Apr 24, 2015 1300 UTC Day 1 Convective Outlook
Updated: Fri Apr 24 13:00:13 UTC 2015 (20150424 1300Z Day 1 shapefile | 20150424 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150424 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 127,097 11,778,331 Dallas, TX...Fort Worth, TX...Arlington, TX...Wichita, KS...Plano, TX...
SLIGHT 260,762 24,663,596 Houston, TX...San Antonio, TX...Austin, TX...Oklahoma City, OK...Kansas City, MO...
MARGINAL 213,877 9,369,638 Memphis, TN...Birmingham, AL...Laredo, TX...Mobile, AL...Springfield, MO...
Probabilistic Tornado Graphic
20150424 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
SIG SEVERE 38,703 7,118,678 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
10 % 62,504 9,258,462 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
5 % 199,513 18,888,672 Houston, TX...San Antonio, TX...Austin, TX...New Orleans, LA...Wichita, KS...
2 % 146,146 8,897,864 Oklahoma City, OK...Kansas City, MO...Tulsa, OK...Corpus Christi, TX...Little Rock, AR...
Probabilistic Damaging Wind Graphic
20150424 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
30 % 84,141 10,260,624 Dallas, TX...Fort Worth, TX...Arlington, TX...Plano, TX...Garland, TX...
15 % 299,368 26,123,084 Houston, TX...San Antonio, TX...Austin, TX...Oklahoma City, OK...Kansas City, MO...
5 % 190,458 9,185,843 Memphis, TN...Birmingham, AL...Laredo, TX...Mobile, AL...Springfield, MO...
Probabilistic Large Hail Graphic
20150424 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
SIG SEVERE 54,882 8,964,796 Dallas, TX...Fort Worth, TX...Arlington, TX...Wichita, KS...Plano, TX...
30 % 117,622 11,496,986 Dallas, TX...Fort Worth, TX...Arlington, TX...Wichita, KS...Plano, TX...
15 % 244,365 23,956,615 Houston, TX...San Antonio, TX...Austin, TX...Oklahoma City, OK...Kansas City, MO...
5 % 228,431 10,226,288 Memphis, TN...Birmingham, AL...Laredo, TX...Mobile, AL...Springfield, MO...
   SPC AC 241300

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0800 AM CDT FRI APR 24 2015

   VALID 241300Z - 251200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS FROM CNTRL TX ENE INTO SRN
   AR/NRN LA...

   ...THERE IS AN ENH RISK OF SVR TSTMS OVER PARTS OF CNTRL AND ERN
   KS...

   ...THERE IS A SLGT RISK OF SVR TSTMS SURROUNDING THE ENHD
   AREA...FROM KS SSE TO THE WRN GULF CST...

   ...THERE IS A MRGL RISK OF SVR TSTMS FROM NEB SSE TO THE WRN AND
   CNTRL GULF CST...

   ...SUMMARY...
   SEVERE THUNDERSTORMS ARE LIKELY THIS AFTERNOON INTO TONIGHT FROM THE
   SOUTHERN PLAINS INTO THE LOWER MISSISSIPPI VALLEY. OTHER SEVERE
   STORMS ARE EXPECTED OVER THE CENTRAL PLAINS. SUPERCELLS CAPABLE OF
   LARGE HAIL...DAMAGING WINDS...AND PERHAPS A COUPLE STRONG TORNADOES
   WILL BE POSSIBLE IN BOTH AREAS.

   ...SYNOPSIS...
   PROGRESSIVE SPLIT-FLOW PATTERN WILL SOMEWHAT AMPLIFY THIS PERIOD AS
   SRN BRANCH TROUGH NOW OVER N CNTRL MEX/SW NM CONTINUES NE TO THE ERN
   TX PANHANDLE THIS EVE...AND INTO ERN KS EARLY SAT...WHILE UPSTREAM
   NRN BRANCH TROUGH AMPLIFIES SE INTO CA. THE SHORTENING WAVELENGTH
   ASSOCIATED WITH THIS PATTERN WILL TEMPORARILY STRENGTHEN THE NM
   DISTURBANCE AND YIELD A BELT OF ENHANCED WSWLY FLOW OVER THE SRN
   HALF OF THE PLNS LATER TODAY THROUGH TNGT.  

