Friday, December 26, 2014

2015 Coming In Unsettled


5PM Friday Update...   My reasoning below is supported by all the new data today.  There are many social media rumors going about about a BIG winter storm next week.   While I can't discount that, there's a much greater chance of a small winter weather event as the storm moves in next Friday, then it changes to a cold rain.  Remember, we're 7 days out and you know how this thing can change.  There will be a round of very cold arctic air moving in by the beginning of next week.  Scouring that out will not happen quickly.  This low level cold air will be conducive to something frozen IF that storm system pulls out of the southwest later next week.  When I say "frozen", I do not mean snow.  The air aloft will be too warm to support that.

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The cold front I said would come in around Christmas should arrive this weekend and take temperatures back down to reality and maybe a little below.  As I blogged about more than a week ago, it would not be a sudden blast of cold air, but it would grow colder and that should be the case next week.

I do not trust the modeling at all past 4 or 5 days, especially when you're dealing with arctic air in place and a potential closed low which should develop over the western United States.  I hear a lot of chatter out there on social media about serious winter weather coming up to start the New Year.  While only one person knows what will happen, and it's not me, I have serious doubts about it.  I think it will be cold.  I'm very confident of that, but that closed low over the western United States really bothers me.  That would have been the moisture for a nice winter event around here.  By the time it comes out, I think it's possible the cold air may retreat for a little while.  Again, I want you to remember the models are just plain bad right now and things can change.  Remember the arctic oscillation (AO) index I talked about?  It was forecast to go negative which usually means cold for us.  It will, but briefly.  All the models indicate a sudden rise into the positive category.  A great meteorologist at the NWS taught me several years ago that a sudden rise typically brings us big rain events or even big thunderstorms.  That's my concern for late next week.  We must also remember there will be cold and dense arctic air at the surface and that's very difficult to erode.  That's why I think it's possible for some of the moisture to start off as something frozen for some portions of the state late next week, then as the cold air retreats, rain.

I can't say this enough, I really don't have much faith in modeling that far out, but that's where things stand as of today (Friday).  Hope you had a Merry Christmas

The AO shows a dip into negative right now and the cold snap is coming, but look at that sudden rise as a storm system approaches.  Sometimes that can correlate to a big rain or thunderstorms.  Courtesy weatherbell.com
This is the European valid next Thursday.  That big red area is a closed low aloft over California.  How that behaves is very difficult to forecast at this point.
Here's the GFS as that low pulls out.  This is valid next Friday evening and this is the surface chart.  The low is tracking south of the state and the model is suppressing it.  This is favorable for wintry weather.  Could this happen?  sure, but I have serious doubts.  With the AO's rapid rise and the models known tendency to suppress storms in the long range, I have doubts.
The Euro has a more northerly track and places the low in northern OK around the same time.  Given the information at this time, I think this is the best forecast.  Again, very, very low confidence past 4-5 days so things can change.

1 comment:

Anonymous said...

Todd,
Joe Bastardi keeps hammering the similarities between this winter and the winter of 77/78. Granted, you are a young fellow. However, what were the impacts to Arkansas during the winter of 77/78? Was it a tame winter?