That Flash Flood Threat Materialized For Some Of Us - Dangerously

While New Hampshire and eastern Vermont were flooding, incredible
hail piled up this morning near Wells, Maine. Photo by Shawna Marie
Druin via Twitter 

While those of us in northwestern Vermont had a quiet weather night and early morning, it was anything but in eastern Vermont and New Hampshire.

That flash flood threat I spoke of yesterday materialized in some of those spots. Thunderstorms, a few of them severe, and torrential showers and thunderstorms developed over night and are continuing in those regions this morning.

All this is a developing situation, but here's what we have as of mid-morning.

Flash flood warnings are up for most of central and northern New Hampshire and bits and pieces of eastern and northeastern Vermont.  

The trouble in New Hampshire is particularly severe, with reports of life threatening flooding in Woodsville, New Hampshire, just across the Connecticut River from Wells River, Vermont.

Water was said to be pouring into the local hospital in Woodsville. Rainfall rates further north in Sugar Hill, New Hampshire were as high as five inches per hour for brief periods.  Flash flood warnings were up this morning in Vermont near Woodsville, in towns like Wells River and Bradford.

As of 8:30 a.m. today, another big are of of  concern in Vermont is a stretch along Route 2 and surrounding hill towns between Marshfield and Danville. 

That flash flood warning near Route 2 was later extended further east and north to include St. Johnsbury and Lyndonville.  There is a river bank mobile home park along the Passumpsic River that is prone to flooding. I worry about that neighborhood this morning.

The rain has really come down hard there and was still pouring as o 9 a.m. Some spots were already up to 3 inches of rain in short order, with more falling. That gush of water is no doubt sweeping down steep hills and mountains, causing a potentially dangerous flash flood situation.

Ominously, the heavy rain appeared to be sitting nearly stationary on radar images over northeastern and eastern Vermont and western New Hampshire through mid-morning. This could get really, really bad.

The storms also look pretty intense, with plenty of lightning strikes in northern Vermont east of the Greens and northern New Hampshire. There's still the risk of severe storms, too, especially further east in New Hampshire and Maine. Hail completely covered the ground near Wells, Maine this morning. The dangerous weather could extend into northern Massachusetts as well.

The flood threat will continue today in those regions through the day, while those of us who were begging for a little piece of the action to the west in the Champlain Valley will see little or nothing.

The main culprit in the troublesome weather east of the Green Mountains is sometning I just talked about here in this blog thingy a couple weeks ago: A mesoscale convective system, or MCS. 

They're common in the Midwest and Plains.  They are much less frequent in New England, but certainly do happen, often with damaging results.

It's too early to really assesswhat kind of damage, ias happened in the area hit by this New England MCS.  I do know there were some severe thunderstorm warnings early this morning in addition to the flood threat.

Vermont is prone to flooding. Different parts of the state have been declared federal disaster zones 13 times in the past decade due to flooding.  I have no idea if today's possible flooding will rise to that level.

People outside the storm zone, like in the Champlain Valley, could see a great lightning show off to the east before dawn today.

In the New Hampshire flash flood warning zone, rainfall rates were/are at times one to three inches per hour, certainly enough to produce a flash flood.

The threat from this MCS, and upper level low pressure system will continue through much of the day as this mess slowly heads east.  Additonal showers and storms will form on the western edges of this in Vermont, mostlly east of the Green Mountains today, which could cause more high water problems.

The danger is even higher in New Hampshire and western Maine, since this mass of storms will keep firing up all day as the upper level low slowly moves overhead.

NOAA's Weather Prediction Center says the heavy rain and storms will persist and actually expand in  areal coverage going into this afternoon. Already, as of 10 a.m., a few showers had expanded into the central Champlain Valley.

In western Vermont, there likely won't be enough activity to cause flood trouble, but this forecast shows that anything east of the Green Mountains in particular might well be in continued trouble for the rest of the days.

Looking forward, we get a sort of break from the humidity tonight and Wednesday before it returns big time by the weekend.  There will be more threats of showers and storms with locally heavy rain occasionally between now and early next week.

Which probably means some areas of the region that are too dry will stay that way, but areas that are too wet face the risk of more water trouble.