Apr 22, 2010 1630 UTC Day 1 Convective Outlook
Updated: Thu Apr 22 16:30:16 UTC 2010
Probabilistic to Categorical Outlook Conversion Table
Categorical Graphic
20100422 1630 UTC Day 1 Outlook Graphic
Probabilistic Tornado Graphic
20100422 1630 UTC Day 1 Tornado Probabilities Graphic
Torndao Legend Image
Probabilistic Damaging Wind Graphic
20100422 1630 UTC Day 1 Damaging Wind Probabilities Graphic
Wind Legend Image
Probabilistic Large Hail Graphic
20100422 1630 UTC Day 1 Large Hail Probabilities Graphic
Hail Legend Image
   SPC AC 221627
   
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1127 AM CDT THU APR 22 2010
   
   VALID 221630Z - 231200Z
   
   ...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT FOR
   PARTS OF THE SRN/CENTRAL PLAINS...
   
   ...CENTRAL/SRN PLAINS THROUGH TONIGHT...
   A STRONG MIDLEVEL LOW CENTERED NEAR LAS VEGAS WILL MOVE SLOWLY EWD
   THROUGH EARLY FRIDAY...AS AN EMBEDDED SPEED MAX ROTATES AROUND THE
   LOW /FROM THE NRN GULF OF CA/ AND EJECTS NEWD TOWARD THE SRN HIGH
   PLAINS.  THE APPROACH OF THIS EMBEDDED SHORTWAVE TROUGH TONIGHT WILL
   CONTRIBUTE TO DEEPENING OF THE LEE CYCLONE NOW IN SE CO.  S/SE OF
   THE LEE CYCLONE...THE DRYLINE WILL BECOME BETTER DEFINED THIS
   AFTERNOON/EVENING FROM EXTREME SE CO/SW KS SWD ACROSS THE CENTRAL TX
   PANHANDLE TO W CENTRAL TX.  OVERNIGHT...A PACIFIC COLD FRONT /NOW IN
   CENTRAL NM/ WILL SURGE EWD WITH THE EJECTING SHORTWAVE TROUGH AND
   OVERTAKE THE DRYLINE ACROSS THE TX PANHANDLE AND W TX.
   
   A MARGINAL HAIL THREAT WILL CONTINUE THROUGH THE DAY WITH ELEVATED
   CONVECTION N OF THE WARM FRONT INTO E CENTRAL/SE KS.  FARTHER
   W/SW...THE WEAK ELEVATED CONVECTION NOW OVER SW KS AND SW OK/NW TX
   WILL MOVE AWAY FROM THE DRYLINE IN CONJUNCTION WITH A WEAK LEAD
   SHORTWAVE TROUGH.  SURFACE HEATING WILL INCREASE IN THE WAKE OF THIS
   CONVECTION AS STRATUS CLOUDS BEGIN TO ERODE FROM W TO E...WHILE
   BOUNDARY LAYER DEWPOINTS OF 60-65 F SPREAD NWD FROM CENTRAL/NW TX
   TOWARD THE TX PANHANDLE AND WRN OK /56-60 F DEWPOINTS ARE EXPECTED
   FARTHER NW INTO KS/.  12Z OBSERVATIONS AND MODEL FORECAST SOUNDINGS
   SUGGEST THAT SURFACE TEMPERATURES OF 75-80 F ALONG THE DRYLINE WILL
   REMOVE CONVECTIVE INHIBITION AND CONTRIBUTE TO MLCAPE RANGING FROM
   1500 J/KG IN WRN KS TO 2500 J/KG NEAR THE TX/OK BORDER.  AT LEAST
   ISOLATED THUNDERSTORM DEVELOPMENT IS EXPECTED ALONG THE CENTRAL TX
   PANHANDLE/SW KS DRYLINE BY ABOUT 21-22Z.  GIVEN THE PRESENCE OF
   MODERATE INSTABILITY AND INCREASING DEEP-LAYER VERTICAL
   SHEAR...SUPERCELLS ARE LIKELY.
   
   THE PRIMARY INITIAL SEVERE THREAT WILL BE ISOLATED VERY LARGE HAIL
   WITH SUPERCELLS ACROSS THE TX PANHANDLE...AND A COUPLE OF TORNADOES
   FARTHER N ALONG THE KS/CO BORDER AS STORMS MOVE OFF THE DRYLINE AND
   CROSS THE WARM FRONT.  THE TORNADO THREAT IS EXPECTED TO INCREASE
   TOWARD EVENING ACROSS THE ERN TX PANHANDLE AND WRN OK AS LOW-LEVEL
   MOISTURE SLOWLY INCREASES AND THE LLJ STRENGTHENS.  ANY SURVIVING
   DISCRETE STORMS FROM LATE AFTERNOON WILL HAVE THE POTENTIAL TO
   PRODUCE AN ISOLATED STRONG TORNADO NEAR SUNSET /OR JUST AFTER/ AS
   SRH INCREASES AND INSTABILITY REMAINS BASED AT THE SURFACE WITH
   RELATIVELY SMALL CONVECTIVE INHIBITION.
   
   OVERNIGHT...A LINE OF THUNDERSTORMS IS EXPECTED TO DEVELOP ACROSS W
   TX AS THE COLD FRONT OVERTAKES THE DRYLINE.  THESE STORMS WILL MOVE
   QUICKLY EWD/NEWD TOWARD CENTRAL/NW TX AND WRN/CENTRAL OK LATE
   TONIGHT.  THE STRONGEST STORMS WILL BE CAPABLE OF PRODUCING LARGE
   HAIL/DAMAGING WINDS...WHILE A TORNADO OR TWO WILL BE POSSIBLE WITH
   EMBEDDED SUPERCELL STRUCTURES.  
   
   ...SE NEW ENGLAND THIS AFTERNOON...
   SCATTERED THUNDERSTORMS WILL LIKELY FORM ALONG A WEAK SURFACE COLD
   FRONT...AND IN ADVANCE OF A WEAK MIDLEVEL WAVE MOVING EWD FROM NY. 
   STEEP LOW-MIDLEVEL LAPSE RATES AND COLD TEMPERATURES ALOFT MAY
   PROMOTE THE FORMATION OF SMALL HAIL...BUT SEVERE STORMS ARE NOT
   EXPECTED GIVEN WEAK VERTICAL SHEAR AND POOR LOW-LEVEL MOISTURE.
   
   ..THOMPSON/ROGERS.. 04/22/2010
   
   CLICK TO GET WUUS01 PTSDY1 PRODUCT

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