DAY 3 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0214 AM CDT FRI APR 12 2013

VALID 141200Z - 151200Z

...NO SVR TSTM AREAS FORECAST...

...CENTRAL PLAINS/MID MS VALLEY...

SIGNIFICANT MID LEVEL SPEED MAX IS EXPECTED TO EJECT ACROSS NRN CO
INTO THE UPPER GREAT LAKES LATE SUNDAY AS UPSTREAM HEIGHTS FALL
ACROSS THE INTERIOR NWRN U.S. REASONABLE CONSISTENCY EXISTS AMONG
THE ECMWF/GFS/NAM REGARDING THE PLACEMENT OF ASSOCIATED COLD FRONT
AT 21Z WITH A POSITION FROM SRN MN...ARCING SWD ACROSS WRN IA THEN
SWWD ACROSS KS INTO THE OK PANHANDLE. WHILE BOUNDARY LAYER IS NOT
EXPECTED TO BE PARTICULARLY MOIST...AT LEAST FOR MID APRIL...A
NARROW AXIS OF LOWER 50S SFC DEW POINTS MAY ADVECT JUST AHEAD OF THE
BOUNDARY SUCH THAT AFTERNOON HEATING WOULD YIELD 500-1000 J/KG
ACROSS NRN MO/SRN IA WITH UPWARDS OF 2000 J/KG POSSIBLE OVER NWRN
OK/SCNTRL KS...IF DEW POINTS CAN RISE INTO THE UPPER 50S. IT/S NOT
ENTIRELY CLEAR WHETHER UPPER 50S WILL VERIFY BUT FRONTAL CONVERGENCE
AND STEEP LAPSE RATES SHOULD PROVE ADEQUATE FOR A FORCED BAND OF
CONVECTION ALONG COLD FRONT. DEEP LAYER SHEAR WILL PROVE FAVORABLE
FOR ORGANIZATION AND HAIL/WIND MAY BE NOTED WITH STRONGEST ACTIVITY.
SEVERE PROBS MAY NEED TO BE ADJUSTED UPWARD ALONG THE COLD FRONT IF
BOUNDARY LAYER MOISTURE/INSTABILITY DO INDEED RETURN AS A FEW MODELS
SUGGEST.


...GULF COAST/FL PENINSULA...

LOW LATITUDE SHORT WAVE TROUGH WILL EJECT ACROSS THE GULF BASIN INTO
GA/FL BY 15/12Z. THIS FEATURE WILL INDUCE A CONSIDERABLE AMOUNT OF
CONVECTION IMMEDIATELY DOWNSTREAM WITHIN BROAD ZONE OF WARM
ADVECTION. LLJ IS EXPECTED TO INCREASE AND FOCUS ACROSS THE LOWER
MS VALLEY EARLY IN THE PERIOD THEN TRANSLATE INTO GA DURING THE
OVERNIGHT HOURS. IF MARITIME TROPICAL AIRMASS IS ABLE TO ADVANCE
INLAND AN ENHANCED RISK OF SEVERE TSTMS...INCLUDING EMBEDDED
SUPERCELLS AND THEIR ATTENDANT WIND/TORNADO THREATS...MAY BE NOTED.
AT THIS TIME CONSIDERABLE UNCERTAINTY EXISTS REGARDING
DESTABILIZATION GIVEN THE EXPECTED WIDESPREAD
CONVECTION/PRECIPITATION.

THE MOST LIKELY AREA OF STRONG BOUNDARY LAYER HEATING WILL BE ACROSS
THE CNTRL FL PENINSULA WELL AHEAD OF THE INFLUENCE OF UPPER TROUGH.
STRONG/POSSIBLY SEVERE DIURNALLY DRIVEN TSTMS ARE EXPECTED ACROSS
THIS PORTION OF FL WITH STRONGER FORCED ACTIVITY MOVING ACROSS THE
FL PANHANDLE/NRN PENINSULA. AS NOTED ABOVE...SEVERE PROBS ARE
PREDICATED ON THE UNCERTAINTY OF AIRMASS DESTABILIZATION.

..DARROW.. 04/12/2013

DAY 4-8 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0350 AM CDT FRI APR 12 2013

