samedi 12 avril 2014

Apr 12, 2014 0600 UTC Day 1 Convective Outlook

SPC AC 120535
   DAY 1 CONVECTIVE OUTLOOK  
   NWS STORM PREDICTION CENTER NORMAN OK
   1235 AM CDT SAT APR 12 2014

   VALID 121200Z - 131200Z

   ...THERE IS A SLGT RISK OF SVR TSTMS FROM CNTRL KS TO WRN SHORE OF
   SRN LAKE MI...

   ...CENTRAL PLAINS TO SRN LAKE MI...

   WEAK HEIGHT FALLS WILL DEVELOP ACROSS THE CNTRL PLAINS DURING THE
   DAY SATURDAY AS BIFURCATED WRN U.S. TROUGH ADVANCES INTO THE
   ROCKIES.  IN RESPONSE...LEE TROUGH SHOULD SHARPEN ACROSS KS/OK/TX
   SUCH THAT DRY LINE WILL MIX TO A POSITION NEAR MEDICINE LODGE
   KS...SWD TO EAST OF CHILDRESS TX.  

   EARLY IN THE PERIOD...STRONG LLJ SHOULD BE FOCUSED ACROSS THE UPPER
   MS VALLEY.  WARM ADVECTION IS EXPECTED TO DRIVE A CLUSTER OF
   ELEVATED CONVECTION SEWD ACROSS PORTIONS OF MN/WI/LOWER MI AS LLJ
   VEERS TOWARD LAKE HURON.  THIS ACTIVITY SHOULD REMAIN SUB-SEVERE IN
   THE ABSENCE OF MEANINGFUL INSTABILITY.

   NRN BRANCH OF THE AFOREMENTIONED TROUGH WILL DIG SEWD ACROSS THE NRN
   ROCKIES AND SFC PRESSURES ARE EXPECTED TO RISE ACROSS THE NRN PLAINS
   FORCING A PRE-FRONTAL WIND SHIFT TO NEAR I-70 OVER KS BY LATE
   AFTERNOON.  NEWD EXTENSION OF THIS BOUNDARY WILL STRETCH ACROSS SERN
   NEB/CNTRL IA SERVING AS THE FOCUS FOR POTENTIAL SEVERE THUNDERSTORMS
   INTO THE EVENING HOURS.

   LATEST THINKING IS INTENSE BOUNDARY LAYER HEATING WILL BE NOTED WEST
   OF THE DRY LINE AND CONVECTIVE TEMPERATURES SHOULD BE REACHED BY
   21-22Z.  ISOLATED HIGH BASED TSTMS ARE EXPECTED TO EVOLVE EAST OF
   THE DRY LINE...ESPECIALLY OVER KS WHERE FRONTAL CONVERGENCE SHOULD
   BE MAXIMIZED JUST EAST OF WEAK SFC LOW.  WHILE NAM CONTINUES TO BE
   QUITE AGGRESSIVE IN ADVANCING MOISTURE INLAND...SFC DEW POINTS HAVE
   RISEN TO NEAR 60F ACROSS SRN OK EARLY THIS MORNING AND THIS MOISTURE
   SHOULD SPREAD INTO PORTIONS OF CNTRL KS PRIOR TO CONVECTIVE
   INITIATION.  AS A RESULT...SBCAPE COULD EASILY EXCEED 3000 J/KG
   WITHIN A FAVORABLY SHEARED ENVIRONMENT FOR SUPERCELLS.  DIURNALLY
   DRIVEN CONVECTION MAY PRODUCE VERY LARGE HAIL INTO THE EARLY EVENING
   HOURS BUT A STOUT CAP WILL LIMIT EWD PROGRESSION OF THIS ACTIVITY. 
   PRIMARY TSTM THREAT AFTER DARK WILL FOCUS ALONG THE SW-NE FRONTAL
   ZONE ACROSS SERN NEB/IA WHERE WARM ADVECTION IS EXPECTED TO ENHANCE
   UVV.  IN ALL LIKELIHOOD PW VALUES WILL NOT INCREASE ABOVE ONE INCH
   ALONG THIS CORRIDOR AS DEPICTED BY NAM AND INSTABILITY SHOULD BE
   NEGATED A BIT BY DRIER DEW POINTS.

   LARGE HAIL IS THE PRIMARY SEVERE THREAT WITH SUPERCELLS AND DAMAGING
   WINDS COULD ALSO ACCOMPANY HIGH BASED UPDRAFTS AND MORE ORGANIZED
   CLUSTERS LATER IN THE EVENING.

   ..DARROW/ROGERS.. 04/12/2014

   CLICK TO GET WUUS01 PTSDY1 PRODUCT

   NOTE: THE NEXT DAY 1 OUTLOOK IS SCHEDULED BY 1300Z
   CURRENT UTC TIME: 1143Z (7:43AM), RELOAD THIS PAGE TO UPDATE THE TIME

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