Saturday, January 04, 2014

Arctic Attack Advances... What Are The Snow Chances?


7:15 PM Saturday Update...  I wanted to wait for a couple of model runs before changing anything.  I think I'm going with a slight adjustment northward with the heaviest snow.   This means central Arkansas will not receive much at all.  I'm not going to rule out a few flake, but the chance is not all that great at this time.  I REALLY HOPE THAT CHANGES!  I want to do a little sledding!  Anyway, as we have maintained for several days now, the biggest impact will be the bitterly cold temperatures and wind chills.  The "WeatherNinja" brought up a good point.  Will schools close due to the cold wind chill temperatures?  I have never seen that and the SCHOOL:CON index does NOT cover that situation.  We'll see.

Will Little Rock see temperatures drop into the single digits?  It's possible.  I have often preached you need 3 things for single digits in Little Rock:  clear skies, no wind, and snow cover.  Without one of these, it's very difficult.  Not impossible, but difficult.  That's why I'm having my doubts.  Without snow, it's going to be close. 

You might need to click to enlarge.  These are ONLY models and not a forecast.  You can see the heaviest snow will be north towards the Missouri border.  Little into central AR.  If the front makes further progress to the south and the wave of low pressure moves along that frontal boundary further south, then it's POSSIBLE for this to shift a little south.  However, that possibility is low at this point.  Only 1 person knows for sure and it ain't me.
This is the late Saturday SCHOOL:CON index.  I'm not sure if I'll issue another one.  Notice I have shifted it north.  Also, what about brutal wind chill readings Monday morning?   Kids at the bus stop at -5 to -15 degrees?  Again, I have never seen this situation before so we're in uncharted waters here.
Wind Chill advisories are in effect Sunday night into Monday.  Those values could be from -5 to -15 across much of central and northern Arkansas.  The southeast corner may have wind chills around -5 to 10 degrees.

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Rhyming and alliteration always help make great headlines. LOL.  I have reviewed the latest data this Saturday morning and I really don't have much in the way of changes.  The best chance for accumulating snows will be across northern Arkansas where a winter storm warning is in effect.  Further south into central Arkansas, yes, I do think flakes will fly.  However, just how much is very much up for debate.  At this time, I really think amounts will range from a dusting to MAYBE an inch just north of the metro.  Even at this late stage in the ballgame, it can still change and I hope it does.  I would really like to have a "sleddable snow" around here.  I'm off work this weekend and will be spending time with my kiddo.  That would be awesome to do with them.

I have brought this up on facebook, twitter, and here on the blog, I still think there could be areas of snow showers even into Monday!  With such a strong vortex spinning over the Great Lakes, this will create a strong northerly flow aloft.  In these situation, very small disturbances will be embedded within this flow.  They are moisture starved, but the arctic air mass can easily squeeze out a few snowflakes.  The computer models I have looked at show no such thing happening.  However, I think it would be wise to watch this!!!!  The best chance for these LIGHT snow showers will be northern into northeastern Arkansas.

I can't stress this enough: PETS, PIPES, AND PEOPLE!  From Sunday to Wednesday, we're going to be in the deep freeze!  We'll come out of it later in the week, but the damage could be significant to pipes.  Make sure you let your faucets drip when the cold settles in.  Bring the puppy dog in and the cat.  Also, PLEASE check on those who may have a hard time in this type of weather!!!  I have seen many creeks and small ponds already frozen over.  I remember a few cases many years ago where kids fell into the ice.  The outcome was not good.  It's tempting for the kiddos to play on that ice, but obviously, it's not a good idea.  Let's get the word out!

I'll show you a few maps below INCLUDING the Saturday morning SCHOOL:CON index.  For those of you who have not seen it before, this idea was developed by our own Scott Inman.  I give credit where it's due.  Thanks Scott!  This is based on a scale from 0-10.  0 means schools will likely be open and 10 means schools will likely be closed.  REMEMBER, I DON'T MAKE THOSE DECISIONS!  It's based on my experience growing up here in Arkansas, knowing what it takes for school administrators to cancel classes, and my latest analysis of the computer model guidance.  Kids, still do your homework regardless! LOL!  That's what my parents always told me.

This is the overnight run of the GFS from weatherbell.com valid at midnight Sunday.  Remember, precip shown indicates amounts over the previous 6 hours.  The front is moving into NW AR.  Green is rain, blue is snow.  The tightly packed black lines are isobars and a strong pressure gradient.  The end result... very strong winds behind the arctic boundary creating bitterly cold wind chills.
By 6AM, the arctic boundary is moving into central Arkansas.  Rain is changing to snow across the northwest.  Look at the heaviest over Missouri.

Sometime between 6 AM and NOON, the rain could change over to some snow over central AR, but notice the heaviest snow is over north central Arkansas where the winter storm warning is in effect.
By 6PM, it's very, very cold.  The precip is exiting.  The wind is howling and temperatures are dropping.  Wind chill readings are in the single digits and teens and getting worse.
This is our exclusive model "FUTURECAST" indicating a light dusting around the metro northward.  Maybe up to almost .5'' in White county.
"Futurecast" shows more than 3'' over the winter storm warning area. This lines up well with other models and the warning issued by the NWS.
Here are the warnings and advisories.  In the warning area, 3 inches or more could fall.  In the winter weather advisory area, around 1-3 inches could fall.  Over the western areas of the state, this will mostly be in the higher elevations.
Here's the newest SCHOOL:CON index.  Read in the main post above for a complete explanation.
The bigger story will be the bitterly cold temperatures.  Look at these wind chills by midnight Monday according to the GFS.  It's BELOW 0 FOR MUCH OF CENTRAL AND NORTHERN ARKANSAS!!!!!!!!
The Euro is not as cold Monday morning with wind chills, but it's still nasty!

1 comment:

Doug Hibbard said...

On the school closings due to cold: friend in Alabama said they were delaying starting back after Christmas break due to the cold.

I'll check for a source.

NOAA Winter Guidance