Wednesday, January 08, 2014

A Little Ice To Wake Up To Thursday Morning

This is something I alluded to last week when I saw the data and I never backed down or flip flopped my forecast.  Many times when the arctic high retreats to the east, a return flow will set up.  The warmer air will chase the cold air out, but during this transition, a period of wintry weather can be expected.  I fully expect this to be a LIGHT event and it will be limited in duration.  HOWEVER, as we all know, it does not take much icing to cause slick spots on the roads.  All of the roads will be prone to some slick spots Wednesday night into Thursday morning due to the recent cold weather making the surface temperatures very cold.  The transition to plain rain will occur during the morning from south to north as the warmer air works into the state.

Will I release a new "SCHOOL:CON" index?  I have been asked this quite a bit.  I'm very hesitant to do this since the duration of this event is limited.  It COULD be one of those situations where schools delay their openings... COULD.  I'll think about it and look at the new morning data and come to a decision.  If you live in northern or western Arkansas, I would pay attention to those closings or delays since you will be in the target area for this event.  Even central Arkansas may deal with a little ice too.

This is our model "Futurecast" which is exclusive to Channel 7.  Ignore the time stamp on this.  It indicates around .1 to .2'' of ice.  Not a huge amount at all, but again, it takes just a very little to cause slick spots and travel headaches.

During the onset of the precipitation, it could be snow flying just west and north of the metro, then it goes to freezing rain/sleet.  The Ozarks up to the Missouri border could stay snow a little longer with some minor accumulations.
This is the European model from and it's showing you snowfall accumulations.  I just don't see this happening.  This model has been prone to greatly exaggerating snow amounts this winter around here.  I love this model, but I think it's "out to lunch".   The temperature profile just doesn't support this.  I think there will be warming aloft as the arctic high retreats.  You must have the complete atmosphere below freezing and I haven't seen a single piece of data indicating that will happen.  It will be interesting to watch, but I just don't see this verifying.
This is baffling as well.  The GFS shows snow accumulations across much of the state, but once again, the temperature profiles don't support this.  Also, it's precip type maps that I'll show below do NOT indicate ANY snow.  Weird!  I hope someone can tell me what's up with the models doing this.
Now onto the timing from the GFS.  This is valid at 6PM Wednesday.  The red line is the freezing line at that given time.  The purple is freezing rain, orange sleet, blue snow, green rain.  No snow around here, but the model accumulates it.  Again, I don't know why it's doing that.  Anyway, you're looking at the total amount of precip. over the past 6 hours.  So this is valid from noon today (WED) to 6PM.  I expect this to start mid to late afternoon across the west with sleet and freezing rain.  I would not be surprised to hear some snow reports, but a transition to sleet and freezing rain will occur.
By midnight, the target area is western and northern AR as that area of the state will be the coldest with the highest amounts of moisture.
By 6AM, many areas could see light icing.  Again, the duration of this will be short and the amounts will be light. Slick spots are likely though.
And by noon, the warmer air is winning and we're going above freezing.  The only portion of the state hanging onto subfreezing air is the northeast.  This is why I'm hesitant of putting a SCHOOL:CON index out there.  By mid to late morning, conditions should be improving.  Will they cancel or delay schools?  I don't make that decision.
The National Weather Service has issued a "winter weather advisory" for the northern 2/3 of Arkansas late today into Thursday morning.

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