May 10, 2015 1300 UTC Day 1 Convective Outlook
Updated: Sun May 10 12:47:44 UTC 2015 (20150510 1300Z Day 1 shapefile | 20150510 1300Z Day 1 KML)
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20150510 1300 UTC Day 1 Outlook Graphic
Day 1 Risk Area (sq. mi.) Area Pop. Some Larger Population Centers in Risk Area
ENHANCED 69,657 5,762,208 Dallas, TX...Omaha, NE...Des Moines, IA...Mesquite, TX...Waco, TX...
SLIGHT 289,681 25,893,930 Austin, TX...Fort Worth, TX...Kansas City, MO...Tulsa, OK...Arlington, TX...
MARGINAL 168,319 20,146,725 Chicago, IL...San Antonio, TX...Memphis, TN...Oklahoma City, OK...Wichita, KS...
Probabilistic Tornado Graphic
20150510 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
5 % 107,935 7,357,848 Omaha, NE...Des Moines, IA...Sioux Falls, SD...Mesquite, TX...Waco, TX...
2 % 254,763 25,682,907 San Antonio, TX...Dallas, TX...Austin, TX...Fort Worth, TX...Kansas City, MO...
Probabilistic Damaging Wind Graphic
20150510 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
15 % 359,907 31,567,765 Dallas, TX...Austin, TX...Fort Worth, TX...Kansas City, MO...Omaha, NE...
5 % 167,066 20,173,754 Chicago, IL...San Antonio, TX...Memphis, TN...Oklahoma City, OK...Wichita, KS...
Probabilistic Large Hail Graphic
20150510 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 26,354 2,020,075 Waco, TX...Killeen, TX...Tyler, TX...Longview, TX...Temple, TX...
30 % 70,269 6,240,776 Dallas, TX...Omaha, NE...Garland, TX...Des Moines, IA...Mesquite, TX...
15 % 289,202 25,436,189 Austin, TX...Fort Worth, TX...Kansas City, MO...Tulsa, OK...Arlington, TX...
5 % 184,462 19,715,194 Chicago, IL...San Antonio, TX...Memphis, TN...Oklahoma City, OK...Wichita, KS...
   SPC AC 101247

   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0747 AM CDT SUN MAY 10 2015

   VALID 101300Z - 111200Z

   ...THERE IS AN ENH RISK OF SVR TSTMS SERN SD TO NWRN MO...

   ...THERE IS AN ENH RISK OF SVR TSTMS SERN OK AND SWRN AR TO CENTRAL
   TX...

   ...THERE IS A SLGT RISK OF SVR TSTMS ELSEWHERE FROM SERN SD/SRN MN
   TO IL AND CENTRAL/S TX...

   ...THERE IS A MRGL RISK OF SVR TSTMS CLOSELY SURROUNDING THE SLGT
   RISK...

   ...THERE IS A MRGL RISK OF SVR TSTMS PORTIONS COASTAL NC...

   ...SUMMARY...
   VARIABLE COVERAGE OF SEVERE THUNDERSTORMS IS EXPECTED IN A BROAD
   SWATH ARCHING FROM EASTERN SOUTH DAKOTA AND SOUTHERN MINNESOTA
   ACROSS ILLINOIS...THE LOWER MISSOURI VALLEY AND OZARKS TO CENTRAL
   AND SOUTH TEXAS.  DAMAGING GUSTS...OCCASIONALLY LARGE HAIL AND A FEW
   TORNADOES ALL ARE POSSIBLE.

   ...SYNOPSIS...
   IN MID-UPPER LEVELS...HIGH-AMPLITUDE TROUGHING WAS EVIDENT FROM
   NRN/CENTRAL HIGH PLAINS SSWWD ACROSS SRN ROCKIES TO NWRN
   MEX...INCLUDING WELL-DEFINED CYCLONE NOW EJECTING NEWD ACROSS
   CENTRAL HIGH PLAINS.  CYCLONE IS FCST TO DEVOLVE GRADUALLY INTO STG
   OPEN-WAVE TROUGH...BUT WITH 500-MB LOW/VORTICITY CENTER REACHING ERN
   SD BY END OF PERIOD.  BASAL SHORTWAVE TROUGH -- ENHANCING SRN-STREAM
   UPPER-LEVEL SPEED MAX -- WAS EVIDENT IN MOISTURE-CHANNEL IMAGERY
   OVER SONORA AND NRN AZ.  THIS FEATURE WILL PIVOT NEWD ACROSS NM AND
   W TX TODAY...WITH LEADING EDGE OF ASSOCIATED DCVA ALOFT REACHING NW
   TX AND SW OK AROUND 00Z.  LATTER SHORTWAVE TROUGH THEN SHOULD WEAKEN
   AS IT MOVES ENEWD ACROSS OK AND NRN/CENTRAL TX. 

