Tuesday Evening Vermont Snow Update: This Huge Winter Storm Confounded Meteorologists

Cars having a hard time negotiating the hill near my
house on Fairfield Hill Road in St. Albans during heavy 
snow early this afternoon.

 The over-performing winter storm in Vermont continued to pull surprises this afternoon in Vermont, dumping more unexpected snow on the Champlain Valley and racking up accumulations in southern Vermont that outdid even some of the more wild-eyed forecasts. 

This had to be one of the most poorly forecast winter storms I've experience in Vermont. 

This is NOT a diss at the meteorologists who tried to forecast it. The storm had all kinds of weird aspects, did weird things and is following a weird path that makes forecasting the damn thing impossible. 

Given the strength and surprises from this storm, problems continued to accumulate all day, almost as fast as the snow. 

Reports continued to come in all day of roads blocked by fallen trees, power lines and branches. 

Power outages peaked at about 38,000 in Vermont around noon before leveling off at around 31,000 for most of the afternoon. That's a lot! 

There were vehicle crashes too. Vermont State Police reported responding to 106 crashes through 3 p.m. today, but so far only three injuries have been reported.

Among the scariest was in Richmond, where a motorist lost control on a slushy road and sideswiped a school bus, causing quite a bit of damage to both vehicles. Luckily, none of the kids on the bus were hurt. The drivers are OK, too.

Meteorologists did get some things right. Yes, more snow fell on some parts of the south than forecast. However, forecasters had warned us for days that the mountains of southern Vermont would be in trouble with deep, heavy, wet snow that would screw around with power lines, and that certainly happened. 

Snow totals continue to impress. The most I've seen so far is an astounding 32.4 inches in Marlboro, Vermont, 28 inches in Wilmington and 27.3 inches in Readsboro.  

Accumulations were just slightly more than expected in central Vermont, amounting to 8 to 12 inches. A little more than that fell in high elevations and a little less in the lowest, warmest valleys.

Northern Vermont continued to way over-perform. Here in St. Albans, forecast accumulations in forecasts from Saturday through Monday ranged from 1.4 to 2.9 inches. When the snow finally tapered off (at least for now) at around 4 p.m. a full 8.0 inches of snow had accumulated. 

Most of northern Vermont has had 6 to 10 inches so far. 

As everybody understands, the snow is wet and heavy.  There's a TON of water in it. 

Pine trees bend under the weight of heavy, wet snow
today in St. Albans, Vermont. 

Here's one way to illustrate it. Today is the sixth anniversary of the infamous Pi Day Blizzard on March 14, 2017. In that storm, Burlington received 30.4 inches of snow. It was cold that day, so the snow wasn't like wet cement. If you melted that snow down, you got 1.13 inches of "rain."

Today, Burlington received about eight inches of snow. If you melt it down, you get just under an inch of rain. The Burlington area might end up getting just a third the amount of snow in the Pi Day blizzard, but at least as much liquid equivalent.  I'm sure some higher elevations, especially in southern Vermont, have already received the equivalent of more than two inches of rain. 

BOTCHED FORECAST

So what went wrong with the forecasts? Especially in northern Vermont.

According to the National Weather Service office in South Burlington, the thinking before the storm was that dry air coming in from the northeast would hinder the intensity of the snowfall in the northern half of Vermont. 

Since the snow would be light, the strong March sun would send some heat through the clouds, and any snow that fell in the valleys would have a hard time accumulating. It would essentially be a white rain of sorts. Forecasters knew higher elevations would get a decent amount. 

What happened instead was an initial storm near Long Island was supposed to weaken quickly in favor of a much stronger storm that would move northwestward from way offshore and move to near Boston this afternoon. 

That second stronger storm acted pretty much as expected, but that Long Island storm hung on longer than forecast. That storm sent what was essentially a weather front that moved slowly northwestward across the entire state of Vermont. 

Snowfall rates were intense in that band, up to three inches per hour. The March sun became a non-entity under that slowly moving snow band, so the slushy stuff really piled up. 

The expected drier air did eventually make it into north central and northeastern Vermont, so only light snow fell there this afternoon. 

But that weather front of sorts stalled in the Champlain Valley, keeping the heavy show going. 

Finally, at around 4 p.m., the drier air from the northeast finally punched into the Champlain Valley, largely shutting down the snow. For now.  

WHAT'S NEXT

You might be forgiven if you don't believe the forecast going forward tonight into tomorrow, but we'll give it a shot. 

It's mostly just flurries in northern Vermont, with a few patches of somewhat heavier snow as of 4:30 today. That will last a little while longer, but the snow will fill back in.

And it will snow most of the night. It shouldn't come down nearly as hard as it did today, but still, two to locally six inches of added snow with up to eight new inches in the northern and central Vermont mountains seems like a reasonable forecast. 

I will note I'm a little suspicious of a somewhat heavier band of snow that set up late this afternoon across central Vermont, but I don't know if that's a passing fancy or is it something that will bring another surprise. 

