Shattered records have been in short supply this summer in Western New York. So far we’ve had five 90-plus degree days, when we average three per summer. In much hotter 1988, we had 16 90-plus degree days, including a highest temp of 97 amidst the longest streak of consecutive 90-plus days on record. This year, our highest has been 93 on July 4th, which was our hottest Fourth of July on record. In one sense, this summer’s heat has been no big deal for the record books.
However, there is no denying it’s been a warmer than average summer. In the 109 days since May 1, just 22 days have had mean temperatures running below average for the date. 82 days have been above-average for the date, and a handful have been average. That’s an impressive ratio.
Skimming the data, what also stands out is the (less precise) number of uncomfortably humid days and the persistence of warm and humid conditions. What constitutes “uncomfortably humid” is more subjective, I freely admit. However, I would venture an educated guess that we have had more muggy days than we are used to for our region.
In a typical Great Lakes summer, we get more frequent interruptions of summer warmth and humidity by fresh, cool air masses from Canada, with lower dew points and below-average temperatures for several consecutive days. Generally, if we’re in a muggy pattern, we usually can count on a noticeable break arriving soon enough, within a few days. For some of us, that is part of the charm of a Great Lakes summer. This warm weather season, we had one day in June when the mean temperature was 8 degrees below average, and two when it was 5 degrees cooler than average. May was the warmest by statistical departure from the monthly mean, running 8.1 degrees above average, with individual days when the means were 15, 10, 11, 17, 10, 11, 16, 13, 15, 14, 14, 18 and 15 above average. The bottom line: it has been warmer and more often humid than in a typical Western New York warm weather season.
What is more likely to be coming in the next two to three weeks in the way of temperatures? More warmer than average days than cooler days seems like a good bet for the remainder of this month.
There are indicators of a break during week of August 20th for a few days. The ensemble/mean of 51 runs of the European model shows a refreshing shade of blue in this graphic by midweek. A cooler trough brings a dip in the jet stream and should afford us two or three days with high temps in the 70s.
The American GEFS ensemble actually shows Wednesday afternoon temps running several degrees below average. Lower humidity will almost certainly accompany this cooling.
This trend will be short-lived. The European ensemble again shows the reestablishment of a warm ridge of high pressure stacked up well into the atmosphere in the east by the following weekend.
The American and Canadian ensembles are in good agreement with the European ensemble, so the return of heat and higher humidity is a good bet. Moreover, there are indications this overall trend will extend into the Labor Day holiday. There are fuzzier hints beyond this time range that this pattern may relax after the first few days of September, with the emphasis on fuzzier.
In the meantime, meteorologists at the National Weather Service Climate Prediction Center/CPC are also confident the last week in August will be warmer in our region than it typically is. Here are their probabilities for above, below, or equal chance temperature averages. The color tells a good part of the story for our region as to what CPC is thinking:
So, if anyone gets the idea of removing a window AC unit next Wednesday when it’s comfortably cool, may I suggest you put a hold on that decision? You won’t regret the hold.