Update 071315

In the post I did on Friday (click here), I discussed the upper high that was building and would bring heat to a large part of the central area of the country.  Today, Monday, should be the hottest day during the period.

Here is the forecast from the National Weather Service of expected high temperatures for Monday. (as usual, click for a larger version)



In addition I also mentioned that the shift in the heat and precipitation to the north might be temporary.  I was thinking that the pattern would shift back into a somewhat cooler and wetter regime later this week.  Even though the upper high has expanded, there should still be thunderstorms along the northern periphery of the circulation.  The high should edge south a bit and allow the North American Monsoon moisture to traverse across much of Colorado and Kansas.  With the increase in storms, high temperatures should be "cooler" or should I say not as hot.

The Weather Prediction Center has this outlook for the next 7 days...

That outlook might not be a bad forecast for the plains and corn belt...although I have a hunch that for this 7 day period the axis of heavier precipitation across Kansas and Missouri may be a bit farther south.  Unfortunately, much of Texas (except the panhandle) will probably stay dry and hot.

This axis of precipitation across the central plains will be tied to the monsoonal moisture rotating around the upper high.  You can see that trajectory on the satellite image.  The whiter the color, the more moisture that is present in the column of air.  It will be interesting too to see where the moisture with Tropical Storm Dolores travels.  Will it get caught up in this trajectory?  If it does, it could increase amounts across Colorado, Utah, Arizona and New Mexico and perhaps even into Kansas.

Looking a little bit ahead, there are still those tropical systems across the western Pacific (which typically results in cooler air across the U.S. a week-10 days down the road). 

It is interesting that with the heat (across the central part of the country) is occurring as the Arctic Oscillation has dipped into the negative.  Usually a negative phase allows cold air to spill into the U.S., at least during the winter months.

 
I don't know if there is a correlation (during the summer), but to me it is interesting.  Regardless, I still think that cooler air will invade a large part of the central U.S. during the next 7 to 14 days (centered on the corn belt).  Summertime responses are often modified significantly so how "cold" is all relative.

Finally, here is the latest Growing Degree Day summary map for the corn belt.  The number of days is falling way behind normal across the central part (although these first few days of this current week will help it catch up).