[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 181311
SWODY1
SPC AC 181309

DAY 1 CONVECTIVE OUTLOOK CORR 1
NWS STORM PREDICTION CENTER NORMAN OK
0809 AM CDT WED AUG 18 2004

VALID 181300Z - 191200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 WNW
CLE 40 ESE FWA CMI 35 NNW COU STJ 25 SSE OMA 20 SSE MSP 15 NW IWD.

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 30 SE
ECG 45 S RIC 35 E CHO 30 E HGR 15 WSW ABE 10 SSW JFK.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 S GBN 25 NNW GBN
60 SE EED 40 NW IGM 25 ESE DRA 45 S BIH 55 NE MER 15 SSW RNO 80 SE
4LW 45 SSE BNO 55 NNE BNO 45 ESE YKM 30 NNE SEA 20 NE BLI ...CONT...
30 N CTB 45 W LWT 30 SE SHR 35 NNW CDR VTN 20 SSE MHE 45 W BRD 45
WNW INL ...CONT... 20 WNW PFN 30 SW MCN 45 S AHN 25 WSW AND 50 WSW
AVL 40 SSW TYS 25 NW RMG 40 S MSL 15 NNW TUP 40 SW DYR 35 SSE CGI 25
NW PAH 15 NNE MDH 10 SE BLV 20 WSW STL 35 WNW TBN 20 WSW JLN 15 S
TUL 10 ENE DUA 30 ENE CLL 35 NNE HOU 25 SE BPT.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE UPPER MIDWEST...

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS THE MID-ATLANTIC
STATES...

CORRECTED TO FLIP SIG WIND LINE

...UPPER MIDWEST...
A STRONG COLD FRONT CURRENTLY ANALYZED ACROSS THE DAKOTAS WILL MOVE
QUICKLY SEWD INTO NEB...IA AND WI THIS AFTERNOON. SFC DEWPOINTS IN
THE 60S F AND TEMPS AROUND 80 F WILL YIELD MODERATE INSTABILITY
AHEAD OF THE FRONT. THE CONVECTIVE LINE CURRENTLY MOVING ACROSS NE
MN SHOULD EXPAND SWD ACROSS WI AS INSTABILITY AND STRONG LOW-LEVEL
CONVERGENCE STRENGTHENS THIS AFTERNOON. A STRONG CAPPING INVERSION
SHOULD HOLD FOR MUCH OF THE AFTERNOON ACROSS IA WHERE ELEVATED
STORMS ARE CURRENTLY ONGOING. THE STRONGEST INSTABILITY IS FORECAST
TO DEVELOP IN IA AND THIS COULD RESULT IN ISOLATED SFC-BASED
CONVECTION LATE THIS AFTERNOON. FORECAST SOUNDINGS SHOW DEEP LAYER
SHEAR OF 40 TO 50 KT ACROSS WI WITH 30 TO 40 KT ACROSS IA...IL AND
IND. INITIALLY...THE SHEAR WILL FAVOR SUPERCELLS ESPECIALLY ACROSS
WI AND THE GREAT LAKES WHERE THE SHEAR WILL BE GREATER. EVEN THOUGH
MID-LEVEL LAPSE RATES WILL BE MARGINAL...SUPERCELLS THAT DEVELOP IN
THE LOCAL AREAS OF HIGHER INSTABILITY WILL BE CAPABLE OF ISOLATED
TORNADOES AND LARGE HAIL CONSIDERING THE AMOUNT OF SHEAR PRESENT.
ISOLATED TO SCATTERED SEVERE STORMS MAY ALSO DEVELOP SWWD ALONG THE
FRONT ACROSS IA AND SE NEB AS THE CAP WEAKENS BY EARLY EVENING. THE
SUPERCELL THREAT SHOULD TRANSITION TO A LINEAR MCS AS LOW-LEVEL
CONVERGENCE INCREASES ALONG THE FRONT. THIS WILL FAVOR A WIND DAMAGE
THREAT AS THE CONVECTIVE LINE MOVES SWD ACROSS MI..SERN WI INTO IL
AND IND THIS EVENING.

...MID-ATLANTIC STATES AND CAROLINAS...
STRONG ONSHORE FLOW ACROSS ATLANTIC COASTAL STATES WILL REINFORCE
UPPER 60 AND LOWER 70S F SFC DEWPOINTS ALREADY IN PLACE. THE
MOISTURE WILL LIKELY YIELD 1000 TO 1500 J/KG OF MLCAPE BY AFTERNOON
AS SFC TEMPS WARM. LOW-LEVEL CONVERGENCE ALONG A SFC TROUGH EAST OF
THE APPALACHIAN MTNS SHOULD HELP INITIATE ISOLATED STORMS ACROSS THE
COASTAL PLAINS. ALTHOUGH LARGE-SCALE FORCING WILL BE
WEAK...MID-LEVEL FLOW WILL BE A BIT STRONGER ACROSS THE MID-ATLANTIC
STATES WHICH WILL RESULT IN A BETTER CHANCE OF SEVERE STORMS THERE.
FORECAST SOUNDINGS ACROSS MD SHOW LOW-LEVEL VEERING WIND PROFILES
AND 30 TO 35 KT OF DEEP LAYER SHEAR. THIS WILL BE SUFFICIENT FOR
SEVERE MULTICELL STORMS CONSIDERING THE AMOUNT OF INSTABILITY
EXPECTED. LOW-LEVEL LAPSE RATES GREATER THAN 9.0 C/KM WILL MAKE WIND
DAMAGE POSSIBLE ESPECIALLY NEAR PEAK HEATING WITH THE STRONGER
CELLS. A HAIL THREAT WILL ALSO EXIST WITH THE STRONGEST CELLS. THE
SEVERE THREAT SHOULD DIMINISH DURING THE EVENING AS INSTABILITY
DECREASES ACROSS THE REGION.

...CNTRL HIGH PLAINS...
A COLD FRONT WILL MOVE SWD THROUGH NEB TODAY REACHING NRN KS BY LATE
AFTERNOON. STRONG SFC HEATING AND SFC DEWPOINTS AROUND 60 F SHOULD
YIELD MLCAPE VALUES AROUND 1000 J/KG. THIS COMBINED WITH LOW-LEVEL
CONVERGENCE WILL BE SUFFICIENT FOR ISOLATED THUNDERSTORM
DEVELOPMENT. HOWEVER...FORECAST SOUNDINGS SHOW WEAK SHEAR.
STILL...LOW-LEVEL DIRECTIONAL SHEAR AND VERY STEEP LOW-LEVEL LAPSE
RATES COULD RESULT IN A MARGINAL WIND DAMAGE OR HAIL THREAT NEAR
PEAK HEATING.

..BROYLES.. 08/18/2004

...NOTICE...
FOR USERS DECODING THE POINTS PARAGRAPH HEREIN...LATITUDE AND
LONGITUDE POINTS FOR THE CATEGORICAL AND PROBABILISTIC OUTLOOK
GRAPHICS ALSO ARE LOCATED IN A SEPARATE PRODUCT UNDER THE WMO
HEADINGS WUUS01 PTSDY1...WUUS02 PTSDY2...AND WUUS03 PTSDY3.  THE
INCLUSION OF POINTS IN THIS PRODUCT WILL EVENTUALLY BE DISCONTINUED.