Jul 22, 2018 0100 UTC Day 1 Convective Outlook
Updated: Sun Jul 22 01:00:23 UTC 2018 (20180722 0100Z Day 1 shapefile | 20180722 0100Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20180722 0100 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 105,810 13,690,242 Charlotte, NC...Atlanta, GA...Montgomery, AL...Columbus, GA...Tallahassee, FL...
MARGINAL 166,879 20,090,564 Greensboro, NC...Birmingham, AL...Winston-Salem, NC...Mobile, AL...Providence, RI...
Probabilistic Tornado Graphic
20180722 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
2 % 13,527 8,227,702 Providence, RI...Toms River, NJ...New Bedford, MA...Fall River, MA...Plymouth, MA...
Probabilistic Damaging Wind Graphic
20180722 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
15 % 106,513 13,745,643 Charlotte, NC...Atlanta, GA...Montgomery, AL...Columbus, GA...Tallahassee, FL...
5 % 154,079 12,310,551 Greensboro, NC...Birmingham, AL...Winston-Salem, NC...Mobile, AL...Chattanooga, TN...
Probabilistic Large Hail Graphic
20180722 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
15 % 106,067 13,773,291 Charlotte, NC...Atlanta, GA...Montgomery, AL...Columbus, GA...Tallahassee, FL...
5 % 154,041 12,244,562 Greensboro, NC...Birmingham, AL...Winston-Salem, NC...Mobile, AL...Chattanooga, TN...
   SPC AC 220100

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   0800 PM CDT Sat Jul 21 2018

   Valid 220100Z - 221200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS ACROSS PARTS OF
   THE SOUTHEAST AND NORTHERN HIGH PLAINS...

   ...SUMMARY...
   A few severe storms remain possible across parts of the Southeast
   and northern High Plains this evening. A strong storm or two will
   also be possible late tonight across the Mid-Atlantic and southern
   New England.

   ...Southeast...
   Scattered strong to severe thunderstorms are persisting within
   northwesterly flow along the southern fringe of a deep mid-level
   trough. Where prior convection has not overturned the low/mid-level
   air mass, clusters of multi/supercells will remain possible for a
   few more hours this evening into early tonight. The highest severe
   potential may be focused near the Georgia/Alabama border, where
   westerly deep-layer flow, sufficient effective shear, and
   moderate/strong buoyancy should maintain a southward-moving cluster
   of strong/severe cells. Large hail and damaging winds will continue
   to be the primary threat. Over time, this cluster should encounter
   an increasingly hostile thermodynamic environment, though, resulting
   in a gradual downturn in intensity.

   ...Northern Plains...
   The primary severe threat will exist ahead of a severe cluster of HP
   supercells progressing south/southeast over western North Dakota
   this evening. Although convective inhibition will increase with both
   time and southeastward extent, a rather mature cold pool should
   encourage new, robust updrafts into early tonight, considering the
   steep mid-level lapse rates noted in the 12Z UNR sounding. Farther
   south, isolated/widely scattered severe storms, capable of large
   hail and damaging winds as well, may also continue into at least
   late evening.

   ...Northeast...
   A strengthening low-level jet and surface destabilization associated
   with an approaching warm front are forecast to yield a conditional
   threat of a brief tornado across coastal areas late tonight. Enough
   low-level instability will be present to foster this threat (via
   stretching of near-surface vorticity), although warming/drying near
   700mb may limit deep updraft acceleration and dampen the threat
   some. Any potential tornado threat should maximize around 06-12Z.

   ..Picca.. 07/22/2018

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