Sep 24, 2016 1300 UTC Day 1 Convective Outlook
Updated: Sat Sep 24 12:57:01 UTC 2016 (20160924 1300Z Day 1 shapefile | 20160924 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20160924 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
MARGINAL 261,658 11,038,104 Oklahoma City, OK...Omaha, NE...Wichita, KS...Lincoln, NE...Lubbock, TX...
Probabilistic Tornado Graphic
20160924 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 % 93,520 2,006,582 Sioux Falls, SD...Fargo, ND...Sioux City, IA...Grand Forks, ND...Minot, ND...
Probabilistic Damaging Wind Graphic
20160924 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 % 260,886 11,073,767 Oklahoma City, OK...Omaha, NE...Wichita, KS...Lincoln, NE...Lubbock, TX...
Probabilistic Large Hail Graphic
20160924 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
5 % 31,573 423,876 Fargo, ND...Minot, ND...Moorhead, MN...West Fargo, ND...West Fargo, MN...
   SPC AC 241257

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0757 AM CDT SAT SEP 24 2016

   VALID 241300Z - 251200Z

   ...THERE IS A MRGL RISK OF SVR TSTMS ERN DAKOTAS/MN TO PORTIONS W
   TX...

   ...SUMMARY...
   ISOLATED STRONG TO SEVERE STORMS ARE POSSIBLE FROM PARTS OF THE
   SOUTHERN PLAINS NORTHWARD INTO THE DAKOTAS AND MINNESOTA THIS
   AFTERNOON AND EVENING.

   ...SYNOPSIS...
   SOMEWHAT PROGRESSIVE AND HIGHLY AMPLIFIED UPPER-AIR PATTERN WILL
   PREVAIL OVER CONUS THIS PERIOD.  STG UPPER RIDGING WILL BE SHIFTING
   EWD TOWARD PAC COAST AND ACROSS UPPER GREAT LAKES AND MS VALLEY
   REGION.  IN BETWEEN...MAJOR SYNOPTIC TROUGH CURRENTLY OVER ROCKY
   MOUNTAIN STATES WILL DIVIDE INTO TWO PRIMARY FEATURES: 

   1.  STG/EJECTING CYCLONE NOW CENTERED OVER SRN WY...WITH TROUGH SWD
   ACROSS WRN NM.  THIS FEATURE SHOULD DEVOLVE INTO STG OPEN-WAVE
   TROUGH BY 00Z FROM WRN ND SWD TO EXTREME ERN CO...PERHAPS WITH
   REMNANT/NEARLY CLOSED CIRCULATION ALOFT OVER NWRN SD/NWRN ND REGION
   CORRESPONDING TO PRIMARY VORTICITY LOBE.  THIS PERTURBATION WILL
   PROCEED ENEWD ACROSS DAKOTAS AND WRN NEB OVERNIGHT.  MEANWHILE ITS
   NRN PART WILL PHASE WITH INITIALLY SEPARATE...EWD-MOVING...NRN-
   STREAM SHORTWAVE TROUGH NOW EVIDENT IN MOISTURE-CHANNEL IMAGERY OVER
   CANADIAN ROCKIES. 

   2.  MID/UPPER-LEVEL VORTICITY BANNER -- NOW ASSOCIATED WITH NLY 
   SPEED MAX OVER GREAT BASIN AND REARWARD OF SYNOPTIC TROUGH.  THIS
   FEATURE SHOULD DIG SWD ACROSS UT/AZ THROUGH PERIOD...RESULTING IN
   INCREASINGLY CUT-OFF CYCLONIC CIRCULATION THAT WILL BE CENTERED OVER
   NERN SONORA BY 12Z.  UPPER RIDGING WILL BUILD ACROSS S-CENTRAL
   ROCKIES...THROUGH COL BETWEEN THIS PERTURBATION AND DAKOTAS FEATURE.

