DAY1SVR: Day 1 Convective Outlook

ACUS01 KWNS 121959
SWODY1
SPC AC 121957

DAY 1 CONVECTIVE OUTLOOK
NWS STORM PREDICTION CENTER NORMAN OK
0257 PM CDT SUN MAY 12 2013

VALID 122000Z - 131200Z

...NO SVR TSTM AREAS FORECAST...

...20Z UPDATE...
LITTLE OR NO CHANGES TO PRIOR OUTLOOK REASONING/LINES...SEE
PREVIOUSLY ISSUED /1630Z/ OUTLOOK DISCUSSION BELOW.

ACROSS THE FL PENINSULA...A FEW STRONG/POSSIBLY ISOLATED SEVERE TSTM
WILL REMAIN POSSIBLE THROUGH LATE AFTERNOON AS STORMS DRIFT EASTWARD
ACROSS ROUGHLY THE EASTERN HALF OF THE FL PENINSULA AMID WEAK
WESTERLY FLOW...ASIDE FROM AN IMMEDIATE EAST-COASTAL SEA BREEZE.

ACROSS THE SOUTH-CENTRAL HIGH PLAINS...OBSERVATIONAL/SHORT-TERM
GUIDANCE TRENDS STILL SUGGEST THAT HIGH-BASED TSTM DEVELOPMENT IS
STILL PLAUSIBLE LATE THIS AFTERNOON/EARLY EVENING NEAR/EAST OF A
SURFACE TROUGH/SURFACE LOW CURRENTLY LOCATED ACROSS FAR SOUTHWEST
KS/OK PANHANDLE. SUCH DEVELOPMENT STILL APPEARS MOST PROBABLE ACROSS
SOUTHWEST KS/TX PANHANDLE/FAR WESTERN OK BETWEEN 21Z-00Z.
CONTEMPORARY MODIFICATIONS TO THE 12Z OBSERVED DODGE CITY SOUNDING
SUGGEST THAT MLCAPE IS ONLY A FEW HUNDRED J/KG...BUT STEEP LAPSE
RATES/SUFFICIENT SHEAR IN CONJUNCTION WITH OBSERVED 30-40F SURFACE
TEMP-DEWPOINT DELTAS MAY SUPPORT LOCALIZED SEVERE HAIL/DOWNBURST
POTENTIAL AS ISOLATED TSTMS SPREAD SOUTH-SOUTHEASTWARD.

..GUYER.. 05/12/2013

.PREV DISCUSSION... /ISSUED 1124 AM CDT SUN MAY 12 2013/

...FL...
SCATTERED STORMS SHOULD AGAIN DEVELOP ACROSS PORTIONS OF THE NRN AND
SERN PENINSULA TODAY AS WEAKLY CAPPED AIRMASS DESTABILIZES WITH
HEATING OF THE DAY. DESPITE WEAK/AMBIGUOUS FORCING ALOFT...GENERALLY
DIFLUENT MID/UPPER LEVEL FLOW AND RESIDUAL FRONTAL ZONE ACROSS NORTH
FL WILL SUPPORT STORM DEVELOPMENT AMIDST SBCAPE ON THE ORDER OF 1500
J/KG BY AFTERNOON. STRONGER SHEAR OVER NORTH FL WILL BE SOMEWHAT
DISPLACED FROM GREATER DESTABILIZATION FARTHER SOUTH AND EAST.
LOCALLY STRONG WIND GUSTS AND PERHAPS SOME HAIL WILL BE POSSIBLE AS
ACTIVITY INCREASES AND CONSOLIDATES ALONG THE FRONTAL AND SEABREEZE
BOUNDARIES BEFORE DIMINISHING AND/OR MOVING OFFSHORE THIS EVENING.
LATEST STORM-SCALE GUIDANCE IS CONSISTENT IN INDICATING GREATER
STORM COVERAGE OF MULTICELLULAR CHARACTER WILL EXIST ACROSS SERN FL
THROUGH THE LATE AFTERNOON. THIS SCENARIO ALSO SEEMS LIKELY GIVEN
LATEST CLOUD TRENDS IN VSBL SATL IMAGERY. HAIL TO 1 INCH AND GUSTY
TO DAMAGING WINDS WILL BE THE MAIN HAZARDS.

...OK/KS BORDER AND NERN TX PNHDL...
STEEP LOW TO MIDLEVEL LAPSE RATES WILL COMPENSATE FOR A RELATIVELY
DRY AIR MASS WITH SBCAPE VALUES APPROACHING 500 J/KG WITHIN
THERMAL/LEE TROUGH BY LATER THIS AFTERNOON. DAYTIME HEATING COUPLED
WITH LOW-LEVEL CONVERGENCE AND DIFLUENT FLOW ALOFT SHOULD AID
ISOLATED STORM INITIATION. FORECAST WIND PROFILES ARE CHARACTERIZED
BY LOW LEVEL SLYS TOPPED BY STRONGER NNWLY FLOW IN THE MID/UPPER
LEVELS RESULTING IN SUFFICIENT DEEP SHEAR FOR SOME STORM
ORGANIZATION/PERSISTENCE. IN ADDITION TO HAIL TO AROUND 1
INCH...HIGH-BASED NATURE OF THE CONVECTION AND DRY SUB-CLOUD AIRMASS
WILL CONTRIBUTE TO A LOCALIZED HIGH WIND HAZARD AROUND ANY STORMS
THAT DO DEVELOP.

...NERN ORE TO NCNTRL ID...
BREAKDOWN OF UPPER RIDGE WILL COMMENCE TODAY AND CONTINUE THROUGH
DAY 2 AS A SERIES OF PROGRESSIVELY STRONGER SHORTWAVE TROUGHS SPREAD
INLAND FROM THE NERN PAC. RELATIVELY HIGH PW VALUES IN EXCESS OF
0.75 INCHES ACROSS INTERIOR ORE AND NCNTRL ID WILL AID IN THE
DEVELOPMENT OF MODEST SBCAPE PERHAPS AROUND 500 J/KG WITH HEATING OF
THE DAY. IF CONVECTIVE INHIBITION CAN BE OVERCOME THROUGH HEATING
AND PERSISTENT LIFT ALONG PRE-FRONTAL TROUGH AXIS...A FEW TSTMS SEEM
POSSIBLE. STRENGTHENING MIDLEVEL FLOW WILL CONTRIBUTE TO ADEQUATE
SHEAR FOR AT LEAST ISOLATED STRONGER UPDRAFTS CAPABLE OF MARGINALLY
SEVERE HAIL AND PERHAPS STRONGER WINDS INTO THE EVENING.

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