Sep 15, 2005 1630 UTC Day 1 Convective Outlook
Updated: Thu Sep 15 17:35:58 UTC 2005
Categorical Graphic
20050915 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20050915 1630 UTC Day 1 Tornado Probabilities Graphic
Probabilistic Damaging Wind Graphic
20050915 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Probabilistic Large Hail Graphic
20050915 1630 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 151602
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   ISSUED BY AFWA OFFUTT AIR FORCE BASE BELLEVUE NE
   1102 AM CDT THU SEP 15 2005
   
   VALID 151630Z - 161200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SSW
   ADM 10 NNE PGO 15 NNE JBR 35 W HOP 55 ESE BWG 20 WNW RMG 40 W JAN 55
   S SHV 35 SSE TPL 20 SE JCT 50 WSW SJT 25 NNE BGS 30 SSW ADM.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SSE P07 40 SSW MAF
   15 W CNM 30 N ROW 25 SSE CVS 55 ESE LBB 20 W FSI 20 SSW TUL 20 NNE
   SGF 10 NNW SPI 15 ENE AZO 65 SE OSC ...CONT... 25 SSW ILM 15 ESE RDU
   20 SE DAN 35 SSW PSK 20 ENE HSS 30 SW AHN 30 SSW CSG 60 SSW SEM 10
   WNW MCB 30 WSW 7R4 ...CONT... 30 SW PSX 50 NW LRD.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM MQT AUW MCW SPW 20 SW
   FSD 35 WNW HON 55 S Y22 15 ESE BZN 45 N FCA.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS PARTS OF TX INTO LOWER MS/TN
   VALLEY...
   
   ...SYNOPSIS...
   THE SRN BRANCH OF AN ACTIVE TWO-STREAM FLOW PATTERN WILL REMAIN THE
   MAIN PLAYER IN THIS PERIOD'S SEVERE WEATHER ACTIVITY.  HEIGHT FALLS
   ALONG THE W CST EXPECTED TO RESULT IN A REBOUND OF SUBTROPICAL RIDGE
   OVER THE SRN RCKYS.  THIS...IN TURN...SHOULD INDUCE AMPLIFICATION OF
   DOWNSTREAM SHORTWAVE IMPULSE NOW OVER WRN PORTIONS OF THE CNTRL/SRN
   PLNS AS THE SYSTEM CONTINUES E/NE TO THE LWR OH/TN VLYS BY 12Z
   FRIDAY.  DEVELOPING SURFACE WAVE NOW IN ERN OK /PARTIALLY MASKED BY
   RECENT CONVECTIVE OUTFLOW/ IS LINKED TO THE PLAINS SHORTWAVE TROUGH.
    THE WAVE SHOULD REDEVELOP E TO THE NE AR/W TN AREA THIS
   AFTERNOON...AND NE INTO THE OH VLY TONIGHT.
     
   ...OK/NE TX INTO LWR TN VLY....
   COUPLED JET STRUCTURE AND UPPER LEVEL DIFFLUENCE ASSOCIATED WITH
   AFOREMENTIONED SHORTWAVE IMPULSE EXPECTED TO KEEP WIDESPREAD AREA OF
   CONVECTION/STORMS NOW OVER OK/NRN AR AND SRN MO MOVING GENERALLY
   E/NE TODAY.  SURFACE HEATING SHOULD SUPPORT MODERATE DESTABILIZATION
   OF REGION ON SRN/ERN PERIPHERY OF COMPLEX CONVECTIVE SYSTEM...WITH
   MUCAPE RANGING FROM 1000 TO PERHAPS 2000 J/KG FROM SE OK/NE TX
   ACROSS SRN AR INTO W TN.
     
   THE STRONGEST LOW LEVEL CONVERGENCE SHOULD SHIFT E/NE INTO ERN AR/W
   TN THIS AFTERNOON AS LOW LEVEL FLOW CONTINUES TO VEER AND SURFACE
   WAVE REDEVELOPS ENEWD. WHILE MID LEVEL TEMPERATURES WILL REMAIN
   FAIRLY WARM...30-40 KT DEEP WSWLY SHEAR SHOULD SUPPORT A FEW
   BANDS/CLUSTERS OF SUSTAINED AFTERNOON/EARLY EVENING STORMS. 
   EMBEDDED BOWING SEGMENTS MAY YIELD LOCALLY DAMAGING WIND AND PERHAPS
   MARGINALLY SEVERE HAIL...ESPECIALLY OVER NE AR...WRN PORTIONS OF
   TN/KY AND POSSIBLY NRN MS.  THE STORMS SHOULD WEAKEN LATER THIS
   EVENING AS FORCING FOR ASCENT/STRONGEST SHEAR MOVE BEYOND LOW LEVEL
   INSTABILITY AXIS.
     
