Apr 23, 2014 1300 UTC Day 1 Convective Outlook
Updated: Wed Apr 23 12:49:38 UTC 2014 (20140423 1300Z Day 1 shapefile | 20140423 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20140423 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20140423 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.
Probabilistic Damaging Wind Graphic
20140423 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.
Probabilistic Large Hail Graphic
20140423 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.
Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
SLIGHT 150,586 4,630,688 Oklahoma City, OK...Wichita, KS...Lincoln, NE...Abilene, TX...Norman, OK...
   SPC AC 231246

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0746 AM CDT WED APR 23 2014

   VALID 231300Z - 241200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/SRN PLAINS...

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE EXPECTED THIS AFTERNOON INTO TONIGHT ACROSS
   THE CENTRAL AND SOUTHERN GREAT PLAINS. LARGE HAIL WILL BE THE
   PRIMARY INITIAL HAZARD...WITH DAMAGING WINDS AND A FEW TORNADOES
   POSSIBLE.

   ...SYNOPSIS...
   PROGRESSIVE UPPER-AIR PATTERN IS FCST ACROSS CONUS THIS
   PERIOD...MAIN INFLUENCING FEATURE ALOFT FOR SVR RISK BEING
   SYNOPTIC-SCALE TROUGH NOW LOCATED FROM BC TO NRN ROCKIES...UT AND
   LOWER CO RIVER VALLEY.  SERIES OF NRN-STREAM VORTICITY MAXIMA WILL
   TRAVERSE THAT PORTION OF THIS TROUGH LOCATED OVER NRN ROCKIES AND
   NRN PLAINS...LEADING TO ITS NET EWD MOVEMENT TO SK...WRN DAKOTAS AND
   WRN NEB BY END OF PERIOD.  MEANWHILE...BASAL VORTICITY LOBE NOW OVER
   SRN SIERRAS IS EXPECTED TO SHIFT ESEWD AND INTENSIFY
   TODAY...EXTENDING FROM SWRN CO TO AZ/NM BORDER BY 00Z.  BY 12Z THIS
   PERTURBATION SHOULD REACH SWRN KS AND TX PANHANDLE...WITH ASSOCIATED
   DCVA PLUME SPREADING OVER CENTRAL KS...CENTRAL/WRN K AND NW TX.

   AT SFC...COLD FRONT ANALYZED AT 11Z OVER ERN WY WILL MOVE EWD AND
   SEWD ACROSS CENTRAL HIGH PLAINS TODAY...WHILE SFC LOW DEVELOPS ALONG
   ITS INTERSECTION WITH LEE TROUGH OVER ERN CO/EXTREME WRN KS.  BY
   00Z...FRONT SHOULD ARC FROM NWRN ND ACROSS CENTRAL NEB AND NWRN KS. 
   INITIALLY DIFFUSE DRYLINE SHOULD BECOME BETTER-DEFINED BY 00Z FROM
   NRN COAHUILA NNEWD OVER ERN TX PANHANDLE THEN NWD ACROSS E-CENTRAL
   KS.  COLD FRONT WILL OVERTAKE DRYLINE FROM N-S TONIGHT WHILE SFC
   CYCLONE MOVES RAPIDLY NEWD TO IA.  BY 12Z...FRONT SHOULD EXTEND FROM
   IA LOW SWWD ACROSS ERN KS...SWRN KS AND SERN CORNER OF NM.

   ...SLGT RISK AREA...CENTRAL/SRN PLAINS...
   SCATTERED TSTMS ARE EXPECTED TO DEVELOP THIS AFTN ALONG COLD
   FRONT...SOME OF WHICH MAY ATTAIN SUPERCELL STRUCTURES BEFORE
   AGGREGATING INTO QUASI-LINEAR/FRONTALLY FORCED MODE.  THIS
   CONVECTION SHOULD BE RATHER HIGH-BASED AND MAY BE PRONE TO
   EARLY-STAGE OUTFLOW-DOMINANCE.  STILL...BAND OF STG-SVR TSTMS SHOULD
   OFFER RISK FOR SVR GUSTS AND HAIL INTO EVENING ACROSS NRN PORTIONS
   OUTLOOK AREA...BEFORE MOVING EWD AND DIMINISHING.  AIR MASS N OF
   ABOUT I-70 IS LIKELY TO STABILIZE DIABATICALLY FASTER THAN THAT
   INFLUENCE CAN BE OFFSET BY THETAE ADVECTION.

