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    Day 2 Outlook >
Aug 21, 2018 0100 UTC Day 1 Convective Outlook
Click to see valid 1Z - 12Z Day 1 Convective Outlook
Updated: Tue Aug 21 00:45:05 UTC 2018 (Print Version | 20180821 0100Z Day 1 shapefile | 20180821 0100Z Day 1 KML)
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 Forecast Discussion
   SPC AC 210045

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0745 PM CDT Mon Aug 20 2018

   Valid 210100Z - 211200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS EVENING
   ACROSS THE MID SOUTH REGION...

   ...SUMMARY...
   Thunderstorms may continue to pose a risk for damaging wind gusts
   and perhaps an additional tornado or two this evening across the Mid
   South.

   ...01Z Outlook Update...
   A lower/mid tropospheric speed maximum (on the order of 30-40+ kt)
   appears to be propagating around the southern through eastern
   periphery of larger-scale troughing gradually turning eastward
   across the middle Mississippi Valley.  This is contributing to
   moderately large deep layer shear across much of the Mid South
   region, where seasonably high boundary layer moisture is supporting
   moderate to large CAPE (2000-3000+ J/kg).  While the lack of both
   colder air aloft and steeper lower/mid tropospheric lapse rates
   appears to be inhibiting severe weather potential, given the current
   modest strength of the synoptic system, the environment still has
   been supportive of thunderstorm activity accompanied by some severe
   weather.  This may linger into the 03-04Z time frame, before
   boundary layer instability wanes with the loss of daytime heating.

   Otherwise, scattered thunderstorm activity lingers within the warm
   sector across the lower Ohio Valley into parts of the Upper Midwest.
   Localized strong surface gusts and perhaps a tornado may still not
   be out of the question this evening, but severe weather potential in
   general appears to be in the process of diminishing.

   Across the Southwest, light southeasterly flow, around the
   southwestern periphery of a mid-level subtropical high centered near
   the Arizona/New Mexico border, is contributing to a slow westward
   propagation of thunderstorms off the higher terrain of southeastern
   Arizona.  As this continues, a hot and deeply mixed boundary layer
   at lower elevations may remain supportive of isolated strong
   downbursts into the 03-05Z time frame.

   ..Kerr.. 08/21/2018

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z

        
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Page last modified: August 21, 2018
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