[SWODY2] SWODY2

[SWODY2 at goshenarc.org]

ACUS02 KWNS 310730
SWODY2
SPC AC 310729

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0229 AM CDT SAT JUL 31 2004

VALID 011200Z - 021200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM OSC 10
WSW MKG 30 SE DBQ 45 SW ALO 30 SSE SPW 50 WNW RWF 30 WNW AXN 45 NW
BRD 35 SW HIB 15 ESE DLH 15 NE IWD 20 S CMX.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 70 SW GBN 35 NNW IGM
20 SE TPH 65 ENE MER 45 W TVL 40 E RBL 40 SW MHS 40 E CEC 30 NW MFR
45 E EUG 45 W PDT 40 NNW ALW 45 NNE 63S ...CONT... 25 S DTW 35 NNE
LAF DEC 25 S UIN 15 NW FLV 15 NNE SLN 45 ENE DDC 25 ENE EHA 35 SSE
RTN 20 NE ONM 30 SSW DMN.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 45 NW DRT 50 ESE JCT
35 NNE CLL 35 SSE SHV 45 NW JAN 25 SSW HSV 40 WSW BLF 25 NW CXY 40
ENE UCA 40 NE PBG.

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE UPPER MS
VALLEY....

...SYNOPSIS...
FLOW REGIME OVER THE CONUS WILL BE CHARACTERIZED BY A CLOSED HIGH
OVER THE SRN HIGH PLAINS AND A BELT OF 40-50 KT MID LEVEL WLYS NEAR
THE US/CANADIAN BORDER.  THE LAST VESTIGES OF THE SYSTEM NOW OVER
THE OH VALLEY WILL LIFT NEWD OVER NRN NEW ENGLAND...PROVIDING A
THREAT FOR A FEW THUNDERSTORMS ALONG THE ASSOCIATED TRAILING SURFACE
BOUNDARY ACROSS THE ATLANTIC AND GULF COAST STATES.  FARTHER
W...LOW-MID LEVEL MOISTURE SHOULD GRADUALLY INCREASE FROM AZ NWD
ACROSS THE GREAT BASIN...TO THE E OF A MID LEVEL TROUGH OVER NRN CA.
 THE GENERAL PATTERN ACROSS THE GREAT BASIN SUGGESTS SOME CONCERN
FOR STRONG WIND GUSTS WITH LARGELY DRY THUNDERSTORMS IN INVERTED-V
PROFILES WITH 30 KT MID LEVEL FLOW...THOUGH INSTABILITY SHOULD STILL
BE QUITE WEAK. LASTLY...A MORE SIGNIFICANT THREAT FOR SEVERE STORMS
CAN BE EXPECTED INVOF A WEAK SURFACE FRONT FROM ERN MT ACROSS THE
DAKOTAS/MN/WI/UPPER MI...NEAR THE SRN FRINGE OF THE STRONGER MID
LEVEL WLY/NWLY FLOW.

...UPPER MS VALLEY AREA...
THE MARITIME TROPICAL AIR MASS IS NOW CONFINED TO AREAS FROM TX TO
OH AND EWD.  HOWEVER...NWD MOISTURE ADVECTION FROM THE SRN PLAINS
AND EVAPOTRANSPIRATION THE NEXT TWO DAYS...BENEATH A PLUME OF STEEP
MID LEVEL LAPSE RATES...WILL RESULT IN SUBSTANTIAL DESTABILIZATION
ACROSS THE UPPER MS VALLEY REGION.  MLCAPE VALUES MAY EXCEED 3000
J/KG DURING THE AFTERNOON FROM ERN NEB TO CENTRAL MN...THOUGH MUCH
OF THE WARM SECTOR MAY BE CAPPED BY THE WARM ELEVATED MIXED LAYER
PLUME. THEREFORE...EXPECT THE MAIN SEVERE THREAT AREAS TO BE
FOCUSED ALONG THE NRN EDGE OF THE STRONGEST INSTABILITY...INVOF THE
WEAK SURFACE FRONT.

THERE WILL BE SOME POSSIBILITY FOR CONVECTION FROM LATE IN THE DAY 1
PERIOD TO PERSIST AND INTENSIFY WHILE DEVELOPING EWD/SEWD ACROSS MN
DURING THE DAY.  IF THIS SCENARIO OCCURS...THEN A
FORWARD-PROPAGATING MCS WITH CONCENTRATED DAMAGING WINDS WILL BE
POSSIBLE.  OTHERWISE...THUNDERSTORMS MAY FORM DURING THE AFTERNOON
ALONG A WEAK SURFACE BOUNDARY ACROSS WRN UPPER MI/NRN WI/CENTRAL MN.
 A FEED OF STRONG INSTABILITY FROM THE S AND 30-40 KT WNWLY MID
LEVEL FLOW SUPPORT A SUPERCELL THREAT WITH THE POTENTIAL FOR
ISOLATED VERY LARGE HAIL...DAMAGING WINDS...AND PERHAPS A TORNADO OR
TWO.  STORMS COULD THEN GROW UPSCALE INTO AN MCS WITH DAMAGING WINDS
BECOMING THE MAIN THREAT DURING THE AFTERNOON AND EARLY OVERNIGHT
HOURS.

...ERN MT INTO NRN SD/ND...
A WEAK SURFACE FRONT IS FORECAST TO STALL ALONG A NW-SE AXIS FROM
ERN MT INTO SD.  THOUGH L0W-LEVEL MOISTURE WILL BE SOMEWHAT LIMITED
THIS AREA...LOW-LEVEL ASCENT ALONG THE FRONT AND STEEP LAPSE RATES
MAY ALLOW ISOLATED THUNDERSTORM DEVELOPMENT DURING THE
AFTERNOON/EVENING.  DEEP LAYER WIND PROFILES WILL BE FAVORABLE FOR
SUPERCELLS...AND ANY PERSISTENT STORMS MAY PRODUCE ISOLATED HAIL AND
STRONG WIND GUSTS DESPITE THE RELATIVE WEAK INSTABILITY.  STORMS MAY
ALSO DEVELOP OVER ND SUNDAY NIGHT AS LOW-LEVEL WAA INCREASES...BUT
LIMITED MOISTURE SUGGESTS THAT ONLY L0W SEVERE PROBABILITIES ARE
WARRANTED.

...NW KS TO SE SD AREA...
THE BACKGROUND PATTERN DOES NOT APPEAR PARTICULARLY FAVORABLE FOR
THUNDERSTORM DEVELOPMENT WITH THE CLOSED MID LEVEL LOCATED
IMMEDIATELY SW OF THIS AREA.  HOWEVER...A REMNANT NE-SW ORIENTED LEE
TROUGH AND STRONG SURFACE HEATING/DEEP MIXING MAY ALLOW ISOLATED
THUNDERSTORMS TO FORM DURING THE LATE AFTERNOON HOURS. ANY STORMS
THAT FORM WILL TEND TO BE HIGH BASED WITH THE POTENTIAL FOR STRONG
OUTFLOW GUSTS. ADDITIONALLY...DEEP LAYER WIND PROFILES MAY BE
SUFFICIENT FOR SUPERCELLS WITH ISOLATED LARGE HAIL.

..THOMPSON.. 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.