Wow, what a day it was over much of Iowa and the central Midwest. Late this afternoon the temperature in Cedar Rapids stood at 88 degrees with a dew point of 67. It was the warmest day of the year by far and it felt like July. What a change! Clarinda in SW Iowa hit 93 and Des Moines reached 91.
In the far northern part of the state temperatures were cooler north of a warm front. That area remained un-capped allowing vigorous thunderstorm updrafts to form. Severe storms developed and rolled near and just north of HWY 20 during the early evening. Wind gusts to 82 mph and damaging hail fell in many areas. Here's a nice shot of a supercell that produced damage near Spillville and Calmar in Winneshiek, County.
The same storm dropped destructive hail that destroyed the siding of this funeral home. I assume it didn't wake the dead but it might have been close!
Tuesday looks to be storm free and unseasonably warm. Highs in many areas are expected to reach the mid to upper 80s with low 90s in spots. Record to near record highs are possible. The EURO has this for highs but I firmly believe the model is a good 2-4 degrees to cool.
Dew points are expected to reach the mid 60s as far north as Minneapolis so it will be a muggy day.
The heat and humidity will create plenty of instability with CAPE as high as 3,000 j/kg
However,storms are not expected during the day as a strong cap (warm air aloft) suppresses development.
That's not likely to be the case Wednesday when a vigorous disturbance arrives later in the day. When the cold front nears instability should be sufficient for another round of storms that could produce additional severe weather. Right now SPC is not showing much of a threat but strong shear and steep lapse rates will be in place. I do expect an upgrade to a least a slight risk. Here's the strong low cutting through NW Iowa at 7:00 PM Wednesday evening.
After the storm passes a major pattern changes gets underway that ends the summer temperatures and brings a very cool change. Here's the big trough that cuts off the warmth.
The projected highs by Friday afternoon. Look at the 40s in Nebraska and South Dakota. Yuk!
So we go from the frying pan to the cooler in short order. I must say, I'm disappointed, I had hoped we had seen the last of this cool weather. From the looks of things, far from it. Once the cool air arrives it should be around most of the remainder of May. Easy come, easy go. Roll weather...TS