Vermont To Get A Taste Of National Storminess: Severe Storm And Flash Flood Threat

UPDATE 1  PM

Boaters head for shore on Lake Champlain near 
Alburgh, Vermont Friday as threatening thunderstorm
clouds loom overhead, Today will bring numerous
storms to the state and a few could contain
damaging winds and/or flash floodingUPDATE 1 PM

A severe thunderstorm watch is now in effect for all of Vermont, most of New York State and western New Hampshire

Damaging winds and hail are the primary threats but there's still a very low, but not zero chance of a brief tornado, 

If this morning is any indication, there's a good chance some of this afternoon's storms could be rambunctious. 

The supposedly "weaker" round of storms this morning were pretty strong

knocking down a couple trees in Northfield Falls, Vermont 

A few locations had hail up to the size of nickels. 

Conditions are even more favorable for strong to severe storms this afternoon than they were this morning, hence the storm watch.

This morning's storms had a TON Of lightning and torrential rains, so those are also dangers. Flash flooding is possible if repeated storms hit the same areas. There has already been flash flooding around Cambridge, Vermont, with water washing out driveway and damaging Route 15 a little east of the Wrong Way Bridge. At last report, Route 15 was closed in that area. 

As of 1 p.m., strong storms were gathering force over central New York and heading our way. 

PREVIOUS DISCUSSION

Today will be a day in Vermont where you want to keep an eye to the skies. Numerous showers and thunderstorms will develop.  A few of them might be locally strong to severe. There's also a local flash flood threat. 

It's Saturday, I guess we have to expect bad weather in the Green Mountain State. 

This won't be nearly as dire as the weather mayhem that struck the Midwest Friday, but we'll need to keep an eye out. (The tornadoes and other storms in the Midwest and South are the subject of another post I'm working for today, so stay tuned for that).

The Vermont mini-drama started to some extent Friday, as scattered thunderstorms developed. They prompted two severe thunderstorm warnings, one in north central Vermont and one near the Canadian border in Franklin County. 

We have no reports of damage in Vermont, but the one that threatened Franklin County caused some tree and wire damage in the town of Mooers, in far northeastern New York. The storm weakened as it crossed the border into Vermont.

SEVERE STORMS

NOAA's Storm Prediction Center has Vermont in a Level 2 risk of severe weather on a one to five point scale. That means there should be a scattering of severe storms, meaning they'll pack winds of at least 58 mph and/or hail at least the size of quarters. 

A cold front will be approaching from the west, which will interact with the humid air over us to set off the storms.

Today. the air is unstable and humid enough in the Green Mountain State to create multiple rounds of heavy showers and storms.  Most of them will come through in the afternoon and evening. 

But they could hit at anytime. A couple small downpours with a little lightning formed over the Green Mountains of northern Vermont around dawn today for instance. More storms were forming in central Vermont and heading northeast as of 8 a.m.

Some models have one round of storms coming through mid to late morning, and more in the afternoon and early evening.  Timing with these things is iffy, so don't hold the timing I gave as gospel. 

While pretty much all of us will get wet, very few of us will see a severe storm or flash flood. Still, some towns will get nailed. It's impossible to tell which ones until just before it happens.  Also, remember that even in non-severe storms, lightning is dangerous so you should be inside even if you get hit by a garden variety storm. 

High winds are the primary risk from today's expected storms. However, there's a very, very low but not zero chance of a brief spinup tornado in Vermont if a supercell thunderstorm or two can get going today,

By the way, today's is NOT the day for a boating excursion on Lake Champlain.

FLASH FLOODING

Since some areas will have several downpours today, that opens the door to possible flash flooding.  Yes, here we go again. 

NOAA's Weather Prediction Center has much of Vermont in a level two of four risk of excessive rain or flooding. That would mean scattered instances of flash flooding, but nothing widespread 

Some today's storms could have rainfall rates of one to as much as two inches per hours. Luckily, the storms will be moving right along instead of lingering in one place, so most downpours shouldn't last that long. 

But in Vermont's steep terrain, rainfall of that magnitude can spell trouble.  I don't expect widespread flooding, but there could well be an instance or two of gravel roads partially washed out, culvert problems, and basement flooding. 

It also looks like there there will be subtle weather front stretched west to east across northern or central Vermont, which might be the focus of repeated downpours, so that will have to be watched.

Now, most of us will only see a half inch to an inch of rain today, not enough to cause problems. It's those local areas that see two or three inches that will create issues. 

Bottom line: Be ready to hear weather warnings that might blare from the National Weather Service today. 

On the bright side, main stem rivers will show rises, but none of them are expected to hit flood stage.

OUTLOOK

The flooding threat will be over tomorrow, but the rain won't. Today's the last day of summer weather for a long time. We have a mostly wet, chilly week to look forward to.

A cold upper level low will be nearby Sunday, ensuring that we have frequent mostly light showers, Temperatures will only be in the 50 and low 60s, quite a change from what we've seen. 

Monday will be even worse, as cloudy skies and scattered showers continue. Highs will barely make it into the low 50s. It should be near 70 this time of year. Tuesday should be almost as chilly, but with a lower chance of rain. 

The forecast for several days ahead gets more uncertain, but chances are high that the second half of the upcoming week will be chilly and rainy.