July - wetter and cooler than normal?

In the post I did yesterday (click here) I showed a rainfall map of rain that had fallen in the previous 7 days, ending yesterday (July 1) morning.  I failed to display the color scale.  Ooops - here is the corrected map.

If you haven't followed along, in the last few posts I discussed the likelihood of a cool down and deteriorating winter wheat harvest weather.  Everything is falling into place, not only for the opportunities for almost daily/nightly rainfall, but for the impending cool down and increasing humidity. 

Looking at this mornings satellite image...

...the upper level ridge/high has shifted very slightly south since yesterday.  The system that had been over south central Canada yesterday had moved into eastern Nebraska.  An area of thunderstorms had already moved into much of Kansas and more is expected to develop and move across much of the remainder of the state.  Overall the pattern has become favorable for rounds of storms, some of which will bring heavy rain.  Some areas won't get a lot but a larger percentage of the area will be getting wet.

The Weather Prediction Center (WPC) has boosted up rainfall totals for the next 7 days (compared to yesterday).  Not every location that is covered by this outlook will actually get that much.  Some more, some less.  But, the trend is certainly there for a lot of rain over the next week.

With the pattern bringing the rains, cooler temperatures and higher humidities will also be in the offing.  Is this cool down and wetter pattern only temporary?  As I have discussed in the previous posts - no, it does not appear so.

In the post I did on the 25th of June (click here), I mentioned the Southern Oscillation Index (SOI) and I had noted that the index was "crashing" and that was usually an indication of an impending cooling trend.   I also discussed tropical activity across the western Pacific and that has now ramped up with several typhoon's.  This type of activity also supports cooler weather across the central U.S. a week or so after that occurs.

In addition, the Madden Julian Oscillation (MJO) has become VERY strong for this time of year and is predicted to remain very active and coherent as it moves east and then southeast over the next several weeks.   Typically I don't discuss the MJO during the summer as it is often a cool season phenomena that impacts the U.S.  But this one is anomalously strong and influencing!  The last post I discussed the MJO was on January 16, 2015 (click here if you want to read it).

Here is the latest MJO chart...

There are what is called phase spaces corresponding to intensity/magnitude and placement across the Pacific.  The black line represents where the center of the coherent MJO was and the colored lines are various ensemble predictions of where it might be at a later time and in what phase space.  The numbers (-3 to 3) represent the amplitude or strength compared to a standard deviation from "normal".  The prediction for 10 to 14 days from now by some computer models (not shown here) are off the scale!   Regardless, the model depicted above is nearing a standard deviation of almost 3.  This is unheard of for Summer!

A corresponding composite chart shows what can be expected (usually) with varying phases for this time year.  In other words, when an MJO occurs this time of year at a specific location (phase space), the corresponding weather that occurs across the U.S. is composited into an outlook.

 The MJO is historically pretty accurate.

So, putting it all together with the MJO, the tropical activity across the western Pacific and with the crashing SOI, then the outlook for much cooler and wetter across the high plains (and much of the central part of the county) seems on track.  In addition, the cycling pattern, that I have discussed before, is also entering the cool phase of the repeating pattern.  This takes us through the majority of July!

Very long range computer forecast outlooks certainly agree.  Remember, these models are run, in general, every 6 hours with updated inputs.  The solutions that they generate often change significantly from one run to the next.  However, the output recently has been consistently cool and wet.  For example, for Dodge City, look at what the latest shows...

For temperature....

The black line represents the ensemble (more than one solution) mean and the gray shading is the range of the forecasts.  This solution is also very similar across much of the corn belt too.  That might be bad if the growing degree days are lagging.  This is a pretty chilly (comparatively speaking for July) outlook!

For precipitation at Dodge City...WET!

Don't take these numbers literally as they change every time the program is run (and each ensemble is a little different), but the signal has been there for some time and it continues.

I think the screaming message here is....

1) Those that haven't got the wheat cut across Kansas will find fewer and fewer opportunities to do so.  This will also extend into northeast Colorado and Nebraska.

2) The corn "may" have issues?  With this cooler regime, the growing degree units (days) will fall behind normal, if they haven't already.  I guess that is alright unless we have an early freeze this fall.  Speaking of which....well it's too early to say for sure, but I'd would start leaning towards an early one. I'll have to discuss that possibility later this month.

3) Flooding.  Those areas that are hit repeatedly will have flooding.

NOTE

I won't have an opportunity to post again until the 10th at the earliest or 13th at the latest. Thanks for reading....