VALID 151200Z - 201200Z

CORRECTED FOR SEVERE THREAT DAYS 5 AND 6

...DISCUSSION...
LOW LEVEL TRAJECTORIES WILL BECOME MORE FAVORABLE EARLY NEXT WEEK
FOR MOISTURE TO ADVANCE NWD ACROSS THE WRN GULF BASIN INTO THE SRN
PLAINS AS UPPER TROUGHING SETTLES OVER THE WRN U.S. ONE SIGNIFICANT
LEAD SHORTWAVE TROUGH WILL FORCE A SFC FRONT INTO OK MONDAY AND DEEP
CONVECTION MAY DEVELOP. HOWEVER...IN THE ABSENCE OF LARGE SCALE
FORCING THIS ACTIVITY SHOULD REMAIN ISOLATED. OF POTENTIALLY MORE
SIGNIFICANCE WILL BE THE CONTINUED MOISTENING THAT SHOULD LEAD TO
MORE ROBUST ORGANIZED SEVERE TSTMS TUESDAY. LATEST MODEL GUIDANCE
SUGGEST SCATTERED SEVERE STORMS SHOULD EVOLVE NEAR A DRYLINE/FRONTAL
INTERSECTION WITHIN BROAD STRONG SWLY FLOW ALOFT. PROGRESSION OF
UPPER TROUGH INTO THE HIGH PLAINS WEDNESDAY SUPPORTS AN EWD SHIFT OF
STRONG/SEVERE THUNDERSTORMS DURING THE DAY5 PERIOD FROM PORTIONS OF
MO INTO NERN TX.

..DARROW.. 04/12/2013

DAY 4-8 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0330 AM CDT TUE APR 02 2013

VALID 051200Z - 101200Z

...DISCUSSION...
...FLORIDA AND SRN GA FRI/D4...
MODELS CONTINUE TO BE IN DISAGREEMENT WITH THE SPEED OF A SHORTWAVE
TROUGH THAT WILL MOVE ACROSS THE GULF COAST AND SERN STATES ON
FRI/D4. THE GFS CONTINUES TO BE MUCH FASTER WHILE THE ECMWF AS WELL
AS NAM MOVE THE SYSTEM SLOWER. WHILE THE SLOWER SOLUTION IS
PREFERRED...PREDICTABILITY REMAINS TOO LOW FOR A 96 HR OUT SEVERE
AREA. THE FASTER SOLUTION WOULD SUGGEST A THREAT OF SEVERE STORMS
THURSDAY NIGHT INTO EARLY FRIDAY...WHILE THE SLOWER SOLUTION
INDICATES A SEVERE THREAT ON FRIDAY. CONDITIONALLY...A DAMAGING
SQUALL LINE APPEARS POSSIBLE...ALONG WITH A FEW QLCS TORNADOES. THE
GREATEST THREAT AREA WOULD BE CNTRL AND NRN FL...PERHAPS INTO FAR
SRN GA...CLOSER TO THE SURFACE LOW TRACK AND WHERE THE STRONGEST
FORCING FOR ASCENT WILL BE. HOWEVER...WIND DAMAGING POTENTIAL COULD
EXTEND INTO FAR SRN FL AS WELL.

...CNTRL/SRN PLAINS MON/D7...
DESPITE SHORT TERM DISCREPANCIES...MODELS ARE IN GOOD AGREEMENT
DEVELOPING A WRN TROUGH...AND EJECTING A LEADING SHORTWAVE INTO THE
PLAINS ON MON/D7. THE GFS IS QUICKER TO BRING MID 60S F DEWPOINTS
INTO OK BY MON...SUGGESTING AN UNBROKEN FETCH FROM THE GULF...WHILE
THE ECMWF MIXES DEWPOINTS INTO THE UPPER 50S TO PERHAPS LOWER 60S.
REGARDLESS...IF THE SPEED OF THE TROUGH HOLDS TRUE...A DRYLINE
SUPERCELL EVENT WILL OCCUR WITH TORNADOES AND VERY LARGE HAIL.
TORNADO DAMAGE POTENTIAL WILL DEPEND HEAVILY ON BOUNDARY LAYER
MOISTURE MAGNITUDE AS STEEP MID TO UPPER LEVEL LAPSE RATES AND SHEAR
PROFILES WILL BOTH FAVOR SIGNIFICANT SEVERE. HOWEVER...GIVEN
MOISTURE QUALITY QUESTIONS...TIMING OF PRIMARY SHORTWAVE TROUGH AND
RELATIVELY SMALL THREAT AREA...NO AREA WILL BE OUTLINED AT THIS
TIME.

...SRN PLAINS INTO LOWER MS VALLEY TUE/D8...
MODELS AGREE MOISTURE WILL CONTINUE TO INCREASE WITH MID TO UPPER
60S F DEWPOINTS LIKELY AS FAR N AS ERN OK/AR BY TUE. WHILE SWLY FLOW
ALOFT WILL REMAIN...RESULTING IN FAVORABLE SHEAR FOR
SUPERCELLS...PREDICTABILITY DECREASES ESPECIALLY IN TERMS OF
POTENTIAL FORCING MECHANISMS. THE GFS SHOWS A FEATURE WHICH COULD
RESULT IN AN OUTBREAK OF SEVERE WEATHER ACROSS THE ARKLATEX
REGION...WHILE THE ECMWF INDICATES RISING HEIGHTS WITH THE MAIN
TROUGH DIGGING SWD OVER THE SWRN CONUS.

..JEWELL.. 04/02/2013