Weird Bright Light To Appear Over Vermont Today (We Hope)

The way it used to be.  A deep blue sky, with a few
puffy clouds as decorations, in Georgia, Vermont on
July 28, 2021.  This used to happen quite frequently
in Vermont but lately we've seen none of this.
Thankfully, the sun will make a grand appearance,
at least for a little while, this week

We awoke in Vermont to another gloomy morning this Sunday, with overcast and patches of fog.

At least it stopped raining in most places. At least for now. 

Given the conditions over the past week or more you might be alarmed at what you will see today. I'm here to assure you there's nothing to be afraid of. 

Later this morning or this afternoon, many of us will see a blinding light in the sky.  Don't worry, as long as you don't look directly at it, you won't get hurt. 

The rare phenomenon you are about to see is called the sun.  It's very common in most other parts of the world, and we used to see it frequently here in Vermont.  You just might not remember since it's been since May 16 since many of us have seen even glimpses of it. 

You'll notice this bright light - the sun - has a warming effect. Instead of being in the 40s to near 50 all day, this sun will bring temperatures into the 50s to near 60.  That's still much cooler than normal for this time of year, but it's a little better than it's been.

The ever-present chance of showers in Vermont will remain.  Not everyone will get them. The best chances of showers are in northern and western Vermont this afternoon and early evening.

MONDAY AND BEYOND

That bright light in the sky sun will assert itself even more on Memorial Day.  Much of the day will be at least partly sunny.  Temperatures will rise further into the 60s, which is only slightly cooler than average for this time of year. 

There is a low, but not zero chance of a brief shower.  You can't escape 'em. Most places won't see them though. 

Tuesday and Wednesday look great! Temperatures should get well into the 70s both days, which is near or very slightly warmer than normal for a change. Both days should feature quite a bit of sun. At this point the chance of showers both days is nearly non-existent. 

SATURATED

We should thank our lucky stars that no big, long-lasting downpours are in the offing for the next few days. The ground is so soaked right now that it would only take roughly two inches of rain in six hours to set off flash flooding. 

That amount of rain in that time period happens fairly frequently during bouts of summer thunderstorms.

Relatively dry weather until at least Thursday means that - hopefully - by the end of the week, the ground will have dried sufficiently so it would take a little more rain than that to set off an flooding.

The forecast is uncertain for the end of the week but it looks unsettled. I don't know yet of the rain will start Thursday night, or postpone until Friday or even Friday night. The computer models are disagreeing.

At least for now, those computer models are mostly agreeing that the end of the week rain shouldn't be torrential enough to set of any flooding. 

But as always, stay tuned for updates.

Debby, Flooding And Vermont: What We Know So Far

As of this morning, forecasts have the remnants of
Tropical Storm Debby going right over Vermont
early Saturday. That is actually a slightly better
scenario for us than if it were to go by a bit to
our east. But a big flood risk continues with this.

 As of this Wednesday morning, Vermont meteorologists are keeping a wary eye on Tropical Storm Debby, and what it means for the Green Mountain State.  

There's definitely the potential for additional, possibly serious flooding out of this.

 Just what we don't need given that we've had two big flood disasters last month, and really can't tolerate another.  Debby has already caused some really bad flooding in Georgia and the Carolinas, so we know this is a big bag of torrential rain. 

It's a little soon to guarantee a new flood disaster, but we still ought to be on alert. 

Anytime a tropical system comes our way, there's the potential for flooding.  Soils are already saturated in large sections of Vermont, especially the southern Champlain Valley, the Northeast Kingdom and parts of north-central Vermont. 

At the moment, NOAA's Weather Prediction Center has Vermont in a moderate risk zone for flooding Friday. That's level three out of four on an alert scale. It's rare to have a moderate risk posted two or  more days ahead of the event, so that's saying something. 

We know there's the potential for two to four inches of rain, with locally higher amounts. So we should get ready, just in case.  Both flash flooding and main stem river flooding are in play. 

FORECAST TRENDS

If you want to find glimmers of good news, there's a couple, though we are by no means out of danger. 

The expected track of the remnants of Debby, at least according to some computer forecasting models, keeps shifting a bit west.  Whereas almost all of the models yesterday had Debby passing by a little to our east, some of the latest ones have it going right overhead in Vermont. 

That sounds bad, but the heaviest rain with this type of system usually falls to the west of its track, not necessarily right underneath it.  That would put the most torrential rain in northwest New York and southern Quebec. The landscape is flatter there than it is in Vermont. 

In Vermont torrential rains rush off the mountains, leading to our dangerous flash floods. Flatter ground away from the Green Mountain State would minimize that. 

There's already a moderate risk
(Level 3 out of 4 alert level) for
flooding Friday and Saturday in
and around Vermont. 

