Long Vermont Dry Spell Still In The Cards, Eventually Much Warmer, Too

Daffodils around my St. Albans, Vermont garden shed awoke
to cool temperatures and blue skies this morning. Those
blue skies will linger for a good week across Vermont.
We will also have a strong warming trend.

 There was a slight chill to the air as I worked in my St. Albans, Vermont gardens last evening. That very wet storm far to our south threw just a few high clouds up our way.  The storm teamed up with cool high pressure to the north to add a brisk north wind to the mix. 

That cool northeast wind was still blowing this morning because that high pressure to the north and storm to the south are still there. It's that blocked up weather pattern that I talked about a few days ago now taking shape. 

The overnight wind prevented frost in many locations, but the cool air flow did bring temperatures down below freezing in a few spots this morning.  For those of  you who got a little too enthusiastic about bringing sensitive plants outdoors, you'll need to bring those plants back indoors or at least cover them up for at least the next two nights.

The brisk breezes today will keep temperatures from getting past the low 60s.  The air is quite dry. Dry air cools off very quickly when the sun goes down and that will be the case tonight. Especially since those winds will diminish. 

Most of us will have at least a light frost tonight, and away from the Lake Champlain, many of us will see a freeze too.  I think the National Weather Service in South Burlington will probably issue a frost advisory for the Champlain Valley tonight, since the growing season is regarded as having started in that area.

Despite the colder temperatures tonight, (27-34 degrees) away from Lake Champlain, I don't think they'll issue any frost or freeze advisories in north central and northeast Vermont, only because the official summer growing season has not started yet in those locations.

From here on into the foreseeable future, it stays rain free in Vermont. We are falling under what is known as a rex block in the atmospheric weather pattern.

A rex block is when strong high pressure sets up pretty much due north of strong low pressure. When this happens, everything just sits and spins and doesn't move until either the high pressure or the low pressure strengthens or weakens, throwing the balance of power between the two off. Until that happens, the weather under the rex block doesn't change much. 

Rex blocks are often hard to dislodge quickly. 

That means for the next several days here in Vermont, it will remain sunny and dry.  That cool high pressure to our north will stay put, and the strong May sun will heat that air mass.

With that heating, each day today through probably Wednesday or Thursday will be a bit warmer than the last. We'll have wide swings in temperature between morning lows and afternoon highs. Despite the warming temperatures, frosts are still possible tonight and Sunday night, and even Monday night in the cool spots. 

Meanwhile, afternoons will gradually heat up, reaching the 60s tomorrow on Mother's Day, upper 60s Monday, 70s Tuesday and Wednesday and 80s by Thursday and Friday. 

Given how long warmer than average weather is expected to last, warmer places like the Champlain Valley just might tonight or tomorrow see their last frost until September or October. No guarantees, but that's possible.  

After a reasonably wet April that got things set up nicely for spring growth, this long dry spell we're entering is a concern. After Wednesday's rain, we could go as long as two weeks with a drop of rain. Or at least close to it. 

The strong May sun and the dry air will really pull moisture from the ground.  Worst case scenario, this would be the start of a flash drought, in which we go from reasonably wet to too dry within a few weeks. 

The more likely scenario, though, is someday later this month, the rex block will finally fall apart, allowing cold fronts and beneficial showers to resume in the North Country