Weekend Vermont Forecast Has Gotten More Complicated, With Downpours, Severe Weather Threat Sunday

A perfect summer day Friday at Taylor Park in downtown
St. Albans, Vermont. The forecast for the rest of this
weekend has suddenly gotten more complicated. 

 This was supposed to be a nice weekend in here in Vermont.  A couple days ago, we thought there might be a couple light showers Saturday night and Sunday morning, that's it. Otherwise, it would be mostly just sunshine and low humidity.  

Well, as everything goes these days, Ma Nature has thrown in a surprise. The weather forecast has suddenly gotten more complicated. And much wetter.  

Suddenly, our oversight tonight and Sunday will feature unexpectedly high humidity, the risk of severe storms in some areas and locally heavy downpours. 

This isn't going to be an end of the world type storm. Most places will just see rain and thunder. But we're now virtually guaranteed to break the record for the most consecutive weekends with precipitation, at least as measured in Burlington. 

Burlington needs at least a trace of rain by midnight Sunday to break that record. Current forecasts call for roughly a half inch of rain there late tonight and Sunday. 

TODAY  

Today is still going to be gorgeous Vermont summer day, with sunshine and low humidity and warm temperatures rising to the low 80s. I would rate today just a mini-step down from Friday, which I will regard as the most perfect summer day we've had this year.

Afternoon temperatures Friday were comfortably warm in the 70s.  The sky was a beautiful deep blue, without a hint of that annoying wildfire smoke we keep getting. That sky was decorated by puffy clouds. The hills and mountains gleamed their rich summer green at us, and a breeze kept the summer flowers dancing in the gardens.

Today will be pretty much the same, except it will be a touch warmer. And there might be some increasing clouds later in the afternoon and into the evening, but there's no worries about rain.

It'll be a perfect day to get outside and enjoy a Green Mountain summer. Especially since tomorrow is now looking problematic. 

TONIGHT/SUNDAY

An approaching cold front now appears likely to grab some higher humidity from the south. A conglomeration of weather disturbance will come in from the west at the same time, adding some lift and energy to the atmosphere. 

That's a recipe for rain and thunderstorms.  That there will be a complicated mix of very small bits and details in this system adds some questions to the forecast. It's unclear how extensive the rain and thunderstorms will become, but now we know it'll definitely rain. And many of us will hear thunder. 

 The first band of showers will come through after midnight to around or just after dawn.  Some of the rain could contain heavy downpours and maybe some rumbles of thunder.

On Sunday, you'll notice a return of high humidity Sunday, at least for awhile, although actually temperatures won't get all that warm, with highs in the 70s to low 80s south.

The door is open for possible severe storms in much of New England.

That severe risk will run from southern Vermont, along and south of Route 4, and on into the rest of southern New England, and most of  southern New Hampshire and coastal Maine.   

Straight line winds and microbursts are the main threat.  As usual, only a few places in the risk zone would actually see a severe storm. Most places won't be so bad.

How many severe storms form depends a lot on how much sun comes out behind the initial band of storms early Sunday and how quickly a sharp cold front comes in from the northwest. 

Northern areas look to be too far removed from the best instability, so they should be safe from severe weather  Plus, a sharp cold front will hit northern areas first, putting an end to the rains by afternoon.  In fact, if northern Vermont is lucky, they could see a sharp drop in humidity and clearing skies by mid to late afternoon. It all depends on the timing of everything. 

NOAA's Weather Prediction Center also has a marginal, low level risk of flash flooding from this, but most meteorologists think we won't 'see enough rain to create trouble.  There will be some torrential downpours, but the storms will be moving along too fast to dump excessive amounts of rain in any one spot. 

A few places could see an inch or more of rain out of this,  but most of us will see something in the neighborhood of a half inch. Note that since the ingredients to this system are complicated, results may vary. We could still see another surprise or two out of this. 

BEYOND SUNDAY

This still looks like it's shaping up to be at least one of the coolest stretches of July weather we've seen in several years. 

You'll wake up to a cool Monday morning, then highs will only get to the low 70s at best in many locations. Some northern areas might not get out of the 60s. All that is a good ten degrees cooler than  normal for this time of year. 

Monday night will get into the 40s in many areas, but probably stay in the low 50s in warmer valleys. The cool high pressure system should stall briefly near us, keeping us sunny, dry and relatively cool on Tuesday. (Highs in the 70s)

We'll finally see a return southerly air flow starting Wednesday, so it should turn noticeably warmer and somewhat more humid for the end of the week.  At this point, it doesn't look like it'll get into the 90s again, but, as usual, no guarantees!