Skip Navigation Links www.nws.noaa.gov 
NOAA logo - Click to go to the NOAA homepage National Weather Service   NWS logo - Click to go to the NWS homepage
Storm Prediction Center
 
   

Search SPC
 

May-12-2004 1630 UTC Day 1 Convective Outlook
Categorical Graphic
1630 UTC Day 1 Outlook Graphic
      
Probabilistic Graphics (more info)
Tornado Damaging Wind Large Hail
1630 UTC Tornado probabilities graphic   1630 UTC Damaging wind probabilities graphic   1630 UTC Large hail probabilities graphic
(Select thumbnails to view full images)
   SPC AC 121622
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1122 AM CDT WED MAY 12 2004
   
   VALID 121630Z - 131200Z
   
   THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 70 NW
   ANJ 30 WNW MKE 20 W UMN 15 SW TUL 30 NNE OKC 15 NE FSI 20 WNW LTS
   GAG 10 WNW LBL 15 SSW LAA 30 E COS 35 ENE DEN 30 NW AKO 30 N GLD 50
   W CNK 35 ENE OMA 25 N FRM 35 ESE INL.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 NE CRP 20 S LRD.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 E MSS 10 WNW MPV
   LCI PSM.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 S P07 15 ENE BGS
   40 SW CDS 60 SW GAG 45 SSE LBL 20 NE CAO 10 ENE RTN 55 N 4SL 45 SW
   CEZ 20 W ENV 40 S OWY 35 NW OWY 45 SSW BOI 50 NE BOI 65 WSW 27U 30
   WNW DLN 40 NNE WEY 20 ENE CPR BFF 10 NE LBF 15 NE BUB 35 NNE SUX 40
   NNW RWF 35 SSW BJI 25 NE RRT.
   
   GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 SSE JAX 45 SSE
   CTY.
   
   ...THERE IS A SLGT RISK OF SVR TSTMS WRN GREAT LAKES SWWD TO
   CENTRAL/SRN PLAINS...
   
   ...SYNOPSIS...
   LARGE SCALE TROUGH REMAINS OVER WRN U.S. THIS FORECAST PERIOD. 
   OVERNIGHT S/WV IMPULSE HAS ROTATED NEWD INTO PLAINS AND WILL
   CONTINUE INTO SRN CANADA THIS AFTERNOON. AN ASSOCIATED SURFACE LOW
   MN WILL ALSO MORE NEWD AND WEAKEN AS STRONG COLD FRONT CONTINUES EWD
   REACHING WRN GREAT LAKES SWWD TO VICINITY MKC BY THIS EVENING.
   
   ANOTHER S/W TROUGH MOVES EWD ACROSS SRN ROCKIES THROUGH BOTTOM OF
   MAJOR TROUGH THIS AFTERNOON. IN RESPONSE TO APPROACH OF THIS
   FEATURE...SURFACE LOW DEEPENS LEE OF SRN CO/NRN NM ROCKIES .  COLD
   FRONT THAT HAS PUSHED SWD OVERNIGHT INTO NWRN TX PANHANDLE AND NERN
   NM SHOULD STALL WITH SURFACE DEEPENING.  DRY LINE EXTENDS SWD FROM
   FRONT THRU ERN TX PANHANDLE TO BIG BEND.
   
   
   ...CENTRAL/SRN PLAINS...
   
   SLY FLOW HAS CONTINUED TO INCREASE GULF MOISTURE TO THE POINT WHERE
   THERE IS POTENTIALLY A VERY UNSTABLE AIR MASS S OF COLD FRONT AND E
   OF DRY LINE. A SUBSTANTIAL CAP WILL DELAY INITIATION UNTIL LATER
   THIS AFTERNOON.  AS SURFACE LOW DEEPENS...SELY FLOW WILL INCREASE
   LOW LEVEL MOISTURE WWD INTO SERN CO.  THIS WILL LIKELY BE AREA OF
   INITIAL CONVECTIVE DEVELOPMENT WITH ADDITIONAL STORMS ALONG COLD
   FRONT KS AND DOWN THE DRY LINE VICINITY OK/TX BORDER.
   
   DEEP LAYER SHEAR OF 40-50 KT AND A VEERING HODOGRAPH IN THE SFC-1 KM
   LAYER..COUPLED WITH MLCAPES LIKELY IN EXCESS OF 3000 J/KG...SUPPORT 
   A SUPERCELL MODE OF STORMS.  PRIMARY THREAT WILL BE VERY LARGE HAIL
   HOWEVER AT LEAST ISOLATED TORNADOES ARE LIKELY IN AREAS OF ENHANCE
   LOW LEVEL CONVERGENCE AND SHEAR VICINITY DRY LINE AND COLD FRONT.
   
   AS LOW LEVEL JET INCREASES THIS EVENING AND CAP WEAKENS FURTHER WITH
   THE ASCENT PROVIDED BY APPROACHING S/WV TROUGH...SEVERE STORMS WILL
   CONTINUE DEVELOPING E/SE ACROSS KS AND WRN/NRN OK.
   
   FURTHER S ALONG THE DRY LINE AGAIN TODAY PULSE SEVERE EXPECTED TO BE
   THE MODE SWD TO TX BIG BEND.  COVERAGE SHOULD REMAIN ISOLATED.
   
   ...WRN GREAT LAKES/MID MS VALLEY...
   AIR MASS AHEAD OF COLD FRONT IS MODERATELY UNSTABLE AND WEAKLY
   CAPPED.  STORMS SHOULD DEVELOP EARLY THIS AFTERNOON ALONG AND AHEAD
   OF THE COLD FRONT.  WITH THE SURFACE LOW EXPECTED TO MOVE INTO
   CANADA AND WEAKEN AND THE MEAN WIND IN THE WARM SECTOR OF GENERALLY
   30KT...STORM MODE EXPECTED TO BE PRIMARILY MULTI-CELLULAR.  WITH
   MLCAPES AROUND 1500 J/KG AND FAVORABLE WET BULB ZERO LEVELS AROUND
   10K FEET...STRONGER STORMS EXPECTED TO PRODUCE LARGE HAIL AND
   ISOLATED DAMAGING WINDS DURING THE AFTERNOON/EVENING.
   
   ...LOWER MS VALLEY/GULF STATES...
   VERY MOIST AND MARGINALLY SHEARED AIRMASS THIS AREA WILL RESULT IN
   PULSE THUNDERSTORM MODE.  COVERAGE OF SEVERE EXPECTED TO BE ISOLATED
   GIVEN THE RATHER WEAK KINEMATICS..
   
   ..HALES/BOTHWELL.. 05/12/2004
   
   ...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 FOR 2000Z
        
Top/Latest Day 2 Outlook/Today's Outlooks/Forecast Products/Home