefly into near winter conditions Sunday before somewhat milder air arrives again.

Back to the tornadoes, after this week's system departs, another, similar storm seems poised to raise another tornado threat during the middle of next week, 

CLIMATE CHANGE

New research indicates climate change will increase the number of supercells hitting the United States overall, and more importantly shift the location of them further east, and extend the time of year they are more prevalent, reports the Associated Press.

The news is from a study by lead author Walker Ashley ad co-author Victor Gesini, meteorologists who study tornadoes and trends. 

A supercell thunderstorm looking north from Sheldon,
Vermont in May, 2018. Studies show supercells
will be getting more common in the eastern 
U.S. with climate change and somewhat less common
in the traditional "tornado alley" in the Great Plains. 

 Supercells are long-lasting, powerful thunderstorms with a very robust, rotating updraft of wind. Unlike garden variety thunderstorms, which typically blossom, then die within an hour or two, supercells often last for many hours over a long path. 

Not all supercells produce tornadoes. But if you're hit by a supercell, you're almost guaranteed to see large, damaging hail, destructive winds, or both. 

When supercells do produce tornadoes, some of those twisters can be extremely powerful, large and long-lasting. The tornado that carved a 59-path across Mississippi last week and destroyed towns like Rolling Fork was part of a supercell thunderstorm.

In general, supercells are increasing in number east of Interstate 35 and decreasing somewhat west of Interstate 35.

That interstate runs north/south through Austin and Dallas, Texas, into Oklahoma City and then curves somewhat northeastward to Kansas City before eventually continuing north through Iowa and eastern Minnesota. 

The research is consistent with what we've been already starting to see in recent years.

As the AP reports: "Cities that should see more supercells as warming worsens include Dallas-Fort Worth, Little Rock, Memphis, Jackson, Tupelo, Birmingham and Nashville, Ashley said 

The eastward shift also puts more people at risk because those areas are more densely populated than the traditional tornado alley of Kansas and Oklahoma, Ashley and Genuine said. The population coming under more risk is also poorer and more frequently lives in mobile or manufactured homes, which are more dangerous places in a tornado."

The mechanisms for this eastward trend in supercells and tornadoes is probably that the Southwest is getting hotter and drier, while the Gulf of Mexico is getting warmer, allowing hotter, unstable and more humid air to stream northward. 

The hotter air increases the strength of a "cap" that hinders supercell development, so under climate trends, the storms can't get going in the Plains like they used to. Meanwhile, the pressure builds under the cap until the wannabe storms near or pass the Mississippi River. Then they can explode into supercells. 

The bottom line is about a 7 percent increase in supercells nationwide and a 25 percent jump in the area and time of year they hit by the end of the century. 

By the way, we in Vermont occasionally see supercell thunderstorms. Though they only infrequently cause tornadoes in the Green Mountain State, they do cause wind damage and hail on average once or twice a year. The projections do show an increase in supercells here in Vermont, too. Though we will always have relatively few supercells, the fact that they might increase a little is a problem. 



Wednesday, March 29, 2023

Wednesday Evening Vermont Storm Update: Gorgeous Late This Afternoon, Dangerous, Wintry Within A Few Hours

The cold front and line of snow squalls looked 
really impressive on satellite imagery late 
this afternoon. Hard to pick out Vermont in this photo
but the line was less than an hour from entering
northwestern New York at around 5:15 when
this shot was taken. 
 As expected, today was an absolutely lovely day by late March standards in Vermont, but also, as expected, trouble lurks pretty soon as showers quickly turn to dangerous snow squalls amid gusty winds and rapidly falling temperatures within a few hours from now.  

(For the record, I'm writing this at around 5 p.m. Wednesday).

In Burlington, the temperature hit 50 degrees for the first time this month. In most years, it gets into the 50s and even 60s in March.  Burlington missed out on a warm shot on March 22 that sent most other places in Vermont into the 50s. 

Today was Burlington's first day that reached 50 degrees since a record high of 56 degrees on February 16.

Now, winter is on our doorstep. 

As mentioned this morning an Arctic cold front is barreling in our direction. The National Weather Service is still predicting intense snow squalls, but there have been a few minor changes to the weather forecast.

This morning, I mentioned the possibility of a line of showers and perhaps a rumble of thunder before the main show begins. That seems to be only sort of happening. I do see a few convective showers late this afternoon in northern New York heading into northwestern Vermont, but they don't look particularly impressive.

Convective showers are the type that come from tall, billowing clouds. You see them all the time in the summer. 

The actual squall line, though, does look impressive. As of 5 p.m., it was around Buffalo, New York and just about to head into Ottawa, Canada. Numerous videos on social media show near zero visibility in the snow squalls in southern Ontario. 

It's moving steadily eastward , and will cross into Vermont between about 8:30 p.m., give or take in the northwest corner of Vermont and leave the state sometime around midnight 

When this thing arrives, expect rain initially, but it will change to snow super fast. And it will come down super hard for awhile. And it will have gusty winds. 

One change in the forecast from this morning: They were saying  the squall would be most dramatic in western Vermont. Now, that's changed a bit. The latest forecast indicates it'll be wild enough in western Vermont, but the squall line will consolidate and intensify further in central and eastern parts of the state, says the National Weather Service in South Burlington. 

Bottom line, you will not want to be on the roads tonight starting at around 8:30.  The snow will be briefly blinding. Road conditions will go from fine to awful in minutes.  

This won't last long in any one place, but the roads will probably stay pretty bad overnight amid those rapidly falling temperatures 

Thursday will be better, I suppose. The sun will come back out, but it will not feel at all like spring. Many northern areas will be really lucky to hit the freezing mark in the afternoon. This at a time of year when normal highs are well into the 40s. 

At least the cold snap will be brief. It'll start to turn warmer Friday, at least for a brief stay. But new storminess is due Friday into Sunday. 

I won't get into that now. I'll post about it tomorrow. 

A Possible Wild Evening Wed. Vermont Evening: Snow Squalls, Wind, Temperature Crash, Thunder?

An intense snow squall sweeps into St. Albans, Vermont
in February, 2022. Similar intense squalls are 
possible in Vermont tonight, 
 Aside from a couple snowstorms, this March in Vermont has been pretty even-tempered. 

It's usually a tempestuous month, with wild temperature changes, lots of wind, abrupt shift in weather that kind of thing. We've seen little of that in the past few weeks. 

Until today and especially tonight. Get ready for a pretty bumpy ride.

Today started gorgeous, with clear blue skies and a frosty bite to the air. 

Temperatures will quickly warm up into the 40s to near 50.  Although you'll start to see some clouds come in this afternoon, and a south breeze will pick up, it will be a nice day.  And a perfect set-up for another wonderful sap run for the maple sugarers. 

But lurking to our west and north is a powerful cold front. What it lacks in its mediocre moisture supply is more than made up for in its energy.  You'll really notice this thing when it approaches and comes through. 

THE "PREVIEW"

The cold front is sort of a winter/summer hybrid, but with a little more emphasis on winter. But the early part of the whole thing will have a summer set up on the weather map.

On those hot, humid days when a cold front is approaching, something called a pre-frontal trough forms ahead of the cold front. The trough is sort of a mini preview cold front.  In the summer, the strongest thunderstorms with the weather system are often along the pre-frontal trough.

In the winter, you don't usually see these "preview fronts." Today, you will, but the strongest storms won't be along this. Still, this thing might well create a line of rain showers, with maybe a rumble of thunder, very late this afternoon and early evening. 

After that, the big show arrives.

THE BIG SHOW

The cold front will arrive, and almost all indications point toward a nasty snow squall along it. When it comes in, especially if you're in relatively low elevations in Vermont, it'll start off as a hard rain, then quickly switch to very heavy, blinding snow. There might be more lightning and thunder. 

It won't last long in any given location, but it'll be a nightmare if you're out driving. Visibility will go to zero. Road conditions will go from fine to incredibly slick in an instant.

Timing wise, the National Weather Service in South Burlington says the big squall line will enter northwestern Vermont at roughly 9 p.m., approach the Green Mountains around 10 p.m. and be getting ready to exit Vermont into New Hampshire at around midnight. 

The strongest weather with this squall will probably be north of Route 4 and along and west of the Green Mountains 

Since this won't last long, we won't get a ton of accumulation. Most of us should come in at around an inch. Some of the mountains maybe up to three inches. Southeastern Vermont should see less than an inch. 

AFTERMATH

Temperatures will plunge overnight into the upper teens and low 20s, ensuring any remaining water or slush on the roads turns to ice for your trip to work tomorrow morning. It'll be blustery and quite cold Thursday.  Even though the sun will make an appearance, especially in the afternoon, most of northern Vermont and the high elevations in South should stay at or below freezing all day, 

This will probably, hopefully, be the last continuously subfreezing day  until next November. But of course we can't be sure as April has almost as wild a reputation as March. 

By the way, more storminess, rain, maybe a little flooding,  a little snow and big temperature fluctuations are due Friday through Sunday. I'll post more on that tomorrow, 

Tuesday, March 28, 2023

So What Happens When All That California Snow Melts?

 A week or two ago, I wrote about how the healthy early March snow in Vermont slightly increased the threat of flooding this spring. 

