From Friday Frost To Sunday 70s
Wall To Wall Sunshine Today
Thursday was no April Fools' joke. We started off April with the coldest day we have seen in a little over two weeks. Midway failed to hit 40° with a high of 39°. O'Hare did manage to make it to 40° but the day ended up 12° below average. That cold start to the second month of spring followed an overall mild March. March ended up 6.3° above average.
Today's highs will be closer to average. Look for highs today to top out near 50°. 54° is the average high for today's date.
Hang on to your Easter bonnet this weekend. It won't be quite as blustery as Thursday but it will remain at least a bit breezy today. Gusts this afternoon will exceed 20 mph and may reach 30 mph at times. The winds will remain fairly strong Saturday with occasional gusts over 30 mph.
Spring Weather Whiplash
The hourly temperature meteogram compares many different forecast models. After our frosty Friday morning our temperatures we will bounce back quickly this weekend. At their peak Sunday afternoon our temperatures will be near 50° warmer than what we started off with today.
The GFS model's forecast for Sunday afternoon has highs near 70° for most of us. There could be a breeze that develops off the lake keeping things cooler lakeside. Easter Sunday will feel more like the middle of May rather than early April.
The GFS model's temperature anomaly forecast shows just how unusually warm those Sunday temperatures will be. Northern Illinois will be around 15° to 25° above average. There will be relatively mild Easter egg hunt conditions from the Midwest to the west coast.
It will be relatively warm on Sunday but we won't break any records for Easter. The warmest Easter on record was 85° back in 1977. The National Weather Service has put together a list of some noteworthy weather that has occurred on Easter Sunday.
Quiet Through Weekend
The GFS model precipitation meteogram keeps things quiet here through Sunday. Rounds of showers and thunderstorms could fire up beginning Monday through Thursday. The best chance of rain overall will be on Wednesday.
Some significant rain in total could fall this week. The GFS model suggests around two to possibly over three inches could come down between Monday through Friday next week. These numbers will probably change but it does appear that we could be in for a wet week when it is all said and done.
Above Average Temperature Outlook
Despite our chilly first day of April the long range forecast still favor a relatively mild pattern into the middle of the month. The signal is not as strong as prior forecasts but the outlook is still for an overall milder than average pattern. The latest 6-10 day temperature probability forecast has us outlooked for above average temperatures overall from April 7th through April 11th. The longer range 8-14 day also has us favored for above average temperatures overall from April 9th through April 15th.
The even longer range Subseasonal Experiment (SubX) forecast is signaling a mild middle to April and then a flip to a cooler than average pattern towards the end of the month. The temperature anomaly forecast for the week ending April 16th has us outlooked to be above average for the period. The forecast for the following week ending on April 23rd has us outlooked to dip back below average overall. It's a fairly dramatic forecast flip.
Drying Out After A Wet Week?
The longer range precipitation probability forecasts suggest a drier pattern once we get beyond next week. The latest 6-10 day forecast has Chicago favored for below average precipitation from April 7th through April 11th. The longer range 8-14 day forecast has us outlooked for below average precipitation overall from April 9th through April 15th too. The risk for spring flooding is above average for many area rivers. More on that below.
Spring Flood Risk Forecast
The National Weather Service considers many risk factors for spring flooding. They include snow cover, soil moisture, and current river conditions.
"A significant snow cover with high water content can increase the chances of flooding once warmer weather melts the snow. Elevated soil moisture conditions reduce the amount of rainfall that is soaked up by the ground and increase the amount of water that then runs off into area streams. Above average river levels reduce the river rise required to reach flood stage, while below average river levels would require an increased amount of river rise to reach flood stage."
The map shows the locations where there is a greater than 50% chance of moderate or minor flooding during March through May 2021.
Their latest forecast suggests the flood risk is above average for many of our area rivers. The Des Plaines and Fox rivers in particular need to be watched closely.
Here is my 7 day forecast:
Today: Sunny, a bit breezy, not as cold High: 51
Saturday: Partly to mostly sunny Low: 37 High: 65
Sunday: Partly to mostly sunny Low: 47 High: 71 (cooler lakeside)
Monday: Mostly cloudy, sct. shower or t-storm possible Low: 50 High: 71 (cooler lakeside)
Tuesday: Mostly cloudy, sct. shower or t-storm possible Low: 53 High: 70 (cooler lakeside)
Wednesday: Periods of showers & thunderstorms Low: 52 High: 67
Thursday: Partly to mostly cloudy Low: 46 High: 66