[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 120556
SWODY1
SPC AC 120555

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1155 PM CST FRI NOV 11 2005

VALID 121200Z - 131200Z

THERE IS A SLGT RISK OF SVR TSTMS TO THE RIGHT OF A LINE FROM 20 E
CNK 10 WNW OLU 20 E YKN 10 NE OTG 30 ENE MKT 35 SSE EAU 25 SSE VOK
25 ENE MLI 25 E BRL 20 N FAM 20 S JBR 40 ESE PBF 50 WNW POE UTS 20
SSE ACT 10 W DAL 35 NE TUL 35 E EMP 20 E CNK.

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.

GEN TSTMS ARE FCST TO THE RIGHT OF A LINE FROM 65 NE BRO 50 N MFE 50
ESE LRD 20 SW COT 55 WSW HDO 45 SSW JCT 25 NE JCT 25 NW MWL 25 SSE
CHK 25 WSW ICT 30 W HUT 15 NW GCK 30 ENE LAA 30 WSW ITR 25 ENE AKO
50 ENE SNY 10 WNW 9V9 25 SW DTL 40 ENE BJI 30 N INL.

...THERE IS A SLGT RISK OF SVR TSTMS FROM THE CNTRL PLAINS/UPR MS
VALLEY TO THE ARKLATEX...

...SYNOPSIS...
AN ACTIVE PATTERN TAKING SHAPE ACROSS THE CNTRL U.S. THIS PERIOD AS
LARGE SCALE PHASING OF NRN AND SRN STREAMS PRODUCES A DEEP AND
PROGRESSIVE UPPER TROUGH FROM THE GREAT PLAINS TO THE GREAT LAKES
THROUGH EARLY SUNDAY. SURFACE LOW...CURRENTLY FORMING ACROSS
NEB...WILL INTENSIFY THROUGH THE DAY WHILE MOVING OVER THE MO RIVER
VALLEY TO SRN MN/NRN IA BY EVENING. INTENSIFYING LOW LEVEL JET AHEAD
OF THE CYCLONE AND ASSOCIATED COLD FRONT WILL CONTINUE TO TRANSPORT
MOISTURE NWD/NEWD FROM THE SRN PLAINS TO THE UPPER MS VALLEY.
MEANWHILE...A DRYLINE WILL MIX EAST ACROSS THE SRN PLAINS AND BE
SITUATED FROM NRN TX TO ERN OK/SWRN MO LATER TODAY. SURFACE COLD
FRONT WILL SURGE ACROSS THE MIDWEST AND LOWER GREAT LAKES REGION
OVERNIGHT AS RAPIDLY DEEPENING SURFACE LOW TRACKS NEWD TO WRN LAKE
SUPERIOR THROUGH SUNDAY MORNING. THE TRAILING PORTION OF THE COLD
FRONT WILL OVERTAKE THE DRYLINE OVER MO AND THEN SETTLE SEWD TOWARD
THE LOWER MS VALLEY THROUGH EARLY SUNDAY.

...CNTRL PLAINS TO MID/UPPER MS VALLEY...
AS SURFACE LOW MOVES OVER NEB/IA THROUGH LATE AFTERNOON/EARLY
EVENING...STRENGTHENING WARM CONVEYOR BELT WILL RESULT IN AN
EXPANDING AREA OF ELEVATED CONVECTION ON THE EDGE OF STRONGER
CAPPING FROM MO TO MN. A RELATIVELY NARROW AXIS OF MODEST
SURFACE-BASED INSTABILITY /MLCAPE 500 TO 1000 J/KG/ IS EXPECTED TO
DEVELOP IN THE WAKE OF THE WARM CONVEYOR CLOUD AND PRECIPITATION
SHIELD...AND BENEATH MID LEVEL DRY SLOT...FROM ERN KS/NEB NEWD TO
IA/SRN MN. STRONG FORCING FOR ASCENT NEAR THE MID LEVEL VORT MAX AND
SOUTH OF THE SURFACE LOW WILL OVERCOME LOW LEVEL CAP TO SUPPORT
SUPERCELL INITIATION OVER ERN NEB BY LATE AFTERNOON. THIS ACTIVITY
WILL THEN SPREAD EAST ACROSS SRN MN/IA AND NRN MO DURING THE EVENING
AND PROBABLY BECOME INCREASING LINEAR AND ELEVATED WITH TIME.

DESPITE THE NARROWNESS OF THE INSTABILITY AXIS ACROSS MO/IA/SRN MN
DURING THE LATE AFTERNOON AND EARLY EVENING...MAGNITUDE OF FORCING
AND EFFECTIVE SURFACE-BASED SHEAR IN THE RANGE OF 200-400 M2/S2 PER
NAM/NAMKF SOUNDINGS...SUGGEST THAT A COUPLE OF TORNADOES ARE
POSSIBLE FROM ANY DISCRETE CELLS DEVELOPING IN THE WARM SECTOR. A
GREATER CHANCE WILL EXIST FOR LARGE HAIL AND PERHAPS A DAMAGING
WINDS AS CONVECTION EVOLVES INTO PREFRONTAL SQUALL LINE FROM SERN MN
TO WRN IL BY LATE EVENING. SEVERE POTENTIAL WILL LIKELY DIMINISH
WITH TIME AS THE SQUALL LINE MOVES EAST AND ENCOUNTERS STABILIZED
BOUNDARY LAYER ACROSS THE LOWER GREAT LAKES REGION OVERNIGHT.

...SRN PLAINS TO LOWER MS VALLEY...
WHILE LARGE SCALE FORCING AND MASS INFLOW APPEAR TO FAVOR MORE
WIDESPREAD TSTM DEVELOPMENT FROM MO NWD...MODEST HEIGHT FALLS WITHIN
THE BASE OF THE CNTRL PLAINS TROUGH WILL OVERSPREAD THE MOIST AXIS
COINCIDENT WITH STRONGER DIURNAL HEATING FROM NERN TX/ERN OK TO WRN
AR/SWRN MO. MODEL GUIDANCE SUGGESTS CAPPING SHOULD BE OVERCOME AHEAD
OF A WEAK DRYLINE IN THESE AREAS AND SUPPORT SURFACE-BASED STORM
INITIATION BEFORE DARK. DEEP LAYER SHEAR ON THE ORDER OF 35-50KT
WILL SUPPORT SUPERCELLS WITH POTENTIAL FOR LARGE HAIL AND PERHAPS A
TORNADO. CONVECTION MAY INCREASE AFTER DARK FROM AR SWWD TO TX AS
INITIAL ACTIVITY MERGES AND DEEPENING COLD POOL MAINTAINS LIFT AND
STORM REGENERATION IN MOIST AND WEAKLY CAPPED AIR MASS ACROSS THE
REGION. MARGINAL WIND AND HAIL THREAT MAY PERSIST WITH THIS LINEAR
MCS AS IT SPREADS SEWD TOWARD THE LOWER MS VALLEY THROUGH DAYBREAK
SUNDAY.

..CARBIN/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.