   AT SFC...LOW ANALYZED OVER S-CENTRAL NEB IS FCST TO MOVE NEWD TO FSD
   AREA BY 00Z...THEN OCCLUDE OVERNIGHT WHILE MOVING OVER SRN MN. 
   NEARLY COLLOCATED PAC FRONT AND DRYLINE SHOULD MOVE EWD ACROSS SERN
   NEB...KS AND NRN OK TODAY WHILE SHOWING LITTLE MOVEMENT FARTHER S
   ACROSS SWRN OK AND W-CENTRAL/SW TX.  MEANWHILE...POLAR COLD FRONT
   INITIALLY OVER WRN KS...OK PANHANDLE...NWRN TX PANHANDLE...AND NERN
   NM...SHOULD MOVE TO CENTRAL KS...NRN/WRN OK...AND SRN TX PANHANDLE
   BY 00Z...OVERTAKING PAC FRONT/DRYLINE FROM N-S.  POLAR FRONT SHOULD
   DECELERATE OR STALL TEMPORARILY OVER SRN HIGH PLAINS IN DEFERENCE TO
   LEE CYCLONE OVER NWRN NM.  LEE CYCLONE SHOULD WEAKEN TONIGHT AS COLD
   FRONT RESUMES SEWD MOTION...REACHING NWRN IL...SRN MO...SERN
   OK...N-CENTRAL TX AND E-CENTRAL NM BY 12Z.  WARM FRONT...NOW EVIDENT
   OVER NRN MO AND CENTRAL PORTIONS IL/INDIANA...SHOULD MOVE NWD TO SRN
   LOWER MI...NRN IL AND CENTRAL/NWRN IA BY 00Z.  BY END OF
   PERIOD...WARM FRONT SHOULD REACH SRN ONT..CENTRAL LM...TO OCCLUSION
   TRIPLE POINT OVER SWRN WI/SERN MN AREA. 

   ...MO VALLEY...IA...MID MS VALLEY REGION...
   MINIMAL ADJUSTMENTS HAVE BEEN MADE TO NRN PORTION OF BROAD OUTLOOK
   AREA...INCLUDING EMBEDDED ENH RISK...FOR THIS FCST CYCLE...AS IT
   WILL REMAIN MOST DISTANT FROM EFFECTS OF SRN-PLAINS MCS ACTIVITY.  

   TEMPS ALOFT ARE FCST TO COOL AND STEEPEN DEEP-LAYER LAPSE RATES AS
   MID/UPPER-LEVEL CYCLONE APCHS.  WINDS ALOFT ALSO ARE FCST TO
   STRENGTHEN AMIDST HEIGHT FALLS...WITH CORRESPONDING INCREASE IN DEEP
   SHEAR...CONTERMINOUS WITH LOW-LEVEL WAA AND MOISTURE TRANSPORT INTO
   THIS REGION E-NE OF LOW-LEVEL CYCLONE.  THESE FACTORS...ALONG WITH
   CORRIDORS OF DIABATIC SFC HEATING...WILL CONTRIBUTE TO INCREASINGLY
   FAVORABLE CAPE/SHEAR PARAMETER SPACE ALONG/AHEAD OF COLD FRONT AND
   ALONG/S OF WARM FRONT THROUGH AFTN.  CONVERGENCE NEAR THOSE
   BOUNDARIES WILL PROMOTE DEVELOPMENT OF TSTMS THROUGHOUT AFTN...WITH
   BACKED NEAR-SFC WINDS AUGMENTING BOTH LOW-LEVEL HODOGRAPHS AND
   STORM-RELATIVE INFLOW.  MLCAPE 1000-1500 J/KG...LOCALLY HIGHER...MAY
   DEVELOP ALONG WITH EFFECTIVE SRH COMMONLY 200-400 J/KG WHERE
   SFC-BASED EFFECTIVE-INFLOW PARCELS ARE FOUND.  AS SUCH...SUPERCELLS
   AND BOWS ARE POSSIBLE...WITH SUPERCELLS OFFERING GREATEST
   HAIL/TORNADO POTENTIAL.  

   RELATIVE MIN IN SVR THREAT -- BUT STILL NOT TOO LOW TO LEAVE IN
   CATEGORICAL SLGT RISK FOR NOW -- APPEARS FROM CENTRAL MO SWD THROUGH
   OZARKS WHERE AIR-MASS INFLUENCES FROM CURRENT AND PRIOR MCS ACTIVITY
   FARTHER S WILL BECOME MORE CRUCIAL TO LOW-LEVEL THERMODYNAMIC
   CHARACTERISTICS.  MORE ON THAT MCS ACTION BELOW...

