[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 130630
SWODY2
SPC AC 130629

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0129 AM CDT TUE SEP 13 2005

VALID 141200Z - 151200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 35 SSE
SPS 60 WSW SPS 50 SSW CDS 25 E PVW 30 SE AMA 20 ENE AMA 55 NNE AMA
50 SSE LBL 35 WNW GAG 40 NE GAG END 40 S PNC 10 NW TUL 35 NW FYV 30
NNW HRO 40 WNW POF 25 W CGI 20 W PAH 45 SSE PAH 35 ENE MKL 30 SSW
MKL MEM 10 NNW PBF 40 SSW HOT 30 ENE PRX 25 SSE DUA 45 S ADM 35 SSE
SPS.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SSW CTY 40 N SAV
45 NNE RDU 20 ESE SBY.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 WNW 3B1 15 W ALB
30 NE SSU 40 SE TYS 45 ENE RMG 25 SSE UOX 45 W GLH 30 NW SHV 35 SSE
DAL 40 SSW ABI 35 SSW FST 40 WNW FST 35 SSE CNM 40 SW CVS 35 NW TCC
40 WNW TAD 30 W DEN 25 WNW FCL 30 WSW BFF 30 NNW AIA 20 N VTN 45 SSE
9V9 65 E ANW 35 E LBF 30 WNW HLC 15 E RSL 35 W P35 10 SSE UIN 15 WSW
CMI 15 NE SBN 20 NE PLN.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE SRN PLAINS TO THE
MIDDLE MS VALLEY...

...SYNOPSIS...
LARGE SCALE PATTERN CHANGE IS UNDERWAY TODAY AS A PERSISTENT WRN
TROUGH BEGINS TO TRANSITION EWD ACROSS THE PLAINS AND UPPER MIDWEST.
MID LEVEL HEIGHT FALLS THROUGH WEDNESDAY WILL RESULT IN A BREAKDOWN
OF THE BLOCKING RIDGE COVERING MUCH OF THE ERN CONUS...AND A COLD
FRONT WILL MOVE FROM THE GREAT LAKES TO NRN NEW ENGLAND.
MEANWHILE...THE FUTURE TRACK OF OPHELIA REMAINS UNCERTAIN THROUGH
MIDWEEK WITH LATEST NAM KEEPING THE CYCLONE NEARLY STATIONARY NEAR
THE ERN CAROLINAS...AND GFS MOVING THE SYSTEM NNEWD ACROSS ERN NC
SIMILAR BUT FASTER THAN LATEST TPC OFFICIAL TRACK FORECAST.

THE LEADING SHORT WAVE TROUGH AND ASSOCIATED SURFACE COLD FRONT NOW
EVOLVING OVER THE NRN PLAINS WILL BE LOCATED FROM THE GREAT LAKES TO
THE CNTRL PLAINS AT THE START THE DAY 2 PERIOD. STRONGEST HEIGHT
FALLS WITH THE UPPER SYSTEM WILL LIFT NEWD INTO CANADA AS SURFACE
FRONT SWEEPS EWD TOWARD THE NORTHEAST...AND ESEWD ACROSS MIDWEST.
THE TRAILING PORTION OF THE FRONT IS FORECAST TO BECOME
QUASI-STATIONARY FROM THE LOWER OH VALLEY WSWWD TO THE SRN PLAINS
BENEATH 30-50KT WSWLY MID LEVEL FLOW.

UPSTREAM SHORT WAVE ENERGY WILL CONTINUE TO SPREAD ACROSS THE WRN
U.S. WITHIN INCREASINGLY ZONAL FLOW. AT LEAST ONE FAST-MOVING SHORT
WAVE TROUGH WILL TRACK EAST FROM THE INTERMOUNTAIN WEST/FOUR CORNERS
AREA TO THE GREAT PLAINS DURING WEDNESDAY. THIS SYSTEM WILL INDUCE
STRONG SLOPED ASCENT ACROSS THE STALLED FRONTAL ZONE SITUATED OVER
THE SRN PLAINS.

