Apr 8, 2021 1630 UTC Day 1 Convective Outlook
Updated: Thu Apr 8 16:24:04 UTC 2021 (20210408 1630Z Day 1 shapefile | 20210408 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20210408 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 41,100 6,305,793 Cincinnati, OH...Lexington-Fayette, KY...Dayton, OH...Muncie, IN...Springfield, OH...
MARGINAL 121,977 23,889,201 Indianapolis, IN...Columbus, OH...Atlanta, GA...Toledo, OH...Louisville, KY...
Probabilistic Tornado Graphic
20210408 1630 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 % 98,334 20,389,186 Indianapolis, IN...Columbus, OH...Atlanta, GA...Cincinnati, OH...Louisville, KY...
Probabilistic Damaging Wind Graphic
20210408 1630 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 % 42,401 6,460,289 Cincinnati, OH...Lexington-Fayette, KY...Dayton, OH...Muncie, IN...Springfield, OH...
5 % 101,029 22,177,399 Indianapolis, IN...Columbus, OH...Atlanta, GA...Toledo, OH...Louisville, KY...
Probabilistic Large Hail Graphic
20210408 1630 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 % 82,427 13,536,825 Atlanta, GA...Louisville, KY...Lexington-Fayette, KY...Shreveport, LA...Knoxville, TN...
   SPC AC 081624

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1124 AM CDT Thu Apr 08 2021

   Valid 081630Z - 091200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS THIS AFTERNOON
   OVER PORTIONS OF SOUTHWEST OHIO...CENTRAL AND EASTERN KENTUCKY...AND
   NORTHEAST TENNESSEE...

   ...SUMMARY...
   Locally damaging wind gusts are possible this afternoon and evening
   with storms over parts of Indiana, Ohio, Kentucky, and Tennessee.

   ...IN/OH/KY/TN...
   Morning water vapor loop shows an intense and negatively tilted
   shortwave trough rotating into the lower OH and TN valleys. 
   Meanwhile at the surface, a cold front is surging eastward into
   central KY and middle TN.  Partial clearing has begun to occur ahead
   of the front, where dewpoints in the mid/upper 50s are present. 
   This will lead to an axis of sufficient MLCAPE (500-1000 J/kg) for a
   few robust and fast-moving thunderstorms this afternoon.  Strong
   midlevel drying associated with the shortwave trough, linear forcing
   along the front, and sufficient deep-layer shear will promote
   linear/bowing structures capable of gusty and locally damaging wind
   gusts.  Therefore have added a SLGT risk for this region.

   ...Arklatex region...
   Low level moisture is returning northward across central TX today,
   with afternoon dewpoint values in the upper 50s and lower 60s
   expected to near the Red River this evening.  Strengthening
   southwesterly low-level winds around dusk may lead to the
   development a isolated thunderstorms.  Several CAM solutions
   indicate this threat, although there is disagreement on placement of
   storms.  Have added a small MRGL risk to account for this potential.
   Large hail appears to be the main concern if storms can develop.

   ..Hart.. 04/08/2021

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