Another Chance At Vermont Rain Seems To Be Fizzling

Blue skies and a breeze this morning in St. Albans, Vermont.
Nice morning, but we still need lots of rain. Sadly, our
next opportunity at rain tonight and Saturday is 
looking less and less impressive.

 As is seemingly always the case this dry summer, the latest chance at getting decent rains is fizzling in Vermont. 

There had been some optimism earlier in the week that we'd be in for several rounds of showers and thunderstorms tonight and Saturday that would give most of us a decent rainfall. Nothing extreme, but still welcome.  

Well, so much for that. 

Some of us will still get some rain, but not a whole lot. Some places will get absolutely nothing, and a few lucky devils could still get bullseyed by a brief downpour in a thunderstorm. But the downpours are really looking like the exception, rather than the rule.

The first round of potential showers would be tonight. But that now looks like it will come in the form of a decaying clump of showers and storms from the Great Lakes area. Usually when you get this set up, the fading showers pretty much manage to produce just sprinkles and brief areas of light rain across the area. 

If we get lucky, a couple semi-decent showers could make it in overnight and early tomorrow morning, but it won't be impressive.

The National Weather Service in South Burlington is forecasting less than a quarter inch of rain by dawn tomorrow, with the higher end of that in northern New York.  Lesser amounts would probably fall in Vermont, with perhaps zero rain in southern parts of the state. 

What once looked like a promising risk of downpours Saturday, along with an unwelcome chance of severe weather, is also diminishing.

True, the cold front with this system is fairly vigorous, even if there's no real cooler air behind it. As the NWS in South Burlington explains in their Friday morning forecast discussion, the most favorable upper air dynamics for storms would be to our north, while the best instability is to our south. 

Over Vermont, dry air several thousand feet overhead and a slight sinking motion to the air would discourage showers and storms. There still could well be a few scattered showers and rumbles of thunder Saturday afternoon, but probably nothing widespread.

NOAA's Storm Prediction Center still has us in a marginal risk zone for severe storms on Saturday.  That's the lowest of five risk levels and means there could be an isolated, brief severe thunderstorm in one or two spots on Saturday.  I can't argue with that, but this doesn't look like it will be a widespread event.

Sunday looks dry and warm. (78-84 degrees for highs.)  Low humidity Sunday will dry things out further, too.

Forecasts for early next week currently call for a rather wet weather front coming into Vermont Monday and Tuesday.  

Right now, these long range forecasts call for an inch or two of rain, which would be wonderful. But since Vermont seems to have an invisible anti- rain shield. I'm (sort of) joking about the anti-rain shield. I'm sure forecast updates will evaporate those rain chances too.

I said I was joking with the crack above, but not entirely.  When there's dry weather or a drought, there's already not a lot of moisture leaching into the air from wet ground and such.  That keeps the summertime humidity down somewhat, allowing less water for potential showers and thunderstorms to work with. 

That's partly why it seems each chance of rain seems to go towards places that already have had a lot of rain lately, and not to places that need it, like northern New England and northern New York. 

The latest weekly U.S. Drought Monitor report came out yesterday, and it didn't chance conditions in Vermont any from the week before. Still a drought in eastern Vermont, abnormally dry but not quite drought in the west, and a small area of not all that dry in far southern Vermont. 

Stream flows in rivers statewide are exceptionally low, though. 

I also have to wonder if the gypsy moth caterpillar infestation we're dealing with in Vermont this summer might be having some effects on the water tables and such. 

Though a small percentage of Vermont's forests are defoliated, there are still big patches of woods that are leafless.

Normally, the tree canopy blocks most sunshine from the forest floor. This tends to slow the drying process in the ground. 

In leafless areas, the sun, now strongest of the year near the summer solstice, is blasting down onto the forest floor. That's probably having localized effects on ground water, and also causing relative small, but real pockets of enhanced forest fire risk.