The Dog Days of Summer

 A somewhat typical summer regime is in place across North America and has been for the past few weeks or so - AFTER the swarm of Iowa tornadoes!   The jet stream has retreated well to the north, which again is typical.  Here is the jetstream map from this morning....

The Big blue H (upper high) is parked right over the central part of the country.  What had been expected by some "weather people" to produce extreme heat has instead just limited the amount of storms.  In the previous postings I did back in June I said "The rainfall across Oklahoma and Texas could very well have a feedback on July weather."   I believe that is what has happened for the central U.S. as moisture near the surface has helped keep temperatures at bay. 

In the post I did early this month on the 15th (read it here), I said "I'm still not seeing much evidence of an extended "very hot" period for the rest of July other than a few days of near 100.  I still see a chance that the average monthly temperature for July will be closer to normal, if not below."    Indeed that is pretty much what this month did.   There were a few days of 100 or close but overall no extended periods of very hot weather.  As for precipitation, some areas will end up drier than normal but other locations will have had above normal July rainfall.  Here is a map of what was observed this past 14 days....

I'll post the July rainfall in the next posting....

Again, some areas benefited from several systems.  It's unfortunate that not all locations received these rains but that is the nature of warm season precipitation.  

Going forward into August....

The biggest player may be that upper level high and where it meanders to.   Back to the previous post on the 15th...."The pattern will continue to wind down in August so it's really uncertain what to expect other than perhaps a short period or two of 100-105 degree days (but maybe not many).  Some of the very long range computer models do hint at normal to above normal precipitation for many areas of the high plains.  I'm definitely not ready to jump on that notion, at least not yet".

Transitioning out of mid-summer and heading towards fall is a very difficult period to make an outlook.  Since the jetstream is so far north, only subtle differences and shifts in the flow aloft and surface pressure can bring changes.   The key for the next week may have been a typhoon across the western Pacific that came close to impacting much of Japan.  There is quite often a downstream energy propagation that promotes cooling across the U.S. and that is what is happening currently.  By the end of the weekend and into much of next week, temperatures will be much cooler (and actually below normal).  As far as precipitation, the majority will shift west across Colorado, New Mexico and west Texas.  There will still be at least a small opportunity for the high plains of Kansas and Nebraska but it may stay west.  Here is the outlook for rainfall through the end of next week - provided by the Weather Prediction Center....

Again, only subtle changes in the flow aloft and at the surface can bring a change.  I wish the rainfall would be farther east, but at this point it does not appear so, at least yet.

As far as for the remainder of August, I still see a couple of periods where high temperatures will top out at over 100 but any period of that type of heat will be relatively short lived.  Some of the computer models that go out well into the extended has still hinted at above normal rainfall.  I would wager to go drier - not completely dry though.  Perhaps similar to July where some areas get some decent moisture but yet some that miss out.

BTW, unrelated to weather, a few of you have asked about my giant pumpkin growing.  As of this morning I have one that has topped out well over 600 pounds (estimated by using a measurement method).  For those interested, I do a blog for that at: https://jeffsgiantpumpkins.blogspot.com/

Trudging along and it's not too bad!

In the previous post I did on June 28th (read it here) I discussed the screwed up weather pattern.  Now it seems that the atmosphere has settled down into a more typical regime.  Or is it?  Did you happen to catch the news of the tornadoes in Iowa yesterday (14th)?  Tornadoes in July really is not that unusual, especially across higher latitudes of the country.  But what made those stand out to me was the intensity, size and how they were able to form in a not-so-favorable environment, especially the size and strength.  Then we slide down into high plains.  An upper level disturbance moving slowly east out of the Colorado Rockies in moderate flow aloft (July standards), was capable of producing a pretty good swath of precipitation.  In the upper air map below, that disturbance (as of this morning) was across southwest Kansas (the red X).

Unfortunately, not everyone got good rain.  But there were some areas that got really decent rains during a period of extended dryness.  In fact that extended dryness this past 2-3 weeks has shown up on the drought monitor map.

A good chunk of the abnormally dry area analyzed on the map for Kansas got those overnight rains - except for areas near the Oklahoma border.

As far as rainfall with this overnight event and others in the past 14 days, here is what has fallen in that 14 day period.

The North American Monsoon has been suppressed into Mexico, Arizona and New Mexico but it will make a return.  With that return, there should be other disturbances that should bring at least scattered thunderstorm rainfall to many areas of the high plains for the remainder of July.  Here is the outlook from the Weather Prediction Center for rainfall through next Thursday the 22nd.

I'm still not seeing much evidence of an extended "very hot" period for the rest of July other than a few days of near 100.  I still see a chance that the average monthly temperature for July will be closer to normal, if not below.  The pattern will continue to wind down in August so it's really uncertain what to expect other than perhaps a short period or two of 100-105 degree days (but maybe not many).  Some of the very long range computer models do hint at normal to above normal precipitation for many areas of the high plains.  I'm definitely not ready to jump on that notion, at least not yet.  I'll try do a bit more analyzing on that outlook and discuss that in the next posting.