   ...NWRN/CNTRL TX...
   DEGREE OF LARGE SCALE FORCING FOR ASCENT APPEARS MORE NEBULOUS ATTM
   FOR NW/N CNTRL TX TODAY AS MAIN SRN BRANCH IMPULSE AMPLIFIES ENEWD. 
   NEAR THE SURFACE...HOWEVER...VERY MOIST/SOMEWHAT CONFLUENT
   FLOW WILL CONTINUE TO IMPINGE UPON WEAKENING COLD FRONTAL SURGE NOW
   NEAR CDS.  A SUBSTANTIAL CAP WILL REMAIN PRESENT...ESPECIALLY WITH
   WWD EXTENT ACROSS THE STATE.  BUT GIVEN FAIRLY STRONG DIURNAL 
   HEATING...BOUNDARY LAYER CONVERGENCE MAY BE SUFFICIENT TO SUPPORT
   TSTM INITIATION BY LATE AFTERNOON FROM NEAR ABI/BGS NEWD TO NEAR
   SEP/MWL.
     
   MODEST DEEP SHEAR WITH A SIGNIFICANT DIRECTIONAL COMPONENT...
   COUPLED WITH STRONG INSTABILITY /MUCAPE TO 2000 J PER KG/...MAY
   SUPPORT A FEW ROTATING STORMS WITH AN ENHANCED THREAT FOR
   HAIL/DAMAGING WIND.  CONCENTRATED AREA OF DEVELOPMENT AND DRY AIR
   ALOFT SUGGEST DECENT POTENTIAL FOR COLD POOL DEVELOPMENT...WITH
   RESULTING CLUSTER LIKELY TO MOVE GENERALLY ESE ACROSS CNTRL TX
   TONIGHT/EARLY FRIDAY.
     
   ...ERN NM/W TX...
   ESELY POST-FRONTAL UPSLOPE FLOW WILL BEAR WATCHING FOR CONVECTIVE
   INITIATION W OF THE CAP ROCK FROM THE TX S PLNS WWD INTO ERN NM. 
   WARMING MID LEVEL TEMPERATURES AND ABSENCE OF LARGE SCALE FORCING
   FOR ASCENT SHOULD...HOWEVER...KEEP ANY SUCH DEVELOPMENT QUITE
   ISOLATED.  IF STORMS DO FORM...DEEP SHEAR WILL BE FAVORABLE FOR
   SUSTAINED SUPERCELLS.
     
   ...NRN MID ATLANTIC/NEW ENG...
   LOW AMPLITUDE SHORT WAVE TROUGH...IN CONJUNCTION WITH ENHANCED DEEP
   SHEAR/TROPICAL INFLOW ASSOCIATED WITH CONFLUENCE BAND DOWNSTREAM
   FROM HRCN OPHELIA...WILL CREATE ENVIRONMENT FAVORABLE FOR A FEW
   STRONG STORMS IN THE SRN NEW ENG/NRN MID ATLANTIC REGION TODAY. 
   HEATING SHOULD BOOST MUCAPE TO AROUND 1500 J/KG BY THIS
   AFTERNOON...BUT WEAK LAPSE RATES SHOULD LIMIT ANY FURTHER
   DESTABILIZATION.  NEVERTHELESS...MODERATE UNIDIRECTIONAL SWLY FLOW
   WITH 30+ KT DEEP SHEAR...POSSIBLE DRY AIR IN THE 850-700 LAYER /PER
   CHH RAOB/...SUGGEST THAT SOME RISK WILL EXIST FOR GUSTY WINDS AND
   POSSIBLY SMALL HAIL IN SOME STORMS.
     
   ...NC/VA/SRN DELMARVA CST...
   PROXIMITY OF HURRICANE OPHELIA WILL CONTINUE TO PROVIDE AT LEAST
   SOME RISK FOR AN ISOLATED TORNADO OR DAMAGING CONVECTIVE GUST 
   TODAY.
   
   ..AFWA.. 09/15/2005
   
   ...NOTICE...
   FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
   LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
   GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
   HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
   INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 2000Z