Jun 21, 2018 0100 UTC Day 1 Convective Outlook
Updated: Thu Jun 21 00:43:14 UTC 2018 (20180621 0100Z Day 1 shapefile | 20180621 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180621 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 99,851 5,601,736 Fayetteville, NC...Columbia, SC...Springfield, IL...Wilmington, NC...Decatur, IL...
Probabilistic Tornado Graphic
20180621 0100 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
No Risk Areas Forecast
Probabilistic Damaging Wind Graphic
20180621 0100 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
5 % 99,517 5,601,188 Fayetteville, NC...Columbia, SC...Springfield, IL...Wilmington, NC...Decatur, IL...
Probabilistic Large Hail Graphic
20180621 0100 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
5 % 44,219 318,560 Bend, OR...Redmond, OR...
   SPC AC 210043

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0743 PM CDT Wed Jun 20 2018

   Valid 210100Z - 211200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS PORTIONS OF
   CENTRAL AND EASTERN OREGON...CENTRAL ILLINOIS...COASTAL
   CAROLINAS...AND THE FLORIDA BIG BEND...

   ...SUMMARY...
   A few strong to locally severe thunderstorms are this evening from
   parts of the coastal Carolinas, central Illinois, Florida Big Bend,
   and Oregon.

   ...Discussion...
   A mid-level low over NE this evening will slide slowly southeast to
   the IA/MO border by daybreak while a mid-level anticyclone is
   centered over the northern Gulf of CA.  A weak impulse evident in
   evening water-vapor imagery is moving through south-central OR. 
   Scattered thunderstorms will likely persist into the late evening. 
   A few of the stronger storms may be capable of a strong to locally
   severe gust and marginally severe hail.  This activity will weaken
   coincident with diurnal cooling this evening.  Farther east, a
   couple of thunderstorms embedded within clusters and propagating on
   outflow over the coastal Carolinas and the FL Big Bend may pose a
   risk for gusts in the 45-60 mph range --capable of damage-- for the
   next 1-2 hours before weakening.  

   Elsewhere, a weak squall line over the middle MS Valley continues to
   move into a less unstable airmass over northern IL and the 00Z ILX
   RAOB showed a tropospheric profile nearly saturated from the surface
   to 500mb but with 2600 J/kg MLCAPE.  A strong gust or two may occur
   before this activity also weakens during the next 1-2 hours.

   ..Smith.. 06/21/2018

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 0600Z