FIRST, THE WEATHER HEADLINES

—Welcome to September!  It’s a month predicted to continue the ABOVE NORMAL TEMP AND BELOW NORMAL PRECIP TREND established overall in August.

–Chicago and the Midwest are on the receiving end of warmth bleeding eastward off the big Western U.S. hot air dome which is setting records there.

–The heat won’t be as extreme here.  But daytime highs again Friday will come within striking distance of 90-degrees–and with moderate humidity levels (i.e. low and mid-60-degree dew points), Friday’s going to feel WARM!

–The warmth continues along with SW winds into the first half of Saturday—BUT CHANGES LOOM with a Saturday afternoon cold frontal passage. Scat thunderstorms may develop–but with limited coverage (30%) with the front Saturday pm.

–That front is to usher in a FULL FETCH (i.e. full length of the lake) “NNE” wind which will lock in and drop temps later Saturday and hold them to cooler levels the remainder of the Labor Day weekend.

–The elevated wind speeds with those “NNE” wind set the stage for wave and rip current generation on Lake Michigan. So mariners and swimmers would be well advised to expected changing lake and swimming conditions later Saturday and Sunday. It wouldn’t be surprising to see wave heights build quickly to 4 to 6 ft. by Saturday night—having started under a foot as Saturday gets underway.

—The month of September dawns with the sun 56-deg above the horizon at noon–having peaked 72-deg above the horizon in July.  Each day this time of year see the sun trek across the sky on a path slightly lower than the day before. That means the sun is in the sky above us a little less time each day—-which is why days shorten.  Also, the fact the sun isn’t as high in the sky as back in late June and July means the sun’s rays arrive less directly. That reduces the energy they carry–and over time helps cool the air.

–WARMER THAN NORMAL temps dominate the coming two weeks. In fact, only one day in that 2-week period has a BELOW NORMAL daytime average temp predicted–and that’s this Sunday. This week is to finish more than 4-deg above normal—-as will NEXT WEEK.

HERE’S OUR THURSDAY CHICAGO METRO FORECAST:

TONIGHT: Partly cloudy and warmer Low 70.

FRIDAY: Clouds break at times allowing some mixed sun, breezy and quite warm with moderate humidities. High 88.

FRIDAY NIGHT: Partly cloudy, warm and a bit breezy. Low 68.

SATURDAY: Opens warm and partly sunny. But clouds gather with gusty, temperature dropping wind shift to the northeast in the afternoon and evening. Some scattered showers, a few possibly thundery may develop and impact 30% of the area. High 86–but falling back to the mid 60s to low 70s along Lake Michigan later in the day.

SUNDAY: Cloudy spells–peeks of sun from time to time. Breezy and noticeably cooler. High 75–but 60s on area beaches.

MONDAY (Labor Day):  Partly cloudy, near seasonable daytime temps and winds continue off Lake Michigan–but at reduced speeds. High 78 inland–but 60s lakeshore.

TUESDAY and WEDNESDAY: A good deal of sunshine–just scattered clouds at times. Seasonable temps and day to day easterly lake breezes onto area beaches. High Tuesday 81. Wednesday’s high 82—but 70s each day on area beaches.

THURSDAY: Partly sunny and warm. High 83.