Snowbanks along Interstate 80 in Donner Pass,
California recently. 
So what happens when 50 or feet of snow has to melt under the strong rays of the spring sunshine? 

I'm not sure, but unfortunately, Californians will soon find out. 

The storms are still rolling into California, maybe with less intensity and frequency than they did a few weeks ago, but regardless, bad enough. A warm atmospheric river recently melted a fair amount of snow in some of the blizzard-wracked foothills. That was enough to unleash some serious, damaging floods.

The Sierra snows should be just starting to melt by now. But snowstorms and continued below normal temperatures are continuing. Probably for at least another week or two. Instead of getting rid of some of the snowpack and its water, more additions are coming. 

At least another foot or two of new snow is expected in the Sierra Nevada mountains of California between this morning and tomorrow afternoon. 

The snowpack in the Sierra Nevada typically peaks around April 1. But forecasts indicate that peak might come later this year, as below normal temperatures and above normal precipitation are forecast to last in California at least into mid-April. 

The later we get into spring, the greater the chance a heat wave could strike. That would unleash a lot of water.

There's plenty of water in that snowpack, that's for sure!

As of the middle of last week, some of California's ski areas had received more than 650 inches of snow this season. That's more than 54 feet of snow. Most of that snow is still on the ground. 

The amount of snow in the Sierra Nevada mountains in California exceeds or will soon exceed that of the winters of 1969 and 1983, which until now had been the benchmark for the most snow you can get. 

The results probably won't be good. Especially if California flips to the kind of weather they've seen later in spring - very hot weather. 

As the Washington Post reports: 

"'It is important to understand that we are in uncharted territory,' said Jeffrey Mount, a senior fellow at the Public Policy Institute of California's Water Policy Center, in an email. 'The amount of water tied up in snow in the watershed is about twice the average amount of runoff in an entire year.'

FULL RESERVOIRS/NEW LAKES

When the 1983 snowpack melted, it flooded 100,000 acres of farmland and temporarily re-created a lake that had been drained generations earlier.    Lake Tulare, as it was called,  had been the largest west of the Mississippi, even bigger than the Great Salt Lake more than a century ago. But, it was drained for extensive farmland in California's Central Valley.

However, Lake Tulare partly reappears in especially wet and snowy years, so, it will probably re-appear this year, says that Public Policy Institute.

  It took two year after the 1983 event to pump out the water in temporary Lake Tulare and restore it to cropland, according to the Public Policy Institute.

If Lake Tulare comes back this year, as seems inevitable, it's not all bad. At least a small proportion of it will seep into underground aquifers, which have been over-pumped for decades to feed agriculture, mostly. 

What would have been better for California would have been a series of several winters that were somewhat wetter and snowier than average. That would have allowed reservoirs to fill, but not overflow. Several consecutive sort of wet but not overly soggy and snowy winters would have built back some of the depleted groundwater in California.  

Instead, California has had an epic winter.  Too much of a good thing. This winter's weather has definitely helped erase, or at least sharply dim the state's long-lasting drought. But a lot of this year's runoff can'r be saved up. There's too much of it.  

Reservoirs are filling up, and there's no capacity for storage

As the Washington Post reports, two reservoirs on the Tule and Kaweah rivers are full, so they can't take on any more water to prevent flooding downstream.  One city, Visalia in the San Joaquin Valley might suffer flooding as soon as this week as water is released from behind the dam on the Kaweah river.

Those two reservoirs mentioned above are relatively small.  The risk of flooding increases when some larger reservoirs fill up. 

A USGS site in the Sierra Nevada mountains '
of California overwhelmed with snow recently. 

Another problem is the scale of the snow and the runoff this spring. It'll take a lot of time to melt literally dozens of feet of snow. Which means high water flowing down from the mountains will last many weeks.

The state has many aging levees that have not been tested by weather like this in years, or even decades. It's one thing to rely on the levees to hold back water for a few days. The pressure of flooding lasting many weeks might be too much for the levees to bear. 

Of course, levees tend to be in worse shape and the most neglected in low income communities and areas without a thriving agricultural industry. Typical story of the haves and have nots. 

SACRAMENTO DANGER

A worst case scenario - pretty unlikely at this point but still in the realm of possibility - is a huge flood in and around Sacramento, California's capital.

As Dan Walters wrote in CalMatters.org earlier this month, Sacramento is at the juncture of two pretty big rivers, the Sacramento and the American. 

Walters explained that a bypass channel protects the city from the Sacramento River, as long as levees along the channel hold nicely. 

But, the American River is a bigger threat. There's a flood control dam upstream from Sacramento called the Folsom Dam/Folsom Lake.  It can store water and ensure moderate stream flows in Sacramento in ho-hum water years. 

