[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 101726
SWODY2
SPC AC 101726

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1226 PM CDT SUN SEP 10 2006

VALID 111200Z - 121200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
PROGRESSIVE SYNOPTIC PATTERN WILL FEATURE BUILDING HEIGHTS ACROSS
MUCH OF WRN CONUS...EXCEPT FOR REGIME OF ZONAL NRN STREAM FLOW
ACROSS PACIFIC NW.  SHORTWAVE TROUGH NOW ANALYZED OVER SRN ALTA IS
FCST TO DIG SSEWD OVER NRN HIGH PLAINS...REACHING CENTRAL HIGH
PLAINS BY 12/12Z.  DOWNSTREAM...BROAD/WEAK MID/UPPER LEVEL LOW --
NOW EVIDENT IN MOISTURE CHANNEL IMAGERY AND PROFILER DATA OVER ERN
NEB -- IS EXPECTED TO MOVE SLOWLY EWD ACROSS MID/UPPER MS VALLEY
REGION.  CONSIDERABLE DISAGREEMENT LINGERS AMONGST LATEST RUNS OF
SHORT-RANGE DETERMINISTIC MODELS AND SREFX MEMBERS REGARDING PRECISE
LOCATION OF CENTER BY 12/00Z AND THEREAFTER...AS WELL AS ASSOCIATED
60 M INTERVAL HEIGHT LINES AT 500 MB.  HOWEVER....MOST PROGGED
SCENARIOS AS WELL AS ENSEMBLE CONSENSUS FAVOR
DIFFUSE/POSITIVELY-TILTED SHORTWAVE TROUGH EXTENDING SWWD FROM THIS
LOW TO SRN HIGH PLAINS AT 12/00Z.

AT SFC...WEAK FRONTAL-WAVE LOW -- NOW ANALYZED OVER S-CENTRAL
NEB/N-CENTRAL KS -- SHOULD BE POSITIONED EARLY IN PERIOD INVOF NRN
MO AND TAKE CYCLONICALLY CURVING TRACK ENEWD/NEWD ACROSS NERN MO/NRN
IL.  CONSIDERABLE PROGNOSTIC VARIATIONS ALSO EXIST IN STRENGTH/TRACK
OF THIS FEATURE...WITH SPECTRAL BEING DEEPEST OUTLIER AND
OPERATIONAL ETA/NGM APPROXIMATING WEAKEST EXTENT OF ENSEMBLE
SPECTRUM.  COLD FRONT SHOULD MOVE SEWD FROM SRN HIGH PLAINS...NRN
OK...SERN KS POSITION AT 11/12Z TO NEAR AXIS FROM SERN
MO...CENTRAL-ERN AR...S-CENTRAL TX BY 12/12Z.

...LOWER OH/MS VALLEY TO NE TX...
SCATTERED TO WIDELY SCATTERED TSTMS ARE POSSIBLE BY MID-LATE
AFTERNOON...IN WEAKLY CAPPED AIR MASS ALONG/AHEAD OF SFC COLD FRONT.
 POTENTIAL EXISTS FOR A FEW ORGANIZED MULTICELL CLUSTERS TO
DEVELOP...MOST INTENSE CELLS PRODUCING STG-SVR GUSTS AND MRGLLY SVR
HAIL.  SEVERAL OFFSETTING FACTORS INDICATE AT LEAST MRGL POTENTIAL
BUT ALSO PRECLUDE MORE ROBUST SVR PROBABILITIES ATTM.  STRONGEST
DIRECTIONAL SHEAR WILL EXIST INVOF SFC FRONTAL-WAVE LOW...WHERE SFC
WINDS ARE RELATIVELY BACKED.  HOWEVER WEAK MIDLEVEL FLOW -- I.E.
15-25 KT AT 500 MB OVER MUCH OF REGION -- WILL PREVENT STRONG
DEEP-LAYER SHEAR FROM DEVELOPING.  UPPER LEVEL FLOW WILL BE
MAXIMIZED BENEATH BROAD SRN STREAM JET BRANCHES OVER  OZARKS AND
FROM TX ACROSS LOWER MS VALLEY...AIDING IN SHEAR THROUGH
CLOUD-BEARING LAYER.  WEAK DEEP-LAYER LAPSE RATES WILL LIMIT
CAPE...AS WILL POTENTIAL CLOUD COVER AND PRECIP OVER MUCH OF THIS
REGION.  HOWEVER...POCKETS OF FAVORABLE DIURNAL HEATING MAY YIELD
SHALLOW/WELL-MIXED BOUNDARY LAYERS MORE CONDUCIVE TO STG
GUSTS...WHILE SFC DEW POINTS GENERALLY IN 60S F SUPPORT MLCAPES IN
1000-2000 J/KG RANGE.

...CENTRAL HIGH PLAINS...
ISOLATED TO WIDELY SCATTERED TSTMS ARE POSSIBLE MAINLY FROM
MIDAFTERNOON THROUGH EARLY EVENING...AS INSOLATION OPTIMALLY
DESTABILIZES BOUNDARY LAYER OVER ERN MOUNTAINS AND ADJACENT
FOOTHILLS AND HIGH PLAINS.  MOISTURE WILL BE MORE LIMITED WITH NWD
EXTENT.  HOWEVER...LARGE SCALE ASCENT ASSOCIATED WITH MID-UPPER
TROUGH OVER NRN/CENTRAL HIGH PLAINS MAY CONTRIBUTE ENOUGH
DESTABILIZATION TO SUPPORT MRGL HAIL/WIND POTENTIAL AS FAR N AS
VICINITY CO/WY BORDER. TSTMS SHOULD MOVE GENERALLY SWD WITH ANY SVR
THREAT WEAKENING CONSIDERABLY AFTER SUNSET.

..EDWARDS.. 09/10/2006