ZCZC SPCSWODY1 ALL
ACUS01 KWNS 142005
SPC AC 142000

STORM PREDICTION CENTER...NWS/NCEP...NORMAN OK 
DAY 1 CONVECTIVE OUTLOOK...REF AWIPS GRAPHIC PGWE46 KWNS.

VALID 142000Z - 151200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM PNS
MSY BTR LFK CLL AUS 25 W BWD CDS CSM BVO JLN 40 SSE SZL SZL
25 NNE TOP MHK 35 NE RSL EAR OMA FOD 30 NNE RWF MSP CGX LUK LEX
BWG CKV MKL TUP 25 ENE 0A8 MGM CEW PNS.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM
35 NNW PIE 30 WNW ORL 15 SW MIA 50 NE EYW.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 ENE CTB LVM RIW
CYS IML GRI SUX FSD BKX AXN BRD RHI DTW HLG CRW 45 WNW GSO
40 E CRE ...CONT... 50 SE 7R4 LFT 55 SSW LFK 60 SSE DRT ...CONT...
20 SSW P07 SJT ABI 45 E LBB CVS 20 WNW DAG BFL 45 ENE MRY SAC LMT
70 NW FCA.

--- SYNOPSIS ---
PROGRESSIVE MIDDLE-UPPER LEVEL PATTERN WILL CONTINUE ACROSS CONUS
REMAINDER PERIOD.  EXPECT DEEP-TROPOSPHERIC LOW -- NOW INDICATED IN
MOISTURE CHANNEL AND PROFILER DATA OVER SW MN -- TO MOVE SEWD
TOWARD NERN IA/NWRN IL/SWRN WI REGION BY 15/12Z.  MINOR
PERTURBATIONS ARE EXPECTED TO MOVE ESEWD ACROSS SRN PLAINS AND SERN
CONUS IN SRN STREAM JET MAX S OF THAT LOW...AND DOWNSTREAM FROM
GREAT BASIN/SRN ROCKIES UPPER RIDGE.  MEANWHILE...STRONG SHORTWAVE
TROUGH AND EMBEDDED CYCLONIC CIRCULATION ALOFT ARE MOVING ONSHORE
CA COAST ATTM AND WILL CONTINUE EWD ACROSS SRN CA/AZ TONIGHT.  

AT SFC...SYNOPTIC WARM FRONT EXTENDS SEWD FROM SWRN MN
CYCLONE...ACROSS NWRN PORTIONS IA AND NRN IL...THEN SEWD ACROSS
INDIANA TO ERN KY.  THIS FRONT SHOULD LIFT NEWD REMAINDER
AFTERNOON/EVENING.  LOW LEVEL CONVERGENCE ZONE EVIDENT FROM WARM
FRONTAL INTERSECTION OVER S-CENTRAL MN...SWD ACROSS IA...SHOULD
PIVOT EWD THROUGH AFTERNOON.  FARTHER S...OUTFLOW-REINFORCED
FRONTAL ZONE EVIDENT FROM NW TX EWD NEAR RED RIVER...THEN ESEWD
ACROSS CENTRAL MS/SRN AL/WRN FL PANHANDLE...WILL REMAIN
QUASISTATIONARY FROM ARKLATEX EWD AND DRIFT SWD OVER N-CENTRAL TX. 
COMBINED HEAT LOW AND LEE CYCLONE -- ANALYZED ATTM JUST N ABI --
SHOULD MOVE ESEWD AS DEEP/INTENSE MIXING IN DRY SECTOR MOVES
DRYLINE EWD ACROSS NWRN/N-CENTRAL TX THIS AFTERNOON.  

--- SRN PLAINS TO ARKLATEX...LOWER MS VALLEY ---
SUPERCELLS WITH DAMAGING HAIL...TORNADOES AND DAMAGING WIND MAY
OCCUR THIS AFTERNOON INTO EARLY EVENING ARKLATEX REGION...WHERE
MODERATE-STRONG INSTABILITY WILL BE JUXTAPOSED WITH WEAKENING CAP
AND FRONTAL LIFT.  REF SPC WW 371 AND ACCOMPANYING MESOSCALE
DISCUSSIONS FOR NOWCAST GUIDANCE.  SEVERE TSTMS DEVELOPING THIS
AREA SHOULD EVOLVE INTO MCS WITH WIND DAMAGE AND LARGE HAIL
POTENTIAL...MOVING ESEWD PARALLEL TO AND INVOF FRONTAL ZONE TOWARD
LOWER MS VALLEY AREA.  

LOW LEVEL MOISTURE-FLUX CONVERGENCE AND MASS CONVERGENCE SHOULD
REMAIN MAXIMIZED INVOF FRONTAL ZONE FARTHER W ACROSS N TX AS WELL. 
TSTM DEVELOPMENT BECOMES MORE CONDITIONAL WITH WWD EXTENT BECAUSE
OF STRONG CAP -- EVIDENT BOTH IN MORNING FWD RAOB AND MODIFIED
MODEL SOUNDINGS FROM RUC/ETA-KF.  THIS WILL BE REINFORCED BENEATH
SHORTWAVE RIDGING BY ADVECTION OF ELEVATED MIXED-LAYER AIR EWD FROM
HIGHER TERRAIN.  HOWEVER...ANY CONVECTION WHICH DOES DEVELOP NEAR
OR W OF METROPLEX MAY BECOME SEVERE EXPLOSIVELY AMIDST 2500-3500
J/KG MLCAPE...67-72 F SFC DEW POINTS...8-9 DEG C/KM MIDLEVEL LAPSE
RATES AND 50-55 KT 0-6 KM AGL SHEAR.  DAMAGING HAIL/WIND ARE
POSSIBLE.

