Tuesday, December 27, 2011

Model Wars To Open 2012

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7:20 AM Wednesday Update...  The model wars continue, but as I expected, the European has backed off of its extreme solution.  It still shows a very significant push of cold air and the Canadian does as well.  The GFS still does not show much amplification with the jet stream, thus the trough is weaker and further to the northeast allowing only a glancing shot of "cool" air.  My gut tells me it will be much colder than the GFS is indicating.  Let's see how well or how bad the model performs.  Its temperature high for Little Rock next Monday is 52 degrees and Tuesday is 54 degrees.  I have a strong feeling we will be in the 30s for highs... maybe lower 40s.

At this point, I don't think the cold will stick around long.  This should be a quick hit with moderating temperatures a couple days later.  Remember, my disclaimer at the bottom of the blog.  This is NOT the official forecast of Channel 7.  We'll see what happens.

Also, we're having a little fun on the right side of the blog with a new poll.  As you know, Snowbirdbob really puts himself out there, which I respect.  But he also made a very bold statement that he would do the polar bear plunge if there wasn't a winter storm warning issued in Arkansas December 20th-25th.  That didn't happen.  As of today, I still don't have the video proof.  Should he make good on his promise?  Vote now on the right side of the blog.  Once I have the video, YOU WILL SEE IT HERE!!!  Good luck snowbirdbob :)
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Boy oh boy do we have a war with the weather modeling next week!  It's the GFS (American model) against the rest of the world.  These are not small differences, they are HUGE and will have a major impact on our weather.  The GFS has been very ho-hum (official meteorological phrase) about a trough and associated cold front swinging through the central and eastern portions of the country.  The GFS numbers show a high temperature in Little Rock in the mid 50s next Monday and Tuesday.  It would take the bulk of the cold air to the northeast in a rapid in and out way.  The European and the Canadian are onto something completely opposite.  They both dig a massive central and eastern trough which would no doubt bring the coldest air so far this winter season.  The European is the most extreme out of those two with a strong upper level storm system in the area which would have the ability to squeeze some moisture out in the form of snow flurries or showers.  Another important point to remember, there's a tremendous lack of snow cover to the north which may help modify the air on its southward push.  If there was snow cover north of Arkansas, I would be even more concerned with extreme cold if the Euro were to verify.

So which one is correct?  Long range forecaster Joe Bastardi with weatherbell.com sent out a tweet today recognizing the differences.  Here's his tweet...  "GFS is too far east on trf I believe the major trough buckling and a storm in east next week, but less than the ballistic blizzard on euro."

I tend to believe what he's getting at here.  Neither model will get this right.  It will be somewhere in the middle.   I think we will be decidedly colder to open up the New Year.  I want to caution you, this is MANY days away and can change.  We're dealing with erratic modeling this winter so stay tuned on facebook: Todd Yakoubian and twitter @katv_weather.

Here are a few model maps below.

This is the European model valid January 3rd at 6 AM.  The red dash line through Texas up the eastern seaboard is what we call the 540 line.  It's usually a good indicator of the rain/snow line.  To see it dig so far south is impressive.  The black lines are isobars.  These lines of equal barometric pressure are packed tightly together due to the difference between high pressure over the Rockies and low pressure near the Carolina's.  This is a very cold and windy solution!  It's the most extreme out of all the models I have seen and I give it a low probability of verifying.  But, we are seeing the movement of colder air!  Just how cold is the question and how deep is the trough?

This is the European model as well valid at the same time period showing 850 mb or about 5000 feet up.  There's plenty of moisture over AR to the northeast.  With the cold air in place, it COULD have the ability to squeeze out moisture in the form of flurries or snow showers.  AGAIN, I DON'T THINK THIS SCENARIO IS LIKELY, BUT IT WILL BE FUN TO FOLLOW!
Here is the Canadian model during the same time period.  It shows the cold air as well, but not to the extreme as the Euro.  The Appalachians are getting a big snow out of this as low pressure rolls up the east coast.  Here, it's just cold and dry!
Here is the American model, GFS, showing high pressure over the state.  It's cool, but definitely not cold like the other models.  The bulk of the cold air is northeast with a weaker and more progressive trough.  The jet stream pattern shows much less in the way of amplification.  The "cool" air would be in and out rapidly!   STAY TUNED!!!!!!!

5 comments:

Anonymous said...

I would bet ark will see highs in the mid to upper 40s next week and dry. Certainly nothing to write home about. I agree with u todd the euro has hardly NO CHANCE to verify. No snow pack in the plains. That makes a 10 degree difference right there.

JasonBHampton said...

Who wins the war? The COLD imo!!! My dates of Dec 30- Jan 6 WSW or Ice Storm is coming up and a couple models are hinting at a Cold active pattern Jan 2-7? Could it be? What goes up must come down and that will be the case "temps" the next 7-14 days. LETS GET READY TO RUMBLE!!!

J.Betnar said...

If you want snow, I think we should look to the AO! It is extremely positive. Our best shot for large snow accumulation is if the AO swings to a negative position. Or even if it evens out. The northern plains are without snow because of how strongly positive the AO is. Hopefully the AO swings soon

JasonBHampton said...

Rollar Coaster ride coming up...if the first week of Jan is any indication of what the whole month will be like we are in for a rollar coaster ride. We may be in for more warm weather after a brief cold shot for a couple days. I guess Jan 6th will be my last day on the blog for the rest of Winter. :-( I shoulda done a plunge. I think we all got a little spoiled from the past 2 Winters. Late Jan and early Feb is our bread and butter, so im not giving up hope yet....Guess ill make the best of the warm weather tlate this week and go for a boat ride. *yawn*

Anonymous said...

Looking at the 7 day forecast...

These are dark times :(