After a Stretch of Warm, Humid, and Unsettled Days, the Holiday Weekend Looks Cool.May 20th, 2013 at 12:27 pm by Don Paul under 4 Warn Weather
As our airmass draws higher dewpoints into the region, the trigger mechanism for any tshowers on Monday afternoon will be the edge of a weak Lk Erie breeze over the hilly terrain well inland to the S & SE. There will be several rounds of convection Tue-Wednesday night, with the atmosphere ripening for somewhat more widespread coverage, especially later Tue and Wed. Winds aloft will be fairly weak, meaning tshowers & more vigorous tstorms will tend to be slower-moving. A few spots could receive gullywashers and experience poor drainage flooding. In addition, this will be our first stretch of Sticky Days and Nights, lasting into Wednesday evening. SPC has WNY at Slight Risk for Severe on Wednesday. Some of that risk will depend on how much destabilization we do or don’t get from solar heating. Modeled profiles suggest some low level directional shear on Wednesday, with winds veering from SSW to SW with increased height. Still, the models as of Monday morning don’t suggest a particularly potent setup…we’d need some less than likely widespread sunshine and a little more shear than what’s expected as of this Monday AM to make things really pop.
By Thursday, we’ll be on the cooler side of this wavy front, with scattered showers. Cool & Dry air will move in for Friday, with daytime highs only in the low 60s and not much warmer on a bright & sunny Saturday. We should be back to the mid and upper 60s by Sunday, and getting closer to 70 for Memorial Day. I can’t rule out some patchy valley frost Friday and/or Saturday night.