   ... SERN PLAINS TO ARKLATEX REGION...
   ONGOING COMPLEX OF TSTMS FROM SRN OK ACROSS N-CENTRAL TX THEN SWWD
   ACROSS EDWARDS PLATEAU WILL POSE RISK OF OCNL STG-SVR GUSTS AND
   LARGE HAIL...ESPECIALLY ON ITS ERN AND TRAILING PORTIONS...AS IT
   MOVES ENEWD ACROSS MORE OF OK AND NE TX THIS MORNING.  REF SPC WW
   153 AND RELATED MESOSCALE DISCUSSIONS FOR LATEST NEAR-TERM INFO.  

   CURRENT INDICATIONS ARE THIS LARGE AREA OF CONVECTION AND PRECIP
   WILL HAVE THREE MAIN INFLUENCES ON SVR THREAT THROUGH AFTN...
   1. DIRECT POTENTIAL FOR INTENSIFICATION AS REMAINING ACTIVITY
   ENCOUNTERS DIABATICALLY HEATED FETCH OF MOISTURE-RICH WARM SECTOR
   AIR -- CHARACTERIZED BY UPPER-60S TO LOWER-70S F SFC DEW POINTS --
   THAT HAS BEEN ONLY MINIMALLY PROCESSED BY PRIOR CONVECTION ACROSS NE
   TX...SERN OK AND SWRN AR.  
   2. DEVELOPMENT OF ADDITIONAL CONVECTION ALONG RELATED
   OUTFLOW/DIFFERENTIAL-HEATING BOUNDARY...WHICH SHOULD BE ALIGNED
   NEARLY PARALLEL TO MID/UPPER WINDS.  THOUGH THIS NORMALLY WOULD
   SUGGEST MESSY/TRAINING/QUASI-LINEAR MODES...STG DEEP SHEAR AND
   RELATIVELY MAXIMIZED LOW-LEVEL VORTICITY FIELD ACCOMPANYING BOUNDARY
   WILL SUPPORT AT LEAST TRANSIENT/HEAVY-PRECIP SUPERCELL POTENTIAL AS
   WELL. 
   3. STABILIZING INFLUENCE IN WAKE OF MIDDLE-NRN PART OF MCS FOR
   SEVERAL HOURS AT LEAST -- DURATION OF WHICH WILL DEPEND STRONGLY ON
   HOW SOON TRAILING CONVECTIVE PLUME CAN SHUT DOWN AND ALLOW
   ASSOCIATED BOUNDARY SEGMENT TO WEAKEN AND RETREAT NWD.  THIS RENDERS
   SVR POTENTIAL ALONG DRYLINE/FRONT VERY CONDITIONAL ACROSS NW TX...OK
   AND PERHAPS AS FAR N AS PORTIONS KS/MO AS PREFRONTAL/PRE-DRYLINE
   TRAJECTORIES EMANATE FROM CONVECTIVELY MODULATED AIR MASS. 

   ADDITIONAL TSTMS MAY DEVELOP THIS EVENING AND TONIGHT ALONG OR JUST
   N OF SW-NE CONVECTIVE BOUNDARY OVER TX...PERHAPS LINKING UP WITH
   SIMILARLY ORIENTED CONVECTION MORE CLOSELY ASSOCIATED WITH COLD
   FRONT OVER AR.  SUCH CONVECTION WOULD OFFER SPORADIC HAIL AND
   STG-DAMAGING GUSTS...WITH VERY MOIST LOW-LEVEL INFLOW AND FAVORABLE
   SHEAR ALONG NWRN RIM OF 35-45-KT LLJ.

   ...COASTAL NC...
   CONVECTIVE STRUCTURE OF TS ANA FIRST LACKED MUCH DEEP CONVECTION
   OVERALL AND THEN HAS LACKED THE SORT OF DISCRETE/SEMI-DISCRETE
   STRUCTURES WITHIN SPIRAL CONVERGENCE BANDS THAT WOULD FOSTER
   SUPERCELL DEVELOPMENT.  HOWEVER...CONVECTION HAS DEEPENED IN ERN
   SEMICIRCLE PER GENERAL INCREASING OF LTG AND COOLING OF IR CLOUD-TOP
   TEMPS OVER PAST FEW HOURS.  SOME OF THIS ACTIVITY MAY POSE RISK FOR
   DAMAGING GUSTS...ESPECIALLY FROM SMALL BOWS/LEWPS...OR A TORNADO
   TODAY WHILE MOVING INLAND CLOSE TO COAST.  MRGL-SVR OUTLOOK HAS BEEN
   SHIFTED AWAY FROM SMALL/CENTRAL CORE REGION OF THIS CYCLONE...WHERE
   MORE STRATIFORM PRECIP STRUCTURE AND WEAKER INSTABILITY HAS BEEN
   OBSERVED AND SHOULD CONTINUE. 

   REF LATEST NHC ADVISORIES FOR TRACK/INTENSITY PREDICTIONS AND LATEST
   WATCH/WARNING INFO REGARDING ANA.

   ..EDWARDS/GLEASON.. 05/10/2015

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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