[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 121630
SWODY1
SPC AC 121628

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1028 AM CST SAT NOV 12 2005

VALID 121630Z - 131200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 SW
FNB 35 N LNK 20 E YKN 35 NW OTG 20 NNE MKT 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 50 E CRP 25 NE COT 25
NNW HDO 15 WSW FTW 20 E OKC 30 ENE CNK 10 WSW OLU 35 E ONL 20 ENE
VTN 35 NNW VTN 25 NNE PIR 15 N INL ...CONT... 35 NW CLE 45 ESE BWG
40 E TUP 30 N HEZ 45 NW LFT 55 SW 7R4.

...THERE IS A SLGT RISK OF SVR TSTMS FROM NERN TX INTO IA...

...SYNOPSIS...
VIGOROUS UPPER TROUGH MOVING EWD ACROSS THE CENTRAL PLAINS IS
FORECAST TO ACCELERATE NEWD TOWARD THE UPPER/MIDDLE MS VALLEY BY
THIS EVENING BEFORE MERGING WITH RAPIDLY MOVING UPSTREAM SYSTEM NOW
OVER THE NRN ROCKIES.  THIS WILL RESULT IN AN UPPER LOW OVER THE FAR
WRN LAKE SUPERIOR REGION BY THE END OF THE PERIOD.  AT THE
SURFACE...A DEEP LOW NOW OVER NORTH CENTRAL NEB IS FORECAST TO
FURTHER DEEPEN AS IT MOVES NEWD ALONG A QUASI-STATIONARY
FRONT...REACHING SWRN MN BY 00Z AND WRN LAKE SUPERIOR BY 12Z.  A DRY
LINE EXTENDING SWD FROM THE LOW ACROSS CENTRAL KS/WRN OK/SWRN TX
WILL MOVE EWD INTO THE ERN PARTS OF NEB/KS/OK AND CENTRAL TX THIS
EVENING.  THE NRN PORTION OF THE DRY LINE FROM KS/MO NWD WILL BE
OVERTAKEN BY A COLD FRONT THIS AFTERNOON AND EVENING...WHICH WILL
SURGE ACROSS THE UPPER AND MIDDLE MS VALLEY TOWARD THE WRN LAKES
THROUGH TONIGHT.  THE SRN PART OF THE DRY LINE WILL MOVE MORE SLOWLY
AND BECOME QUASI-STATIONARY FROM NRN AR ACROSS CENTRAL TX.  THE COLD
FRONT/DRYLINE WILL BE THE PRIMARY FOCUS FOR STRONG/SEVERE CONVECTION
THIS AFTERNOON INTO TONIGHT.

...MIDDLE/LOWER MO VALLEY...
LOW LEVEL MOISTURE IS INCREASING NWD FROM THE SRN PLAINS INTO ERN
PARTS OF KS AND NEB AND EXTREME WRN MO/IA THIS MORNING...WITH
SURFACE DEW POINTS IN THE UPPER 50S-LOWER 60S EVIDENT ACROSS THIS
REGION.  A RELATIVELY NARROW MOISTURE/INSTABILITY AXIS IS FORECAST
TO BECOME ESTABLISHED FROM CENTRAL/ERN TX ACROSS ERN PARTS OF
OK/KS/NEB INTO WRN IA/MO BY LATE AFTERNOON WITH MLCAPE OF 500-1000
J/KG.

SATELLITE IMAGERY SHOWS DYNAMIC FORCING FOR LARGE SCALE ASCENT IS 
ASSOCIATED WITH THE CLOUD SHIELD FROM ERN OK/WRN AR NWD INTO ERN
NEB/WRN IA...WITH A PRONOUNCED MIDDLE/UPPER LEVEL DRY SLOT
IMMEDIATELY UPSTREAM FROM THE DEEP LAYER MOISTURE PLUME.  THIS IS
RESULTING IN CLEARING ALONG THE WESTERN PART OF THE LOW LEVEL
MOISTURE AXIS AHEAD OF THE DRY LINE...WHERE AN AXIS OF DIABATIC
HEATING AND DESTABILIZATION IS EXPECTED TO OCCUR THIS AFTERNOON. 
EXAMINATION OF FORECAST SOUNDINGS FROM THE 12Z ETA..14Z RUC..AND 09Z
ETAKF CONTROL MEMBER FROM THE SREF INDICATE THE CAP WILL DIMINISH IN
THE 20-22Z PERIOD AHEAD OF THE DRY LINE AS COMBINATION OF LOW LEVEL
CONVERGENCE AND UPPER LEVEL PV ADVECTION PROVIDES SUFFICIENT LIFT. 
THIS WILL RESULT IN CONVECTIVE DEVELOPMENT TO OCCUR...INITIALLY OVER
EXTREME ERN NEB SPREADING RAPIDLY EWD INTO WRN IA WITH ADDITIONAL
SWD DEVELOPMENT INTO EXTREME ERN KS AND WRN MO.  DESPITE RELATIVELY
MODEST VALUES OF MLCAPE...STRONG DEEP LAYER SHEAR AND LOW LEVEL SRH
INDICATE POTENTIAL FOR SEVERE STORMS TO DEVELOP...INCLUDING A FEW
TORNADIC SUPERCELLS.  THIS ACTIVITY WILL MOVE RAPIDLY EWD/NEWD
THROUGH THE EVENING HOURS IN ASSOCIATION WITH THE ACCELERATING UPPER
TROUGH/SURFACE COLD FRONT...AND WILL GRADUALLY MOVING EAST OF THE
LOW LEVEL MOISTURE/INSTABILITY AXIS.  THIS SUGGESTS THAT SEVERE
POTENTIAL MAY DIMINISH AFTER 03-06Z ALTHOUGH SMALL POTENTIAL FOR
STRONG WIND GUSTS WITH A LOW TOPPED BAND OF STORMS MAY PERSIST
ACROSS THE MS VALLEY INTO PARTS OF WI AND IL LATER TONIGHT.

...ERN OK/WRN AR/NORTH CENTRAL/NERN TX/NWRN LA...
INCREASED LOW LEVEL MOISTURE AND LARGER INSTABILITY WITH MLCAPE OF
1000-1500 J/KG WILL EXIST FROM ERN OK/WRN AR INTO CENTRAL AND ERN TX
THIS AFTERNOON INTO TONIGHT.  A BAND OF STRONG/SEVERE STORMS IS
EXPECTED TO DEVELOP OVER ERN OK INTO NORTH CENTRAL/NERN TX LATE THIS
AFTERNOON AND EVENING...WITH THE NRN PART OF THE BAND MOVING MORE
RAPIDLY EWD INTO AR WHILE SRN PART OF BAND MOVES SLOWLY EWD ACROSS
ERN TX.  THIS WILL RESULT IN THE BAND BECOMING MORE
NORTHEAST-SOUTHWEST ORIENTED WITH TIME.  DEEP LAYER SHEAR WILL BE
SUFFICIENT TO ENHANCE STORM ORGANIZATION AND INTENSITY WITH SEVERE
STORMS LIKELY TO OCCUR.  PRIMARY THREAT WILL BE LARGE HAIL AND
DAMAGING WIND GUSTS.

..WEISS/CROSBIE.. 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.