WET AROUND THE "EDGES"...
After a couple top notch days, the weather pattern undergoes a change that will bring a couple periods of showers and thunderstorms this weekend. Before that happens, Thursday will prove to be another excellent day as high pressure holds for one last day. Highs will again be back in the low to mid 80s under a mostly sunny sky. A keeper!
Late Thursday night, especially Friday, the change takes places that unleashes the more active period anticipated over the weekend. As the heat wave out west gradually inches deeper into western Iowa, my area is positioned in a spot where energy (vorticity) rounds the periphery of the southwest based heat dome. That is likely to trigger showers and thunderstorms. (Wet around the edges, the theme of this summer). You can see the first wave of energy Friday riding southeast through eastern Iowa Friday.

For several days now models have consistently forecast Friday's disturbance. Unfortunately, there is a lack of agreement as to where the thunderstorm complex (MCS) will precisely track. The EURO is more into my southwestern counties, the GFS more over the northeast. Either way, there is enough consistency and overlap for high confidence that the majority of the area will see rain.
The next concern is how much rain falls. Water vapor levels are expected to increase to a substantial level once again reaching 1.5 to 2.00 inches Friday morning.

Assuming a thunderstorm complex develops Thursday night and Friday (an MCS), A swath of heavy rain is likely somewhere due to the high moisture levels and the slow to moderate speed of the system. Once this passes Friday, the convective firing grounds should shift slightly south Saturday. That appears to be the focus for another round of storms Saturday night or Sunday morning which would most likely impact my southern counties.
Between the two potential complexes, models are suggesting these rain totals ending Sunday evening. The GFS, 3K, and 12K NAM are all more geared to the northeast half of my area for the first round Thursday night and Friday.
The GFS

The 3k NAM

The 12K NAM

The EURO

The Weather Prediction Center indicates this.

The NBM, national blend of models depicts this.

It is becoming more apparent that the heaviest rains are most likely to be found in the northeast half of my area if current trends hold.
Temperatures over the weekend look fairly seasonal with highs generally in the range of 80-85. Friday probably is the coolest with some clouds and rain cooled air to overcome. What will become a more noticeable factor is humidity. With moisture on the increase, dew points will climb into the 70s and once again. That familiar July steam will be back in place. Oh boy!
After the seasonal warmth of the weekend, models are trending warmer again in the long range, especially July 21st to the 28th. Here's the 5 day temperature departures through Monday, the coolest period.

Days 5-10 July 18-23rd are warmer.

Days 10-15 July 23rd-28th are looking hot and steamy as some of that western heat sneaks into the pattern. At least that's what the EURO is cooking up.

Here's what the EURO 10 day meteogram looks like out through July 23rd in Davenport.

The GFS goes off the rails once again showing a 109 high July 25th. I will believe that when I see it.

I will sign off saying Thursday will be the last day where the forecast looks clear cut. After that, showers and thunderstorms will bring challenges over the weekend. Beyond that, the question of heat and humidity becomes an issue as guidance is trying to send a hot shot into the central Midwest around July 19th-26th. Lots of challenges on the table going forward. Have a sensational day everyone and as I always say, roll weather...TS
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