Aug 12, 2019 1730 UTC Day 2 Convective Outlook
Updated: Mon Aug 12 17:19:35 UTC 2019 (20190812 1730Z Day 2 shapefile | 20190812 1730Z Day 2 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190812 1730 UTC Day 2 Outlook Graphic
Day 2 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 42,807 19,983,242 Philadelphia, PA...Baltimore, MD...Washington, DC...Arlington, VA...Alexandria, VA...
SLIGHT 117,742 30,579,210 New York, NY...Nashville, TN...Newark, NJ...Jersey City, NJ...Yonkers, NY...
MARGINAL 328,664 38,997,080 Dallas, TX...Columbus, OH...Memphis, TN...Fort Worth, TX...Virginia Beach, VA...
Probabilistic Graphic
20190812 1730 UTC Day Probabilitic Graphic
Probability of severe weather within 25 miles of a point.
Hatched Area: 10% or greater probability of significant severe within 25 miles of a point.
Day 2 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
30 % 42,832 19,873,665 Philadelphia, PA...Baltimore, MD...Washington, DC...Arlington, VA...Alexandria, VA...
15 % 118,354 30,671,113 New York, NY...Nashville, TN...Newark, NJ...Jersey City, NJ...Yonkers, NY...
5 % 327,131 39,074,031 Dallas, TX...Columbus, OH...Memphis, TN...Fort Worth, TX...Virginia Beach, VA...
   SPC AC 121719

   Day 2 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1219 PM CDT Mon Aug 12 2019

   Valid 131200Z - 141200Z

   ...THERE IS AN ENHANCED RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE CENTRAL APPALACHIANS EASTWARD TO THE MID-ATLANTIC...

   ...SUMMARY...
   Severe storms are expected Tuesday afternoon and early evening over
   the Middle Atlantic into the Ohio and Tennessee Valleys. Other
   strong to severe storms are possible over the Upper Mississippi
   Valley and the central High Plains.

   ...Mid-Atlantic/Ohio and Tennessee Valleys...
   A subtle cyclonic mid-level flow pattern will be in place on Tuesday
   from the north-central states eastward into the Northeast. At the
   surface, a cold front will advance southward into the Mid-Atlantic
   extending west-southwestward into the mid Mississippi Valley. A
   surface low along the front will move eastward across the central
   Appalachians. Surface dewpoints ahead of the front should be in the
   lower 70s contributing to a corridor of moderate instability by
   afternoon. Scattered thunderstorms are forecast to develop along the
   front during the afternoon from southern Ohio eastward across the
   Virginias into Maryland. Cells may tend to organize into lines and
   MCS development will be possible from late afternoon into the early
   evening.

   NAM forecast soundings along the front from West Virginia into
   northern Virginia and southern Maryland suggest that MLCAPE values
   could reach 2500 J/kg at peak heating. Winds are veered to the
   southwest at the surface with about 30 kt of westerly flow in the
   mid-levels. This combined with steep lapse rates in the lowest 3 km
   AGL will be favorable for damaging wind gusts associated with line
   segments.  If a cold pool can develop with a larger-scale line
   segment, then numerous damaging wind gusts will be possible from
   eastern West Virginia eastward to Delaware and southern New Jersey. 


   ...Upper Mississippi Valley...
   A minor shortwave trough will move east-southeastward into the Upper
   Mississippi Valley on Tuesday. At the surface, a low will track
   southeastward from central Minnesota to near Minneapolis and then
   along the Mississippi River. Ahead of the surface low track, an axis
   of maximized low-level moisture will exist with surface dewpoints in
   the mid 60s F. In response to surface heating, a pocket of moderate
   instability may develop by afternoon. Convection is forecast to
   initiate ahead of the shortwave trough and move southeastward across
   eastern Minnesota and western Wisconsin during the mid to late
   afternoon. MLCAPE values in the 1000 to 2000 J/kg combined with 0-6
   km shear of 35 to 45 kt may be favorable for an isolated severe
   threat with hail and strong gusty winds possible. Poor lapse rates
   should keep any threat marginal.

   ...Central Plains...
   A low-amplitude upper-level ridge will move across the western U.S.
   on Tuesday as west to northwest mid-level flow remains over the
   central High Plains. At the surface, a mesolow is forecast to
   develop in southeastern Colorado ahead of a front, moving southward
   into northeastern Colorado. Convection appears likely to initiate
   along the front during the late afternoon with thunderstorms moving
   southeastward into western Kansas by early evening. Strong
   directional shear profiles along with steep lapse rates may be
   enough for hail in the stronger cores. A few marginally severe wind
   gusts will also be possible.

   ...MAXIMUM RISK BY HAZARD...
   Tornado:   5%     - Slight
   Wind:     30%     - Enhanced
   Hail:     15%     - Slight

   ..Broyles.. 08/12/2019

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