Monday, December 20, 2010

Tracking The Chance For A White Christmas

NEW VIDEO BLOG DISCUSSION WEDNESDAY.

5:30 PM Tuesday Update... Here's my advice, don't get too excited yet!  As I stated today, it's only Tuesday and these computer models could just as easily move the other direction tomorrow, but I will say this... THE TREND IS OUR FRIEND!


I am continuing my idea of snow accumulations up north.  How far south is still very questionable.  Below are two of the midday computer model runs showing snowfall accumulations.


I will have a new post and video blog discussion Wednesday.


18Z NAM showing 1-2 inches of snow across northern Arkansas by Christmas morning
18Z GFS showing snowfall accumulations of at least 1'' across portions of central and northern AR.


 2 PM Tuesday Update... Just looked at some of the data in depth and I'm sticking to my guns with the chance for a little snow across northern Arkansas Christmas Eve and early Christmas Day.  I do think it's possible for few flakes to fly as far south as Little Rock, but if anything accumulates, it should be the far north.  Still time to change and I'll keep you updated.

12:30 PM Tuesday Update... If you have been following the latest information on twitter, you know there is some real excitement about the prospects for snowfall Christmas Eve and Day!  I want to caution everyone not to get too worked up about the idea just yet.  It's only Tuesday, but there are some very encouraging signs.  The track of the low is further south and maybe even slower.  I still expect rain with a change over to some frozen precipitation later in the day.  All we can continue to do is wait and see.


This is all fairly amazing to watch considering today we're pushing 70 degrees.  The record is 74 set in 1889.  I don't think we'll hit that due to cloud cover, but watch out.... temperatures will tumble in the coming days!!!  I'll keep you updated here and on twitter!
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All of you know I have been "wishcasting" Christmas snow for several days now.  I think it's time now to officially "forecast" it.  Here's what I want to stress... not everyone will see it and it won't be much.

If this all comes together, it will be the second straight year portions of Arkansas have seen a white Christmas.  You may remember last year an intense storm brought several inches of rain Christmas Eve.  On the back side of the storm, the rain changed to accumulating snow for northwestern sections while central Arkansas saw a few flurries after midnight.  This system is NOT as intense, but locations north of Little Rock may have an opportunity to see some light snow before the system moves away.  There could be light accumulations, but it's still too early to know for sure.

Each run of the computer generated models indicates a southern track for our system Thursday and Friday.  I would like to see it slow down some and more cold air get involved, but then I would go back to "wishcasting".  At this point in time, it looks like rain (much needed) will overspread the state Thursday.  As colder air comes into the area, it may change over to some light snow or flurries across the north later in the day and into the morning on Christmas Day.

On Christmas Day, I expect a few lingering flurries across the northeast, then clouds will decrease.  Highs will struggle to get out of the 30s for central and northern Arkansas with northerly winds 10-20 mph and gusty.

Remember, things can and likely will change.  I will update here often and plan a "Video Blog Discussion" Wednesday.

Now onto some computer models...

The chart below is from the European showing a surface low near New Orleans.  The red lines are isobars.  With a 1036mb high coming out of Canada, the pressure gradient shows a cold, northeasterly wind flow at the surface.  The "540 line" is slicing through Arkansas with some lingering precipitation north of it.  This is the area where a little changeover to some light snow could occur before ending.

Tuesday 00Z European valid Christmas morning
The same model is indicating some light amounts of snowfall across the north.  I'm not sure if I buy the southern extent of it yet.

Tuesday 00Z European snow cover
The next piece of data is the GFS.  This map is available on the "computer model" section of the blog.  This is more in line with my thinking, very light amounts for north central and northeast Arkansas.  This would add up to a dusting at the most with the heavier snow amounts into Missouri.

00Z Tuesday GFS 120 hour snow accumulation
The next map is the GEM.  It too shows the best chance for accumulating LIGHT snow across the northern two rows of counties with MAYBE higher amounts along the Missouri border.
00Z Tuesday GEM total snow cover

As you can see, the models continue to show anything in Arkansas as light and mainly affecting the north.  Remember, it's only Tuesday and things can change with the track, timing, and strength of the system.

Once again, I will have updates throughout the day on twitter and on the blog.  I will also produce another video blog discussion Wednesday.  Until then snow lovers, let's keep hoping!

27 comments:

dan said...

todd let snow let snow what about the 28,and jan2, is it showing snow let hope not ice could some one tell me...

Anonymous said...

Could you say something on the post about chances for severe with the Christmas eve system? Thanks!

jimmylee42 said...

Todd-

Our White Christmases in the last 50 years according to my records are 1962,63,75,83,90,2004. Some would argue 2000 and it might qualify because we had ice and sleet on the ground the day of Christmas.

My definition of a White Christmas would be measureable snowfall sometime during Christmas or snow remaining on the ground from previous snows measured on level ground in full sun.

Mitchell McDill said...

This dry weather sucks! Even just a plain old heavy rain would be interesting now. I haven't seen lightning or thunder in months it seems.

Daryl Stout said...

