[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 130604
SWODY2
SPC AC 130603

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0103 AM CDT FRI MAY 13 2005

VALID 141200Z - 151200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 40 NNE
ROC 20 SE ELM 20 NNE CXY 45 SE LBE 15 WSW BKW 30 E CHA 10 SE HSV 35
SW MKL 25 NNE PAH 30 E IND 15 SSW TOL 50 NNW CLE.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 25 ENE EFK 20 ENE
PWM.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 SSW DMN 20 WNW ONM
35 SSW GNT 40 ESE INW 45 SSW PRC 30 S LAS 65 S NFL 10 N TVL 55 NW
NID 35 NNW BFL 35 SSE UKI 10 SW EKA OTH 10 ESE OLM 25 WSW BLI.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 35 NNE HVR 50 W GGW
65 ENE BIL 30 ENE WRL 50 SSW DGW 35 NNW GLD 15 S EHA 35 WNW CDS 15
NNW DUA 20 N PGO 30 SE TBN 35 NNW DNV 30 ESE DTW.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE OH / TN VALLEYS AND
LOWER GREAT LAKES...

...SYNOPSIS...
MID-LEVEL TROUGH / LOW -- INITIALLY CENTERED OVER THE WRN UPPER
LAKES / UPPER MS VALLEY -- WILL MOVE ESEWD WITH TIME ACROSS THE
UPPER LAKES / OH VALLEY THROUGH THE PERIOD...ACCOMPANIED BY 60 TO 70
KT JET STREAK. FURTHER W...WEAK SHORT-WAVE TROUGH IS PROGGED TO
SHIFT EWD ACROSS THE GREAT BASIN / ROCKIES THROUGH MEAN RIDGE.

AT THE SURFACE...ELONGATED AREA OF LOW PRESSURE FORECAST FROM THE
LOWER GREAT LAKES INTO THE OH VALLEY REGION SHOULD CONSOLIDATE BY
LATE AFTERNOON INTO A SINGLE LOW CENTER OVER THE LOWER GREAT LAKES. 


PRIMARY COLD FRONT ASSOCIATED WITH THIS LOW SHOULD EXTEND WWD ACROSS
THE LOWER OH / MID MS VALLEYS INTO TX INITIALLY...AND WILL MOVE EWD
WITH TIME ACROSS THE OH AND TN VALLEYS.  MEANWHILE...MODELS SUGGEST
THAT SECOND COLD SURGE SHOULD MOVE SEWD ACROSS THE PLAINS DURING THE
DAY.  BY THE END OF THE PERIOD...THIS SECONDARY FRONT SHOULD MERGE
WITH INITIAL FRONT...AND EXTEND FROM ERN NY SWWD IN LEE OF THE
APPALACHIANS...AND THEN WSWWD ACROSS THE GULF COAST STATES INTO
CENTRAL TX.

...OH / TN VALLEY REGION...
MODELS SUGGEST THAT WIDESPREAD PRE-FRONTAL CONVECTION SHOULD BE
ONGOING ACROSS MUCH OF THE SLIGHT RISK AREA...WHICH MAY PROVE TO BE
PROBLEMATIC IN TERMS OF AIRMASS DESTABILIZATION -- AND ASSOCIATED
SEVERE THREAT -- LATER IN THE AFTERNOON.

EVOLUTION OF ONGOING STORMS IS UNCERTAIN ATTM...BUT SEVERE THREAT
MAY PERSIST INTO THE AFTERNOON WITH A FEW CLUSTERS OF STORMS AS THEY
 MOVE EWD ACROSS THE OHIO VALLEY REGION.

HOWEVER...AS UPPER TROUGH SHIFTS EWD THROUGH THE DAY...STORMS ARE
FORECAST TO REDEVELOP ALONG COLD FRONT BY MID AFTERNOON...LIKELY
FROM PARTS OF ERN INDIANA / WRN OH SWWD ACROSS WRN KS / WRN TN.  

STORM INTENSITY / SEVERITY MAY BE MODULATED TO SOME DEGREE DEPENDING
UPON AMOUNT OF PRE-EXISTING CONVECTION AND ASSOCIATED DEGREE OF
HEATING / INSTABILITY WHICH CAN OCCUR AHEAD OF FRONT. 
HOWEVER...ASSUMING SUFFICIENT DESTABILIZATION CAN OCCUR...DEEP-LAYER
WIND FIELD IS FORECAST TO BE STRONG / ROUGHLY UNIDIRECTIONAL FROM
THE WSW ABOVE THE BOUNDARY LAYER.  THEREFORE...WIDESPREAD SEVERE
THREAT SHOULD EXIST DESPITE POTENTIALLY LIMITED INSTABILITY --
PARTICULARLY FROM NRN KY NWD WHERE DEEP-LAYER WIND FIELD SHOULD BE
STRONGEST.  

