Wednesday was another GORGEOUS DAY—and temps away from Lake Michigan responded big time, reaching the upper 70s and low 80s. While temps hit 82 at Joliet and Peotone and 83 at Tinley Park, mid-afternoon lakeshore air temps held to 58 at Lake Forest and 59 at Waukegan Harbor and Zion.

It was 100% Sunny Wednesday with a 25° lakeshore to inland temp spread (58° in Lake Forest and Waukegan to 83° in Tinley Park—May’s opening 10 days among the driest 25% since 1871—but more clouds and showers in our future later this week; flow off Lake Michigan plus clouds suggest cool weekend ahead…

Coming days will see increased clouds—though Thursday should see temps surge broadly to the low 80s inland with mixed sun making for another beautiful day—rain chances surge Friday and could include scattered t-storms as winds off Lake Michigan cut into daytime warming

A broad and persistent northward flow of Gulf moisture is predicted to increase clouds–particularly Thursday night and through the weekend. Dew points will be surging to the 60s Friday and into the weekend. Rain chances are to take off–but currently modeling suggest the widest coverage rainfall looks likely to occur Friday, thinning out in frequency and coverage Saturday–only to increase Sat night, Sunday and Sunday night.

Models offer rainfall estimates of 0.6″ to as much as 1.50″ by Monday morning–though rainfall is to arrive in waves.

I wouldn’t be surprised to see cool winds off Lake Michigan interact with all the moisture in the air to produce lakeside foggy spells over the coming weekend. And strengthening northeast winds with a tightening pressure gradient over the weekend is likely to take a toll temps–particularly along Lake Michigan–where weekend highs could struggle to make the upper 50s and may stay in the low 50s Sunday.

View Slideshow of the Current Weather Situation:

This AURORA FORECAST out of the University of Alaska Geophysics Dept. for Thursday night.

NORTHERN LIGHTS potential over an expanded area of North America in coming nights

NOAA’s Space Weather Prediction Center runs the OVATION AURORA FORECAST MODEL—which predicts the potential for Northern Lights displays. Also posted is the Space Weather Prediction Center’s GEOMAGNETIC STORM FORECAST. Geomagnetic storms can impact radio transmissions and have impacts on power grids and pipelines

Coronal Mass Ejections—so called “CME’s”—send clouds of charged particles—PLASMA—which excite Earth’s upper atmosphere into giving off light when contact is made by this “plasma” cloud and produce geomagnetic storms.

A G3 (Strong) geomagnetic storm watch is now in effect for 11 May with a partial halo CME that erupted from the Sun on 9 May.

Thursday night Northern Lights potential from the University of Alaska: