PLAYING WITH FIRE....
No doubt about it, the Midwest is going to be playing with fire the next 5-10 days...(the "ring of fire" to be exact). That's the summertime weather pattern that arises when vigorous storm complexes rotate around an orb of steamy heat and moisture. We'll be in on one of those categories (storms or heat) much of the next 7 days
The heat is evident on the GFS Tuesday when it projects triple digit heat for parts of the central Midwest.
The northern periphery of the heat, where cooler drier air buts up against the steam is where storm complexes like to form. At 500mb you can see the spawning grounds over southern Minnesota and northern Iowa early next week.
Since the set-up is still in the formative stages, we've yet to see the core of the heat which arrives Monday through Wednesday of next week. That said, warm air advection has already generated a storm complex that is in a weakening phase Saturday morning as it runs into a less favorable environment than where it formed Friday night. These remnants bring the chance of scattered showers and storms at least through the morning hours. Since the whole disturbance is fizzling as it crosses my region models are indicating generally light rain amounts in my area. The chances for anything decent will be greatest the further west you go where more intensity is expected, especially well west of the Mississippi.
Highs both Saturday and Sunday should pretty much be in the mid-80s. The big difference though is how it will feel. Dew points will go from the uncomfortable 70s Saturday to the sublime 30s and 40s in some areas Sunday. The GFS shows the punch of dry air Sunday afternoon behind the disturbance.
That little slice of heaven won't be around long as the heat dome amplifies sending hot more humid air back into the region Monday through Wednesday. That takes us into the issue of triple digit heat which the GFS is indicating Tuesday and Wednesday. Here's it's meteogram through next Sunday. 102 in Cedar Rapids both days!
The EURO is more conservative but still indicates 93 and 94 those days.
As a rule, it's pretty tough to get triple digit heat August 24th and 25th. To do it you generally need very dry antecedent conditions. That's certainly been the case for weeks now in my central counties (especially in Iowa) where in Cedar Rapids rainfall deficits are pushing 12 inches (11.70") since January 1st.
That has eliminated top soil moisture and severely restricted crop evapotranspiration. Notice how that results in much lower dew points Tuesday in my drought stricken northern counties (low to mid 50s). However, where it's been wet in my southern counties dew points in the very same air mass are much higher in the low 70s
The point I'm making is that if the cap holds bringing ample sunshine Tuesday and Wednesday, I don't think its unreasonable to think the GFS and its 100 degree highs in spots is out of the question.
Without a doubt the degree of heat is going to be determined by the placement of the ring of fire. The northern edge of the westerlies which constitutes the ring looks pretty far north indicating the best storm potential those days are from northern Iowa and Minnesota into Wisconsin. It's possible a few ridge riders could make it into my NE counties but with the warmth aloft the prospects appear dim in most areas. If we avoid storms and convective debris it's going to get hot. As such, I am leaning on highs in the low to upper 90s (maybe a couple 100's) with only limited storm chances Monday through Wednesday.
Finally, a front is expected to sink just south of the region late week and essentially turn stationary. Where that happens will determine where the ring of fire ends up Thursday through Sunday of next week. There are signs my area may be in the location where storm complexes form and that could bode well for rainfall at that time. No guarantees but that trend is prominent in modeling. The GFS the next 16 days shows lots of rain around the upper Midwest but the heaviest of it tappers off just before reaching my region. Even if it did have us in the bullseye I would be reluctant to believe it unless it was centered over my southern counties.
At some point in time the drought will break but whether or not the next 6-10 days will get the ball rolling remains to be seem. At least there's hope with the ring of fire languishing close by. Have yourself a great day and roll weather (rain too!) TS.