Feb 1, 2015 1300 UTC Day 1 Convective Outlook
Updated: Sun Feb 1 12:54:30 UTC 2015 (20150201 1300Z Day 1 shapefile | 20150201 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150201 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 119,204 13,766,774 Houston, TX...New Orleans, LA...Baton Rouge, LA...Mobile, AL...Jackson, MS...
Probabilistic Tornado Graphic
20150201 1300 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 % 28,060 1,470,514 Jackson, MS...Hattiesburg, MS...Meridian, MS...Vicksburg, MS...Clinton, MS...
Probabilistic Damaging Wind Graphic
20150201 1300 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 % 119,164 13,766,536 Houston, TX...New Orleans, LA...Baton Rouge, LA...Mobile, AL...Jackson, MS...
Probabilistic Large Hail Graphic
20150201 1300 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 011254

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0654 AM CST SUN FEB 01 2015

   VALID 011300Z - 021200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM PARTS OF SERN TX EWD TO
   PARTS OF WRN AL...

   ...SUMMARY...
   A FEW MARGINALLY SEVERE THUNDERSTORMS MAY OCCUR THIS AFTERNOON AND
   EARLY EVENING FROM PORTIONS OF SOUTHEAST TEXAS TO THE LOWER
   MISSISSIPPI VALLEY REGION.

   ...SYNOPSIS...
   MORNING WATER VAPOR IMAGERY INDICATES A MIDLEVEL SHORTWAVE TROUGH
   AMPLIFYING OVER THE CNTRL PLAINS. ASSOCIATED SFC LOW
   PRESSURE...ANALYZED ALONG THE KS/MO BORDER...WILL DEVELOP EWD TOWARD
   THE OHIO VALLEY AND CNTRL APPALACHIANS IN TANDEM WITH THE
   PROGRESSION OF THE SHORTWAVE TROUGH. IN THE WAKE OF A COLD FRONT
   TRAILING SW OF THE DEEPENING SFC CYCLONE...SPRAWLING SFC HIGH
   PRESSURE WILL REINFORCE CONTINENTAL POLAR AIR OVER THE GREAT PLAINS.
   MEANWHILE...AHEAD OF THE COLD FRONT...POLEWARD MASS FLUXES WILL
   ENCOURAGE THE INLAND ADVANCE OF PARTIALLY MODIFIED GULF MOISTURE. BY
   EARLY MON...THE COLD FRONT IS FORECAST TO EXTEND FROM PORTIONS OF
   THE CNTRL APPALACHIANS TO THE ERN GULF COAST.

   ...PORTIONS OF SOUTHEAST TX TO THE LOWER MS VALLEY REGION...
   SFC OBSERVATIONS INDICATE DEWPOINTS FROM THE UPPER 50S TO AROUND 60F
   EXTENDING INLAND FROM THE TX COAST TO THE DFW METROPLEX...IN ADVANCE
   OF THE COLD FRONT. THIS FRONT IS ANALYZED FROM THE KS/MO-AREA LOW
   PRESSURE SWWD TO THE TX S PLAINS. AS MASS FIELDS RESPOND TO SFC
   CYCLOGENESIS OCCURRING WELL N OF THE REGION...SIMILAR DEWPOINTS WILL
   OVERSPREAD AREAS FARTHER E TOWARD THE LOWER MS VALLEY AHEAD OF THE
   FRONT...WHERE 12Z RAOBS INDICATE A DRY/COOL BOUNDARY LAYER PRESENTLY
   IN PLACE.

   A STEADY SUPPLY OF MOISTURE E OF A NWRN-MEXICO MIDLEVEL
   CYCLONE...COUPLED WITH MODEST ISENTROPIC ASCENT IN THE ENTRANCE
   REGION OF A SFC-CYCLONE-PRECEDING LLJ...WILL MAINTAIN CLOUDS AND
   AREAS OF PRECIPITATION ACROSS THE WARM/MOIST SECTOR. THIS WILL STUNT
   DIURNAL DESTABILIZATION. HOWEVER...AS THE STRONGEST LOW-LEVEL MASS
   FLUXES BECOME CONCENTRATED OVER THE OHIO AND TN VALLEYS...BREAKS IN
   CLOUD COVERAGE/DECREASING CLOUD-OPACITY MAY PROMOTE MARGINAL
   PRE-FRONTAL DESTABILIZATION. A CORRIDOR OF 200-500-J/KG MLCAPE WILL
   LIKELY MATERIALIZE AHEAD OF THE FRONT BY MID-AFTERNOON...FROM SERN
   TX TO CNTRL MS. THIS WILL BE SUFFICIENT FOR THE DEVELOPMENT OF
   ISOLATED TO SCATTERED THUNDERSTORMS INVOF THE FRONT DURING THE
   AFTERNOON...WITH THIS ACTIVITY SPREADING EWD INTO THE EVENING.
   ADDITIONAL CONVECTION MAY MATURE WITHIN THE
   PRE-FRONTAL/ISENTROPIC-ASCENT REGIME THROUGHOUT THE DAY FROM CNTRL
   LA TO CNTRL/S-CNTRL/ERN MS...WITH THIS ACTIVITY SIMILARLY SHIFTING
   EWD.

