LIVING ON THE EDGE...
Thursday a weak front made its way through the area on its journey southeast. It kicked up some clouds, especially over the southwest half of the area. A few light showers or sprinkles were also noted in eastern Iowa but by and large it was a dry day with comfortable temperatures. The heavier rains were confined to counties just to the west as you can see by the Doppler rainfall estimates.
The aforementioned front will be the focus for our sensible weather the next few days at it stalls and meanders over Iowa and northeast Missouri. Friday with the front locked just to the west it will divide very warm and progressively moist air from cooler and drier air over the majority of my area. (We'll be living on the edge). That puts the region in a spot where warm advection clouds and perhaps some precipitation (mainly in eastern Iowa) will be a possibility. The rain itself looks scattered and light but the extent of the clouds will play a major roll in temperatures. Current indications are the cloud canopy will be extensive enough for many places to remain in the 70s, maybe low 70s in spots where a shower pops up or the day is entirely overcast. The EURO shows this for highs.
Saturday significant warming is anticipated as the boundary makes a small push north as a warm front. Hot steamy air will make a run at the area with the south taking the biggest hit. Readings near and south of I-80 are likely to reach or exceed 90. (The far south, south of HWY 34) may approach 95. Further north mid to upper 80s seem to be a solid bet. I like what the EURO is expecting.
With dew points inching into the upper 60s to near 70 it will be a muggy day. Heat index values will range from 90 north to the upper 90s south. A couple counties in the far southeast may approach advisory status.
Both Friday and Saturday contain some rain chances with the emphasis more west of the Mississippi. Friday looks to be the day with the best opportunity for anything worthwhile and even that looks light unless you are west of a line from Waterloo to Cedar Rapids and on to the south. CAPE is not impressive and forcing is weak. The end result is rainfall will be spotty and measurable amounts most likely contained to my counties in Iowa. Anything Saturday looks fairly isolated and most areas stay dry. Models are suggesting this for rainfall amounts Friday-Sunday.
The NBM (National model blend)
The Weather Prediction Center assessment.
The 3k NAM, a little heavier and slightly further east.
Saturday night a kicker will halt the warm front and turn it south as a cold front. That squashes Saturday's warm-up and ends the limited rain chances. A cooler and drier pattern ensues for the long range period. The Climate Prediction Center is all about that showing a 6-10 day outlook like this.
Here's the 500mb pattern that brings the exceptional late summer weather August 15th-20th.
On a closing note the long range guidance is pointing towards a trend of ridging much of the next 4 to 6 weeks implying a relatively zonal westerly flow aloft. Such a set-up would be restrictive to moisture and would result in below normal precipitation for much of the central Midwest. The EURO weeklies show this for rainfall deficits for the 46 day period ending September 26th. That would have positive agricultural impacts as it would enhance the maturing and drying of the regions corn crop should the pattern develop as shown.
Temperatures are expected to average a little above normal which would lead to some pretty good weather in the weeks ahead. We shall see.
Then there is this. While our weather is pleasant, look at the snowfall the weeklies show over northern North America by September 26th. That would lead to the build up of cold air that could very well have implications on the coming winter. If you build it, it will come!
With that I say bring on the weekend and by all means, roll weather....TS