Spells of wet weather ahead for Chicago–the greatest rain/isolated t-storm concentration expected Friday; a let-up in rain coverage expected Saturday–then an increase in coverage and frequency of rainfall likely again sat night into Sunday morning—longer range: huge warm dome forecast to develop over west Canada next week and this is to buckle the jet stream northward there sending it crashing southward into the Midwest and driving cool weather into Chicago–warming follows the following week.

Spells of rainfall in Chicago over coming days are to accompany the arrival of Gulf moisture. But rainfall coverage and intensity is to vary in the Chicago area from day to day—maximizing Friday, dropping off as NE winds off still chilly Lake Michigan stabilize the air mass a bit Saturday. Rains will diminish to sporadic drizzle or sprinkles– and even stop at times Saturday. Then a surge of moist air up and over an unseasonably cool, full fetch (that means “full length of Lake Michigan” flow into Chicago Sunday is likely to see rain coverage increase again Sat night into Sunday.

HERE’S MY LATEST THURSDAY CHICAGO METRO FORECAST (5/11/2023)

TONIGHT: Clouding over, mild. Low 60.

FRIDAY: Cloudy and warm away from the lake. Growing prospects for showers—a few may include thunder. The widest coverage and most frequent rain in the late morning and afternoon. A wide spread in temps from 75 inland to mid 50s to low 60s beaches.

FRIDAY NIGHT: Cloudy, shower coverage decreases by late. Haze likely—possible fog patches along Lake Michigan. Low 51.

SATURDAY: A good deal of cloudiness, cooler with haze and some patchy sprinkles or drizzle on occasion. High 65—but 50s lakeshore.

SATURDAY NIGHT AND SUNDAY: Rain chances increase into Sunday morning—then ease and become more occasional Sunday afternoon, turning breezy and cooler. Low Saturday night 52. High Sunday 56—low 50s lakeshore.

MONDAY AND TUESDAY: A good deal of sunshine. Milder. High Monday 69. Tuesday’s high 77.

WEDNESDAY & THURSDAY: Partly cloudy, windy and cooler. High Wednesday 55. Thursday’s high 63.

HEAVIEST RAINS TO FALL IN THE PLAINS

Flood watches are out in those areas as you can see in the accompany watch/warning map and estimated total precipitation graphics I’m posting.

BACK TO CHICAGO–AND LOOKING INTO NEXT WEEK

Rain scatters and ends later Sunday and Sunday night and we enter a dramatically different upper air steering pattern next week being driven by the build-up of a huge dome of unseasonably warm air over western Canada next week. Such warm air domes produce northward buckles in the jet stream around the warm air’s periphery. The steering winds which sweep southward on the east side of such a warm dome latch on to cooler air which is then forced southward into the Midwest.

This sets up a situation where summer like warmth breaks high temp records over western Canada while unseasonable chilly air takes control in Chicago.

WARMING INDICATED IN THE WEEK WHICH FOLLOWS

Not to worry warm weather fans. The wavy jet stream pattern around the west Canadian warm air dome flattens in the week which follows and this is likely to produce significant warming here the week after next with temps likely to surge to 80-deg–perhaps warmer.

So buckle up. We in for varying temps in the coming two weeks!