Winds have been gusty at times and that will get worse tonight and tomorrow. Later tonight, as temperatures drop, the snow that's falling should become a little less like wet cement and a little more powdery. So there will be issues with blowing and drifting snow, especially in open areas. 

Down in the buried areas of far southern Vermont, another four to eight inches of snow tonight should add to the crushing piles of snow on the ground down there. 

Snow will taper off and in many places end on Wednesday. But it will be by no means a nice day. North winds should gust to 35 mph with possible gusts to 45 mph in the Champlain Valley. That could take down more snow-laden trees, and at the very least making life much more difficult for the crews who will surely be continuing to repair all those downed power lines.

Temperatures should stay near or a little below freezing all day Wednesday. 

The next storm on Friday and Saturday still looks like it will be mostly rain. Which will make a mess of the snow but shouldn't add on too many additional problems. It won't rain hard enough and not enough snow will melt to produce any real flooding. 

 

 

One Last Hot Day; Thunderstorm Chances Iffy Here In Vermont

Clear skies above the flowers on my St. Albans, Vermont

deck this morning. Another hot, oppressively humid day is 

on tap today, but it's the last in a series, for now.

There is a low chance of strong storms later.

 Thursday turned out to be mostly a bust for thunderstorms here in Vermont, despite almost all the ingredients coming together for at least a few severe storms statewide.  

A lack of damaging thunderstorms is of course a good thing, but still, forecasts were off. 

An area of clouds, mostly just left over debris from storms that had dissipated near the eastern Great Lakes earlier, came into Vermont around noon, was what prevented the storms.   Though the air was unstable, there wasn't much of a trigger to start the storms off. 

The trigger would have been strong sunshine, which would have created some updrafts to overcome what is known as a cap. A cap is a warm, stable layer of air a few thousand feet overhead that acts as a roadblock against the type of towering clouds that produce thunderstorms 

One way to break the cap is for sunshine to roil the atmosphere with updrafts below the cap.  These updrafts would poke at the cap a few thousand feet overhead, and finally break through.

Once the cap breaks, the clouds could tower to heights as high as 20,000, 30,000 or even more feet tall, which would be our severe thunderstorms. 

As those clouds arrived just when the sun would have been strongest, it prevented the updrafts that would have poked holes in that cap.  Which meant showers and thunderstorms were few and far between. None of few that formed north of Route 4 were severe. 

The clouds did hold temperatures in northern and central Vermont below 90 degrees, so the heat and humidity wasn't as terrible as forecast as well.

It was sunnier and hotter in the early afternoon in far southern Vermont, so an area of severe storms raced west to east along Route 9 between Bennington and Brattleboro

TODAY'S TRY AT STORMS

Today will be the last in a string of hot, humid days.  As of this early this morning, it was steamy, temperatures were rising rapidly and the sky was clear, with no signs of it clouding up anytime soon.

So a cap will break today and we'll get a lot of big storms, right?

Well, no. Not exactly.

Thunderstorm chances are there, but they look iffy, for slightly different reasons than yesterday. 

The hot high pressure that has been pumping the heat and humidity our way this week is reasserting itself. When high pressure builds like this, it tends to make air sink a bit, which inhibits thunderstorms. A few storms might overcome this sinking air this afternoon, but if they do get going, there won't be many and they probably won't last long.

Still anything that can get going in this soupy air today could be briefly strong, with a highly localized torrential downpour or two.

Otherwise, expect another oppressive day today with heat advisories once again in effect in Vermont's valleys.

By this evening, that beloved cold front in Canada will finally be making its approach toward Vermont.  That would increase the chances of showers and storms tonight.

But by then, we've lost the sun, so instability in the atmosphere will be waning. So yes, there will be storms around tonight, some with locally briefly torrential rains. But the storms will not be as widespread or intense as they would be had the cold front been approaching during the day.

That said, we're in a marginal risk zone for severe storms today and tonight. That means we can expect isolated instances of severe storms. 

This relative lack of rain is bad news for Vermont north of Route 2. Much of this area is still in drought, having missed out on most of July's heavy rain that hit much of the rest of New England.,

We're in for an extended dry spell, with the next chance of rain after this cold front coming along next Thursday.  And at this point, I'm not all that impressed with the chances for rain even then.

On the bright side,  you'll notice a dramatic change in the air happening during the day Saturday as the cold front sweeps on east of here.  It will be delightfully dry and pleasant Sunday and Monday.

More heat lurks, though, as a strong ridge of high pressure looks likely to re-establish itself over our neck of the woods next week.  It won't be as humid as this latest stretch was, but we can still expect highs well into the 80s all of next week after Monday.  Humidity levels, though falling short of this week's levels, will still creep up. 

Saturday's Storm Forecast Was A Bust; Heat Forecast Is The Real Deal

NOAA's Storm Prediction Center at midafternoon 
Saturday was contemplating issuing a severe thunderstorm
watch for northern New England. They ultimately
decided not to, which was smart, since
turned out widely expected severe thunderstorms
failed to materialize. The storm initiation that
the SPC expected in this map also didn't form.

