Tuesday, April 09, 2013

Update... Springs 1st Severe Punch


For almost a week now we have been alluding to the possibility for severe storms Wednesday.  Remember, I urged you not to get bogged down with specifics at that point, but to keep an eye on how this evolved.  The picture is ALMOST crystal clear.  I say that because no matter how much data you look at, the weather can always throw curve ball, especially in Arkansas.  That's why my motto is "Never Say Never To Arkansas Weather."

This really is one incredible storm system affecting the central United States!  Let's loosen our focus on Arkansas for a second and look at a wider picture.  This is a large and powerful system affecting millions.  For example.  The plains of Colorado had severe storms with tornado warnings Monday, now they're having a blizzard.  The temperature yesterday in Denver made it into the lower 70s!  Now it's snowing hard and in the mid teens this morning with wind chills around 0!  You thought our weather was crazy?!  

Back to our weather.  The other day I was talking to the "WeatherNinja".  We both discussed the situation and agreed it looked like severe storms over Oklahoma Tuesday.  Those storms would weaken as they moved towards Arkansas, then intensify later Wednesday as the system encountered more instability further east.  That's looking like a good forecast at this point.

There was some concern for storms firing today (Tuesday) and while I can't completely rule it out, it looks unlikely.  There's a "lid" on storm development which will be difficult to overcome.  It's like the cap on a 2 liter bottle of Coke.  Shake that bottle up and that's the instability.  If the lid is loosely put on that bottle, it will explode upward.  That would result in storm development and a mess.  However, that "lid" or cap is on that bottle tightly today.  There's a lot of energy in that bottle, but it's not likely to get out.  That's a simple way of looking at it I guess.  If something forced that lid off like a front, disturbance, or enough surface heating, then look out! 

Now onto the day we have been focusing in on... Wednesday.  Those storms firing in Oklahoma today will weaken and move into western Arkansas early Wednesday morning.  The timing of this will allow some instability to develop ahead of the front and this should take place mainly across eastern Arkansas.  As the "forcing" moves into that section of the state, severe thunderstorms will be possible.  We'll have to watch for all modes of severe thunderstorms including hail, wind, very heavy rain, and isolated tornadoes.  While central and western Arkansas could have severe thunderstorms, I think there's a lower chance, but it can't be ruled out.

Here are a few maps explaining the situation.

This is simulated radar Wednesday at 7AM.  See those storms in NW Arkansas?  Those are strong, but probably not severe.  Just ignore the grey areas.
This is valid at 7PM Wednesday.  Remember, models are NOT perfect and this won't exactly verify.  This line of storms intensifies and moves into eastern Arkansas along the front.  All of that rain in western Arkansas is behind the front and the threat here will be heavy rain and maybe some hail.
Here's surface based instability Wed. PM.  Look at that area of red and blue over the east.  If storms develop in that environment, they could be severe.  This portion of the state will have the chance to develop this instability during the heating of the day.
The Storm Prediction Center has placed most of the state in a slight risk Wednesday.
The SPC has outlined an area in Red which includes most of the state for a 30% chance of severe weather within 25 miles of any given point.  In the purple area, that is increased to a 45% chance of severe weather within 25 miles of any given point.
As I have been telling you, heavy rain will be possible and maybe some flooding.   3'' or more could fall across the eastern half of the state with the southeast corner into east central Arkansas getting the most.

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