However, this year, we'll see a bigger snow melt surge over the next weeks and months coming down from the Sierra Nevada range. Folsom Lake could well be too small to deal with such a long, sustained snowmelt flood.

The winter rains and snows in California have seriously dented, if not eliminated drought in much of the state. That, of course, is a good thing. But, as always, there's a downside. 

As Walters reported: "'I hope I'm wrong, but I'm afraid people celebrating the great snows in the Sierra Nevada are seriously underestimating the risk of spring flooding in California, including reservoir operators and state and federal managers,' Peter Gleick, one of the state's foremost experts on water, tweeted."

Warm atmospheric rivers - ribbons of intense moisture in the air that wring out tons of rain, hit California at mid-month. That melted a lot of the snow in the some of the foothills, mostly at elevations between 1,500 and 3,000 feet above sea level.

 Even though some rain came down in rather high elevations of the Sierra Nevada, those warm storms might have done more harm than good,

Winter rains actually don't melt much snow, but they do soak into the snowpack, making the amount of water primed to run off as melting in the spring that much more intense. 

As Daniel Swain, a climate scientist at UCLA's Institute of the Environment and Sustainability, told The Fresno Bee, California is now in uncharted territory.

Swain continued explaining to The Fresno Bee:

"'There is so much water stored in the southern Sierra snowpack, at or above record levels,' Swain told The Bee. 'And we haven't had a climate as warm as we currently do with a snowpack this large.' An early season heat wave, which has become a more occurred e in recent years 'could happen in the spring and could cause a lot of this snow to melt quickly.'"

Part of the reason why California had been in such an extensive drought in recent years is intense spring heat waves prematurely melted what little snowpack had accumulated in the Sierra.

So what happens if it's suddenly really hot and sunny in April and May this year?  Swain sounds nervous, as I would be.  

As in almost every other place, if temperatures are moderate in April and May, the snow melt in California would be gradual enough to prevent severe flooding. So, it's really a tossup as to whether the serious flooding the state has experienced will last into the beginning to the so-called "dry" season in May. 

Of course, California is also famous for its wildfires. The extreme snows and rains could make the fire season go either way. 

Above 6,000 feet, especially if the snow melt is gradual, it'll stay wet in the high spots through the bulk of the fire season. That would suppress high elevation fires, Swain told the Fresno Bee. 

The problem would come at lower elevations. All that rain is making plants, underbrush and such to grow exuberantly. If it's a hot, windy summer in California, all that new brush will dry out. So will the stuff that blew down in the high winds this winter. That could create a nasty fire season. 

It seems nowadays, any kind of weather creates a new crisis in California. 


 

Cyclone Freddy Turned Much More Tragic As It Broke Records For Longevity, Power

Satellite photo of Cyclone Freddy between Madagascar and
Mozambique.  It caused catastrophic flooding and 
will go down in history as the world's longest 
lasting tropical cyclone on record. 
 Back on March 9, I posted on a storm known as Cyclone Freddy, which was near the east coast of Africa that day. 

It was about to break records for the longest lasting tropical cyclone on record for anywhere on Earth.

So here's a followup: 

Unfortunately, since then, Freddy strengthened, and slammed into Mozambique for a second time, and in this second hit, unleaded floods that killed hundreds. 

At last check, Freddy had killed no fewer than 522 people in Mozambique, Malawi and Madagascar. 

As Al Jazeeri reports, Mozambique and Malawi were both dealing with cholera outbreaks before the storm, so this will only make things worse.

The storm finally dissipated last Wednesday inland over Mozambique as it continued to unleash its torrential rains. 

It looks like Freddy lasted 36 days, which would exceed the record by Typhoon/Hurricane John in the Pacific Ocean back in 1994. It's unusual for a tropical system to last more than a couple weeks. 

It's unclear how climate change affected Freddy's strength and longevity, but it's certainly more than plausible that had an effect.  Climate scientists warn that in many parts of the world, tropical cyclones are becoming more powerful and persistent under the influence of a warming planet. 

As Guy On Climate put it:

"It's fairly easy to see why Freddy's behavior can be blamed on climate change. They system traversed warmer than average waters on its long path across the Indian Ocean and between Madagascar and the African coast."

The World Meteorological Organization will examine the history of Freddy and later certify whether or not it was indeed the record hold for most long-lived tropical cyclone. 


Monday, March 27, 2023

Did The Mississippi Tornadoes Friday Night Have To Be So Deadly?

Victims pick through the destruction of a deadly 
tornado in Rolling Fork, Mississippi, Photo via Twitter
by Aaron Rigsby @AaronRigsbyOSC
The death toll from Friday night's tornadoes in Mississippi rose to 26 as more severe weather and possible tornadoes pummeled the South on Sunday. 

