[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 250547
SWODY1
SPC AC 250546

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1246 AM CDT THU AUG 25 2005

VALID 251200Z - 261200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM EMP
RSL HLC MCK IML 30 ENE FCL CYS 55 SSE DGW 35 NNW BFF 45 ENE AIA VTN
9V9 FAR 30 SSE TVF 35 E BJI MSP FOD DSM 25 ESE P35 30 ESE OJC EMP.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 20 E CZZ 35 WNW TRM
EDW 45 WNW BIH 45 SSE U31 40 NE U24 25 SSW WRL 20 SSW GCC RAP 35 NNW
MBG 55 N DVL ...CONT... 35 WSW CMX VOK 40 WNW RFD FDY HLG 35 S EKN
20 ESE CHA 25 NE ANB LGC 35 W SAV 50 E SAV ...CONT... 15 WSW BRO 30
WNW ALI AUS 30 SW SHV TXK PGO 50 SW TUL 35 S END CSM BGS 40 SSW FST
95 SSE MRF.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS CENTRAL/NRN PLAINS AND
LOWER/MID MO VALLEY...

...SYNOPSIS...
BROAD MID/UPPER LEVEL ANTICYCLONE WILL PERSIST ACROSS ARKLATEX
REGION...WITH ASSOCIATED RIDGING RENDERING WARM MIDLEVEL TEMPS AND
WEAK FLOW ALOFT OVER SRN HALF OF CONUS.  NRN STREAM PATTERN WILL BE
DOMINATED BY PRONOUNCED MID/UPPER LEVEL CYCLONE -- NOW EVIDENT IN
MOISTURE CHANNEL IMAGERY OVER SWRN/S-CENTRAL SASK.  SFC LOW WILL
BECOME VERTICALLY STACKED WITH CYCLONE ALOFT BY EARLY IN
PERIOD...FOLLOWED BY GRADUAL FILLING TREND AS DEEP-TROPOSPHERIC LOW
DRIFTS NEWD OVER WRN/NRN MB.

ASSOCIATED SFC FRONTAL ZONE -- ANALYZED INITIALLY FROM NERN ND SSWWD
ACROSS BLACK HILLS REGION INTO CENTRAL WY -- IS FCST TO MOVE SLOWLY
EWD OVER NRN MN...SEWD ACROSS SD/NRN NEB...AND SWD OVER CENTRAL HIGH
PLAINS THROUGH PERIOD.

...CENTRAL/NRN PLAINS...
INTENSE SFC HEATING -- COMBINED WITH NEAR-FRONTAL LIFT -- SHOULD
RESULT IN CAP BREAKAGE AND RAPID DEVELOPMENT OF DEEP TSTMS DURING
LATE AFTERNOON.  GREATEST SEVERE PROBABILITIES ATTM APPEAR OVER
PORTIONS NEB INTO SIOUX-LAND REGION...WHERE AIR MASS WILL BE
CHARACTERIZED BY FAVORABLY STEEP MIDLEVEL LAPSE RATES AND 70S F SFC
DEW POINTS.  MLCAPES IN WARM SECTOR SHOULD REACH 4000 J/KG IN SOME
AREAS...DECREASING WITH NWD EXTENT ACROSS WRN MN.  FROM SRN NEB EWD
TOWARD MO VALLEY...LARGE BUOYANCY AND INCREASING TSTM COVERAGE LATE
AFTERNOON INTO EVENING SHOULD OFFSET RELATIVELY WEAK LOW-MIDLEVEL
SHEAR AND RESULT IN POTENTIAL FOR CONCENTRATED CLUSTER OF DAMAGING
WIND AND HAIL EVENTS.  VERTICAL SHEAR IS FCST TO INCREASE WITH NWD
EXTENT...FAVORING SUPERCELLS MAINLY INVOF SFC FRONT.

FARTHER W OVER SERN WY AND NEB PANHANDLE...WEAK ELY COMPONENT TO
BOUNDARY LAYER FLOW ALONG AND N OF SFC FRONT SHOULD ADVECT MOISTURE
UPSLOPE OVER REGION.  WIDELY SCATTERED TSTMS MAY DEVELOP WITH
AFTERNOON HEATING OVER THIS REGION.  THOUGH LOW LEVEL WINDS ARE
PROGGED TO BE WEAK...SUBSTANTIAL VEERING WITH HEIGHT COMBINED WITH
30 KT MIDLEVEL WINDS SHOULD YIELD ENOUGH DEEP-LAYER SHEAR TO SUPPORT
ISOLATED SUPERCELLS...WITH HAIL AND STRONG-SEVERE GUSTS POSSIBLE.

MOST LIKELY AREA FOR ORGANIZED SEVERE THREAT AFTER DARK APPEARS TO
BE SERN NEB/WRN IA/NERN KS/NWRN MO REGION...WHERE POTENTIAL MCS
SHOULD INTERCEPT MOIST/35-40 KT SWLY LLJ AND MOVE ESEWD TO SSEWD. 
STRONG VEERING WITH HEIGHT AND ASSOCIATED LOW LEVEL WAA PROFILES ARE
EXPECTED...WITH ELEVATED MUCAPES EXCEEDING 2500 J/KG.

...SRN FL -- TS KATRINA...
OFFSETTING FACTORS COMPEL MARGINAL/SUBCATEGORICAL TORNADO
PROBABILITIES ATTM.  LATEST NHC FCST SCENARIO IS FOR TS KATRINA TO
INTENSIFY TO HURRICANE STRENGTH BEFORE MOVING SLOWLY ONSHORE
ATLANTIC COAST OF S FL...DURING LATTER HALF OF PERIOD. THIS
SCENARIO WOULD BEGIN TO STRENGTHEN LOW LEVEL VERTICAL SHEAR PROFILES
AND ENLARGE LOW LEVEL HODOGRAPHS ACROSS COASTAL PORTIONS OF
CENTRAL/NRN FL AFTER 26/00Z...BUT ESPECIALLY AFTER 26/06Z AS
MIDDLE/OUTER PART OF NERN QUADRANT BEGINS TO AFFECT LAND.  A FEW
DISCRETE/MINI SUPERCELLS MAY DEVELOP OVER GULF STREAM AND MOVE
ASHORE LATE.  MOISTURE CHANNEL IMAGERY AND AVAILABLE 00Z RAOBS --
I.E. EYW...MIA AND KINGSTON -- SUGGEST SIGNIFICANT MIDLEVEL DRYING
MAY NOT BE DRAWN INTO CIRCULATION DURING THIS PERIOD.  THAT
FACTOR...PLUS LACK OF SIGNIFICANT BAROCLINIC ZONES FOR SYSTEM TO
INTERACT WITH...AND FCST TRACK TIMING RELATIVE TO SFC HEATING MIN
OVER LAND...ALL SUGGEST RELATIVELY LOW TORNADO POTENTIAL.

REF NHC ADVISORIES -- I.E. WMO HEADER WTTN22 KNHC -- FOR TRACK/
INTENSITY GUIDANCE AND VALID WATCHES/WARNINGS.

..EDWARDS/CROBSIE.. 08/25/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.