Jan 18, 2017 0600 UTC Day 1 Convective Outlook
Updated: Wed Jan 18 05:44:24 UTC 2017 (20170118 1200Z Day 1 shapefile | 20170118 1200Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20170118 1200 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 15,798 1,481,147 Beaumont, TX...Lake Charles, LA...Baytown, TX...Port Arthur, TX...Alexandria, LA...
Probabilistic Tornado Graphic
20170118 1200 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
20170118 1200 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 % 15,798 1,481,147 Beaumont, TX...Lake Charles, LA...Baytown, TX...Port Arthur, TX...Alexandria, LA...
Probabilistic Large Hail Graphic
20170118 1200 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
No Risk Areas Forecast
   SPC AC 180544

   Day 1 Convective Outlook  
   NWS Storm Prediction Center Norman OK
   1144 PM CST Tue Jan 17 2017

   Valid 181200Z - 191200Z

   ...THERE IS A MARGINAL RISK OF SEVERE THUNDERSTORMS ACROSS PORTIONS
   OF SOUTHWESTERN LOUISIANA AND SOUTHEASTERN TEXAS...

   ...SUMMARY...
   Isolated damaging wind gusts cannot be ruled out with thunderstorms
   tonight across portions of southwestern Louisiana and southeastern
   Texas.

   ...Synopsis...
   An area of midlevel cyclonic flow, and a jet streak along its
   eastern flank, are forecast to track eastward across portions of the
   south-central States. As this occurs, a weak wave is forecast to
   develop northeastward along a surface front draped from south Texas
   to the lower MS Valley region.

   ...Portions of southwestern Louisiana and southeastern Texas...
   Despite the very modest low-level mass response to the approaching
   jet streak, onshore flow ahead of the wave will maintain a moist
   boundary layer across portions of the western/central Gulf Coast
   vicinity. Tuesday evening soundings at Lake Charles and Corpus
   Christi indicate mean mixing ratios around 13-15 g/kg, and similar
   moisture will support marginal buoyancy on the warm side of the
   front through the period.

   Areas of showers and thunderstorms will likely be continuing into
   the day across portions of eastern TX and western LA, in response to
   initial warm advection. Thereafter, a renewed potential for
   thunderstorm activity will likely accompany low-level ascent related
   to the progressive frontal wave tonight, after additional inland
   moistening occurs. Sufficient deep shear will exist around the jet
   streak to support weakly organized convective clusters, perhaps
   supporting localized damaging wind gusts.

   However, the presence of weak low-level flow and poor midlevel lapse
   rates will marginalize the severe risk. The Marginal area has been
   confined to areas of anticipated greatest inland moistening amid the
   enhanced vertical shear, though areal reductions or removal of the
   Marginal area may become necessary in subsequent outlooks.

   ..Cohen/Dean.. 01/18/2017

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z