...SRN PLAINS TO MID MS VALLEY...
FORECAST SCENARIO ACROSS PARTS OF THE AREA IS COMPLICATED BY THE
POSSIBILITY OF A NUMBER OF SEVERE WEATHER EPISODES AS A VARIETY OF
FORCING MECHANISMS AFFECT MESOSCALE DYNAMICS WITHIN A VERY MOIST AND
UNSTABLE AIRMASS. THE FIRST POSSIBILITY OF SEVERE TSTMS WILL OCCUR
AS A POTENTIALLY STRONG MCS OUTFLOW BOUNDARY SAGS SWD INTO
INCREASINGLY UNSTABLE AIR MASS ACROSS ERN OK AND AR. DEEP LAYER
SHEAR IS FORECAST TO STRENGTHEN COINCIDENT WITH TSTM DEVELOPMENT
ALONG THE OUTFLOW RESULTING IN ORGANIZED STORMS AND A FEW SUPERCELLS
PRODUCING HAIL AND HIGH WINDS FROM ERN OK/AR TO THE MO BOOTHEEL/WRN
TN.

STRONG CAP WILL LIKELY EXIST ACROSS PARTS OF SRN/WRN OK AND NWRN TX
INTO THE AFTERNOON. HOWEVER...FRONTAL/OUTFLOW INTRUSION INTO THIS
AREA...COUPLED WITH STRONG UPSTREAM HEATING AND ADVANCING
DRYLINE...SHOULD ACT TO OVERCOME THE CAP AND RESULT IN STORM
INITIATION. MAGNITUDE OF INSTABILITY AND SHEAR WILL SUPPORT
SUPERCELLS WITH VERY LARGE HAIL...HIGH WINDS...AND A POSSIBLE
TORNADO OR TWO. LARGE SCALE ASCENT ACROSS THIS REGION SHOULD
STRENGTHEN FURTHER BY LATE AFTERNOON AS A SHORT WAVE TROUGH MOVES
EAST FROM NM/CO. THIS IMPULSE WILL INDUCE INCREASING MASS TRANSPORT
INTO/ACROSS THE FRONTAL ZONE AND THIS PROCESS COULD MAINTAIN ONGOING
SEVERE STORMS...OR RESULT IN ADDITIONAL SEVERE TSTM DEVELOPMENT FROM
THE TX PNHDL EWD INTO OK.

FORECAST PROBABILITY OF SEVERE WEATHER ACROSS THE REGION MAY
INCREASE AND RESULT IN A CATEGORICAL UPGRADE IF THE ABOVE MENTIONED
SCENARIOS BECOME MORE CERTAIN AND BETTER DEFINED.

...OH VALLEY TO WRN NY...
MODEST DESTABILIZATION AHEAD OF THE COLD FRONT MOVING INTO THESE
AREAS SHOULD MAINTAIN THE CHANCE FOR STRONG TO OCCASIONAL SEVERE
STORMS ALONG/AHEAD OF THE ADVANCING BOUNDARY. AT PRESENT...NAM/GFS
MODEL DISCREPANCIES IN FORECAST INSTABILITY ACROSS PARTS OF OH/WRN
PA/NY LEADS TO UNCERTAINTY REGARDING COVERAGE OF SEVERE THREAT OVER
THESE AREAS DESPITE RELATIVELY STRONG FORCING AND FLOW. FARTHER
SOUTH AND WEST ALONG THE FRONT...WEAKER SHEAR AND FORCING ACROSS THE
OH VALLEY SHOULD KEEP OVERALL STORM ORGANIZATION LIMITED WITH ONLY
ISOLATED HAIL/WIND EVENTS POSSIBLE.

...ERN NC...
ISOLATED TORNADO THREAT MAY ACCOMPANY LANDFALL OF OPHELIA ACROSS A
RELATIVELY SMALL PART OF THE AREA.

..CARBIN.. 09/13/2005

...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.