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Mesoscale Discussion 80
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   Mesoscale Discussion 0080
   NWS Storm Prediction Center Norman OK
   0907 AM CST Wed Feb 21 2018

   Areas affected...Central/Southern LA...Far Southeast TX

   Concerning...Severe potential...Watch possible 

   Valid 211507Z - 211700Z

   Probability of Watch Issuance...40 percent

   SUMMARY...Damaging wind gusts and perhaps a tornado or two are
   possible across portions of central and southern LA during the next
   several hours. An upgrade to 5% tornado probabilities is anticipated
   across portions of the area in the forthcoming 1630Z Convective

   DISCUSSION...Regional radar imagery shows a cluster of supercells
   along the southern TX/LA border in or entering Vernon and Beauregard
   parishes. KPOE reveals the rotation within these storms well with
   the storm in Vernon perish showing the strongest rotation and
   updraft strength. Downstream airmass is moist, uncapped, and
   moderately unstable, suggesting these storms should remain strong
   for at least the next hour. Any storm weakening or dissipation would
   likely be a result of negative storm interactions not thermodynamic
   or kinematic factors. Additional development is possible within or
   just ahead of this cluster as low-level confluence continues ahead
   of the approaching cold front. 

   VAD wind profile from KLCH recently sampled 0-1 km SRH over 250 m2
   per s2 and both KLCH and KPOE sampled 0-1 km shear around 25 kt. 
   This type of kinematic environment is favorable for low-level
   rotation and the potential for a few tornadoes. Given the
   anticipated persistence of this environment, portions of this area
   will be upgraded to 5% tornado probabilities with the upcoming 1630Z
   Convective Outlook and a watch is being considered.

   ..Mosier/Thompson.. 02/21/2018

   ...Please see for graphic product...


   LAT...LON   30669401 31479357 31959275 32139210 32069157 31869138
               31509142 30949168 30619186 30379200 30079218 29839241
               29629301 29729368 30049400 30669401 

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