May 27, 2017 0730 UTC Day 3 Severe Thunderstorm Outlook
Updated: Sat May 27 07:11:04 UTC 2017 (20170527 0730Z Day 3 shapefile | 20170527 0730Z Day 3 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
0730 UTC Day 3 Outlook Graphic
Day 3 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 122,908 18,050,472 Charlotte, NC...Atlanta, GA...Raleigh, NC...Durham, NC...Montgomery, AL...
MARGINAL 162,521 30,430,348 Philadelphia, PA...Baltimore, MD...Washington, DC...New Orleans, LA...Virginia Beach, VA...
Probabilistic Graphic
20170527 0730 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 3 Prob. Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 122,908 18,050,472 Charlotte, NC...Atlanta, GA...Raleigh, NC...Durham, NC...Montgomery, AL...
5 % 163,194 30,577,833 Philadelphia, PA...Baltimore, MD...Washington, DC...New Orleans, LA...Virginia Beach, VA...
   SPC AC 270711

   Day 3 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0211 AM CDT Sat May 27 2017

   Valid 291200Z - 301200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE GULF COAST STATES...GEORGIA AND CAROLINAS...

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS OUTSIDE OF THE
   SLIGHT RISK AREA ACROSS PARTS OF THE GULF COAST
   STATES...GEORGIA...CAROLINAS AND MID-ATLANTIC...

   ...SUMMARY...
   Severe thunderstorms associated with wind damage and hail will be
   possible across parts of the Gulf Coast States east-northeastward
   into the Carolinas on Monday.

   ...Gulf Coast States/Georgia/Carolinas/Mid-Atlantic...
   An upper-level trough is forecast to move across the Upper Midwest
   on Monday as a cold front advances southeastward into the Gulf Coast
   States, Georgia and Carolinas. Surface dewpoints ahead of the front
   should be in the upper 60s to near 70 F resulting in a corridor of
   moderate instability from southern Alabama east-northeastward into
   the eastern Carolinas by midday. As the airmass becomes sufficiently
   heated by early afternoon, thunderstorm initiation should take place
   with the main focus along the front. It appears that several
   convective clusters will develop in the mid to late afternoon and
   move eastward across the slight risk area.

   GFS forecast soundings along the corridor of maximum instability at
   21Z on Monday show MLCAPE values generally from 1000 to 2000 J/kg.
   Deep-layer shear is forecast to be strongest across North Carolina
   where supercells associated with large hail and wind damage will be
   possible. An isolated severe threat could also develop northward
   into the Mid-Atlantic but weaker instability may keep the severe
   threat marginal there. Further southwest into the Gulf Coast States,
   0-6 km shear is forecast to be in the 30 to 35 kt range suggesting
   that multicell will be the favored mode. In the case that a
   multicell line segment or two can organize from southern Alabama
   east-northeastward into South Carolina during the late afternoon and
   early evening, wind damage would be the primary threat.

   ..Broyles.. 05/27/2017

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