--- UPPER MS VALLEY...NERN PLAINS ---
WIDELY SCATTERED TSTMS IN CLUSTERS WILL CONTINUE INVOF WARM FRONT
ERN IA/NRN IL AND POSSIBLY EXPANDING INTO NRN MO...WRN INDIANA AND
NRN KY WITH TIME.  ISOLATED TO WIDELY SCATTERED SEVERE TSTMS ALSO
EXPECTED TO CONTINUE DEVELOPING FROM NEAR MO/IA BORDER NEWD ACROSS
IA INTO SRN MN...IN REGION OF STRONG MIDLEVEL COOLING AND SFC
DIABATIC HEATING.  -20 DEG C 500 MB TEMPS INDICATED WITH 8-8.5 DEG
C/KM MIDLEVEL LAPSE RATES AND SFC DEW POINTS MID-UPPER 50S
F...YIELDING MLCAPE 500-1000 J/KG.  DAMAGING WIND AND LARGE HAIL
ARE MAIN THREATS AMIDST GENERALLY UNIDIRECTIONAL DEEP-TROPOSPHERIC
FLOW...AS OBSERVED IN REGIONAL VWP/PROFILER DATA AND RUC FCST
SOUNDINGS.  A FEW BRIEF TORNADOES MAY OCCUR IN ARC OF CONVECTION
JUST S-E OF UPPER LOW...WHERE SUB-GRID SCALE BACKING AND
PERTURBATIONS INVOF CONVERGENCE LINES MAY BACK BOUNDARY LAYER FLOW
AND LOCALLY ENHANCE VERTICAL SHEAR PROFILES.  REF SPC WWS 369/370
AND RELATED MESOSCALE DISCUSSION FOR NEAR-TERM INFORMATION ON THIS
REGION.  

--- LOWER MS VALLEY TO CENTRAL GULF COAST ---
REF SPC WW 368 AND ASSOCIATED MESOSCALE DISCUSSIONS FOR LATEST
NOWCAST GUIDANCE CENTRAL/NRN MS.  THIS ACTIVITY MAY UNDERGO
WEAKENING TREND NEXT 2-3 HOURS...HOWEVER ADDITIONAL DEVELOPMENT
POSSIBLE ALONG ASSOCIATED OUTFLOW BOUNDARY SWD THROUGH MOIST SECTOR
TO GULF COAST SEA BREEZE.  WEAK LOW LEVEL FLOW WILL LIMIT SR INFLOW
AND VERTICAL SHEAR...HOWEVER DEEP-LAYER SHEAR SHOULD BE SUFFICIENT
TO SUPPORT THREAT OF SEVERE WIND/HAIL...PARTICULARLY WITH CELLS
MOVING ALONG OUTFLOW-REINFORCED WARM FRONT WHERE VORTICITY/LIFT ARE
ENHANCED.  
 
--- SRN/WRN FL PENINSULA -- 
WIDELY SCATTERED TO SCATTERED TSTMS WILL CONTINUE TO DEVELOP
ANOTHER 2-3 HOURS IN SEABREEZE CONVERGENCE ZONES -- PRIMARILY WRN
HALF OF PENINSULA.  ORGANIZED MULTICELLS POSSIBLE GIVEN THAT
MODIFIED RAOBS AND RUC2 FORECAST SOUNDINGS SHOW WEAK LOW LEVEL
FLOW...BUT 70-80 KT WINDS AT ANVIL LEVEL AND 30-40 KT IN MID/UPPER
LEVELS BELOW THAT.  MLCAPE APPROACHING 2000 J/KG IS POSSIBLE.  MOST
INTENSE TSTMS WITH SEVERE MICROBURST POTENTIAL SHOULD BE INVOF
SEA/LAKE BREEZE BOUNDARY INTERSECTIONS AND OUTFLOW/SEABREEZE
INTERSECTIONS.  
MARGINAL SEVERE HAIL IS ALSO POSSIBLE.

--- SRN ROCKIES TO NERN TX PANHANDLE/NW OK ---
ISOLATED TO WIDELY SCATTERED HIGH-BASED TSTMS SHOULD DEVELOP NEXT
FEW HOURS OVER HIGHER TERRAIN...IN ENVIRONMENT OF MARGINAL LOW
LEVEL MOISTURE BUT STEEP MIDLEVEL LAPSE RATES.  MLCAPE 300-800 J/KG
POSSIBLE INVOF RATON MESA...SOMEWHAT SMALLER NWD TO PALMER RIDGE. 
TCU EVIDENT ATTM ALONG EACH TOPOGRAPHIC RIDGE.  A FEW TSTMS OVER
THESE AREAS MAY PRODUCE SEVERE HAIL/GUSTS...BUT PROBABILITIES
APPEAR TOO LOW ATTM FOR CATEGORICAL SEVERE OUTLOOK.  TSTMS MAY
EITHER EVOLVE FROM DIURNAL OROGRAPHIC CONVECTION...OR DEVELOP
SEPARATELY AFTER DARK IN ZONE OF ELEVATED WAA/ISENTROPIC ASCENT
OVER OK PANHANDLE AND ADJACENT PORTIONS TX/OK/CO/KS.  CONVECTIVE
COVERAGE MAY INCREASE AFTER 09Z...WITH OCCASIONAL HAIL POSSIBLE.

..EDWARDS.. 05/14/03

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