Cool Thursday night with a great start to the Memorial Day weekend

What’s the forecast for Thursday night?

A swath of the Chicago area, including parts of Cook, DuPage and northwest Will counties, has been classified as in severe drought by the new NWS/USDA “drought monitor,” the official indicator of drought in the United States. It is not surprising that such an assessment was made. May saw 0.42 inches – just 12% of today’s normal of 3.54 inches.

With little prospect of additional rain for the rest of May 2023 (which ends at midnight CDT next Wednesday, the month is on track to become the 2nd driest May in the 153-year official weather record here in Chicago, dated 1871. This follows a measly 2.02 inches in April, which was only 54% of normal.The National Weather Service classifies the current dry spell as an “accelerated drought.”

8 of the last 12 months have ended with less than normal rainfall. The current dry spell followed a series of wetter months from December to January, February and March.

Today was cool!! The maximum temperature of 60 degrees is equal to the normal temperature more than a month earlier – April 17-19.

The air mass is dry, so temperatures will drop quickly tonight, dropping to 40 degrees in the coolest parts of the country and 46 degrees in the city. Frost and freeze reports also spread across Wisconsin’s North Woods Peninsula and much of Michigan’s Lower Peninsula.

A blocking pattern aloft is holding the current high pressure in the area into next week. As its winds, which will still be blowing off the lake and keeping it cool on Friday, weaken over the next few days, the air mass will begin to warm over the upcoming Memorial Day holiday weekend.

The weekend looks dry with daytime temperatures rising, but the air mass remains dry and thus may cool overnight. There will also be an easterly/northeasterly lake breeze each day which will keep the warming on the beaches at bay. The weekend still looks pretty comfortable, with temperatures in the upper 60s on Friday heading into Saturday with mid-70s inland and 80s inland on Sunday, 84 on Memorial Day, and lakeside temperatures on Saturday highs in the mid to upper 60s and 70s Sunday and Monday.

Warming next week will bring temperatures in Chicago to within 90 degrees of the lakeshore on Tuesday, Wednesday and Thursday.

And a modest increase in humidity in the second half of next week could lead to showers and storms later in the week.

There are also signs that northeasterly surface winds may stop next weekend, which will lead to cooler temperatures after the warming forecast for mid to late next week.

HERE’S MY LATEST CHICAGO SUBWAY FORECAST FOR THURSDAY (05/25/2023)

TONIGHT: Clear and cool for the season with periods of calm (ie NO wind) later this evening. Low 46—but cooler near 40 in outlying areas.

FRIDAY: Sunny and a bit milder, but still BELOW NORMAL for late May. A northeast lake breeze is increasing along Lake Michigan. A high of 67, but a low of 70 degrees far inland, but temperatures in the mid to upper 50s on the beaches and immediate coastline.

FRIDAY EVENING: Sure, it’s cold again. Winds are weakening. A low of 48, but the lower 40s are cooler inland.

SATURDAY: Generous sunshine gives way to clouds in the afternoon. Warner. high temperature 75-60 on the beaches.

SUNDAY: Clouds with a break allow sunny, warmer. High in the 80s, but near 70 on the beaches.

MONDAY (Memorial Day) and TUESDAY: Daily warming continues. Partly sunny. Localized easterly/northeasterly lake breezes coming in on the beach. Monday’s high is 84 with beaches in the low to mid 70s. On the beaches on Tuesday, the air temperature is 89-70.

WEDNESDAY: Partly sunny, quite warm. High 92, but immediate lakeshore in the mid to upper 70s.