[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 121253
SWODY1
SPC AC 121251

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0651 AM CST SAT NOV 12 2005

VALID 121300Z - 131200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SW
FNB 35 NNE LNK 35 NNW SUX 10 NW OTG 35 SSE MSP 30 NE RST 45 NNW DBQ
25 NW MLI 25 SSE BRL 45 WSW FAM 30 SSE BVX 25 ENE ELD 50 WNW POE UTS
20 SSE ACT 10 W DAL 35 NE TUL 25 ENE CNU 20 SW FNB.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 15 ENE ANJ 10 NNE BAX
15 SE DAY 20 NE BNA 25 W MSL 30 N HEZ 35 SSE POE 65 SW 7R4
...CONT... 65 NE BRO 50 N MFE 50 ESE LRD 20 SW COT 55 WSW HDO 45 SSW
JCT 25 NE JCT 25 NNW MWL 25 N OKC 35 NW PNC 45 S RSL 25 SSW HLC 10
SW GLD 40 E AKO 45 SE AIA 40 ENE AIA 20 SSE PIR 25 SW DTL 40 ENE BJI
30 N INL.

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON INTO TONIGHT
FROM NE TX TO IA....

...SYNOPSIS...
A MID LEVEL SHORTWAVE TROUGH OVER THE HIGH PLAINS OF TX/OK/KS/NEB
THIS MORNING WILL MOVE ENEWD TO IA/MO/AR BY THIS EVENING...AND
ACCELERATE NEWD WHILE GRADUALLY PHASING WITH A SEPARATE MID LEVEL
TROUGH /NOW OVER THE NRN ROCKIES/ LATE TONIGHT OVER THE UPPER MS
VALLEY AND UPPER GREAT LAKES REGION.  AN ASSOCIATED 994 MB SURFACE
CYCLONE IN CENTRAL NEB WILL DEVELOP NEWD ALONG A PRE-EXISTING
BAROCLINIC ZONE...REACHING CENTRAL MN THIS EVENING AND LAKE SUPERIOR
LATE TONIGHT.  THE SURFACE TROUGH/DRYLINE TRAILING THE SURFACE
CYCLONE WILL BE THE PRIMARY FOCUS FOR SEVERE STORM DEVELOPMENT THIS
AFTERNOON INTO TONIGHT.  

...NE TX TO IA AREA THIS AFTERNOON INTO TONIGHT...
BOUNDARY LAYER DEWPOINTS IN THE UPPER 50S TO MID 60S ARE SURGING NWD
FROM TX ACROSS CENTRAL OK/KS TOWARD ERN NEB.  REGIONAL SOUNDINGS
FROM 00Z AND 12Z REVEAL A DEEP MOISTURE PLUME OFFSET E OF THE
SURFACE MOISTURE AXIS...IN THE REGION OF ASCENT DOWNSTREAM FROM THE
EJECTING MID LEVEL TROUGH.  IT APPEARS THAT THIS BELT OF ASCENT WILL
BE E OF THE SURFACE WARM SECTOR BY THIS AFTERNOON ...AND MAY SUPPORT
SOME ELEVATED CONVECTION FROM ERN OK/WRN AR ACROSS MO/WRN IL/ERN IA.
 W OF THIS BELT OF CLOUDS/CONVECTION...A NARROW INSTABILITY CORRIDOR
/MLCAPE VALUES OF 500-1000 J/KG/ IS EXPECTED FROM NE TX/ERN OK NWD
ACROSS EXTREME ERN KS/WRN MO TO WRN AND CENTRAL IA THIS EVENING.

THOUGH THE DEEP LAYER FORCING FOR ASCENT WILL BE E OF THE SURFACE
DRYLINE AND WARM SECTOR THIS AFTERNOON...THE COMBINATION OF
LOW-LEVEL LIFT ALONG THE BOUNDARY AND SURFACE HEATING SHOULD BE
SUFFICIENT FOR SCATTERED THUNDERSTORM DEVELOPMENT BY MID AFTERNOON
INVOF THE MID MO VALLEY.  STORMS ARE EXPECTED TO MOVE QUICKLY NEWD
DURING THE EVENING ACROSS IA...WHILE DEVELOPING SWD INTO MO.  THE
MODERATE INSTABILITY AND DEEP LAYER FLOW/SHEAR ACROSS THE DRYLINE
APPEAR SUPPORTIVE OF DISCRETE SUPERCELLS...AND PERHAPS SHORT LINE
SEGMENTS...WITH THE POTENTIAL FOR LARGE HAIL AND DAMAGING GUSTS.  A
COUPLE OF TORNADOES MAY ALSO OCCUR DURING LATE THIS AFTERNOON S OF
THE SURFACE LOW ACROSS IA/MO WHERE STRONG LOW-LEVEL SHEAR COINCIDES
WITH THE SURFACE MOISTURE AXIS.  

TONIGHT...THE STORMS ACROSS MO/IA WILL MOVE QUICKLY E OF THE
DIMINISHING SURFACE WARM SECTOR.  THE THREAT FOR SEVERE STORMS WILL
DIMINISH NEAR AND E OF THE MS RIVER AS INSTABILITY WEAKENS AND
STORMS BECOME ROOTED ABOVE A PRONOUNCED STABLE LAYER NEAR THE
GROUND.  FARTHER SW...A BAND OF THUNDERSTORMS WILL LIKELY FORM
DURING THE EVENING ALONG THE SURFACE DRYLINE/FRONT ACROSS ERN OK/WRN
AR...WITH STORMS EXPECTED TO MOVE EWD ACROSS AR AND DEVELOP SWWD
INTO NE TX OVERNIGHT.  INSTABILITY AND VERTICAL MAY SUPPORT
SUPERCELLS AND/OR EMBEDDED BOW ECHOES EARLY TONIGHT ACROSS THIS
AREA.  HOWEVER...THE SEVERE THREAT SHOULD DECREASE BY ABOUT MIDNIGHT
AS INSTABILITY GRADUALLY WEAKENS...AND VERTICAL SHEAR DECREASES IN
RESPONSE TO THE MAIN SYNOPTIC SYSTEM LIFTING WELL N/NE OF THIS AREA.

..THOMPSON/JEWELL.. 11/12/2005

...NOTICE...
THE STATION RELATIVE POINTS IN THIS PRODUCT ARE NOW AVAILABLE
SEPARATELY UNDER THE WMO HEADINGS WUUS01 PTSDY1...
WUUS02 PTSDY2...WUUS03 PTSDY3.  THE INCLUSION OF POINTS
IN THIS DISCUSSION WILL BE DISCONTINUED AFTER THE 2005
CONVECTIVE SEASON.  A PUBLIC NOTIFICATION STATEMENT (PNS)
WILL PROVIDE DETAILS ON THE TRANSITION.