A Few Patches Of Frost Tonight
Even after the warmest summer on record for Chicago we can't hold off fall forever. Tonight will be the coolest night of the season so far and the coolest since the middle of May. It will be cold enough for some frost to form in northern Indiana with a frost advisory in effect for Porter and LaPorte counties from 1 AM until 8 AM Saturday morning. There could be a few patches of frost west of the city too tonight although it wouldn't be widespread.
The GFS model has lows Saturday morning falling into the lower 40s west and southwest of the city with lower 50s downtown. The coldest lows will dip into the middle to upper 30s in northern Indiana.
We still have a cool couple of days with highs in the 60s before a warm up hits next week. Highs today and tomorrow will be in the 60s but near 70° by Sunday and near 80° by Thursday next week. Average highs this time of the year are around 74°.
Those warmer than average temperatures might stick around at least through the start of October. The 6-10 day and 8-14 day temperature probability forecasts have us outlooked for above average temperatures overall from September 23rd through October 1st.
The soggy start to September did help put a dent in the drought here. The numbers have improved since last week. The area in a moderate drought in Illinois has diminished by more than half falling from 17.07% of the state last Thursday to 7.60% yesterday.
Northern Indiana's drop hasn't been as dramatic. The area in a moderate drought has diminished from 14% last week to 12.79% this week.
Today will be the fifth rain free day in a row. That dry run could last all the way through next week. The GFS meteogram doesn't show an real rainfall threat until a week from this Sunday. That means the drought here could deepen again.
The GFS total precipitation accumulation forecast confirms the lack of rainfall for the next several days. There is no rainfall forecast between today and a week from Saturday here and only a trace of rain in the northwest part of Illinois and north central Indiana.
This dry pattern could last through the start of October. Both the 6-10 day and 8-14 day precipitation probability forecast has us outlooked for below average precipitation overall from September 17th through October 1st.
Here is my 7 day forecast:
Today: Partly to mostly sunny, breezy High: 64
Saturday: Sunny skies Low: 47 High: 66
Sunday: Sunny skies Low: 48 High: 70
Monday: Mostly sunny Low: 51 High: 74
Tuesday: Mostly sunny Low: 56 High: 77
Wednesday: Mostly sunny Low: 58 High: 78
Thursday: Partly to mostly sunny, breezy Low: 60 High: 80