   AT LWR LVLS...EXPECT A SFC LOW TO CONSOLIDATE OVER THE OK PANHANDLE
   BY THIS EVE...WITH THE LOW CONTINUING NE TO NEAR KANSAS CITY EARLY
   SAT. IN RESPONSE...DIFFUSE WARM FRONT NOW EXTENDING ROUGHLY WNW-ESE
   ACROSS WRN OK/N TX AND SRN LA WILL ADVANCE N/NEWD THROUGH THE
   PERIOD. ITS POLEWARD NWD MOTION WILL...HOWEVER...LIKELY BE RETARDED
   BY THE CONTINUING PRESENCE OF STORM CLUSTERS AND CLOUDS OVER ERN
   PARTS OF THE SRN PLNS.

   ...SRN PLNS TO LWR MS VLY TODAY/TNGT...
   SEVERE WEATHER SCENARIO WILL BE COMPLICATED IN THIS REGION BY
   OUTFLOW FROM OVERNIGHT AND ONGOING STORM COMPLEXES...DIFFUSE NATURE
   OF WARM FRONT...AND PRESENCE OF THICK MID/HIGH-LVL CLOUDS DOWNSTREAM
   FROM NM UPR TROUGH. NEVERTHELESS...COMBINATION OF SFC HEATING AND
   LOW-LVL UPLIFT ALONG OUTFLOW BOUNDARY ON SRN SIDE OF N TX CONVECTIVE
   BAND...AND UPLIFT ALONG WARM FRONTAL SEGMENTS IN THE
   VICINITY...SHOULD PROVE SUFFICIENT TO SUPPORT THE DEVELOPMENT OF
   STRONG TO SVR STORMS BY MID TO LATE AFTN.  THE ACTIVITY SHOULD BEGIN
   IN CNTRL TX...WHERE INTERSECTION OF EWD-ACCELERATING DRY LINE WILL
   ASSIST IN LIFTING PARCELS TO THE LFC. STORMS MAY THEN FORM AND/OR
   INTENSIFY A BIT LATER EWD ALONG THE OUTFLOW BOUNDARY TOWARD THE
   ARKLATEX. GIVEN 50+ KT WSWLY DEEP SHEAR ORIENTED ROUGHLY PARALLEL TO
   THE OUTFLOW BOUNDARY/FRONT...AND RICH BOUNDARY LAYER MOISTURE /PW
   AOA 1.75 INCHES/...POTENTIAL WILL EXIST FOR SUPERCELLS AND SUPERCELL
   COMPLEXES WITH A RISK FOR VERY LARGE HAIL...HIGH WIND...AND
   TORNADOES. GIVEN STRENGTHENING SWLY LOW-LVL FLOW ASSOCIATED WITH THE
   EJECTING UPR TROUGH...THE STORMS LIKELY WILL MERGE INTO A FAIRLY
   EXTENSIVE QLCS THIS EVE/TNGT. EMBEDDED SUPERCELLS WITHIN THIS
   ACTIVITY COULD CONTAIN BOWS AND LEWPS POSING A CONTINUING SVR THREAT
   EWD ACROSS SRN AR AND NRN/CNTRL LA INTO NRN/CNTRL MS EARLY SAT. 
     
   ...CNTRL PLNS THIS AFTN INTO TNGT...
   A SEPARATE SVR THREAT AREA LIKELY WILL EVOLVE OVER PARTS OF CNTRL
   PLNS THIS AFTN AND EVE...WHERE SFC HEATING AND THE APPROACH OF THE
   SRN BRANCH TROUGH WILL FURTHER DESTABILIZE REGION. SOME ASPECTS OF
   THE SITUATION ARE CERTAINLY FAVORABLE FOR SUPERCELLS...ESPECIALLY
   ALONG A ROUGHLY SW-NE DIAGONAL AXIS ACROSS CNTRL AND ERN KS. BUT THE
   SFC LOW WILL REMAIN RATHER LOOSELY-ORGANIZED THROUGH THE DAY...AND
   THE STRONGEST MID-UPR LVL FLOW WILL REMAIN S OF THE REGION.  COUPLED
   WITH THE PRESENCE OF ONLY MODEST MOISTURE RETURN DUE TO CONTINUING
   PRESENCE OF STORMS FARTHER S...AND PERSISTENT CLOUD COVER...DEGREE
   OF STORM COVERAGE AND INTENSITY IS UNCLEAR ATTM.
   NEVERTHELESS...ESPECIALLY ACROSS PARTS OF KS...POCKETS OF ENHANCED
   BUOYANCY/CONVERGENCE LIKELY WILL YIELD AT LEAST SOME STORMS CAPABLE
   OF LARGE HAIL AND TORNADOES...IN ADDITION TO LOCALLY DMGG
   WIND...INTO EARLY TNGT.

   ..CORFIDI/COHEN.. 04/24/2015

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