[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 191707
SWODY2
SPC AC 191705

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1205 PM CDT THU AUG 19 2004

VALID 201200Z - 211200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 45 WNW
DRT 30 E FST 40 WNW HOB 45 SE CVS 30 N ABI 30 NNW ACT 35 NE AUS 15
ESE SAT 10 SE DRT.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SW GDP 30 NNE ELP
85 WNW TCS 25 NW PRC 40 NNW NID 45 SSE TVL 40 NE MFR 45 SSE DLS 40
NNW 63S ...CONT... 70 NW GGW 45 NNE BIL 25 WNW GCC 25 NNW CDR 30 SW
MHN 25 E IML 55 S GLD 30 S EHA 35 NNE CDS 30 SSW OKC 25 WNW TUL 30 S
EMP 25 SSE FNB 20 WSW OTM 15 NNW CGX 65 SE OSC ...CONT... 60 WNW 3B1
10 SW BHB ...CONT... 30 SW PSX 35 NW LRD.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF SWRN AND CNTRL
TX...

...SYNOPSIS...
BROAD...CYCLONIC FLOW REGIME /ANCHORED BY DEEP LOW INVOF OF HUDSON
BAY/ IS FORECAST ACROSS MUCH OF THE CONUS THROUGH THE DAY 2 PERIOD.
WITHIN THIS PATTERN...SHORTWAVE TROUGH OVER N TX THIS MORNING WILL
LIFT NEWD FROM MO ACROSS THE OH VALLEY...WHILE SEVERAL WEAK
PERTURBATIONS TRANSLATE SEWD THROUGH THE INTERMOUNTAIN W INTO THE
CNTRL AND SRN PLAINS.

AT THE SURFACE...COLD FRONT /LIKELY EXTENDING FROM NEW ENGLAND SWWD
ACROSS THE OH VALLEY INTO SWRN TX BY LATE AFTERNOON/ WILL BE THE
PRIMARY FOCUS FOR STRONG TO POTENTIALLY SEVERE TSTM DEVELOPMENT.

...SWRN/CNTRL TX...
CO-LOCATION OF STEEP MID-LEVEL LAPSE RATES /7-8 C/KM/ ATOP
BOUNDARY-LAYER DEWPOINTS IN THE MID 60S TO LOWER 70S WILL CONTRIBUTE
TO AIRMASS DESTABILIZATION ALONG AND S OF COLD FRONT. WITH
TIME...CLOUDS SHOULD TEND TO DISSIPATE/MIX OUT IN WAKE OF SYSTEM
LIFTING NEWD AWAY FROM REGION...ALLOWING FOR INCREASED INSOLATION
WITH AFTERNOON MLCAPES INCREASING TO 1500-2500 J/KG. A SERIES OF
WEAK MID-LEVEL PERTURBATIONS APPROACHING FROM THE NW...FRONTAL
CONVERGENCE...AS WELL AS POST-FRONTAL UPSLOPE FLOW...SHOULD ALL
CONTRIBUTE TO AN INCREASE IN STORM COVERAGE AND INTENSITY THROUGH
THE AFTERNOON AND EVENING HOURS.

STRONGLY VEERING WIND PROFILES INVOF OF FRONTAL ZONE AND RESULTANT
35-40KTS OF DEEP-LAYER SHEAR INDICATE THE POTENTIAL FOR SUPERCELLS
WITH INCIPIENT STORM DEVELOPMENT. EXPECTED ANA-FRONTAL CHARACTER OF
BOUNDARY SUGGESTS THAT STORMS WILL EITHER BECOME ELEVATED ABOVE
FRONTAL ZONE /WITH INHERENT LARGE HAIL THREAT/ OR EVOLVE INTO
FORWARD-PROPAGATING STORM CLUSTERS ALONG FRONTAL ZONE WITH DAMAGING
WINDS BEING THE PRIMARY SEVERE WEATHER THREAT.

...OH VALLEY INTO SRN NEW ENGLAND...
ISENTROPIC ASCENT INTO ENTRANCE REGION OF UPPER JET STREAK OVER SERN
CANADA IN CONJUNCTION WITH FORCING AHEAD OF SHORTWAVE TROUGH LIFTING
THROUGH THE OH VALLEY SHOULD SUSTAIN LARGE PRECIPITATION SHIELD NEWD
ACROSS REGION. RELATIVELY POOR LAPSE RATES /AOB MOIST ADIABATIC/
WILL LARGELY LIMIT DESTABILIZATION OF DOWNSTREAM AIRMASS...HOWEVER
MOIST BOUNDARY-LAYER /I.E. DEWPOINTS OF 65-70F/ WILL LIKELY
CONTRIBUTE TO POCKETS OF MODERATE INSTABILITY WITH MLCAPES
APPROACHING 1000-1500 J/KG. INSPECTION OF FORECAST SOUNDINGS
SUGGESTS THAT ETA BMJ INSTABILITY FORECASTS MAY BE TOO HIGH OWING TO
ACTIVE SHALLOW CONVECTION SCHEME.

NONETHELESS...POTENTIAL FOR AT LEAST ISOLATED SEVERE WEATHER
EPISODES /NAMELY DAMAGING WINDS/ WILL EXIST ALONG FRONTAL ZONE
WITHIN MODERATELY SHEARED ENVIRONMENT. THIS IS ESPECIALLY THE CASE
AHEAD OF MIGRATORY LOW ATTENDANT TO MID-LEVEL SHORTWAVE TROUGH WHICH
WILL DEVELOP NEWD ALONG FRONTAL ZONE...AS WELL ANY DOWNSTREAM
LOCATIONS THAT MAY LOCALLY EXPERIENCE STRONGER DAYTIME HEATING AND
RESULTANT HIGHER INSTABILITY. POOR LAPSE RATES/LIMITED INSTABILITY
AS A RESULT OF EXPECTED WIDESPREAD CLOUDS/PRECIPITATION PRECLUDES
CATEGORICAL RISK ATTM. DAY 1 UPGRADE TO SLIGHT RISK MAY WELL BE
REQUIRED OVER PORTIONS OF DISCUSSION AREA ONCE FINER-SCALE DETAILS
BECOME MORE CLEAR.

..MEAD.. 08/19/2004

...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.