Mar-20-2005 1300 UTC Day 1 Convective Outlook
Updated: Sun Mar 20 12:44:02 UTC 2005
Categorical Graphic
20050320 1300 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20050320 1300 UTC Day 1 Tornado Probabilities Graphic
Probabilistic Damaging Wind Graphic
20050320 1300 UTC Day 1 Damaging Wind Probabilities Graphic
Probabilistic Large Hail Graphic
20050320 1300 UTC Day 1 Large Hail Probabilities Graphic
   SPC AC 201240
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   0640 AM CST SUN MAR 20 2005
   
   VALID 201300Z - 211200Z
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 4BK 50 ESE CEC 50 ESE
   MHS 30 ESE FAT 35 SW FAT MRY.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 ENE BLI 20 SE SEA
   15 SSE ONP.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 30 E CRP 15 NW SAT 50
   NE JCT 40 ESE CDS 55 W GAG 35 SE LHX 35 W TAD 10 NW 4SL 60 NNE IGM
   25 NNE DRA TPH 35 NE LOL 45 NE WMC 30 WSW GEG 30 ENE 63S 40 W FCA 20
   NE BTM 30 SE JAC 25 E RKS 20 NNW CYS 40 ENE SNY 35 N EAR 30 WNW JLN
   40 N TXK 35 SW GWO 20 W 0A8 20 SW CEW.
   
   ...NO SVR TSTM AREAS FORECAST...
   
   ...LOWER MS RIVER VALLEY ACROSS THE CENTRAL GULF COAST...
   MCV FROM OVERNIGHT MCS IS WELL DEFINED OVER S-CENTRAL LA AT
   12Z...WITH ARCING LINE OF THUNDERSTORMS EXTENDING WELL INTO THE WRN
   GULF OF MEXICO.  THOUGH MCV WILL LIKELY REMAIN WELL DEFINED AND
   SHIFT EWD ACROSS THE CENTRAL GULF COAST THIS MORNING AND EARLY THIS
   AFTERNOON...QUALITY OF BOUNDARY LAYER AIR REMAINS RATHER
   QUESTIONABLE.  SYSTEM APPEARS TO BE TRACKING EWD FASTER THAN
   PRECEEDING SSELY SURFACE WINDS CAN BRING MODIFIED GULF AIR NWD INTO
   THE CENTRAL GULF COAST STATES THIS MORNING.  EXPECT ONGOING
   THUNDERSTORMS WILL UNDERGO FURTHER WEAKENING AS A RESULT. 
   HOWEVER...WITH SOME HEATING AND ADVECTION OF 60+F SURFACE DEW POINTS
   ALONG AND JUST INLAND FROM THE CENTRAL GULF COAST... THUNDERSTORMS
   MAY DEVELOP AGAIN NEAR THE MCV LATER THIS MORNING.  IN
   FACT...MODIFIED 12Z SOUNDING FROM SIL /USING SURFACE TEMP AROUND 70F
   AND DEW POINT NEAR 60F/ INDICATES LARGE HAIL WILL REMAIN POSSIBLE
   SHOULD SUFFICIENT CLEARING OCCUR IN WAKE OF MORNING STORMS...GIVEN
   STEEP MID LEVEL LAPSE RATES.  AREA MAY NEED UPGRADE TO SLGT RISK
   LATER THIS MORNING IF IT BECOMES APPARENT AIR MASS WILL INDEED
   RECOVER.
   
   ...ERN TX INTO SWRN KS/NWRN OK... 
   STRONG MID/UPPER LEVEL JET WILL SPREAD INTO CENTRAL TX LATER TONIGHT
   ASSOCIATED WITH UPPER TROUGH EXPECTED TO DEEPEN OVER THE CENTRAL/SRN
   HIGH PLAINS.  IN RESPONSE...SURFACE CYCLOGENESIS WILL OCCUR OVER
   SERN CO WITH A DRY LINE/TROUGH EXPECTED TO BECOME WELL DEFINED FROM
   THE LOW SSEWD INTO WRN OK AND NWRN/CENTRAL TX BY LATER TODAY.  EAST
   OF THIS BOUNDARY...SLY LOW LEVEL WINDS WILL INCREASE ACROSS THE SRN
   PLAINS.  HOWEVER...EXTENSIVE COLD POOL FROM MCS OVER THE WRN GULF OF
   MEXICO WILL HINDER GULF MOISTURE RETURN ACROSS THE REGION FOR MUCH
   OF THE DAY.  THUS...BOUNDARY LAYER MOISTURE WILL REMAIN RATHER
   SPARSE WITH DEW POINTS AOB 50F EXPECTED NORTH OF THE RED RIVER
   VALLEY.  DESPITE THIS...MODEST HEATING AND VERY COLD MID LEVEL
   TEMPERATURES SUGGEST LAPSE RATES WILL STEEPEN SUFFICIENTLY FOR
   MARGINAL INSTABILITY ALONG AND EAST OF THE DRY LINE THIS AFTERNOON. 
   SHOULD STORMS FORM THIS AFTERNOON...ACTIVITY WILL LIKELY REMAIN
   QUITE ISOLATED WITH AN ATTENDANT THREAT OF MARGINALLY SEVERE
   HAIL/WIND.  ELEVATED THUNDERSTORMS APPEAR MORE LIKELY FROM
   CENTRAL/ERN KS AND OK INTO NERN TX AFTER DARK AS SLY LLJ STRENGTHENS
   ABOVE STABLE BOUNDARY LAYER.  STRONGER STORMS MAY PRODUCE HAIL DUE
   TO THE STEEP MID LEVEL LAPSE RATES AND MODEST CLOUD-LAYER SHEAR. 
   GIVEN QUESTIONABLE MOISTURE AND INSTABILITY...OVERALL THREAT LEVEL
   REMAINS BELOW A SLGT ATTM.
   
   ...NRN/CENTRAL CA...
   MID LEVEL TEMPERATURES WILL REMAIN QUITE COLD ACROSS THE REGION
   TODAY...AS STRONG UPPER TROUGH SHIFTS EWD INTO THE PAC NW.  ONGOING
   STORMS EARLY THIS MORNING HAVE PRODUCED HAIL...AND ADDITIONAL
   DEVELOPMENT CAN BE EXPECTED LATER THIS AFTERNOON AS HEATING STEEPENS
   LAPSE RATES.  THOUGH INSTABILITY WILL REMAIN MARGINAL...STRONGER
   CELLS WILL REMAIN CAPABLE OF HAIL APPROACHING SEVERE LEVELS.
   
   ..EVANS/CROSBIE.. 03/20/2005
   
   ...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.
   
   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1630Z