The slow departure of the pesky upper level storm will mean gradual but very noticeable improvement in the weather across New England heading into and through the weekend. A few sprinkles accompanied the north to south passage of a vorticity maximum Friday morning in Eastern New England, but these were relatively meaningless with regard to the amount of precipitation they produced. Sunshine quickly re-emerged behind that band of clouds, and continued shining elsewhere, boosting temperatures quickly from a start that was in the 30s for some cooler valleys. Deep mixing today thanks to so much dry air and a steep enough pressure gradient to crank up the winds, too, bringing the 30-40 knot winds at 850 mb down to the surface. I was originally thinking 35 mph gusts, but a wind report of 19 mph sustained from David Majercik, our weather observer in Westfield, MA, in the early morning hours impressed me enough to boost the forecasted gusts to 40, and given the observations right now, looks like that'll verify - so many thanks for his daily observation that held more information than he probably assumed!
A few showers are still a good bet in Northern New England, where terrain will assist in lifting the air to initiate convective processes, but the vorticity maximum evident on satellite imagery dropping south out of the St. Lawrence River Valley will do most of that job on its own, which is why I carry a chance of showers not only for Northern New England, but also for Eastern New England. Timing on the shortwave passage is mid to late afternoon in most Eastern areas, and coverage should be limited enough with north-south motion of showers quick enough that overall impact on the day is minimal, so still a great day. Skies clear with loss of diurnal heating tonight.
Saturday brings one final vorticity lobe and the pool of cold air will be weakening, but still comparable in 500 mb temperature to what was seen in Western New York, where a few showers were recorded yesterday, so I have to believe that a few isolated showers will develop in Maine - and possibly along the MA coastal plain - again. These should be so few and far between that they warrant only a mention. Temperatures will continue rising even though a northwest wind prevails, largely because of the input of sunshine. We're approaching our strongest sun angle of the year in less than a month, and it will do its job on Saturday, even though a cooler airmass is technically in place. High pressure builds over the Ohio Valley, dropping south from Hudson Bay, through Sunday, and the warmth that's been across the Central US begins wrapping north. As mentioned earlier this week, that warmth takes an indirect path to New England, which is why the warmup is so gradual for us, but it does make inroads. By Memorial Day, a southwest wind is freshening and warmth keeps coming ahead of a shortwave that will induce low pressure development in Southern Quebec, and fire up an active cold front near the Canadian border on Monday. This should spark a round of North Country thunder, and it's possible that with a northwest flow aloft these will carry southward a bit late on Memorial Day - especially with increasing instability - but right now I'm not too worry about that. Tuesday brings a southward settling of the front with sharply cooler air in the North Country, and probably maximized warmth just ahead of the front south before strong afternoon thunder is possible.
Matt
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