A LONG AND WINDING ROAD...
Before I get to the topic of heat in our future, just a recap on the rain that fell over the past 24 hours. If you read my previous post, you know what a challenge that event was for models and forecasters alike to get a handle on. Right down to the end it defied prediction showing once again (the powers that be) always hold the last card. Here's what Doppler estimates showed. Note the southern band in Missouri and Illinois that was well forecast. The northern band near and north of I-80 that was not.
While there are some parts of my area that could still use a good rain (namely the south), in other areas there's been plenty. Notice the change in Iowa City. Back in late June amounts were running about 5 inches below the long term norm. Thanks to rains over the past two weeks, Iowa City has erased its deficit and is back to normal with 14.4 inches through June 7th. That's about 15 inches below the big flooding summer of 1993 when the yearly total eventually reached 56.36 inches. The bright red line represents 2022 rainfall, the dashed is the long term mean back to 1892.
I also found this to be interesting, especially for you folks down in southeast Iowa. This appeared on the Iowa mesonet site (a great place for weather info) Friday.
For at least the next two days rain is out of the forecast and the weekend is shaping up nicely. Humidity levels will remain in check and with highs of 81-85 things are looking good.
Monday we get back into a brief period of increased heat and humidity ahead of an approaching cold front. Southerly winds will send dew points back into the 70s with highs of 85 to 90. That should get CAPE (instability) up to healthy levels.
That should allow the cold front to kick up at least scattered thunderstorms as it passes late in the day or during the evening hours Monday.
Following the front, a healthy east coast trough allows northwest flow to dominate the region through the remainder of next week. You can see the pattern nicely at 500mb
Note the impacts on temperatures with 5 day departures running 3-5 degrees below normal through Friday of next week. Additionally, moisture will be scant allowing comfortable humidity levels and dry conditions.
That leads me to the issue of heat in the long range forecast. Before I get into it, I need to stress that the period in question is roughly a week out. Additionally, the operational GFS is the model indicating intense heat without the support of the EURO. Ensembles are also leaning more towards the seasonal (more tempered warmth) shown by the EURO. As a result, the odds are against the GFS being correct. The only reason I'm even showing the GFS is the outcome is so extreme that it would provide impactful conditions over much of the central U.S. people should be aware of and for that reason I think it's worth a mention. It reminds me of one of those winter time situations where you see a model showing three feet of snow and you know that just never happens around here, the chances are slim and none. Even so, you wonder, is this the rare occasion where the model is actually on the right track? Probably not in my opinion. So, take the GFS with a grain of salt and seriously hope it's nothing more than temporary eye candy.
Once again, let's use Iowa City as a case example. Here's what its meteogram shows for highs. Notice on the 23rd it spits out 113 degrees.
Around the state of Iowa it has readings as warm as 118 in Sioux City, 115 in Des Moines, and 109 in Moline. I have no idea what is triggering this outrageous solution but I would bet heavily against it.
The critical ingredient driving the GFS heat is the 500mb high it develops at over 600 decameters in central Missouri. It's weather's version of the demogorgon in Stranger Things.
Notice that the EURO does not develop a similar solution at 500mb. It's structure does not depict the heat monster and as such, it's a friendlier and cooler pattern. It depicts nothing more than a couple 90s without a hint of a 100 degree high.
So my feeling is that the brunt of the ridge stays out to the west and south providing the Midwest with more of a west-northwest flow that is void of the significant heat the GFS shows. I'll keep an eye on the situation but for now, what the GFS is selling is something I'm not buying.
Well then, time to get on with things. Enjoy you weekend and don't get turned upside down...if you know what I mean. Roll weather...TS