Get Ready For Some Fall Weather Whiplash
Warm Weekend Then Big Drop
In the span of four days we will see high temperatures go from 15° above average to 15° below average. That's a dramatic drop of 30°. Today will be the 5th day in a row with above average temperatures and that streak should continue through Sunday. That will be followed by at least 6 days in a row with below average temperatures.
Let's focus on the warmer days first. Today's highs should climb into the upper 70s with a few spots hitting 80°. That is nearly 10° above average.
Saturday will be the warmest day we see for possibly a long time. Saturday's highs will climb into the middle 80s or 15° above average. We cool down a bit on Sunday but still above average with highs well into the 70s. The really cool air comes crashing in on Monday and highs by as early as Tuesday or Wednesday could fall into the 50s.
It's striking to look at this drop in terms of temperature anomalies for Tuesday afternoon. The anomaly forecast highlights which parts of the country will be above average, which will be near or at average and which will be below average. The dark blue stretching from the Great Lakes to the Gulf coast shows the biggest anomalies which includes Chicago and the midwest. Temperatures by Tuesday afternoon will be around 15° to 20° below average.
Jacket Weather For A Few Weeks?
This cool pattern change that is coming could stick around for several days. Even more blue showing up on the long range temperature forecasts. Both the 6-10 day and the 8-14 day temperature probability forecasts have us outlooked for high probabilities of below average temperatures overall from September 30th through October 8th.
Some More September Rain On The Way
Today will mark the 12th straight day without rain. September's soggy start though means our rainfall for the month is still above average despite the dry spell. We have seen 2.78" of rain so far this September which is .17" above average. There are still portions of the area in a moderate drought so the rainfall forecast for next week will be welcomed. There could be a few showers late Sunday into Sunday night but the greatest chance of rain comes Monday into Tuesday with more scattered showers on Wednesday.
The GFS precipitation accumulation forecast shows a total of nearly an inch to possibly two inches of rain could fall between Sunday and Wednesday afternoon here.
Drought Diminishes In Illinois But Deepens In Indiana
The US Drought Monitor updated the drought conditions here in Illinois and Indiana yesterday. The portion of Illinois in a moderate drought has dropped by nearly 2% compared to last week and is now down to 5.78%. Indiana's drought has deepened this past week. The portion of that state in a moderate drought has increased by almost 3% and now stands at just under 16%.
After this upcoming week's rain we could be developing another dry pattern for the start of October. The 6-10 day precipitation probability has us near normal for rainfall from September 30th through October 4th but then shifting to below average rainfall overall from for the 8-14 day forecast that runs from October 2nd through the 8th.
Here is my 7 day forecast: Today: Mostly sunny & warm High: 80 Saturday: Mostly sunny, breezy & warm Low: 63 High: 85 Sunday: Partly to mostly cloudy, scattered showers mainly late Low: 67 High: 77 Monday: Mostly cloudy, scattered showers Low: 55 High: 65 Tuesday: Partly to mostly cloudy, scattered showers Low: 49 High: 59 Wednesday: Partly to mostly cloudy, scattered showers Low: 45 High: 57 Thursday: Partly to mostly sunny Low: 45 High: 55