Ironic that last year was the wettest on record for many parts of Arkansas, and now, we can't buy a drop of rain!! Yet, they're getting heavy snow (again) from Montana through Minnesota into the Ohio Valley...and flooding rain in California. It's feast or famine (sigh!). I'm sure the ham radio operators are busy with emergency communications in these areas.

Daryl, AE5WX
The Weather Wonder (Wx1der)

Jason H said...

Im dreaming of a White Christmas....Looking alot better for me this morning! Ya never know!

Jason H said...

Not that it matters much, but Weather.com has me "Randolph County,Ar" 25%-50% of a White Christmas now. Wooohoo!

SNOWBIRD BOB said...

You better watch out, you better not cry, you better not pout, I am telling you why, a low pressure system is coming south of town, he bringing some moisture,& checking it twice, I see snowflakes coming to your house, he knows if youve been posting or not, a low pressure system is coming south of town. He may bring snow or rain, It all depends where you live in Ark. Sooo, You better keep watching the models, because they are in your favor, you just want him to slow down & deepen, If he does that, we might have some blog pictures on Christmas Day..lol Anyway Merry Christmas to everyone, I hope yall see some snow, In my opinion I am giving I-40 north a 80% chance of seeing some light snow & maybe some accumalating snow with this Christmas Eve system, I am a little wishcasting & from the past it does help sometime lol...

raishaw said...

Still feeling like snow's stepchild here in Pine Bluff. I'm not getting my hopes up until I see a big white patch of precipitation on the radar headed our way...:-)

Amy said...

Snowbird Santa......I like your wishcasting!!!! It's very Christmasy!! Come on Snow!! And get out of here muggy, Spring temps!!! You are warming up the ground too much for all the snow to stick on Christmas Eve!!!

Chad Gardner said...

Nice one Bob!

Anonymous said...

looks.like all this wishcasting wont help.little rock much. it might help north ark but not central. i c just another wet and chilly christmas . oh well maybe jan is our month again.maybe not just have to wait and c.

Caleb said...

Hey everyone,
Snowbird that was a very good song you made up. It made me laugh. I was also going to say that I happened to be reading the Mempis, TN NWS forecast disscussion and it said quote " main focus is on a possible winter storm for late week." I think are chances are growing for a white christmas especially since everybody is talking about the system digging further south. Let it snow! Let it snow!

Eric said...

Hey todd u are a amazing meterologist. Thanks so much for taking the time out of your busy schedule to update us all bloggers. I hope we in little rock could see a dusting somehow . it would make for a perfect christmas come on system dig more south come on come on !

Amy said...

Good Morning America defined a White Christmas this morning as 1 inch of snow cover on the ground. That may be the case in NYC, but here in Arkansas, a dusting ought to do it!!!

tboyce1979 said...

So when you said "North" of Little Rock...did you mean North Little Rock??? My 10 yr old daughter said this morning... "What's Todd saying? I just want ONE White Christmas mom!"

Anonymous said...

We need a video blog discussion!

tboyce1979 said...

Nat'l Weather Service now has a 60% chance of rain snow for the NLR area!

Alan said...

Todd,

thanks for the snow poll. Looks like so far most people say a "White Christmas" is more than a few flakes flying.

Jason H said...

Im not gonna get too excited yet, even though the models are looking good. Still a LONG way out and alot can change. Wouldnt shock me to see things shifting to the North and being warmer by this time tomorrow.

snowentiast said...

I think it will snow (snow flakes) in Little Rock Friday Night but how cold the ground will be and when the change-over time will be will depend on accumulation amounts. A white Christmas would be awesome

Anonymous said...

tboyce1979 some questions are just to dumb to answer lets hope u were joking cause if u are so am i. Anyway this system is fun to watch and monitor great job todd on the blog. i know i will be up at 4 in the morning reading noaas forecast discussion.tomar should be the day we know what could be instore either a white christmas for little rock or a very cold rain an sleet or a variety of everthing.

dan said...

i wont to place a order for some snow todd i know you can do it.

The WeatherNinja said...

For those who classify a White Christmas as flakes flying..then how can you forget last year. We had a trace of snow that fell between 11:30 Christmas Eve and 2:30 Christmas Day. It kept me out of the lake (polar bear plunge) because I said it would snow on Christmas Day.

Now..on the BUZZ this morning we classified it as snow on the ground making the ground white so that should include a dusting.

tboyce1979 said...

Um... Anonymous...I'll let you figure that out. Thanks for being such a sweet heart.
Wxguru...I didn't like your tweet a min. ago :(

Anonymous said...

Im with u todd i been reading your tweets i dont think little rock will see anything but rain out of this system , its a mostly missouri snow event an northern 2 rows of counties in arkansas. It will be a wet christmas eve an a dry an cold christmas day. I think alot of people in central ark gettin excited over nuthin an they will be disappointed

Jason H said...

Still think this storm is too far South and too dry. I say most of NEA will see 2-3 inches with some places getting more. Also I am going with a big Ice Storm with the system around New Years. We shall C!