   FARTHER S...COVERAGE SHOULD BE MORE WIDELY SCATTERED IN FIRST 2-3
   HOURS FOR DRYLINE-INITIATED CELLS FROM WRN KS TO NW TX...WITH
   DISCRETE SUPERCELLS PROBABLE.  CHANCE FOR DISCRETE SUPERCELLS WITH
   ENOUGH MOISTURE CONTENT FOR SIGNIFICANT/DAMAGING HAIL APPEARS
   LARGEST IN ERN TX PANHANDLE...WRN OK AND NW TX.  SOME INITIALLY
   DRYLINE-FIRED CONVECTION MAY AGGREGATE INTO CLUSTERS THIS EVENING
   AND MOVE EWD ACROSS PORTIONS OK OR N TX WITH POTENTIAL FOR BOWS AND
   EMBEDDED SUPERCELLS.  WHERE ANY DISCRETE SUPERCELLS LAST INTO
   EVENING...THEY WILL ENCOUNTER RAPIDLY ENLARGING HODOGRAPHS DUE TO
   STRENGTHENING LLJ...CONCURRENT WITH LOSS OF DIURNAL MIXING AND
   RESULTANT ADVECTION-RELATED BOOST IN INFLOW-LAYER MOISTURE THAT
   LOWERS LCL.  TIME WINDOW NEAR SUNSET AND INTO TWILIGHT THEREFORE MAY
   POSE SOME TORNADO RISK...WHERE TSTM MODES STILL ARE SUITABLE...AND
   BEFORE NOCTURNAL COOLING PROHIBITIVELY STRENGTHENS SBCINH.

   SUFFICIENT DIURNAL HEATING WILL OCCUR ON BOTH SIDE OF
   DRYLINE...AIDING IN AFTN DEVELOPMENT...DESPITE PERSISTENT/ANTECEDENT
   HIGH CLOUDS.  MEANWHILE...CORRIDOR OF RETURN-FLOW MOISTURE ADVECTION
   WILL BE OFFSET BY AFTN VERTICAL MIXING SUCH THAT SFC DEW POINTS MAY
   NOT RISE MUCH ABOVE CURRENT VALUES OVER MUCH OF NW TX...OK AND KS. 
   HOWEVER...AROUND 00Z AND INTO EVENING...60S F DEW POINTS MAY REACH
   RED RIVER REGION WITH 50S INTO KS. EFFECTIVE SHEAR MAGNITUDES MAY
   REACH 40-50 KT ACROSS PRE-DRYLINE/PREFRONTAL CORRIDOR BY 00Z.

   ...W-CENTRAL/SW TX...
   ISOLATED TSTMS ARE POSSIBLE OVER THIS CORRIDOR...INITIATED BOTH
   INVOF DRYLINE AND OVER HIGHER TERRAIN OF NRN COAHUILA.  LATTER
   CONVECTION MAY REACH ADJOINING PORTIONS TX RIO GRANDE VALLEY BEFORE
   DISSIPATING.  ANY OF THIS ACTIVITY MAY DEVELOP SOME SUPERCELL
   CHARACTERISTICS WITH LARGE HAIL AND DAMAGING GUSTS BEING MAIN
   CONCERNS...THOUGH POTENTIAL COVERAGE/DURATION APPEAR MORE LIMITED
   THAN FARTHER N.  GREATEST POTENTIAL LONGEVITY MAY BE FOR CONVECTION
   MOVING OFF SERRANIAS DEL BURRO RANGE AND FOOTHILLS...GIVEN
   RELATIVELY MAXIMIZED BOUNDARY-LAYER MOISTURE CONTENT OVER THIS AREA.

   ..EDWARDS/ROGERS.. 04/23/2014

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