Severe T-Storm Watch #552

[CanisLupusArctos]

NOAA's Storm Prediction Center (SPC) in Norman OK has issued severe thunderstorm watch #552 for the following counties in New Hampshire until 10 p.m.:

Belknap - Grafton - Hillsborough - Cheshire - Merrimack - Sullivan

This watch is in effect as of 3:30 p.m. EDT.

The sun is beginning to come out as this low cloudiness moves east. This added heating is helping to destabilize the atmosphere. In New York State, this has been happening all day, and several lines of severe thunderstorms have formed in all parts of New York state. They are moving east into Vermont.

Large hail and damaging wind are possible with these storms.

Severe thunderstorm watches are now in effect everywhere from the lakes region southwestward to northern Virginia and most of Kentucky.

Use this thread for comments about the storms, and/or damage reports, if they materialize for the lakes region.

If they do materialize, a severe thunderstorm warning would be be issued for the areas directly in their paths, usually with about 15 minutes' lead time.

[kjbathe]

Looking at the cams around the lake tonight most of the lake is calm. But there appears to be a distinct onshore wind toward the Black Cat weather cam and a pool of pollen around the dock. I typically think of storms originating from the NW end of the lake, not the wind blowing in that direction. Is tonight's wind direction unusual?

[Lakegeezer]

Its pretty cool for a nasty storm. 63 last I looked. My guess is that we get away with little to no rain and no severe storm. Looks bad to the south.

[CanisLupusArctos]

Kjblithe, tonight's wind direction is not unusual at Black Cat WeatherCam. The two most dominant wind directions are from the NW and from the SE, along the length of the lake. Black Cat Island has a very exposed location, which has been a "storm magnet" over the years. A few years ago I phoned in an observation to Ch. 4's Barry Burbank in Boston and reported a SE wind averaging 30 mph and waves 2-3 feet every 3 seconds. He was amazed, and told me everywhere else was calm. Two hours later, it was calm here, too. Stuff happens here that only happens on the open lake - often the open lake generates its own weather.

Southeast is the 'default direction' here. When the wind is calm everywhere else, the wind will kick up out of the SE here. It is the direction of almost all fair weather winds and all sundown winds.

Severe storms most often develop to the west of here. Every severe storm has an updraft feeding it. This can cause wind to get sucked toward the developing line of storms. However, this isn't the way it always happens.

Today's SE wind was probably a product of the ocean influence, which we never lost. We came very, very close to breaking into sunshine today. Satellite images showed the bulk of the clouds leaving us, but the low-level depressing junk remained. As you noted, the temp was a bit cool today. That was another product of the ocean influence.

LG, You are right in saying the air just didn't seem right for a severe thunderstorm; the watch #552 has been canceled. SPC thought for sure that the clouds would break and allow the sun to destabilize the atmosphere here, but the ocean influence held on tight. You're also right in noting the nasty look to the south. Very heavy rain is now traversing Massachusetts and parts of southern NH. This is the remnants of the severe thunderstorms. They produced golfball size hail in western Mass. this afternoon.

The ocean influence here may have made for a depressing sort of weather day, but it did keep the damaging storms away. Radar showed them dying as they moved into our cooler air mass.