AND THEN IT WAS SUMMER....
Our old nemesis the wind was back with us Monday but his buddy Jack Frost was nowhere to be found. Summer exploded out of the gates allowing all of my area to experience the warmest readings of the year so far. In the Quad Cities the maximum of 88 was the warmest reading at the NWS office since September 30, a stretch of 221 days!

Look at the 4:00pm observations from around the central United States. 90s extend from western Iowa to New Mexico. A swath of 100 degree temperatures was baking western Oklahoma and Texas. A reading of 107 was showing up in Lawton, Oklahoma! However, with a dew point of 23 in Lawton it only felt like 98. Not much worse than it was around the Midwest.

From Lake Superior to the Texas Panhandle readings were 15-20 degrees above normal.

Here's the 500mb pattern that's driving the summery temperatures. It's likely to remain in place through Friday meaning a toasty week's in store for all of the Midwest.

These are the temperature departures for the upcoming period Tuesday through Saturday. Relative to normal, the warmest readings in the entire country will be found right here.

What makes this early season warmth especially impressive is the amount of water vapor that accompanies the heat. Typically, highs this warm in early May come with a relatively dry air mass. Not the case this time around with dew points projected to be in the 70s through Friday. That's really big considering crops have not emerged and some trees are just beginning to show leaves, evapotranspiration which is a big humidity driver in July is a minimal factor now.
As a result of the moisture, heat indices will soar into the low to mid 90s Tuesday through Thursday. The EURO even has heat index values as warm as the upper 90s Wednesday in SE Iowa. Goodness gracious, what a change.

This all comes at a critical time for agricultural interests. As you can see as of Monday, corn planting was 22 percent below normal for the nation as a whole.

Before the heat kicks in again later Tuesday, some areas, especially those NW of a line from Cedar Rapids to Dubuque dealt with thunderstorms overnight. A nearly stationary boundary just to our NW combined with the low level jet popped storms in that area after sunset. Most of those should be gone by daybreak as the low level jet weakens and the atmosphere quickly mixes out Tuesday morning. Most models keep the rains NW of a line from Galena to Iowa City. Whatever happens, the sun emerges in all areas mid-morning and we are set up for a hot sticky Tuesday with highs in the upper 80s to near 90.
Tuesday night a similar scenario is expected with scattered storms again a possibility. Best chances appear to be closer to the front in the northern half of my area. Again, not all areas will see storms but where they do fire, a couple strong storms are possible. Some heavy downpours are likely in the stronger updrafts. SPC shows this for a severe weather risk Tuesday night.

The rest of the week still carries a scattered storm threat but outflow boundaries and capping issues will make it difficult to pinpoint where. We'll need to take that on a day by day basis. Otherwise it's steady as she goes with plenty of sunshine and very warm muggy conditions to close out the week.
Cooler temperatures will gradually work into the region Saturday and especially Sunday. This is to be expected as the extreme readings of this week will be pushing records, levels that can't be maintained for a lengthy period of time. Even with the cooling, temperatures should remain seasonal to a bit above normal. The EURO shows this.

Before I close I want to show you how unprecedented the coming heat is. These are the records for Tuesday, Wednesday, and Thursday. Most areas will probably come in just short of these benchmarks but it's going to be close. At any rate, we're in the top 5 percent of of all-time warmth for May 10-12th. Here's where we have to get for record highs in my area.
RECORDS FOR MAY 10th
Moline................93, 2011
Cedar Rapids....92, 1896
Dubuque............92, 1896
Burlington..........92, 2011
RECORDS FOR MAY 11th
Moline................91, 2011
Cedar Rapids....90, 1922
Dubuque............90, 1879
Burlington..........91, 2007 RECORDS FOR MAY 12th Moline...............94 in 1983 Cedar Rapids....90 in 1896 Dubuque...........90 in 1896 Burlington.........94 in 1956
So, all of you who have wished for the warmth of summer, it is time to rejoice and raise a toast. At least for now, those cold dreary days are a thing of the past. Forgive me if I can't scare up any tears. Roll weather...TS
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