I don't seen any reports of additional deaths on Sunday from the severe weather.  But I have to ask myself: Did that many people have to die in Friday's storms? 

This was the worst kind of tornado you could get. It was exceptionally strong, so unless you were in a storm shelter or extreme fortified building, chances of survival weren't great.

The tornado raced forward at 70 mph through the Mississippi darkness.  Before people knew it, it was upon them, despite warnings from the National Weather Service and highly dedicated, professional television meteorologists. 

People have a habit of relying on visual cues when endangered by a tornado. At night you don't have those cues.

With all those factors, it was almost inevitable there would be deaths and injuries. Even so, I'm convinced the toll of deaths and injuries cold have been lower.  

I've seen a lot of accurate commentary that the tornado hit an area with a lot of mobile homes, substandard housing and relative poverty.  Fear of a tornado tragedy like the one that hit towns like Rolling Fork have been a concern for years. 

True, some safe rooms and shelters opened to the public in some parts of Mississippi before Friday's storms. But I don't think there were enough community storm shelters for people in those mobile homes, or an effective system to coax residents out of their unsafe homes and into shelters in the hours before tornadoes touched down. 

Part of that is all the false alarms you get. Sometimes, a tornado watch is issued, but the tornadoes that do form don't seem particularly destructive. Or they are devastating, like on Friday night.  But these storms cover narrow paths. 

Thousands of people were at home just a few miles from the tornado path, blissfully unaware of the horrors nearby. 

Typically a tornado warning is issued anytime between a few minutes and a little less than a half hour before a twister strikes a particular location. That doesn't give much time to flee and drive to a shelter. It's really dangerous to be caught in a car during a tornado.

But forecasts continue to get better ahead of severe weather and tornadoes, with more lead time. Meteorologists are more and more frequently alerting specific target zones an hour or two ahead of time when they suspect a particularly dangerous situation will develop.

Friday night, about an hour and a half before the tornadoes starting raining death and destruction on Mississippi, NOAA's Storm Prediction Center released a statement. It said that thunderstorms that were about to cross the Mississippi River from Louisiana were entering an atmospheric environment that would encourage strengthening storms and tornadoes in Mississippi.

The statement said those atmospheric conditions seemed primed to create strong to intense tornadoes

This NOAA statement was released to the public, as all such short-term storm forecasts are,  but there were few systems in place to act on it. In a perfect world, that statement would have been the cue to quickly get people out of mobile homes in the northern half of Mississippi and into safer shelters for the night. 

NOAA released similar statements in the hour or two before a horrific tornado struck Mayfield, Kentucky in December, 2010.   Tornadoes that night killed 89 people, most of them in and near Mayfield. 

After that tornado, there were complaints that people were not allowed to leave work places or other sites to seek safe shelter in the time between the NOAA statement warning of impending danger and the time the tornado struck.  Similar complaints were made after a tornado warning came to fruition in Illinois that night, killing six people at an Amazon warehouse

It would take coordination and a little money to form a chain when these warnings are issued. You'd need shelters ready to open, then someone to help quickly flush people out of unsafe housing and into shelters in time for the tornado's arrival. 

A system like this would be especially helpful in the South, from Arkansas and Louisiana to Georgia. It's a region especially prone to strong, night time tornadoes, with large areas of poverty and substandard housing that's especially dangerous in such storms. 

As forecasting continues to improve in severe weather events, it's time to take that increased meteorological precision and put it to work for some of American's most vulnerable people. 

A new outbreak of severe weather seems likely late this week in the South and Midwest. If the Storm Prediction Center puts out more dire statements an hour or two before a powerful tornado, and people take heed, that will be a win. Hopefully the first of many wins. 

Sunday, March 26, 2023

Vermont Weather Week Ahead: Meh! And Still Waiting For Spring

It's that kind of early spring, with half-melted snow
holding fast on the ground, clouds, scattered cold
rain and wet snow showers. And bits of sun. The
upcoming week will bring more of the same to Vermont. 
Thankfully, the snow in Saturday mostly under-performed rather than over-performed, as I had feared.

Judging from Vermont Agency of Transportation web cams and my own travels, most places in central and northern parts of the state got about a half inch to an inch of snow.The Champlain Valley south of Georgia, and low elevations in southwestern and southeastern Vermont got nada. Lucky of them! 

 I had about a half inch at my place in St. Albans, Vermont, which melted, only to be replaced by another half inch overnight. 

It's going to be that kind of week. 

We're going to stay in somewhat of a holding pattern in Vermont  this week. Spring won't really advance much, but winter won't win any really big battles. 

