Sensational Spring Weather Today But Wintry End To Week
Seasonably mild May weather today followed by 40s on Friday with even a few flakes of snow possible. The hourly forecast has highs surge into the middle 60s this afternoon but a cold front arrives late this afternoon and the winds turn in off the lake as temperatures tumble. We fail to climb out of the 40s on Friday and with winds gusting to 30 mph the wind chills will dip into in the 30s. The precipitation threat stays low on Friday but spotty sprinkles, a few flurries and even a bit of graupel are possible especially in the afternoon.
And then it gets even colder....
Lows by Saturday morning could plummet into the middle to upper 20s for most areas. A freeze watch is in effect Friday night into Saturday morning. The NAM model shows widespread 20s away from the city by early Saturday with lows closer to freezing in Chicago.
We aren't alone though. From the plains to New England and all the way south from Texas to northern Florida this unseasonably cold air will be felt. Most of the country will be 10° to 25° below average by Saturday morning.
There are signs of hope for warmer weather though looking longer range. Seems like the flip was switched in April. It was the first below average month (-.6°) since November last year and May has continued this cool trend averaging about -1.7° below average so far.
The small sign of hope as we head into the middle and latter part of May is the trend to see less blue on the longer range temperature probability forecasts. We still are favored for below average temperatures overall (from May 12-20) but the blue shades that depict this are getting lighter. That means the probability of staying cooler than average is falling. This could be marking a change in the pattern that may favor a return to average or even above by the end of the month.
Even with a cooler than average outlook for the next couple of weeks there will still be days at or even above average. Here is the GFS model for temperatures on May 18th. Lower to middle 70s could return in less than two weeks.
Here is my 7 day forecast:
FREEZE WATCH LATE FRIDAY NIGHT INTO SATURDAY MORNING
Today: Sunny start then becoming partly cloudy High: 65 (59 Lakefront)
Friday: Partly/mostly cloudy, spotty shwr (flurries/graupel) possible, windy Low: 38 High: 46
Saturday: Mostly sunny Low: 29 High: 56
Sunday: Mostly cloudy, on & off rain Low: 42 High: 54
Monday: Partly to mostly sunny Low: 36 High: 55
Tuesday: Mostly sunny Low: 39 High: 59 (52 Lakefront)
Wednesday: Partly to mostly sunny Low: 43 High: 66 (58 Lakefront)