SWOP Weekly Weather Discussion

HEADLINE

After the recent stretch of volatile weather, generally quiet conditions are anticipated through the Easter holiday.

DISCUSSION

An upper-level ridge of high pressure currently over the Rockies/High Plains will build eastward into the Midwest this weekend...pushing temperatures back above normal into the lower to middle 70s by Sunday, April 13th. The return to warm springtime weather will be short-lived however as a series of short-wave troughs dropping southeastward out of Canada keep readings generally near or slightly below normal next week. The first wave and its associated cold front will pass through central Illinois during the morning of Monday, April 14th...while a second front will swing through the region by next Thursday or Friday. While widespread severe weather is not expected with either frontal passage, we will need to keep an eye on the late week system as some medium range computer models suggest a fair amount of instability and shear may be present. After that, another system may approach from the southwest by Easter Sunday: however, confidence is low at that time range.

The Arctic Oscillation (AO) and North Atlantic Oscillation (NAO) are currently positive...but both are progged to become neutral or slightly negative over the next week. This supports a trend toward cooler than normal conditions. The Week 1 CFS also supports below normal temperatures: however, a consistent signal toward much above normal temperatures has been noted in the Week 2 and 3 time frame for the past several days. As a result, confidence is growing for a big warm-up after the Easter holiday.

The latest 6-10 day outlooks (Apr 17-21) from the Climate Prediction Center (CPC) suggest BELOW normal temperatures and NEAR normal precipitation across central Illinois.

Issued: 4/11/25