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Jul 22, 2017 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat Jul 22 07:28:43 UTC 2017 (Print Version | 20170722 0730Z Day 3 shapefile | 20170722 0730Z Day 3 KML)
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 Forecast Discussion
   SPC AC 220728

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0228 AM CDT Sat Jul 22 2017

   Valid 241200Z - 251200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE NORTH CENTRAL U.S....

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OVER PORTIONS OF
   THE NORTHEAST...

   ...SUMMARY...
   Isolated strong/severe storms may occur over portions of the
   northern Plains vicinity, as well as across parts of the central
   Appalachians and mid Atlantic region.

   ...Synopsis...
   As an upper trough over the northeast U.S. lifts gradually
   northeastward and a weak trough/low lingers off the West Coast,
   large-scale ridging will prevail across a large portion of the
   country.  Once other exception will be over the far north-central
   portion of the country, as a mobile upper low traverses the Canadian
   Prairies and brushes the adjacent portions of the U.S.

   At the surface, a weak low pressure system will move across parts of
   the Northeast in conjunction with the upper system crossing the
   area, while a stronger cold front trailing south from the Canadian
   Prairie storm system is forecast to shift southeastward across the
   north-central states through the period. 

   ...Northern Plains region...
   While stronger ascent and more favorable flow aloft associated with
   the central Canada upper system will remain largely north of the
   international border, moderate mid-level westerlies will spread
   across the Dakotas and vicinity.  As such, isolated storms
   developing within an amply unstable warm sector near the trailing
   cold front may become locally organized/severe during the afternoon
   and evening hours.  Combination of potentially limited storm
   coverage, and differences in timing of this system amongst various
   models, suggest that MRGL/5% risk is most appropriate to introduce
   to the forecast at this time.

   ...Parts of the Northeast...
   Relatively widespread convection and associated cloud cover will
   likely linger across the northeast U.S. for much of the period, as
   the upper trough moves gradually across the area.  However, pockets
   of heating/destabilization will likely occur over portions of the
   area, which will likely support locally stronger afternoon storms --
   aided by moderate cyclonic mid-level flow field atop the region. 
   While a lack of clarity prevails regarding details at this point,
   will introduce a MRGL/5% risk over portions of the central
   Appalachians and east to the mid Atlantic and southern New England
   Coasts, for locally gusty/damaging wind and marginal hail risk.

   ..Goss.. 07/22/2017

   CLICK TO GET WUUS03 PTSDY3 PRODUCT

   NOTE: THE NEXT DAY 3 OUTLOOK IS SCHEDULED BY 0730Z

        
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Page last modified: July 22, 2017
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