The map below shows the departure from normal for daily temperatures for the 7 day period starting July 3 and ending yesterday (Thursday - 9th). As you will see, that is a large area of below to significantly below normal temperatures! Click for a larger map.
The cold was centered over Iowa and impacted much of the corn belt. Temperatures for this period were around 10 degree below normal across western Nebraska and this is climatologically very significant! Across the High Plains temperatures were also much below normal.
As for precipitation, the map of expected rainfall provided by the Weather Prediction Center (click here if you want to see that) had a large swath of significant rainfall from northeast New Mexico across Kansas into northern Missouri. The amounts in general verified, but the location was WAY off! Why? It appears the cold front associated with several strong upper systems was just too strong for July and forced everything south. There were also other mesoscale processes involved. There was spotty heavy rain (for instance Elkhart, KS and south of Ulysses in southwest Kansas). Here is the map of 7 day precipitation ending early this morning. (again, click for larger version).
Looking ahead
The Friday afternoon satellite image showed a very messy upper level wind field. There was a anomalously strong upper low across Nevada with a fairly strong (July standards) southwest flow of air at about 25,000 feet extending into the plains. Around this low there were numerous minor disturbances that could enhance thunderstorms across the mountainous regions. But, the issue for the plains may be heat that was building in the upper levels associated with a strengthening upper level high pressure system. This pattern has also disrupted the North American Monsoon flow (at least temporarily).
It looks like the high pressure aloft will begin to dominate the southern and central plains weather through at least the first few days of next week. Surface temperatures will be soaring. But at the same time, recent rainfall may mitigate daytime readings from getting out of hand. Also, the best chance for rainfall will be shifting north. The Weather Prediction Center (WPC) offers this forecast:
This heat and northward shift of rainfall may be temporary though. Across the Pacific basin there were several typhoons, one of which was a very strong typhoon that was poised to strike China. With this activity, the pattern may shift back into a somewhat cooler and wetter regime by the mid to late part of next week. More on that later.
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