Sunday, February 12, 2012

Tracking The Arkansas Slushie. Sunday Update


12:50 PM Sunday Update... The morning run of the GFS and NAM are complete and they both agree central Arkansas could see 1-2'' of snow before a change over to ice, then rain.  I think it will be on the lower end of this scale, but we'll have to watch this very, very carefully.  Our model Futurecast insists we'll see around 3'' of snow.  I'm still not buying that yet, but I'm considering it.  At this point it looks like Little Rock will be on the edge of any accumulating snow.  If you go just north or west of town, the ground will whiten up.  This may end up being a situation where the metro area gets a dusting to 1'', but the hills in west Little Rock out into western Pulaski county can get up to 2''.  If you live at a higher elevation, you stand a much, much better chance for accumulating snowfall.  Remember, snow forecasting is difficult and we're doing our best to pinpoint all of this for you.  This can still change and I'll keep you updated.  The new version of Futurecast is below.

The picture is becoming very clear with the exception of one piece of data that MUST be watched.  As I have maintained all along, this is not the ideal set up for a major winter storm across Arkansas.  We have definitely seen bigger storms in the past compared to what will happen Monday.  It's crucial for an east to northeast wind at the surface to supply us with a cold pump of air.  Surface winds will be out of the south and southeast which will lead to warming temperatures during Monday.  Also, a push of warm air aloft will spread over the state from the southwest.  This will also change the snow over to ice, then rain.  I don't want to downplay the fact that there will likely be slick spots on the roads, especially bridges and overpasses.  As the warmer air comes in, the afternoon looks like conditions will improve.  However, northern Arkansas will stay frozen longer!  I continue to think the hardest hit areas will be north and west of Little Rock, especially the higher elevations.  Little Rock COULD be on the edge of accumulating snow.  This could wind up being a situation where downtown Little Rock maintains enough heat with little if any accumulation, but just go to west Little Rock or Sherwood and the ground whitens up a little.  Most of the models agree snow amounts in central Arkansas will range from a dusting to 1.5''.  Not much, but considering the mild winter, this will not doubt be a big deal for snow lovers!  The heavier amounts will stay north and west.  When all is said and done, the forecast will not be perfect.  It never is when forecasting winter weather.  For some places it will be right on and others not.  Remember, by Tuesday, readings will go well into the 40s to near 50 and it will all be a distant memory.

Now, the one piece of data which bothers me a little is our own computer model "Futurecast".  The past couple of runs have insisted on higher snowfall amounts for western and central Arkansas.  This is an outlier right now, but if the Sunday morning run continues the trend, we will have to take a harder look at it.  I'll show that below along with a bunch of weather maps.

Finally, I want to thank each and every one of you for coming to the Arkansas Weather Blog for your in depth and detailed information.  This blog is a passion of mine and I love doing it.  Thanks for reading it and coming back again and again.

I'll have more updates throughout the day, especially on social media!

This is the Sunday AM run of Futurecast which continues to insist on around 3'' in Little Rock.  Not buying it yet, but watching this carefully!

This is the overnight run of Futurecast indicating higher snow amounts across western and central Arkansas.  This is the only model showing it, so I'm not buying it yet.  Another run of this and I'll take a harder look.  For snow lovers, this would be awesome, but it has a low chance of verifying
This is the NAM forecast sounding for 6 AM Monday.  The black line going from the bottom to the upper right is the freezing line.  The actual forecast temp. is the red line going up.  We're looking at the atmosphere from the ground to 10's of thousands of feet up!  As long as the red line stays to the left, the entire column is below freezing, thus snow!  However, there's a warm nose of air punching in around 850 mb (5000').  This will eventually change the snow to ice then rain as the surface warms.
BY 6PM, you can see the lower portion of the atmosphere in central AR is above freezing.  This is rain!  The warm nose has done its job.
The NAM shows snow (pink) moving into western AR at 6AM.  The leading edge may evaporate as it falls due to very dry air in place.  It may take awhile for the atmosphere to saturate. I don't expect the precip. to start in central AR until after 7 or 8 AM.
By Noon, the snow is across the north with a mix in central sections as the warm nose of air changes the precip. type.  All rain across the south. (green)
The NAM shows some freezing rain for central and western Arkansas.
Total snow amounts from the NAM show minimal amounts for much of central AR.  However the higher elevations of western and northern AR could see a few inches.


Brittany said...

I am so ready for this winter weather! And I love following the blog I watch it everyday for my weather thanks for having this!

Yo Pimp J said...

we are all gonna diiiieeeeeeeee ;j haha keep up the good work Todd!

Anonymous said...

Well, looks like this "winter event" has turned out as a disappointment. Hopefully there is another winter chance this month or early March? We're running out of time!

Anonymous said...

Hey guys just look back two years ago in feb . I think it was supposed to be very little snow for little rock. Ended up over 7 inches . Just saying little rock has always has been on the snow line in these kind of situations. Be careful when u discount the rock out of the snow. I seen this time an time again when the weather experts have to come back the next day and eat crow. And also say ummm the models insisted no snow. Lol

Anonymous said...

a day off of work without it counting against me,and getting to play in the snow....makes for a great day!!! Lookin' forward to it...with crossed

snowfreak15 said...

does anyone else have a feeling that this could be an overachiever? just like ALL of our other storms have been in the past few years

snowfreak15 said...

I still believe that the models will all make a last minute change in their forecasts at 00z and the snow will be on!

WinterLover said...

@ snowfreak15 . I know, I have had the EXACT thoughts all along, I've just got this feeling that they're be more snow, less rain, colder temps, and further south. I'm completely with ya :)

Anonymous said...

I think the stage is set for a classic arkansas smushie. First for snowball ark over to marshal 8 inches wet snow. For clinton ark 6.3 inches. Conway to little rock 4 inches of heavy wet snow. Crime bluff i mean pine bluff 1.1 inches. Hot springs 3 ,7 inches. LADIES AND GENTLEMEN ITS ALMOST SHOW TIME!!!!!!!!!

Jeff said...

Is it just me or does it look like the storm is speeding up just a bit? I can't see it taking 12+ hours for the precip to get from NE Texas to central AR.

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