Saturday was surely a lot quieter than expected.

Severe thunderstorms that were widely forecast to develop across northern Vermont failed to materialize, as we now know. 

I suppose if there's a botched forecast it's good that we didn't have damaging storms, instead of the other way around.  It would have been worse had un-forecasted storms materialized.

One forecast I'm much more confident will come true - and is coming true as we move into this Sunday afternoon - is a real early season hot spell in the Green Mountain State.

But first, let's get into what went wrong with Saturday's forecast for storms.

On paper, everything looked set for scattered severe storms from mid-afternoon into the evening Saturday.  Temperatures were rapidly rising into the 80s across Vermont by late morning. Montpelier managed to tie a record high of 85 degrees for the date.

Weather disturbances were marching across Ontario toward Quebec to help pull the trigger on the storms that would then move southward into Vermont, New Hampshire and Maine. 

Pretty much all the weather models were on board with this. Remember the other day when I said weather models had gotten a lot better than they used to be on forecasting small scale features, like thunderstorms in a narrow area?

That's true, but they still have their shortcomings.  The models didn't handle Saturday's situation well at all. 

Before noon, a band of clouds and light showers formed in New York's St. Lawrence Valley.  They blotted out the sun in northwestern Vermont by noon, and dropped some sprinkles. This light band of showers blossomed into a line of moderate thunderstorms on a line from just south of Burlington to St. Johnsbury, then continued to march east into New Hampshire. 

This band of lighter activity was not forecast to develop, and even as it did, wasn't expected to hold together all the way southeast to the Massachusetts coast.

This initial band was not at all forecasted.  Instead of continued sun the band stabilized the atmosphere, helping to prevent the kinds of towering clouds you get as thunderstorms develop. This band also left behind a whole bunch of what I would call debris clouds. That meant the sun really couldn't come back out and start to churn the atmosphere and make it unstable again.  

WMUR meteorologist Eric Weglarz noticed a boundary running across
northern Vermont and New Hampshire Saturday evening
that under many circumstances would have triggered some
hefty storms, but not all the ingredients were there to 
set them off, so no severe weather occured.

The forecasted disturbances did make it into southern Quebec in the late afternoon and evening. Thunderstorms, some severe, blossomed in the Montreal area and started heading southeast. 

One cell had together for hours and ended up crossing the border near Newport, Vermont. But the relatively stable air prevented this storm from growing into something severe. 

Even during the time of day when the storms were forecast to blow up and failed to do so, most of the ingredients were there. 

The weather disturbances were trying to add lift to the atmosphere. There was a subtle but sharp temperature boundary last evening running from about Ottawa to Burlington to northern New Hampshire near Conway. 

This was a recipe for strong to severe storms, but that instability wasn't enough to create chaos.  You could tell we were almost there.  Last evening, small downpours appeared seemingly out of nowhere north of Route 2.  

An example was around my place in St. Albans. One swing of the radar showed almost nothing around us. A couple minutes later, we had a brief downpour.  Another look at the radar just a few minutes after my previous peek showed a brand new cell zipping rapidly away from St. Albans and heading east. The Northeast Kingdom was also suddenly pockmarked by little downpours. 

At the time these little downpours were popping up, the sun was setting.  The sun wasn't going to add any energy to an otherwise volatile atmosphere. The severe threat was over. 

HOT WEATHER

The forecast for today and tomorrow is a lot more straight forward and less prone to complications and mishaps.

The atmosphere today is just a tiny bit warmer than yesterday, but there's a lot more sunshine.  That is allowing today's temperatures to go well above those on Saturday. 

It was already 87 degrees at noon in Burlington, so we're almost a shoo-in for reaching 90 degrees.  That's despite the fact that there will be more clouds mixing with the hazy blue skies as the afternoon wears on. 

There are no strange and risky weather disturbances to trigger widespread thunderstorms. But lake breezes along Lake Champlain, updrafts that mountains are helping to create, and just some residual general instability will probably trigger a few widely scattered showers and storms later this afternoon and evening. 

It'll be very hit and miss, with most of us probably not getting any rain. If thunderstorms do develop later today, they won't be severe. 

Monday will be the hottest day of the hot spell, and if more record highs are set, Monday will be the most likely day.  The record high in Burlington tomorrow is 94 degrees and Montpelier's record is 89.  Both are definitely in jeopardy. 

A cold front from Quebec will be approaching us Tuesday, so temperatures might be a couple degrees cooler, especially north and east of Interstate 89. But it will still be hot and humid. 

The cold front is expected to fully come through Wednesday.  If the front is a bit slower than forecast, we'll endure more warmth and humidity, along with the risk of storms.  If the front is faster, it'll get more comfortable, especially later in the day, and there would be fewer showers and storms. We'll see.