SHEAR WILL BE FAVORABLE FOR SUPERCELLS...AND SUFFICIENT VEERING IN
AT VERY LOW LEVELS SUGGEST A POTENTIAL FOR A COUPLE OF TORNADOES --
PARTICULARLY WITH MORE ISOLATED / PRE-FRONTAL STORMS. 
HOWEVER...MAIN CONVECTIVE MODE SHOULD TRANSITION TOWARD A SQUALL
LINE...WITH DAMAGING WINDS LIKELY.  STORMS SHOULD CONTINUE EWD
ACROSS PA / THE TN VALLEY REGION THROUGH THE EVENING...WITH
CONTINUED THREAT FOR MAINLY DAMAGING WINDS.

ATTM...WILL UPGRADE OVERALL SEVERE THREAT TO 25% -- THOUGH QUESTIONS
DO PERSIST REGARDING ONGOING CONVECTION / POSSIBLY CONTAMINATED
AIRMASS AHEAD OF FRONT.  SHOULD CONVECTION BE LESS WIDESPREAD AHEAD
OF FRONT THAN CURRENTLY ANTICIPATED ALLOWING MORE SIGNIFICANT
HEATING / DESTABILIZATION...LARGE-SCALE PATTERN SUPPORTS THE
POTENTIAL FOR A MORE SIGNIFICANT SEVERE WEATHER EVENT.

...SERN PA SWWD INTO THE WRN CAROLINAS...
MODELS SUGGEST THAT A WEAK TROUGH MAY EVOLVE IN LEE OF THE
APPALACHIANS DURING THE AFTERNOON...WHERE AROUND 1000 J/KG
MEAN-LAYER CAPE IS ANTICIPATED.  THOUGH REGION SHOULD BE UNDER THE
INFLUENCE OF LARGE-SCALE RIDGING ALOFT...CONVERGENCE ALONG POSSIBLE
SURFACE TROUGH MAY SUPPORT THE DEVELOPMENT OF SCATTERED TO ISOLATED
STORMS.  ASSUMING STORMS DEVELOP...SHEAR WOULD LIKELY BE SUPPORTIVE
OF A SEVERE THREAT -- PARTICULARLY FROM NRN NC NWD.  ATTM...WILL
INTRODUCE ONLY 5% SEVERE PROBABILITY E OF THE APPALACHIANS GIVEN
UNCERTAINTY REGARDING CONVECTIVE INITIATION.

...PECOS AND RIO GRANDE VALLEYS OF TX INTO ERN NM...
PERSISTENT ELY / SELY FLOW IS EXPECTED AT LOW LEVELS AS COLD FRONT
SAGS SWD INTO TX.  WITH SUFFICIENTLY MOIST / UNSTABLE AIRMASS
ANTICIPATED...UPSLOPE FLOW -- AND POSSIBLY WEAK CONVERGENCE ALONG
REMNANT COLD FRONT -- SHOULD ALLOW SCATTERED TO ISOLATED STORMS TO
DEVELOP BY AFTERNOON ACROSS PARTS OF WRN AND CENTRAL TX INTO ERN
NM...AND POSSIBLY AS FAR S AS THE LOWER RIO GRANDE VALLEY.

THOUGH MID-LEVEL FLOW SHOULD BE RELATIVELY WEAK ACROSS THIS
REGION...ELY / SELY LOW-LEVEL FLOW BENEATH WLY FLOW ALOFT MAY YIELD
SUFFICIENT DEEP SHEAR FOR ORGANIZED / ROTATING UPDRAFTS.  MAIN
SEVERE THREAT SHOULD BE LARGE HAIL...ALONG WITH LOCALLY DAMAGING
GUSTS...AS CLOUD BASES SHOULD BE RELATIVELY HIGH -- PARTICULARLY
ACROSS THE WRN 2/3 OF THE OUTLOOK AREA.

WITH THESE STORMS LIKELY DRIVEN PRIMARILY BY DIURNAL
PROCESSES...CONVECTION / SEVERE THREAT SHOULD DIMINISH OVERNIGHT.

..GOSS.. 05/13/2005

...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.