Aug 23, 2019 2000 UTC Day 1 Convective Outlook
Updated: Fri Aug 23 19:55:33 UTC 2019 (20190823 2000Z Day 1 shapefile | 20190823 2000Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20190823 2000 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 154,872 6,368,536 Virginia Beach, VA...Raleigh, NC...Norfolk, VA...Chesapeake, VA...Durham, NC...
MARGINAL 214,159 16,834,153 Charlotte, NC...Greensboro, NC...Winston-Salem, NC...Amarillo, TX...Knoxville, TN...
Probabilistic Tornado Graphic
20190823 2000 UTC Day 1 Tornado Probabilities Graphic
Probability of a tornado within 25 miles of a point.
Hatched Area: 10% or greater probability of EF2 - EF5 tornadoes within 25 miles of a point.
Day 1 Tornado Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
2 % 72,040 3,704,935 Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
Probabilistic Damaging Wind Graphic
20190823 2000 UTC Day 1 Damaging Wind Probabilities Graphic
Probability of damaging thunderstorm winds or wind gusts of 50 knots or higher within 25 miles of a point.
Hatched Area: 10% of greater probability of wind gusts 65 knots or greater within 25 miles of a point.
Day 1 Wind Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 154,949 6,341,415 Virginia Beach, VA...Raleigh, NC...Norfolk, VA...Chesapeake, VA...Durham, NC...
5 % 193,017 16,835,432 Charlotte, NC...Greensboro, NC...Winston-Salem, NC...Amarillo, TX...Knoxville, TN...
Probabilistic Large Hail Graphic
20190823 2000 UTC Day 1 Large Hail Probabilities Graphic
Probability of hail 1" or larger within 25 miles of a point.
Hatched Area: 10% or greater probability of hail 2" or larger within 25 miles of a point.
Day 1 Hail Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
15 % 94,168 809,470 Greeley, CO...Cheyenne, WY...Casper, WY...Garden City, KS...Gillette, WY...
5 % 164,825 5,906,447 Virginia Beach, VA...Norfolk, VA...Chesapeake, VA...Richmond, VA...Newport News, VA...
   SPC AC 231955

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0255 PM CDT Fri Aug 23 2019

   Valid 232000Z - 241200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS OF
   THE HIGH PLAINS REGION...AS WELL AS PARTS OF SOUTHERN VIRGINIA AND
   NORTHEAST NORTH CAROLINA...

   ...SUMMARY...
   Severe thunderstorm risk continues this afternoon into early tonight
   for portions of North Carolina and Virginia, as well as the central
   High Plains.

   ...Discussion...
   Evolution of ongoing convection remains largely in line with the
   most recent outlook reasoning and areal outlines.  Storms are
   increasing across parts of southern Virginia, within the SLGT risk
   area, and where newly issued WW #612 is in effect.  Farther west,
   convection remains thus far subdued over the high Plains, but should
   increase over the next couple of hours.  For additional short-term
   information across this area, please refer to recently issued MCD
   #1839.

   ..Goss.. 08/23/2019

   .PREV DISCUSSION... /ISSUED 1125 AM CDT Fri Aug 23 2019/

   ...VA/NC this afternoon/evening...
   A surface cold front will continue to move slowly southward across
   VA this afternoon into NC overnight, in the wake of a midlevel
   trough crossing New England.  The southern fringe of the westerlies
   extends south to near the VA/NC border, where a series of subtle
   speed maxima/embedded MCVs will translate eastward this afternoon. 
   Low-level convergence/ascent along the front and an accompanying
   differential heating zone should support thunderstorm development by
   early afternoon across central VA, and storms will spread
   east-southeastward through the remainder of the afternoon/evening. 
   Though midlevel lapse rates will be rather modest, surface heating
   will steepen low-level lapse rates and boost afternoon MLCAPE to
   near 1500 J/kg.  Given effective bulk shear in the 25-35 kt range,
   and mix of organized multicell clusters and some low-end supercells
   can be expected in a broken band along the front this afternoon. 
   Damaging winds should be the main severe threat.

   ...Central High Plains this afternoon into tonight...
   A midlevel shortwave trough is moving slowly eastward over the
   northern Rockies, as other subtle embedded waves progress eastward
   over the central Rockies.  Steep midlevel lapse rates, daytime
   heating, and low-level upslope flow will promote an environment
   favorable for afternoon thunderstorm development east of the Front
   Range from northeast NM northward into eastern WY.  Deep-layer
   vertical shear will not be particularly strong over most of the High
   Plains.  The corridors of the somewhat stronger vertical shear will
   be immediately east of the midlevel trough in WY, and in the
   vicinity of southeast CO where low-level east-southeast flow will
   reside beneath the more westerly flow aloft, contributing to
   effective bulk shear of 30-35 kt.  Thus, expect a mix of multicell
   clusters and some low-end supercells capable of producing damaging
   winds and large hail.  A few clusters will likely persist into
   tonight in association with warm advection and a modest low-level
   jet.

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0100Z