[SWODY1] SWODY1

[SWODY1 at goshenarc.org]

ACUS01 KWNS 121616
SWODY1
SPC AC 121611

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1111 AM CDT SUN SEP 12 2004

VALID 121630Z - 131200Z

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 50 NW DRT 45 ENE P07
60 WSW SJT 10 NNE SJT 35 W BWD BWD 45 W TPL 30 SW CLL 45 WNW HOU 30
NNE HOU 40 SW POE 40 SW MLU 45 ENE LIT 20 WSW MDH 25 SW LUK 35 SSE
UNI 15 ENE BKW 15 S PSK 15 NW AVL 55 ENE RMG 35 WNW ATL 40 NW MCN 45
SSE AHN 25 W CAE 15 SW FLO 25 ENE CRE ...CONT... 20 NNW HUL 50 NW
3B1 ...CONT... 60 ENE ELO 25 NE BRD 45 N ATY 20 WSW MHE BUB 25 ESE
IML 35 S AKO 30 S LHX 35 SE RTN 15 ENE ABQ 25 SSE GNT 70 NW TCS 50
NE SAD 70 E PHX 40 NW PHX 45 E YUM 25 ESE BLH 35 SE EED 50 ENE DRA
30 W P38 35 S ENV 30 NNW DPG 55 W OGD 60 NNE ENV 40 NNE EKO 40 NNW
EKO 25 N WMC 65 ESE 4LW 15 NE 4LW 70 SSE RDM BKE 30 SE GEG 30 NNW
63S.

...NO SVR TSTM AREAS FORECAST...

...NRN PLAINS...
VIGOROUS UPPER TROUGH OVER THE PACIFIC NW IS FORECAST TO MOVE EWD
ACROSS THE NRN INTERMOUNTAIN REGION AS PROGRESSIVE FLOW PATTERN
AMPLIFIES OVER THE NRN STATES. NE/SW ORIENTED COLD FRONT WILL
BECOME BETTER DEFINED FROM NERN ND SWWD ACROSS WY THIS
AFTERNOON...AS DOWNSTREAM WARM FRONT OVER THE UPPER MS VALLEY LIFTS
NWD TO NEAR THE NRN MN/CANADIAN BORDER.  SURFACE CYCLOGENESIS IS
FORECAST TO OCCUR THIS AFTERNOON ALONG THE FRONT OVER NERN WY IN
ADVANCE OF THE UPPER TROUGH...WITH THE LOW MOVING ENEWD INTO SD
TONIGHT.

STRONG SOUTHERLY LOW LEVEL JET OVER THE ERN DAKOTAS IS EXPECTED TO
LIFT NEWD ACROSS NRN MN THIS AFTERNOON...WITH MOISTURE SPREADING NWD
ACROSS NRN MN. ALTHOUGH AIR MASS WILL DESTABILIZE AS DIURNAL
HEATING OCCURS...MODEL GUIDANCE INDICATES A CAP WILL PERSIST IN THE
WARM SECTOR AS WARMING ALOFT SPREADS ENEWD FROM THE PLAINS. 
CONVECTIVE POTENTIAL WILL BE VERY LIMITED SOUTH OF THE WARM FRONT
THIS AFTERNOON AND EVENING WITH THE PRIMARY THUNDERSTORM THREAT
OCCURRING IN THE WARM ADVECTION ZONE OVER SERN MANITOBA AND NWRN
ONTARIO.

THUNDERSTORM PROBABILITIES ARE EXPECTED TO INCREASE OVER PARTS OF
NRN WY/SRN MT LATER THIS AFTERNOON AND EVENING AS DYNAMIC FORCING
FOR LARGE SCALE ASCENT IN ADVANCE OF THE UPPER TROUGH PROGRESSES EWD
ACROSS THE ROCKIES.  ISOLATED STRONG WIND GUSTS MAY OCCUR WITHIN
ENVIRONMENT CHARACTERIZED BY A DEEP MIXED LAYER AND STEEP LAPSE
RATES. PRIMARILY ELEVATED STORMS ARE EXPECTED TO INCREASE IN
COVERAGE TONIGHT OVER THE NRN HIGH PLAINS AS A STRONG SOUTHERLY LOW
LEVEL JET REDEVELOPS WWD INTO SD...ENHANCING CONVERGENCE AND WARM
ADVECTION ALONG/NORTH OF THE FRONT.  THIS CONVECTION WILL SPREAD
ENEWD ACROSS NRN SD AND PARTS OF ND THROUGH THE OVERNIGHT HOURS. 
ISOLATED HAIL MAY BE POSSIBLE WITH STRONGER CELLS BUT ELEVATED
INSTABILITY OF LESS THAN 500 J/KG IS EXPECTED TO LIMIT SEVERE
THREAT.

...TN VALLEY...
WELL-DEFINED UPPER LOW IS DRIFTING SEWD ACROSS SERN MO/NERN AR
TOWARD WRN TN. SYSTEM IS ASSOCIATED WITH RELATIVELY COOL 500 MB
TEMPERATURES OF -10 TO -11C ACCORDING TO 12Z LZK SOUNDING AND LATEST
RUC HOURLY ANALYSES.  STRONG HEATING IN ADVANCE OF THE UPPER LOW
COMBINED WITH AMPLE LOW LEVEL MOISTURE /SURFACE DEW POINTS AROUND
70F/ IS RESULTING IN AN AXIS OF MAXIMUM INSTABILITY  WITH MLCAPE
NEAR 2000 J/KG FROM WRN TN INTO MS.  ALTHOUGH WATER VAPOR IMAGERY
SHOWS APPARENT SUBSIDENCE WITHIN THIS AXIS...CU IS DEVELOPING WWD
ACROSS NRN MS AND WRN TN AND NEW STORMS ARE FORMING OVER NWRN TN. 
THIS SUGGESTS THAT ADDITIONAL STORMS WILL DEVELOP THIS AFTERNOON AS
UPWARD VERTICAL MOTION AHEAD OF THE UPPER LOW SPREADS EWD.  PRESENCE
OF DRY AIR ABOVE 700 MB AND MODERATE INSTABILITY INDICATE POTENTIAL
FOR A FEW CELLS TO PRODUCE HAIL AND STRONG WIND GUSTS. GENERALLY
WEAK VERTICAL SHEAR IN THE LOWEST 6 KM SHOULD LIMIT OVERALL SEVERE
THREAT.

..WEISS/JEWELL.. 09/12/2004

...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.