Update - May 6, 2020

I'm starting this post by reviewing recent outlooks.  As you may recall in the post I did on April 14 I mentioned a possible light freeze or frost between May 1 and May 6 across the high plains.  I put the odds at rather small - but at that point there were absolutely no computer models hinting at much more cold for the remainder of the spring.  And, many forecasters said we were done with the cold.  In the post I did on April 22 I refined that cold outlook to May 5-6 (and the long range computer models STILL did no indicate any cold).  The cold arrived right on schedule!  Here is a map (at least for Kansas) of minimum temperatures ending May 5.



Here is a map of lows this morning (May 6).



Unfortunately there looks to be one more cold period at the end of this week.  Frost or a light freeze seems pretty certain either Friday morning or Saturday morning, or both.

In that last post, I also said that the May 5-6 period would probably be the next chance for widespread precipitation and probably severe thunderstorms.  Well both occurred, but only across the northern part of the high plains and on into eastern Kansas and Oklahoma.  That in itself is a little discouraging going forward and I'll explain later in this post.  Here is a map of severe weather reports for 05/04 ending 05/05...



So I feel pretty good that I was able to time the cold but why was the precipitation and severe weather displaced?  For early May there is typically a rich source of gulf moisture.  But because of frequent strong cold fronts this spring, the deeper moisture has often swept all the way through Texas and into the Gulf of Mexico.  So, because the lower atmosphere moisture has been less than normal for the high plains in advance of weather systems, the elevated mixed layer (capping inversion) has been strong enough to displace thunderstorms north and east of the majority of the high plains.  Will that continue?  To a point, probably but as we get deeper into May I think things should turn around.

In the previous outlooks I mentioned May 10-28 as being particular active.  I still believe that will be the case. Hopefully the majority of the active period will be wetter in lieu of severe weather but I'm pretty confident that severe weather episodes will ramp up.  Still - I have this uneasy feeling that  much of the high plains may be on the edge of the widespread rains.  It's just a feeling.  I'm still counting on much more rainfall.  Do you remember last year?  It was really dry until late April and then the faucet was turned on.  So far, that may repeat for a period this month.  But if it doesn't happen during this month, we may be in trouble.

Back to previous posts and outlooks.  Earlier in the winter, I was pretty confident that April would be cooler than normal and wetter.  The temperature outlook wasn't too bad.  But the precipitation outlook was trash!  There were systems but they were too fast and there wasn't enough boundary layer moisture in most cases.  Here is the percent of normal for April....



As a result, the drought has begun to expand once again across the high plains. There is that uneasy feeling again.  Here is the map of precipitation that fell during the previous 14 days ending this Wednesday morning (May 6)...



At least the northern part of the high plains did well.

And with that continued lack of precipitation across much of the high plains....the drought map.




So for that period of May 10-28...

To start, there should be several opportunities next week.  But before then, a weak disturbance moving southeast from the northwest U.S. (the red X on the satellite image below) will ignite widespread showers and thunderstorms this Wednesday night but unfortunately will largely miss the high plains again!



All indications from the Jetstream configuration should benefit at least part of the high plains next week.  One indication is the tropical connection.  That is indicated by the green arrows on the satellite image (bottom left stretching up into the Texas and Oklahoma panhandles).   That is likely tied to a rather robust (for May) MJO that continues propagating through the Maritime Continents.

Here is the outlook from the Weather Prediction Center through next Wednesday.



I'll do my best to update early next week.