We'll just plod on, like we mostly have over the past couple of weeks, with a slow snow melt, with some minor setbacks with bits of snow here and there. 

Today sets the tone.  It'll be blustery and chilly, but not super cold for this time of year. A few rain showers will dampen the pavement here and there, and no doubt your spirits, too. The mountains and hills will see a few snow showers, and they'll get a bit of additional snow, probably two inches or less. 

Monday and Tuesday will feature some sun, some clouds, and daytime temperatures hovering in the upper 30s to low 40s as they  have been all month.  

Of course as they week goes on, and the forecast gets more long range, the reliability of these weather predictions starts to fade a little.

Still, it looks like a sharp cold front might come in Wednesday or Wednesday evening, first with maybe a few rain showers. It's possible this could end up giving us some snow squalls, too. Meteorologists will keep an eye on that. 

If we do get those snow squalls, it'll be just a couple of inches of snow, not some big foot deep blizzard. We have to keep trying to look on the bright side here. 

Thursday looks like it might actually be one of the colder days of this entire month. From this vantage point it looks like the afternoon would barely get above freezing. 

Early indications are we'll sort of warm up, and get some (mostly!)  rain next weekend. Let's just  hope it does turn out to be some light rain, and doesn't change into a late season snowstorm. I doubt it will, but judging how grudging this early spring has been so far, nothing would surprise me. 

There's not much hope looking into the first week to 10 days of April, either. The trends for the beginning of April are still leaning toward chillier than average weather with  near to slightly above normal rain and, um, snow.

Eventually, we'll have the kind of bright, sunny warm spring days we all deserve. But not anytime soon, the way it looks. 




Saturday, March 25, 2023

Stormy, Ugly Day, Saturday Evening In Vermont

Clear skies and light winds at dawn this morning in St. 
Albans, Vermont seemed to promise a lovely Saturday.
Instead, we'll get blasted by a burst of wet snow,
gusty winds, cold rains and raw conditions. 
 If you were looking to enjoy the Great Outdoors in Vermont today, think again. 

It's going to be a stormy day and evening, with snow, rain, schmutz and wind. Though this will be no means be a paralyzing storm, it will just be unpleasant to say the least. 

As dawn broke, it didn't seem so bad out there. I was greeted by beautiful clear skies and calm winds at daybreak today  in St. Albans, Vermont, for instance.  But things will go downhill pretty quickly. 

From late morning into the afternoon, a band of relatively heavy precipitation will roam the state, heading southwest to northeast.  Before that hits, temperatures will rise above freezing, so you'd think we'll just get a cold rain. 

But the moisture associated with this band of stuff will cool the atmosphere, so most of us will see a burst of heavy, wet snow. 

I suspect it might snow hard enough for a time in any given location, even in the valleys, to make the roads slick for a little while at least.   It won't be much snow, but a little dab will do ya, especially if it's wet snow like this will be.

Most of any accumulation will be on grassy surfaces and on existing snow cover. Maybe one to at most two inches in the valleys and a little more than that in the mountains. Be aware that this burst of snow might over-perform. I've seen several situations in the past where in this weather set up, an expected dusting of snow turns into a few inches. 

That over-performance is not guaranteed today, but it's something to keep an eye on. 

While this is going on, the winds will be picking up. In most places, the gusts will reach to 35 or 40 mph. With snow changing to a light rain, with temperatures staying in the 30s, it's going to feel awfully raw out there. 

The western slopes of the Green Mountains are going to be even windier. A wind advisory is up for those parts of the state from mid-afternoon to about midnight tonight. Winds there could gust to 50 mph, or even more in a few favored spots. 

I expect a few scattered power outages out of this. But it won't be nearly as bad as the storm we had on March 14 and 15, when tens of thousands of Vermonters lost power in a heavy, wet snowstorm. 

The burst of snow will taper for a time to light rain showers in the valleys, with light mixed stuff in the mountains. 

Another period of mostly rain will come through later tonight. Temperatures overnight will only be in the mid-30s, the same as readings during the expected snow this afternoon. But by late tonight, warmer air will have  moved in aloft. 

Mountains could still get a little snow and sleet out of this, but most of us will see a cold rain.

Sunday will end up with typical March weather: Blustery, kind of chilly, maybe some scattered rain and snow showers, especially in the morning and in the mountains. 

We should count ourselves lucky with today's storm.  It's not nice, but it's also not destructive here in Vermont. The same storm spawned a deadly tornado in Mississippi last night, which I have more details on in another, separate post this morning in this here blog thingy. 


BREAKING: Violent Tornado Kills At Least 23 In Mississippi

Storm chaser Max Olsen, @MesoMax919 on Twitter,
captured the massive Mississippi tornado illuminated'
by lightning last night. 
A powerful tornado or tornadoes swept through western and central Mississippi overnight, killing at least 23 people, and causing widespread destruction. 

