Are you ready for some April? Like it or not, late season chill is coming to a corn field near you. The long advertised change comes after a 7 day stretch where the average high in Cedar Rapids has been 83 degrees. Here's the 500mb jet stream pattern that delivers the cool air Wednesday.
The cool air will be accompanied by clouds and showers.You can see them here on this GFS surface depiction at 1:00pm Wednesday. The cold front is right over the Mississippi.
Precipitation should be light as moisture will be limited. Most places should see 1/4 to 1/2". The 3k NAM has this.
The EURO has this for rain through Wednesday.
With the combination of clouds, showers, and northerly winds Wednesday will see highs only in the 60s. Parts of Minnesota, NE Iowa, and Wisconsin won't get out of the 50s. These highs are more typical of early to mid April.
In some places readings will be 15-20 degrees below normal. Here's the departures on the GFS.
Moisture is scoured out of the Midwest by Thursday in the strong northwest flow behind the trough. Available water vapor (PWAT's) are quite low for mid-June all across the central U.S.
With clearing skies, light winds, and dry air, temperatures will plunge Thursday morning. Some spots may get close to record lows which are in the 40s.
The NAM is especially chilly showing these figures for lows Thursday morning. 39 in Decorah and 43 here in Cedar Rapids.
Here's a larger perspective.
Once the cool air arrives, it should dominate the pattern much of the remainder of June. The 8-14 day temperature outlook from the Climate Prediction Center.shows the trend.
Before the cool-down sets in we can anticipate another mild day today. Most places should end up in the range of 75-80. Then it's the other side of the pillow to close out the week. Roll weather...TS