   THE PRESENCE OF 55-60-KT H5 WSWLYS WILL OFFER SUFFICIENT DEEP SHEAR
   FOR ORGANIZED CONVECTIVE STRUCTURES. SMALL BOWING SEGMENTS MAY YIELD
   A FEW INSTANCES OF MARGINALLY SVR WIND GUSTS. LOW-LEVEL FLOW WILL BE
   SLIGHTLY BACKED RELATIVE TO THE FLOW ALOFT IN PROXIMITY TO A
   LOW-LEVEL CONFLUENCE AXIS EXTENDING SSW OF THE CYCLONE TO THE CNTRL
   GULF COAST THIS AFTERNOON. PRE-FRONTAL CONVECTION EVOLVING IN THIS
   REGIME MAY OCCASIONALLY EXHIBIT MIXED CONVECTIVE MODES...PERHAPS
   INCLUDING SEMI-DISCRETE SUPERCELLS. THIS WOULD PARTICULARLY BE THE
   CASE ACROSS PORTIONS OF CNTRL/SRN/ERN MS AND ADJACENT SECTIONS OF
   NERN LA AND WRN AL. CURVED...ELONGATED LOW-LEVEL HODOGRAPHS
   SUPPORTING 100-250 M2/S2 OF 0-1-KM SRH SUGGEST THAT A BRIEF/WEAK
   TORNADO CANNOT BE RULED OUT IN THESE AREAS. 

   HOWEVER...THE DEARTH OF BUOYANCY WILL BE A MITIGATING FACTOR FOR
   MORE ROBUST SVR-TSTM POTENTIAL...ESPECIALLY GIVEN INCOMPLETE
   MODIFICATION OF THE AIR MASS OVERLYING THE GULF OF MEXICO AND THE
   PRESENCE OF ONLY MODEST MIDLEVEL LAPSE RATES. FURTHERMORE...THE
   SPATIAL DISPLACEMENT BETWEEN THE STRONGER DEEP ASCENT/SFC
   CYCLOGENESIS AND GREATER BOUNDARY-LAYER THETA-E WILL BE A MITIGATING
   FACTOR FOR A MORE SUBSTANTIAL SVR-TSTM POTENTIAL. AS SUCH...ONLY
   MARGINAL-SVR-TSTM DELINEATION IS IN EFFECT. ANY SVR-TSTM RISK WILL
   DIMINISH AS CONVECTION SPREADS E OF WRN AL THIS EVENING...AND
   NOCTURNAL COOLING BREEDS AN INCREASE IN BOUNDARY-LAYER STATIC
   STABILITY.

   ...EXTREME ERN NC INCLUDING THE OUTER BANKS...
   STRENGTHENING LOW-LEVEL SLYS AHEAD OF THE SHORTWAVE TROUGH WILL
   FOSTER AN INFLUX OF LOW-LEVEL MOISTURE FROM THE SWRN NORTH ATLANTIC
   LATE TONIGHT...ALONG WITH SOME UPTICK IN CONVECTION. DESPITE STRONG
   FLOW JUST ABOVE THE SFC...FORECAST SOUNDINGS INDICATE A PAUCITY OF
   BUOYANCY OWING TO STATICALLY STABLE THERMODYNAMIC PROFILES IN THE
   LOW LEVELS. THE NOCTURNALLY ENHANCED STABLE LAYER WILL MINIMIZE THE
   OPPORTUNITY FOR DOWNDRAFTS TO MANIFEST STRONG WINDS AT THE SFC.
   THEREFORE...NO SEVERE PROBABILITIES HAVE BEEN INCLUDED.

   ..COHEN/CARLAW/MEAD.. 02/01/2015

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z