[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 311732
SWODY2
SPC AC 311731

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1231 PM CDT SAT JUL 31 2004

VALID 011200Z - 021200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM ANJ 15
NW PIA 15 W UIN 30 SSW IRK 35 NNE STJ PIR 20 S P24 15 W DVL FAR AXN
DLH.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 SW YUM 35 NNE BLH
40 SSW DRA TPH 50 NNE WMC 50 ESE MHS 55 SSE RBL 35 NW UKI CEC EUG
PDT 3TH 55 NNW FCA ...CONT... 15 NNE MBS BEH DEC BLV SGF ICT 50 WSW
RSL GCK CAO 20 WSW 4CR 40 W ELP.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NW DRT TYR 25 NE
GLH MSL JKL DUJ SYR 30 ENE MSS.

...THERE IS A SLGT RISK OF SVR TSTMS PORTIONS OF THE NRN PLAINS AND
UPPER MS VALLEY REGION...

...SYNOPSIS...
UPPER TROUGH...CURRENTLY LOCATED OVER THE OHIO VALLEY...IS FORECAST
TO LIFT NEWD INTO NEW ENGLAND...IN RESPONSE TO HEIGHT FALLS ACROSS
THE SRN CANADIAN PROVINCES. LARGE HIGH PRESSURE ALOFT WILL COVER
MUCH OF THE SOUTHERN PORTION OF THE NATION AND INTO THE CENTRAL
ROCKIES....WHILE A BAND OF 40-50 KT MID LEVEL WLY WINDS WILL PERSIST
FROM THE NRN ROCKIES/PLAINS EWD INTO NEW ENGLAND. A WEAK COLD FRONT
WILL ACCOMPANY THE UPPER TROUGH THROUGH NEW ENGLAND....WHILE A
QUASI-STATIONARY FRONT WILL STRETCH FROM MT SEWD INTO SD AND THEN
EWD ACROSS SRN MN/WI.

...UPPER MS VALLEY AREA...
SURFACE LOW PRESSURE....EXPECTED TO REMAIN ALONG THE FRONT IN
THE SD AREA THROUGH THE NEXT 48 HOURS...WILL AID IN ADVECTING LOWER
70 DEWPOINTS FROM THE SRN PLAINS INTO THE REGION BY SUNDAY
AFTERNOON. THIS RICHER BOUNDARY LAYER MOIST PLUS 
EVAPOTRANSPIRATION...BENEATH A PLUME OF STEEP MID LEVEL LAPSE
RATES...WILL RESULT IN SUBSTANTIAL DESTABILIZATION ACROSS THE
REGION. MLCAPE VALUES ARE LIKELY TO APPROACH 4000 J/KG FROM ERN
NEB/SD INTO SRN MN/NRN IA BY SUNDAY AFTERNOON. THE WLY FLOW ALOFT
WILL RESULT IN WARM MID LEVEL TEMPERATURES AND A CAPPING INVERSION.
THIS CAP SHOULD WEAKEN NEAR THE FRONT AS INCREASING
DIFFLUENCE/DIVERGENCE ALOFT INCREASES THE LOW LEVEL CONVERGENCE...
WITH STORMS EXPECTED TO DEVELOP ALONG AND NORTH OF THE BOUNDARY BY
LATE AFTERNOON. THE EXTREMELY UNSTABLE AIR MASS AND 40 KT DEEP LAYER
SHEAR WILL SUPPORT SUPERCELLS DURING THE STORMS INITIAL DEVELOPMENT.
HOWEVER...THE 40 KT MID LEVEL FLOW...STRONG INSTABILITY AND BOUNDARY
ARE FAVORABLE FOR STORMS TO EVOLVE INTO A FORWARD-PROPAGATING MCS
WITH CONCENTRATED DAMAGING WINDS POSSIBLE ...ESPECIALLY ACROSS SRN
MN/NRN IA AND SRN WI SUNDAY NIGHT. EXPECT ENOUGH REPORTS FOR
MODERATE RISK...BUT MODELS VARIANCE IN LOCATION AND TIMING OF
CONVECTIVE INITIATION FROM PREVIOUS MODEL PRECLUDES THE HIGHER RISK
ATTM.

...SD/ND...
THOUGH SURFACE DEWPOINTS WILL BE LOWER THAN ACROSS THE UPPER MS
VALLEY...STEEP LAPSE RATES WILL SUPPORT MUCAPES OF 2000-3000
J/KG...WITH THE STRONGEST INSTABILITY IN NERN SD. A WEAK IMPULSE IS
FORECAST TO MOVE THROUGH THE FLOW AND ENSEMBLES SUPPORT ELEVATED
STORMS DEVELOPING ACROSS PORTIONS OF THE AREA SUNDAY NIGHT. DEEP
LAYER WIND PROFILES WILL BE FAVORABLE FOR SUPERCELLS...BUT STABLE
BOUNDARY NORTH OF THE FRONT SUGGESTS THAT HAIL WILL BE THE MAIN
THREAT.

...CENTRAL AND ERN KS/NEB EWD INTO MO...
STRONG INSTABILITY AND STRENGTHENING MID LEVEL NWLY FLOW AT 20 TO 30
KT WILL PROVIDE A FAVORABLE ENVIRONMENT FOR ROTATING STORMS. 
FORECAST SOUNDINGS SHOW THE AREA REMAINS STRONGLY CAPPED...BUT GIVEN
THE AFOREMENTIONED CONDITIONS AND WEAK COLD ADVECTION AT 500 MB...A
5% PROBABILITY FOR SEVERE IS FORECAST SHOULD STORMS DEVELOP.

...NERN U.S...
MODELS FORECAST 30 KT DEEP LAYER SHEAR WITH MLCAPES FROM 1000-1500
J/KG...SUPPORTIVE OF ISOLATED SEVERE STORMS AS COLD FRONT MOVES INTO
THE AREA DURING THE AFTERNOON. HOWEVER..150-200 NM EXTENSIVE CLOUD
BAND CURRENTLY EXTENDS ALONG AND AHEAD OF FRONT ACROSS NY/PA  AND
THE OH VALLEY...AND SUSPECT THESE CLOUDS WILL LIMIT THE SEVERE
WEATHER THREAT ACROSS THE AREA ON SUNDAY.

...GREAT BASIN...
MID LEVEL MOISTURE ON THE BACKSIDE OF THE UPPER RIDGE SHOULD
GRADUALLY SPREAD FROM AZ NWD INTO THE REGION. DESPITE MARGINAL
INSTABILITY...FORECAST SOUNDINGS SHOW MOIST SOUNDINGS FROM 550
MB-300 MB...WHICH SHOULD BE SUFFICIENT FOR HIGH BASED THUNDERSTORMS
TO DEVELOP OVER HIGHER TERRAIN. LARGE INVERTED-V SOUNDINGS BELOW THE
MID LEVEL MOISTURE AND 30 KT MID LEVEL FLOW INDICATE A THREAT OF
STRONG GUSTY WINDS.

..IMY.. 07/31/2004

...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.