Reports were still just coming in as of dawn today, but the towns of Silver City and Rolling Fork were devastated. 

The disaster in Mississippi adds a new tragedy to a tornado year that has already been busy and threatens to be more destructive than average as we head into peak severe storm season during the mid and late spring. 

This tornado was the most dangerous you can get due to its size, timing, forward speed  and location.  

It was clearly a powerful, wide tornado that had a forward speed of roughly 70 mph. That speed is often too fast to keep ahead of warnings. It happened at night, when people are either sleeping, or can't seen visual cues that something dangerous is headed their way. '

It also hit a part of the nation with lots of mobile homes and substandard housing which are particularly prone to a tornado's destructive power. 

The 23 deaths - and possibly more - add to the nine deaths from other tornadoes earlier this year.  And we haven't even gotten to the peak months for tornado deaths in April, May and June. 

In all of last year, only 23 people died in twisters, so at least as many people died in Mississippi last night as in all of 2022. That's tragic, to put it mildly. 

Some experts fear that unusually warm Gulf of Mexico waters will contribute extra heat and moisture to storm systems this spring. That is one ingredient needed for tornadoes.

I'll have updates as warranted on this later today.  

Friday, March 24, 2023

The March Spring Thaw Is Both Ugly And Beautiful. In Video And Pics

The March melt and mud season in Vermont isn't the 
state's prettiest look, but it can have its quiet
anticipatory beauty. 
 March in Vermont this year is turning out the way it was when I was a kid decades ago

As we get into the closing week of the month, the snow cover is finally starting to lose the battle to spring. But only grudgingly.

Video of this year's March melt and mud is at the bottom of this post.  

 One day we have some strong sun that opens up more bare patches in the reflected sun's heat near the pine trees. The next day, rain washes some of the crusty old ice and snow away.  

It's an old fashioned year. Under our  climate change regime, we've gotten these weird, warm days in March which disappeared early in the month, and got the crocuses blooming way early - sometimes by St. Patrick's Day. 

Not this year. It actually feels a bit novel to have a throwback March like this. Though even this March is running somewhat warmer in Vermont than the long term average.  

This isn't the prettiest time of year. Old snow sort of half-heartedly glows under the overcast next to expanses of brown grass in open fields. Mud is everywhere. Along road sides, litter that has been buried in snow now glares at us with its own ugliness as we pass by in our mud-flecked and road salt encrusted cars. 

But this "ugly"  seasons is also hopeful, and in a strange way beautiful. On rainy days, the fog curls over remaining patches of snow, as if the damp south wind is trying to steam away the remaining ice. The melting snow and is cheered on by the calls of newly arrived red wind blackbirds. 

Garden plants have gotten used to getting an early start, thanks partly to climate change. This year, an odd, balmy January got daffodils, crocuses trying to come up in mid-January. Only to be denied in active. February and March snowfalls.

These daffodil shoots in St. Albans, Vermont aren't waiting
for the snow to melt to get on with the spring show. 
But the head start was already there, so these early perennials are in a premature schedule. It looks like they're saying, "Screw it. I know there's still a bunch of snow on the ground, but I'm coming on strong anyway."

 So daffodil shoots are popping up through the tops of fading snowbanks. 

Spring this year continues on in its uncertain fashion.  A new storm is probably going to give us a headache inducing mix of rain, ice and snow Saturday and Saturday night. 

Current forecasts don't indicate too much snow and ice accumulation in the valleys, but you never known. We could end up being tricked. Even if we don't. it'll slow down our spring melt a bit.  

There's also no spectacularly warm spring days in the immediate forecast. Eventually, real spring will come. But the tentative daffodil shoots, the mud and yes, even the roadside litter gives us hope that greener, warmer days are around the corner.   

Watch the video below to see what I mean by all this. It starts with a sunny phase of the thawing Wednesday, and moves on to the rainy phase on Thursday. Either click on this link to view, or if you see the image below click on that.




Thursday, March 23, 2023

Factors Coming Together To (Possibly!) Create Nasty Tornado Season In the U.S.

Screenshot from a video showing a
tornado blasting through Montebello,
California Wednesday. It's already 
been a busy year for U.S. tornadoes,
and factors are coming together that
could make for many more twisters,
 A day after a (somewhat) rare tornado stirred up quite a bit of damage in a Los Angeles, California neighborhood, forecasters are eyeing an area in the southern Mississippi Valley that could see another round of destructive tornadoes today.   

These developments come as some factors are coming together to make the dawning core of the tornado season especially dangerous. More on that in a moment. 

