Before we get to the weekend, we’ll have to get through a limited severe thunderstorm threat Wednesday afternoon, with the threat greatest along the outer edge of a gusty Lake Erie breeze, away from most of the Niagara Frontier.
The lake is much milder than average for the date at 62 degrees, running an unusual 10 degrees ahead of schedule. Still, 62 degrees is much cooler than the air mass surface temperatures and will help provide stabilization for the lower atmosphere anywhere near the metro area, weakening convection.
During the afternoon, the best chance for strong to severe storms will be far south and east of the metro area, with a 15% risk estimated by the Storm Prediction Center. The northern two-thirds of Western New York are estimated at a marginal 5% risk, though at least one model seems to have a slightly higher risk at the northern edge of the breeze closer to Lake Ontario. In any case, even in the Southern Tier this doesn’t look like a true tinderbox setup for widespread, concentrated severe storms.
After a few lingering early evening showers with some thunder, a much cooler air mass will take over. By Thursday, morning lows will be in the upper 40s to 50. The northerly flow will hold Thursday’s daytime highs to the low 60s, with upper 50s on the hills.
The storm system just to the west will be ushering one particularly nasty Friday, quite unlike any day we’ve had in a long while. An increasingly gusty, cold east-northeast wind with nearly steady rain developing will add to the chill, and hold daytime highs to the mid-40s, near 50.
There are two positives to add to this perspective. First, we’ll be getting the worst of the weather out of the way in advance of the actual weekend. Second, we really do need the rain. Buffalo is now running at just 1.06 of rain in this important growing season month, which is 1.61 inches below the average of 2.67 inches. For the year, our 9.66 inches is -5.11 inches, or more than a third below average. Friday’s rainfall should be the most impressive in recent weeks, especially south of the Thruway.
While a few stray light Saturday showers can’t be ruled out in the Southern Tier, the rest of the weekend looks dry for all the region. Saturday will be mostly to partly sunny, breezy, and cool, with a high from the upper 50s to near 60. It will be a risky day for boaters due the brisk northeast breeze averaging more than 15 knots on both lakes, with stronger gusts of 22-24 knots, creating some larger waves and swells.
Sunday will be on the cool side, but bright sunshine and lighter wind speeds will help with high temps in the mid to upper 60s. Boaters will deal with 8-12 knot winds out the northeast and north. The UV index will be very high most of Saturday, as well as on Sunday and Monday. Remember, the UV index is not lessened by cooler temperatures. Low humidity means goosebumps will bloom when you step out of the pool, due to evaporational cooling off your skin.
Memorial Day will be the mildest of the three days, with full sun and readings getting back to seasonable low 70s. It looks tranquil for boaters, and ideal for memorial ceremonies and parades.
As we get into the first week of June, the upper air pattern appears to favor a decent probability in our region for somewhat above average temperatures most days, though shy of midsummer heat. Drier conditions again seem favored, so this Friday’s rainfall will be very important for our growers. Most of the nation’s moisture will be found in the south central states, where rainfall and cloud cover will hold temperatures below average.