Dec 13, 2020 1630 UTC Day 1 Convective Outlook
Updated: Sun Dec 13 16:23:52 UTC 2020 (20201213 1630Z Day 1 shapefile | 20201213 1630Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20201213 1630 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 9,163 959,703 Beaumont, TX...Lake Charles, LA...Baytown, TX...Port Arthur, TX...Texas City, TX...
MARGINAL 38,653 7,714,308 Houston, TX...Baton Rouge, LA...Pasadena, TX...Lafayette, LA...Sugar Land, TX...
Probabilistic Tornado Graphic
20201213 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
5 % 9,035 978,614 Beaumont, TX...Lake Charles, LA...Baytown, TX...Port Arthur, TX...Texas City, TX...
2 % 14,909 5,763,308 Houston, TX...Pasadena, TX...Lafayette, LA...Sugar Land, TX...Missouri City, TX...
Probabilistic Damaging Wind Graphic
20201213 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 % 9,233 997,159 Beaumont, TX...Lake Charles, LA...Baytown, TX...Port Arthur, TX...Texas City, TX...
5 % 36,067 7,286,179 Houston, TX...Baton Rouge, LA...Pasadena, TX...Lafayette, LA...Sugar Land, TX...
Probabilistic Large Hail Graphic
20201213 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 % 12,273 6,237,716 Houston, TX...Pasadena, TX...Beaumont, TX...Sugar Land, TX...The Woodlands, TX...
   SPC AC 131623

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1023 AM CST Sun Dec 13 2020

   Valid 131630Z - 141200Z

   ...THERE IS A SLIGHT RISK OF SEVERE THUNDERSTORMS FROM SOUTHEAST
   TEXAS INTO SOUTHWEST LOUISIANA...

   ...SUMMARY...
   A few damaging wind gusts and a couple tornadoes are possible across
   a portion of southeast Texas and southwest Louisiana, this afternoon
   to early evening.

   ...Southeast Texas into southwest Louisiana...

   Late this morning a warm front extends from a weak surface low in
   southeast TX, eastward to near Palacios TX and into the northwestern
   Gulf. The front will move north through the day, likely reaching the
   Houston metro early this afternoon and continuing into the southwest
   LA coastal area by late afternoon. Rich low-level moisture with
   upper 60s to 70 F dewpoints reside along and south of the warm
   front, and will contribute to MLCAPE from 800-1200 J/kg. Numerous
   showers and scattered thunderstorms are developing across southeast
   TX within corridor of isentropic ascent north of this boundary. This
   activity will remain elevated with minimal severe risk. A somewhat
   greater threat for severe storms should evolve this afternoon. Some
   CAMs suggest surface-based storms will develop along confluence
   boundaries just offshore. A couple of these storms might move inland
   and interact with the warm front where low-level hodographs with
   200-400 m2/s2 storm relative helicity and strong effective bulk
   shear will support potential for supercells capable of producing a
   tornado or two. Otherwise, additional surface based storms will be
   possible as the cold front advances southeast and interacts with the
   moist warm sector. Storms might eventually evolve into linear
   structures along the cold front this evening as they spread east
   into LA with a threat for mainly a few strong to damaging wind
   gusts. The marginal thermodynamic environment with weak lapse rates
   and widespread low clouds, along with tendency for deeper forcing
   for ascent to remain north of warm sector, could potentially serve
   as limiting factors for a more robust severe threat.

   ..Dial/Moore.. 12/13/2020

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z