Vermont Severe Threat Today: Iffy, But Watch Skies Anyway

NOAA's Storm Prediction Center has a risk of 
severe storms today over much of the 
Northeast, including most of Vermont. 
Highest risk of severe storms is in orange,
lower risk in dark green, yellow is 
somewhere in the middle.

UPDATE:12:15 p.m.

That model I dismissed as unlikely in the earlier post may actually be coming at least partially to fruition.

Showers and storms were already starting to fire up in central New York and the Adirondacks as of noon. 

There's potential for them to grow as they move rapidly toward western Vermont early this afternoon.

NOAA's Storm Prediction Center says it will likely issue severe thunderstorms watches for parts of Vermont, New York and Pennsylvania soon.

Be on the look out for rapidly changing weather. Strong, gusty winds with possible destructive microbursts in a few locations are possible this afternoon.

Even if any storm that hits you turns out not to be severe, you'll still see some gusty winds, dangerous cloud to ground lightning and briefly torrential downpours.  

PREVIOUS DISCUSSION, 10 a.m.

I'm late to the party this morning so let's get right to it on today's severe weather threat in Vermont.

Only a few of us will see strong to severe storms today, but of course, picking out who the lucky ones will be is impossible to predict until the storms are actually formed and approaching. 

But we can get clues as to the general idea now that it's late morning, a few hours before the storms get going.

Overall, there is a severe thunderstorm threat along and east of the Appalachians from Kentucky all the way up through Maine. The highest threat seems to be around Maryland and eastern Pennsylvania where the best ingredients are coming together for storms there later today. 

Here in Vermont, most of the state is under a slight risk of severe storms, level two of five alert levels, meaning they expect scattered, mostly short lived severe storms. The northwest corner of Vermont is under level one marginal risk, meaning there might be an isolated storm.

Whether we get big storms, and how widespread they'll be depend upon a lot of factors happening late this morning. 

A band of showers and scattered thunderstorms was making its way through Vermont at mid-morning. These showers would tend to stabilize the air, reducing the chances of storms. Clearing behind this fast moving line of showers will work to destabilize the air again.  

What happens this afternoon largely depends on how much clearing we get. It's obvious from satellite imagery that skies were rapidly going to partly sunny behind the showers.  The degree to which the air becomes unstable depends on how sunny it gets, how many breaks in the clouds develop and how long it lasts.

It's also growing more humid out there, and will become even muggier behind the morning showers, so that's a factor in favor of storms. 

A boundary coming through Vermont this afternoon would be a trigger for storms. However, usually air collides at these boundaries, causing updrafts and encouraging thunderstorms. The collision of air along this boundary isn't very direct, more akin to a sideswipe car collision. So there's lift there, but it's not as extensive as it could be. 

Damage from severe storms in Sheldon, Vermont in 
July, 2019. It's possible there could be a few scenes like
this by the end of the day in Vermont. 

The air doesn't change directions with height much, so that would help us avoid rotating, long lived thunderstorms. But the wind is strong aloft, so any storms that do develop could at least briefly bring those strong winds down to the surface.

One run of a  short term model called the HRRR has clusters of storms developing mostly across central and eastern Vermont this afternoon. Another run seemed to indicate a line of storms forming very early this afternoon near western Vermont and crossing all but the far northwestern part of the state.

To be honest, I'm not really buying that idea of a semi-solid line of storms crossing the state between 12:30 and 2:30 p.m. today. I think the peak of the storms will be slightly later, like between 2 and 5 p.m, last in eastern Vermont. I also think they will be more hit and miss. That said, keep an eye on the skies anytime after noontime in case anything develops early. 

The model, for what it's worth, brings more showers and storms across the border from Canada into northwestern Vermont early this evening, but that line would weaken as it moves south deeper into the state.  We'll see how that plays out. 

Bottom line, don't go for a hike or out onto the lake today. Conditions could rapidly change from sunny to stormy. It does seem like any storms that do form will zip along pretty quickly. I think there's a decent chance they'll issue a severe thunderstorm watch by early afternoon that will include at least parts of Vermont. More likely south and east of a Newport to Burlington line. 

A few severe thunderstorm warnings will pop up and if you get one of those warnings, take cover in a good building immediately. Like I said, these storms will be coming at you pretty quickly.   

I also expect a few false alarms with those severe thunderstorm warnings. And possibly a few severe storms that aren't forewarned by the National Weather Service. 

No, the NWS will NOT be asleep at the wheel today. They're watching this super carefully. The problem is, if a severe storm develops, it could go from a nothingburger to something nasty almost immediately. 

Once it becomes nasty, the NWS would issue a severe storm warning. Then, a few, but not all of the storms could weaken quickly.  Best bet is to take all severe storm warnings seriously. In a few instances, the winds could be locally quite destructive. Especially if you get caught under a microburst, which this weather situation seems to favor. 

In some cases, a microburst can be as damaging as a tornado, which is why you want to take severe thunderstorm warnings seriously. 

I'll try to update as warranted. This surely isn't going to be the most widespread severe storm event in Vermont history, but it's enough where you want to pay attention to the sky.