Another trend we should hope will continue is that some models ramp up the forward speed of Debby's remnants. That means the downpours wouldn't linger as long, leaving less time for rainfall to pile up.

  Instead of soaking rains all day Friday and Saturday, the rain could shut off pretty quickly on Saturday. That is IF the forward track slows down. 

All that said, we shouldn't let our guard down. At all.

First of all, several computer models keep the center of Debby a little to our south and east. That would put Vermont in the crosshairs of the heaviest rains. 

Even if Debby takes a more westward path, we're absolutely not out of the woods. We might see less overall rain that way. Or at least the heaviest rain wouldn't be quite as widespread.

But the rain we'd get with this more inland journey for Debby would tend to come more in the form of intense showers and thunderstorms with super high rainfall rates here in Vermont.  

We saw a hint of that yesterday with an outbreak of downpours ahead of Debby in Pennsylvania, New Jersey and New York.  Islip, Long Island had about a half inch of rain in just five minutes.  Much of Hackensack, New Jersey was under water last evening. Flash flooding was widespread in that region. 

Those are the kinds of downpours we could see if Debby goes overhead or to our west. These would absolutely pose a nasty flash flood risk. So not great.

The timing of this would put Vermont in a flood risk from Friday morning, lasting well into Saturday.

UNCERTAIN FORECAST STILL

There's still a lot of questions as to Debby's exact path and speed, so there will surely be changes to the forecast leading up to Friday.  What we should hope for is a continued trend westward with Debby.  Again, absolutely no guarantee that will happen.

But the further west it goes, the better off we'll be in general. 

If you live in a flood prone area, now is the time to get ready.  We're a couple days away from the event, so you still have an opportunity to move stuff that can get damaged out of the way, if you can.  Even if we don't end up with a flood, getting ready like that is good practice for the inevitable future floods in Vermont. And if we do see a flood, you will have minimized damage some.

Of course, there's no way to move houses, businesses and farms out of harm's way, so we'd better hope we manage to dodge a bullet here. 

Stay tuned for updates! 

Refreshing Air Arrives In Vermont, But Frustrating Flood Potential Forecast For End Of Week

Forecast rainfall for the next seven days. Anything orange
is three inches or more. Darker shades near NYC indicate
at least five inches. Yellow in the Carolinas is over
ten inches. This forecast is big time subject to
change, especially in the Northeast. 

 As expected, it's much cooler and drier out there this morning, a state of affairs that will last most of the week.  

Clouds are forecast to gradually clear today after yesterday's rain. That rain was torrential in spots, nearly non-existent in others. 

Burlington received just 0.02 inches of rain. Meanwhile, a stripe of Addison County was under a flood warning for a time last evening as a patch of torrents passed through.

 Luckily, I've so far seen no reports of any serious damage in that neck of the woods. 

Now that we're done with the storms and oppressive weather,  there is pretty much no sign of any return to high temperatures combined with high humidity for the foreseeable future, so all good, right?

Unfortunately, no. Or at least maybe not. As I've mentioned a couple times already in previous posts, there's big time flood potential later in the week up and down the Eastern Seaboard. 

We don't know yet whether that includes flood-weary Vermont. 

DEBBY DANGER

Tropical Storm Debby so far is pretty much following forecasts, meandering around the Southeast, dumping incredible amounts of rain that is and will cause historic flooding in swaths of Georgia and the Carolinas. 

It's about to limp its way from Georgia and park itself just offshore. Since the center will be a little off the coast, Debby will have a chance to re-strengthen for awhile. All that time, it will be slamming huge amounts of rain into Georgia and South Carolina. 

It'll take until about late Friday or Saturday for Debby or its remnants to become "unstuck" and head on off to the northeast at a decent pace. 

During this time, we'll have that cool high pressure near us, keeping us partly to mostly sunny through Thursday, though clouds might be thicker south. 

Meanwhile another storm will be coming in from the west. We know the combination of that system from the west and Debby will cause a dangerous flood situation up and down the East Coast.  What we don't know is exactly where that will happen. The question marks are biggest in New England. 

This is a situation for a classic set up know as a Predecessor Rain Event or PRE.  Often, ahead of a tropical system, an area of torrential rain will develop well to the north and west of the tropical storm. It often but not always forms in an area that will eventually get hit by the actual tropical storm or hurricane.

A PRE can develop as much as 600 miles north or west of a tropical storm, and they're really hard to forecast. That's why meteorologists are still hemming and hawing about where flooding rains will strike at the end of the week. 

VERMONT QUESTIONS

As the National Weather Service in South Burlington points out in its forecast discussion this morning, computer  models are still all over the place when it comes to where the heavy rain sets up in New England toward Friday and Saturday.

The models are sort of leaning toward the heaviest rain focusing on southern Vermont, but there is absolutely no unanimity among the computer models, and various runs of those models. 

