That Was A Weird Storm That Rolled Through Saturday

Possible tornado damage in Mastic, Long
Island, New York Saturday. Photo from
Twitter Alison Michelle

Even if there was nothing that odd for November weather right at your home for the past couple of days, New England has just experienced two weird storms, with Saturday being the most remarkable.

For two days in a row, there were tornado warnings in New England, a super rarity, especially for this time of year. Over in New York, at least one tornado touched down Friday in the lower Hudson Valley.  

Even stranger, the two islands off of southeast Massachusetts had this:  Nantucket was under a tornado warning for a time Friday.  Then Saturday, Martha's Vineyard had a tornado warning.  This ain't exactly tornado alley, folks!  

Judging from radar and reports of pockets of pretty intense wind damage in Long Island and in Massachusetts, Connecticut and Rhode Island.

I bet at least a couple tornadoes did touch down yesterday. Crews from National Weather Service offices will inspect the damage today to determine if the damage was caused by straight line winds or tornadoes.

Here's another oddity:  Two tropical storms made landfall in Westerly, Rhode Island this year. The odds of that happening are next to nil. Now, it's also possible there was a tornado in Westerly yesterday. Not sure, but possible. That's under investigation.

Here in Vermont, the storm Saturday wasn't nearly that dire, but it sure was interesting. Relatively rare thundersnow crackled over the far southern Green Mountains. 

This storm in the Northeast also had a lot of hail, also odd for November. Hail reached as far north as St. Albans, Vermont. A brief, heavy burst of small hail rolled through here during the mid afternoon.

Rainfall was heavier than expected, especially in western Vermont. Burlington logged 0.86 inches, and my unofficial rain gauge in St. Albans caught about the same amount. 

As expected, rain turned to snow in much of Vermont during the evening.  Precipitation tapered off before it could get cold enough for snow in the Champlain Valley, but much of the rest of the state had some. 

Snowfall reports for Vermont were sparse as I wrote this early Sunday evening. There was 3.6 near Readsboro last evening. Shortly before 6 p.m., two inches was reported in Shrewsbury, and it was still snowing at a pretty good clip at the time. Judging from web cams I looked at this morning, amounts over two inches in Vermont from this storm are pretty few and far between. 

During the changeover to snow, at one point, normally warm spot Bennington in far southwestern Vermont was snowing, while high elevation and normally cold Jay Peak was still raining. (It eventually switched to snow at Jay).

Vermont Agency of Transportation web cam shows a winter
wonderland this morning along Route 9 near Searsburg,
Vermont.

All this weirdness with Saturday's storm had a lot to do with its orientation and how it interacted with airflow in higher levels of the atmosphere. 

Storms usually form along the right side of U-shaped southward dips in the jet stream.

The bottom of the U-shaped dip in the jet stream was tilted so that the bottom of the U pointed toward the southeast, not due south.  

When this happens, there's more lift in the atmosphere.  Rising air usually leads to precipitation. If you add some mojo like this to the rising motion of the air, storms become more intense, precipitations also intensifies and you boost the chances of severe weather.

Negatively tilted troughs, as they're called aren't rare at all, but this storm really took advantage of the situation.  There was also plenty of wind in the atmosphere, and that wind changed direction with heights.  This allowed some supercell thunderstorms and possible tornadoes to organize in southern New England and near Long Island and New Jersey.

That's pretty rare for this part of the nation.

Saturday's storm zipped along into Canada as expected and we're between systems. The sun is actually out in parts of Vermont this morning.  I have a feeling the clouds will fill in a bit more this afternoon.

The next system coming in tonight is not nearly as dynamic as Saturday's, so we'll just have some light rain and light snow, depending on your elevation. Most of us who do get snow will see an inch or less. The mountain peaks could get a few inches out of this.

Another windy storm system is due Thursday.  I also highly doubt that one will have any tornado weather with it.