Thursday, October 29, 2020

Updated 10/29/20

 If you didn't have a chance, please read the post I did on the 22nd.  Click here.

In that post the discussion centered on the cold and then the potential storm for mid-week (which just occurred).  The cold air was certainly very cold.  I said it wasn't going to be record setting but I probably should have looked a records a little closer.  Low temperatures didn't set a record but the very cold calendar day high temperatures did set a few records this past Monday.  There were high temperatures that were only in the teens (I was expecting 20s which for the most part is what occurred).  The attention then turned to this mid-week system.

Here is the important part I discussed in that posting on the 22nd..."But....will it amplify and follow the blue line track?  This would occur in concert with a building ridge (the blue zig-zag) across the eastern Pacific because of the upper low.  That would mean a more favorable storm track and possible significant precipitation event for the central U.S. by mid-week.  This would also be a part of the pattern that would repeat at some frequency during the winter and spring."

The digging of the system I was talking about developed into a huge closed low aloft and well west of the high plains.  It's what I call an anticyclonic wave break.  This event has very SIGNIFICANT implications on this years pattern.  A similar event occurred in September (the previous widespread precip event).  Even though that was part of the former weather pattern, what forced that storm is likely what forced this current storm.  So that part of this new weather pattern will repeat again going through winter and through the spring months (and even into the summer).  However, and as I mentioned in that last post, the big question will be "how often".  Maybe every 30 days - maybe 60.  Unfortunately I won't know until it occurs again.  Plus, the next time it could be farther north...or maybe farther south!  Or maybe too far west or east!  But, what is encouraging is that it actually happened. 

This current storm, that has now moved east, "could of" been MUCH more significant!.  First, if it wasn't for the very cold air moving all the way to the Gulf, the extent of the precipitation would have been bigger and the amounts would have been even heavier.  Second, the hurricane that went into Louisiana also "robbed" the plains system of moisture to work with.   The gradient of who got a lot and who got very little was very tight.  Without the aforementioned hurricane and very cold air, I bet the precipitation would have been farther west and north.

Here is a map of what fell yesterday....

And here is what fell this past week (including Monday and Tuesday's snow and freezing rain) - this map includes additional reports and radar data... 

Look at the snow that fell around the high plains, especially across Texas and Oklahoma!

So, what's next?

The very cold air is not likely to return for at least 2 weeks.  It will be mostly milder with an occasional cold frontal passage (first may be late in the weekend) but no significantly cold air is expected.  Any precipitation would likely remain across the higher terrain of the Rockies .  Here is the expected precipitation (from the Weather Prediction Center) through next Thursday...

Long range forecast models are starting to converge on a possible through (dip in the jet stream) about November 10-15.  That could lead to warm and windy followed by a return of some pretty cold air.  Precipitation would be highly dependent on the amplitude and orientation of the jet stream.  That is impossible to predict at this point.  Again, the weather pattern is just getting set up and return intervals of specific orientations of the jet stream just can't be predicted at this point.  Keep your fingers crossed that we get those amplifying jet streams or anticyclonic wave break storms more frequently and to the west.  I wouldn't count on a frequent occurrence but hopefully enough that others that missed the precipitation this time will benefit the next. 

I'll shoot for an update around the 5th.

Thursday, October 22, 2020

Update for October 22, 2020

 If you haven't had a chance to view the previous post, please read it by clicking here.

There still hasn't been much to discuss as far as the outlook through the winter and into the spring.  Yes, there are major changes occurring with the short term weather.  But what about that outlook?

First this shot of cold air coming in waves (today into Friday and Sunday into Tuesday) will bring an end to the growing season for most vegetation (if it hasn't already due to the drought).  It's not unusual for what we will be experiencing tonight and Friday and into Saturday morning as temperatures will be fall into the 20s.  But the shot of cold late Sunday into Tuesday is touching on unseasonably cold.  Not a record, but pretty dang cold.  Those with pivots running should be prepared as temperatures Monday will likely not get above freezing and lows Tuesday morning will fall into well into the teens at most locations.  I wouldn't be surprised to see a few single digit readings across eastern Colorado and northwest Kansas.

As far as precipitation, there will likely be some, especially Monday and Monday night but it really doesn't look that significant.

Attention turns to what could occur by mid-week.  There are several upper level storms lined up from northwest to southeast.  Look at the map:

The X with the superscript 2 is what I'm watching carefully (plus the upper level low - the red L - across the Pacific.  This just might be a clue for part of the weather pattern this winter and into next spring. 

Will that storm (X2) follow X1 (red dashed line)?  If so then it won't bring much, if any,  precipitation to the central plains. But....will it amplify and follow the blue line track?  This would occur in concert with a building ridge (the blue zig-zag) across the eastern Pacific because of the upper low.  That would mean a more favorable storm track and possible significant precipitation event for the central U.S. by mid-week.  This would also be a part of the pattern that would repeat at some frequency during the winter and spring.

BUT....if there is no linking between the upper low (building ridge) and the developing storm, then it would likely move faster and farther north limiting the extent of precipitation for at least the high plains.  If that occurs, the confidence increases of this terribly dry weather continuing going into winter and into next spring. I'm not saying NO rain or snow this winter, but rather odds would continue to favor below normal amounts.

I'll try and update in about a week.

Thursday, October 8, 2020

Updated 10/8/2020

As many of you know from what I've discussed a million times, the "new" weather pattern starts to develop during the early fall, specifically around the first week of October.  Since that weather regime is just now getting started, there really isn't much to contribute to this posting that is different from the post I did on September 24 or prior on September 15.  I have had concerns during the past 1 to 1 1/2 years of significant dryness returning, which obviously it has.  The question is how bad (what magnitude) and how long it will last.

Here is the latest drought map....and this should be alarming to many folks....

The outlook from the Climate Prediction Center is pretty dang pessimistic through the end of the year.

Again, the pattern is just now getting established so I'm not ready to throw in the towel all together.  But, again it's been expected to turn significantly drier.  Look at the anomaly of precipitation from May 2018 through April of 2019.  When it's THAT wet, the pendulum will swing back the other way.  We just hope not to extreme levels.  Could this be another 2011 coming up?  Again, without the new pattern being fully established, it's pretty hard to say.  I wouldn't discount it completely, although it's not likely to those levels.

Here is that map from May 2018 through April of last year....just as a comparison of where we were then and were we are now.  BTW, that was the wettest 12 month period on record (nationwide)...

As far as the balance of October, many of the long range computer models have absolutely nothing!  That is NO moisture through October 31!  On the other hand, there are a couple of computer models that have a shot of significant precipitation in about a week.  It really is going to depend on amplification of weak weather systems coming out of the Pacific Northwest.  There is just a VERY slight indicator that it could happen.  The dry outlook for the next 10-15 days is much more likely than wet. If there does happen to be amplification of the jetstream during the next week and we get moisture, that will be just one of the clues to the upcoming pattern.  We better hope for that amplification!

BTW, the hurricane will not help for the high plains.

From the Weather Prediction Center into next Thursday the 15th...