Back in October when this weather pattern got established and as fall progressed, there was a pretty good signal that there were going to be periods of active weather systems impacting the western high plains. But, as is often the case for this area, weather systems require gulf of Mexico moisture to become efficient precipitation producers. Those that have paid close attention; during the fall, winter and early spring there were many cold front passages and weather systems near by. Sometimes the systems were wet, but mostly they were merely windy and dry. As we entered spring, these cold fronts pushed the gulf moisture well south and even some times out into the Gulf! As weather systems approached, the gulf moisture was late in returning, thus much of the area missed out on beneficial rain/snow. Then to make matters worse, the elevated mixed layer (EML) - essentially the warm layer aloft (Capping Inversion) was a bit strong so that showers and storms formed farther north and east.
I thought April would have at least average precipitation. But that thought was dead wrong. I blame it again on the gulf of Mexico moisture being shunted too far south and east (and the airmasses were a tad chilly). Then for May, I was expecting a particularly active period from May 10-28. That didn't work out too well although there were plenty of systems - just a lack of gulf of Mexico moisture again. I've rarely seen a May with a lack of surface moisture so often! In the post I did on May 6, I started stating that uneasy feeling that the high plains were going to be on the edge of the more significant precipitation. I repeated that once again in the following blog post on May 14. Now, I'm REALLY worried!
For the past 2 years, I've been stressing that the high plains has been blessed with above normal precipitation - and in some areas excessively for multiple years. If history was to repeat itself, the pendulum would definitely swing the other way. Unfortunately, I think that has started. There are now strong signals that dryness will accelerate. Here is the latest drought map (caution - it's ugly)...
Here is the precipitation map for the past 14 days....
Here is the percent of normal for May (very ugly for the high plains)…
The drought area that developed last fall did see some precipitation this past several weeks but not nearly enough or widespread enough to help much.
Now with hot and windy conditions, it will only get worse. Will there be some help soon? Unfortunately, it doesn't look like it. Here is the satellite image from this evening...
That is not a very typical winds aloft configuration for late May. One thing of note is the convection (thunderstorms) across Mexico. I would hesitate to call that the birth of this years North American Monsoon, but it's something to watch. Another interesting area is the large high pressure center northeast of Hawaii! Could this be tied to what is now happening with Pacific Equatorial waters? They have cooled significantly during the past several months. Here is the latest 7 day average (notice the below normal waters now)….
The prediction is for a La Nina to develop this fall or winter. Tied with water temperatures cooling down significantly across the north Atlantic could very well contribute to an expanding drought. But wait! Remember I said that the pattern that developed last fall had quite a few active systems? Yes, but here is the problem. We are now in the Summer season. Weather systems shift north (typically). So, the active pattern would benefit the northern plains at least, maybe as far south as I-70 in Kansas.
Well then. Does that mean that the high plains of Kansas will be dry until infinity? No, I still insist that there will be several opportunities for widespread thunderstorms. I'm just afraid that those opportunities will be fewer as things have shifted north. IF during the opportune times that other processes are going on (like the warm layer aloft being too strong, or for what ever reason surface moisture is lacking, etc), then the drought will get worse and may start to expand east, despite some rainfall.
Here is my hope. Back in one of the blogs I did in April (22nd), I mentioned June 18-19 as a curiously and potentially BIG period. Could it be for the high plains? There are hints by some longer range computer models that the last half with odds favoring above normal rainfall. I'm not buying in on that just yet. It's not out of the range of possibilities that as the latter part of June arrives, that we get into a northwest flow aloft pattern. That could yield what are called MCS's (Mesoscale Convective Systems) that are typically good rainfall producers - but unfortunately often bring a lot of wind. If we don't get those, then it's going to get really bad.
Lastly, here is the outlook from the Weather Prediction Center through the end of next weekend. Ugh.
With a lot on my plate (personal obligations) - I may not get another post done until ~ June 10 (the earliest would be the 8th).
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