Thursday, December 3, 2015

Update - 12/3/2015

It's been really busy for me personally - thus the gap in postings.


In the last entry I did (read it here) I discussed the well advertised "Thanksgiving storm".   In the end, the freezing precipitation got farther east and south than originally expected.  Major accumulations of ice were noted at many locations across Oklahoma and Kansas.  Liquid, freezing and frozen precipitation amounts were record breakers at some observation sites.  As the storm system finally lifted out of the Rockies and across the midwest, it brought heavy snows to the upper midwest.  All told, the storm system brought copious amounts of moisture.  Here is the estimated precipitation map:

Parts of southeast Oklahoma and northeast Texas are approaching 85 inches of precipitation for the year!  Unreal!

What's next?

In previous posts at various times this past year, I have discussed the weather pattern that establishes in the fall and persists well into the following summer.   I encourage you to go back through some of those postings to get an idea of what I'm faced with in determining the pattern.  Unfortunately, I still don't have a clear and obvious signal, but it's getting closer.  There are apparently intermediate harmonics that formed and which may contribute to a great deal of active weather this winter and following spring.  So the cycle length this year may be as short as 26 to 29 days or as much as 52-58 days.  Hopefully I'll know more in a couple of weeks.

But, regardless, I'm seeing enough evidence from the current upper level pattern and jet stream orientation across the Pacific that it may get pretty active again in 10 days or so.  More on the outlook in a bit.

Looking at the eastern satellite image (looking west) from this morning...



The first item that strikes me is the moisture laden air across the northwest U.S. as a strong system approaches that area.  Extreme amounts of precipitation will fall in that region of the country and southwest Canada through the rest of the week.  Higher elevations will get clobbered by many feet of snow.  If you have been following this blog, you know that during an El Nino this should not be happening!  All the precipitation should be south.  That is why I ALWAYS rely on what really goes on with the atmosphere and not just basing it on an El Nino event.  I think for now the above normal sea surface temperatures that had been across the northern Pacific basin and off the southwest U.S. coast may have a part in this.  But, this type of event should change as we get deeper into winter, i.e., eventually shifting south.

The other thing that has my attention is the jet stream from central Mexico into the southeast U.S..  It has shifted quite a ways east for an El Nino pattern (but will also shift back west, I believe).

Here is a look at the western satellite...





 

The "X" just west of California will move across the central plains early this weekend but the atmosphere will be too dry to support any precipitation, other than a sprinkle or two.  But as it gets into the Mississippi Valley it will become a decent storm.  And even stronger as it rides up the east coast.

The "L" in the Gulf of Alaska will be a major storm for that region.  The other "L" near the tip of the Aleutian islands  should bring addition rain and snow to the northwest.  Once this system gets to the northwest U.S., it may amplify, IF, the western Pacific behaves as expected.  The jet stream across the Pacific basin will become extended and perturbations flowing along should finally help the jet stream amplify across the western U.S.  The most likely time for this to happen will be towards the end of next week or weekend.  But, there are WAY TOO MANY uncertainties to get specific about any particular event.  I think it's safe to say though, at this point, is that starting around December 12 and persisting for a week or two, the weather pattern will get active and likely stormy across much of the western and central U.S..  I will put this out there...I would not be too surprised to see an outbreak of severe thunderstorms by mid-month (or a little sooner) that could be as far west as eastern Kansas and eastern Oklahoma!  Could we have another December tornado in Kansas like what occurred in Harper County on December 14, 2014?  I'm not saying it will happen (would be extremely rare), it's just something that is in the back of my mind.

Until then, "mild" and dry weather can be expected across the high plains for at least a week or more.

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