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 daymaximizing 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 Saturday night into Sunday.

FOLLOW THE LATEST SPRING STORM AND ITS PRECIP’S MOVEMENT in the series of FORECAST MAPS below (produced by the National Weather Service’s GFS ensemble model.) as it progresses from 7am CDT Friday to 7am CDT Monday, when precipitation has moved out, sunshine’s back and east winds off Lake Michigan will ease to allow temporary warming


Flood watches are out in those areas as you can see in the accompany watch/warning map:

CHICAGO: 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.


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 degrees—perhaps warmer.

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


Abnormally Dry in Parts of the Chicago Area

Lack of widespread rainfall has parts of the Chicago area labeled “abnormally dry” by the latest weekly drought monitor: 

Extreme, to locally exceptional drought conditions persist across sections of the Plains states: 

Chicago rainfall tally April 1-May 11: 2.31″ vs NORMAL of 5.37″—–only 43% of normal 

Chicago rainfall May 1-11: 0.29″ vs NORMAL of 1.62″—–18% of normal 

Source: National Drought Mitigation Center (NDMC) at the University of Nebraska-Lincoln, the National Oceanic and Atmospheric Administration (NOAA) and the U.S. Department of Agriculture (USDA).

The system responsible for the hail and for tornadoes in sections of Colorado and Kansas was still active Thursday as seen in the Thursday GOES EAST weather satellite image courtesy of CIRA/RAMBB at Colorado State