Tuesday, October 17, 2017

Update - October 17, 2017

In the last post I did on the 7th (read it by clicking here) I discussed the brief cold and mentioned that some areas would get down to around freezing and there would be "some" frost.  For the most part, that is indeed what happened.  Otherwise, for the majority of the high plains there has yet to be a killing or growing season ending freeze.  For quite a while (several months) I've held onto the notion that the first widespread killing freeze would be later than normal and towards the end of this month.  To date, that first BIG shot of cold has not been showing up...until now.

Looking at the latest satellite image....



The biggest feature on this map is the position and intensity of the MJO (Madden Julian Oscillation -  I've talked about the MJO a million times over the past several years).   Part of this MJO was a strong tropical storm about 800 miles east-southeast of the Philippines that should become a rather intense typhoon (Typhoon Lan) by late Wednesday or earlier.  It will track towards Japan by the weekend (20th-22nd).  The robust MJO along with the developing typhoon will likely trigger (high confidence) a series of amplifications in the jetstream that will ultimately end up dumping a developing high latitude cold airmass into the U.S..  It usually takes 10 to 14 days for this to happen.  So if I was betting, "good-bye growing season" will occur by Halloween, most likely Oct 27-30.  There could be several shots of the cold into the first few days of November.

Moving on...there has been viral sharing again from a certain person on Facebook that routinely posts computer forecast output when the forecast model shows "big" winter weather in it's solution.  If you are one of those sharing this crap...STOP, PLEASE!  These computer models often fail in the first several days, let alone 10 to 15 days out.  One of these models were showing significant winter weather across Colorado through Kansas around the 27th - for just ONE computer run! The other runs, NOTHING - as should be expected!  Every once in a while, the model is correct.  This time, probably nothing will happen, but at least it is getting to the period when I expect the change to colder.   We'll see.  Prepare for the cold.

Speaking of precipitation - here is the latest thinking from the Weather Prediction Center through October 24....


There will be a decent system coming through this weekend that will impact mainly far eastern Kansas and Oklahoma/Texas (and on east).  There could be some severe weather down towards OKC over the weekend.  Regardless, some areas that have been seeing some drying in that area should get some rain.

Also, here is a map of rainfall since the 1st of the month....



Some locations are probably still too wet to do much, while others have not had much rain in this past 2 to 3 weeks or so and have continued to dry out.

The US drought monitor shows those dry areas, as of last Thursday...



Looking down the road....

For those that have been following this blog for several years, you know that I don't like to make late fall and winter predictions until the pattern establishes - which takes a month or so. The "new" pattern (unrelated to the previous spring/summer, etc.) begins to form during October, or as the jet stream starts intensifying across the northern hemisphere.  Pattern recognition does not really show up until sometime in November. There will be several areas of forcing for the new pattern such as the equatorial Pacific, north Pacific, north Atlantic, land masses being impacted by early snow and ice (higher latitudes), the Arctic Oscillation, North Atlantic Oscillation, small scale interactions that really are not too detectable, etc, etc.

One area that has shown it's early hand, is the robust MJO.  Will this continue off-and-on throughout the winter?  It's something I will watch carefully.  If it does, it would favor occasional periods where storms would intensify into the southwest U.S (usually a wetter signal).   But then the cooling for the equatorial Pacific somewhat signals a drier pattern. The ocean water configuration across the northern Pacific would favor occasional amplification of the jetstream across far western Canada, which could dislodge Arctic air into the states.   But then there was an early indication of a "brief" signal of low pressure across the Arctic, which does NOT favor cold for the high plains.  Thus, there are conflicting signals! The only indicator to go off of is perhaps an analog year, which really isn't statistically that significant.   So what I'm saying is that it is entirely too soon to make a prediction based on anything concrete and scientifically based.

You want a wild guess for the high plains?

Here is my gut spewing, subject to much change after the pattern shows itself....

For the high plains....

Early fall - drier than normal for an average.  Temperatures near to above on average (but with some brief cold).

Late fall - near normal precipitation on average.  Temperatures near to below on average.

Winter (Dec-Feb) - near to above normal precipitation on average.  Temperatures near average but with a couple of bitter periods (short lived).

Spring - I have no clue - ok, I'll guess normal precip and temperatures

Summer - drier and hotter than normal.

Remember - that's just a big ol' guess at this point! 

Once the pattern establishes and starts repeating, then I'll fine tune (and probably completely change my guess).  Your turn...



No comments:

Post a Comment