   AT SFC...PRONOUNCED LOW WAS ANALYZED AT 11Z OVER W-CENTRAL/NWRN
   SD...WITH PAC COLD FRONT ARCHING SEWD OVER CENTRAL NEB THEN SSWWD
   ACROSS WRN KS...TX PANHANDLE AND SERN NM.  LOW SHOULD MIGRATE
   GENERALLY NWD TODAY BEFORE BECOMING NEARLY STACKED WITH APCHG MID/
   UPPER VORTICITY MAX OVER WRN ND.  LOW THEN WILL EJECT NEWD ACROSS
   SRN MB OVERNIGHT.  MEANWHILE...COLD FRONT SHOULD PROGRESS EWD BY 00Z
   TO ERN DAKOTAS...S-CENTRAL NEB...AND W-CENTRAL KS...STALLING
   TEMPORARILY OVER TX PANHANDLE AS MAIN UPPER WAVE EJECTS AWAY FROM
   REGION.  BY 12Z...FRONT SHOULD REACH NRN/CENTRAL MN...CENTRAL
   IA...NWRN MO...NWRN OK...AND SRN PANHANDLE/TX SOUTH PLAINS REGION. 

   ...CENTRAL CONUS...
   BEGINNING WITH ONGOING...BKN BAND OF NON-SVR CONVECTION FROM TX
   PANHANDLE TO ERN NEB...SEVERAL ROUNDS OF TSTMS ARE LIKELY TODAY IN
   THIS LENGTHY ARC FROM W-CENTRAL TX TO IA AND DAKOTAS.  ISOLATED
   DAMAGING GUSTS ARE POSSIBLE THROUGHOUT OUTLOOK AREA...AND ISOLATED
   SVR HAIL OR A TORNADO MAY OCCUR OVER NRN PLAINS/UPPER MIDWEST
   PORTION.  MORE CONCENTRATED AREA OF SVR THREAT MAY DEVELOP WITHIN
   THIS CORRIDOR.  HOWEVER....POTENTIAL REMAINS TOO
   MESOSCALE-DEPENDENT...CONDITIONAL AND UNCERTAIN FOR MORE THAN
   MRGL-LEVEL UNCONDITIONAL PROBABILITIES TO BE ASSIGNED ATTM. 

   OVER DAKOTAS AND WRN MN...COOLING ALOFT AHEAD OF EJECTING MID/UPPER
   PERTURBATION WILL CONTRIBUTE TO RELATIVELY STEEP MIDLEVEL LAPSE
   RATES...JUXTAPOSED WITH ISALLOBARICALLY STRENGTHENED/BACKED NEAR-SFC
   WINDS THAT WILL ENHANCED LOW-LEVEL SHEAR AND HODOGRAPH SIZE.  THESE
   FACTORS...ALONG WITH SOMEWHAT FAVORABLE CROSS-BOUNDARY COMPONENT OF
   MEAN-WIND AND DEEP-SHEAR VECTORS...SUPPORTS CONDITIONAL RISK FOR
   PERIOD OF DISCRETE AND PERHAPS SUPERCELLULAR CONVECTION IN ARC
   EXTENDING EWD/SEWD FROM DEEP-LAYER CYCLONE.  POTENTIAL FOR
   DEVELOPMENT OF SUBSTANTIAL BOUNDARY-LAYER INSTABILITY APPEARS MRGL
   AND UNCERTAIN...HOWEVER.  

   DEEPER...LONGER-LIVED AND MORE DENSELY CONCENTRATED CONVECTION IS
   POSSIBLE FARTHER S FROM SIOUXLAND AREA ACROSS KS TO PORTIONS W TX
   PLAINS...WHERE LOW-LEVEL MOISTURE AND THETAE WILL BE GREATEST. 
   HOWEVER...LARGE-SCALE/UPPER-LEVEL SUPPORT WILL BE LACKING COMPARED
   TO FARTHER N...AND WINDS ALOFT WILL BE SUBSTANTIALLY PARALLEL TO
   ORIENTATION OF CONVECTIVE FOCI.  1000-2000 J/KG MLCAPE AND 40-50 KT
   EFFECTIVE-SHEAR MAGNITUDES STILL SHOULD SUPPORT AT LEAST TRANSIENTLY
   ORGANIZED CELLS CAPABLE OF ISOLATED SVR.

   ..EDWARDS/PICCA.. 09/24/2016

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