Update - August 5, 2015

We're well into the time of year that forecasting precipitation is extremely difficult since there are a  number of factors that can help and deter thunderstorm development.  Since there are so many mesoscale processes in existence and the fact that just a degree of warming at around 10,000 feet can prevent storms from forming, it is sometimes nearly impossible to accurately predict weather.

Take for instance what happened in July.  I had forecast normal to above normal rainfall for the month for much of the plains.  Indeed some areas were extremely wet, but at the same time there locations even in the same county that did not fare so well.  Look at the map below of rainfall for July.  (click for a larger version)

 

Look at the amounts just south of Elkhart.  That is between 12 and 14 inches, just for July!  Incredible!  But, then go just 30 miles straight east and only 2 to 3 inches fell.  Predicting that type of occurrence on a spatial scale is impossible.  Roughly 90 percent of the area did have above normal rainfall, but a small percentage was close to normal or below. Who would have predicted 18 inches of rain south of Tulsa?  And then go west about 50 miles from there and there was only 2 to 3 inches.   That's ridiculous!

Anyway, this rainfall that fell in the panhandles for July has continued into August.  Look at the rainfall up until the 4th across the panhandles.  That is more than a months average already at some locations! 

The wet July and rainfall so far this month has had a direct impact on temperatures and humidity.  This afternoon Elkhart and Liberal had a temperature of around 90 and a dew point (measure of moisture in the air) of 72!  This type of occurrence for an afternoon condition in August is exceptional!

Those that tried dryland corn this growing season across the high plains may or may not have benefited from the summer weather so far. I know a few that 1) had adequate sub-soil moisture from awesome farming practices; 2) have had perfectly timed rains; and 3) have had a surplus rains (above normal). They will benefit financially.  But I know of some others (a couple in Stafford county for instance) that have been begging and praying for more rain.  Looking at the map of July rainfall...yep, they somehow have been missing the storms.  Unlucky?  But I guess if you could afford the risk, this would have been the year.

So now what?

The river of air above us (jet stream) is reaching it's weakest point as we get deeper into summer.  It's hard to track systems across the central U.S. and now warming temperatures aloft may impact thunderstorm development. Here is the satellite showing several features:

The upper high pressure ridge centered over northern Mexico will expand rapidly to the north during the next several days.  In essence it will force a lot of the thunderstorm activity well to the north.  

But, at the same time, there was a relatively strong upper system across western Canada that will slide southeast and it's associated front will approach the central plains.  I think several things may happen.  There should be additional thunderstorms complexes that will dump lots of rain on Nebraska and the Dakota's.   A big question mark, and possibility, is that the complexes of storms will produce several outflow boundaries (that act as fronts) that will actually make it all the way south into northern Oklahoma.  This could help shift subsequent thunderstorm complexes farther south.  I think most of Texas (except the panhandle) will stay rain free for the next week to 10 days (through the 15th).  Here is the outlook for rainfall through August 13th provided by the Weather Prediction Center:

I wouldn't be surprised to see a shift in heavier rainfall to the south (covering more of Kansas).  But for that to happen, the complexes of storms across Nebraska will have to produce strong outflow boundaries.