 Some of them have a  best case scenario (for us, anyway) of having almost no rain over central and northern Vermont and bringing the bad stuff to southern New England.  

Other models have a worst case scenario of dumping inches of torrential rains smack dab over the middle of the Green Mountain State.  

Other computer models have something in between those two extremes.   

Obviously, we want to avoid the worse case scenario, especially after the kind of summer we've had so far. Some Vermont communities have had serious flooding five times in the past year.  We've had more than our fill. 

To get forecast clarity, we'll have to wait until we see how Debby's path evolves, and how Debby and its moisture interact with that storm system coming in from the west. 

Hopefully, we'll start to get a clear picture by Thursday, so that we have a little time to prepare for flooding, if that's the direction we're headed. We just don't know. 

Just Like That, Two Big March Vermont Snowstorms Have Increased Spring Flood Threat

Snow-laden trees and deep snow this week around
St. Albans, Vermont.  A now much deeper snowpack
has somewhat increased the risk of spring flooding.

 Lo and behold, after pretty much an entire winter in which the snow pack in Vermont was well below average, the snow is now deep just as we're on the cusp of spring. 

That extra snow increases the flood threat in the coming weeks, but something like that is fortunately far from guaranteed.  It's still worth keeping an eye out on, though.  

The National Weather Service in South Burlington releases a winter and spring flood potential statement every other Thursday. Conveniently, the latest came just after the much larger of the two March snowstorms ended. 

Thursday's statement says the flood potential in northern and central Vermont is about normal. But it cautioned we'll have to start carefully watching weather patterns starting in about a week and a half. 

The amount of snow on the ground across Vermont - and the water in it - is now in many places above normal for this time of year.

The snow depth just below summit level on Mount Mansfield was  62 inches on Monday, just slightly below normal By Wednesday afternoon, the snow depth on the mountain had ballooned to 90 inches, which is roughly 15 inches above normal for the date.  

The snow water equivalent - the amount of "rain" available from the water in the snow and ice covering the ground is about 1.5 to 4 inches in the valleys, and four to eight inches at elevations between 1,500 and 2,500 feet.  I saw one measurement from Shrewsbury that showed 5.03 inches of "rain" locked up in the snowpack there. 

This week's snowstorm added one to three inches of snow water equivalent to the snowpack. Isolated areas in the high country of far southern Vermont added four inches of "rain" to the snow pack.

The snow cover in January and the first half of February was practically non-existent in Vermont. But much of the snow that has fallen since mid-February is still on the ground despite generally above average temperatures. That is in part because most of the above average temperatures have happened at night. Daytime readings have been closer to normal. So that limited much thawing so far. 

WHAT'S COMING

If you get the wrong kind of weather, that's a recipe for flooding.  The "wrong" weather is a sudden shift to much above normal temperatures combined with heavy rainfall.  

Jackson the Weather Dog is dwarfed by the big snow banks
he's inspecting for spring flood potential around
our house in St. Albans, Vermont. 

In the short term, that won't be a problem. Some light snow Thursday added a little tiny bit of potential flood water to the snow. 

Light rain causes some snow melt on Friday.  I noticed brooks and rivers rose somewhat with the thawing and rain, but nothing came close to flooding. And there's plenty of snow left to melt. 

A quick blast of chilly air will dump another dusting of snow in the valleys and a few inches in the central and northern Green Mountains. Again, just another small installment into the spring run-off potential from the mountains. 

Most of next week will have great sugaring weather, with highs near 40 and lows in the 20s. Great sugaring weather is also great flood prevention weather. A little snow melts each day, then things freeze up each night, so runoff isn't a problem.

Beyond that, it's beginning to look like we'll have a turn toward milder weather. The first shot at any spring flooding this year might be next weekend,  depending on the strength and path of the next storm system.  That storm is nearly a week away, so we don't know if it will be a warm, heavy rain, which would cause problem, or something more along the lines of what we had Friday, which wasn't at all scary.  

Even if the storm a week from now is warm and wet - again far from guaranteed - there will be plenty of snow left at mid-elevations and mountains to cause potential problems heading into April. Again, only if those spring rainstorms turn out to be hefty and drenching. 

Lake Champlain's lake level later this spring has gotten potentially more interesting, too. The lake level is around 96.4 feet, which is just slightly higher than normal for this time of year. 

Now, a lot of water has the potential to enter the lake from the surrounding countryside and mountains.  Especially if we have a lot of rain between now and May. 

Flood stage on the lake is 100 feet. I think we have a pretty good chance of achieving that. But minor flooding like that isn't a big problem. It's when we get up to 101 feet or so when trouble really begins. At this point, I don't think that will happen, but it is possible in a sort of low chance kind of way.

Whether we see any flooding this spring or not, I'm sure a lot of people will be relieved to see the snow banks around their homes gradually shrink and fade away under the warming rays of the sun.