SPC AC 250727

   Day 3 Convective Outlook CORR 1
   NWS Storm Prediction Center Norman OK
   0227 AM CDT Thu Jun 25 2020

   Valid 271200Z - 281200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM EASTERN OHIO
   ACROSS PENNSYLVANIA AND PARTS OF SOUTHERN NEW YORK...

   CORRECTED GRAPHICS

   ...SUMMARY...
   Scattered afternoon thunderstorms may pose a risk for mainly
   damaging winds across much of Pennsylvania and portions of
   surrounding states on Saturday.

   ...Synopsis...
   As a mid-level short-wave trough shifts out of the Midwest and
   across the central Appalachians region, a larger trough is forecast
   to dig southeastward across the northwestern U.S. through the
   period.

   At the surface, a cold front will progress southward and eastward
   across the northwestern quarter of the country, with some degree of
   severe potential likely evolving over portions of the northern
   Intermountain region/northern High Plains.  A weak cool front will
   also cross Pennsylvania/New York and vicinity, and will also be
   accompanied by risk for locally severe storms.

   ...Eastern Ohio across Pennsylvania and southern New York...
   Some uncertainty still exists with respect severe potential across
   the central Appalachians region, given the likelihood for ongoing
   convection at the start of the period which would influence
   potential for subsequent afternoon destabilization.  Still, with
   moderately strong west-southwesterly flow aloft across the region
   ahead of the weak upper trough/cool front, any uptick in afternoon
   convective coverage would likely be accompanied by risk for damaging
   winds given fast-moving storms.  A SLGT/level 2 risk area is being
   introduced across the area given what appears to be reasonable
   potential for locally damaging wind gusts, with threat likely to
   peak during the late afternoon before waning into the evening hours.

   ...Portions of Idaho northeastward across parts of Montana...
   Cooling aloft with the approach of upper troughing, combined with
   diurnal heating, will permit modest destabilization to occur across
   the northern Intermountain region through the afternoon.  As this
   occurs, isolated storm development is expected along an advancing
   cold front, primarily from southeastern Idaho northeastward into
   central Montana.  Meager low-level moisture will likely be a
   limiting factor with respect to ample destabilization for a more
   widespread/substantial severe risk, but isolated gusty/damaging
   winds will be possible --- aided by the deep mixed layer and
   associated potential for evaporatively augmented downdrafts.  Risk
   may continue well into the evening, as storms spread eastward toward
   eastern Montana.

   ..Goss.. 06/25/2020

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