The tornado that hit Montebello, California was a high-end EF-1 with top wind speeds of 110 mph. It injured one person, and damaged 17 buildings.  Eleven of those buildings had serious damage. 

It was the strongest tornado to strike the L.A. metro area in 40 years. 

Another tornado touched down in a mobile home park in Santa Barbara County, California.  

The storm that spawned the California twisters has pushed east now.   This is a rather unscientific comment, but I've noticed that most times when there's a tornado or two in California, a much more serious tornado outbreak flairs up in the Plains, South or Midwest. 

Which brings us to today. 

NOAA's Storm Prediction Center says there's a moderate risk of severe storms and tornadoes in an area surrounding the Mississippi River in Arkansas, Louisiana and Mississippi.  That's a level four out of five alert levels, or second highest risk ranking. 

As of 2:30 p.m. Friday, a tornado watch was already in effect for parts of far east Texas, Arkansas and Louisana,. This tornado threat will grow and spread east through the late afternoon and evening. 

BUSY TORNADO YEAR?

Long range forecasts extending into early April suggest a continued rather busy storm track from the southern Rockies and southern and central Plains, on into the Great Lakes and New England. 

Each storm could carry a tornado risk south of the parent storm track.  There's no way of knowing if that busy storm track will continue on toward the peak of tornado season in May 

On top of that, the Gulf of Mexico is much warmer than normal for this time of year. As the Washington Post reports, this could intensify the frequency and strength of tornadoes in the next couple of months or so. 

A crucial ingredient for tornadoes is very warm, humid air. Winds coming off the Gulf of Mexico would be warmer and carry more moisture if the water temperatures there are higher. So it stands to reason that this would contribute to a busy tornado season. 

Of course, tornadoes need a bunch of other ingredients, such as winds that veer and change speed with height, blasts of lingering cold air coming down from Canada, and punches of dry air coming in from northern Mexico and the Desert South west. 

If those and other factors don't happen this spring, then the bulk of tornado season in 2023 could end up being pretty mellow, despite the hot, wet breath of the the Gulf of Mexico. 

The Washington Post correctly points out that predicting tornado seasons is still not very easy.  Scientists are still having trouble figuring out months in advance whether a season would favor tornadoes or not. 

We do know the water in the Gulf of Mexico was toastier than normal all winter, and that was one contributor to an oddly busy winter for tornadoes. 

The U.S saw 168 tornadoes in January, the second most on record for that month. February saw 55 tornadoes, about double the average for the month. Tornadoes touched down in oddly northern areas for winter including Ohio and New Jersey. 

We have so far caught a bit of a break in March, with just 44 tornadoes reported through Wednesday, which is running a little behind normal. However, as noted above, the number of twisters this month seems poised to increase, perhaps dramatically. 

FLOODING?

By the way, all that hot, wet air from the Gulf of Mexico isn't only a tornado problem. It's a flood problem. At least potentially. 

The hotter and wetter the air, the more rain can be wrung out of the atmosphere as storms pass by. 

The storm expected to cause tornadoes tomorrow is also likely to unleash quite a bit of flooding in the Tennessee and Ohio River valleys today and especially tomorrow,  

That area has been getting a lot of rain all winter. On the bright side, that rain and snow has extended westward to the Mississippi Valley. Water levels were at near record, dangerous low levels last fall, but water levels have now recovered so there's no longer any problems with barge traffic. 

VERMONT EFFECTS

As we know, we don't see many tornadoes in Vermont. We average perhaps one a year, and the bulk of those occur in the summer, when the warm Gulf of Mexico doesn't matter as much. 

I suppose the warm Gulf could get us off to a somewhat early start with severe thunderstorms in late April or May, but that's just a guess. Flip a coin if you want the truthful answer

If the storm track across the nation remains busy, and most of the storms end up in New England, I suppose that could increase the flood threat somewhat over the next few months. 

Already, the year is running a little ahead of normal for precipitation. Burlington on Thursday just went a bit above normal for rain and melted snow for the entire month of March, and we still have eight days to go in the month. Another storm is expected to dump another third to a half inch of rain and melted snow and ice tomorrow and tomorrow night.  

The year 2011 was a landmark, extreme busy spring for both U.S. tornadoes and flooding here in Vermont. I can almost guarantee this year won't be anything like 2011 in Vermont. 

There's much less snow in the mountains to melt than there was at this time in 2011. March that year was much wetter than average. April and May, 2011 saw record high rainfall amounts in Vermont. I really doubt history will be repeated this year 

That said, Vermont is a flood-prone state. It wouldn't surprise me if we do see some flooding this spring as I noted the other day. It's just that the risk isn't all that extreme.