[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 090549
SWODY2
SPC AC 090548

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1248 AM CDT SAT SEP 09 2006

VALID 101200Z - 111200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

LATEST MODEL GUIDANCE SHOWS A LARGE DEGREE OF VARIABILITY IN
EVOLUTION OF MID/UPPER-LEVEL CIRCULATION EMBEDDED WITHIN A WEAK
SUB-TROPICAL BRANCH OF WESTERLIES OVER THE CNTRL/SRN PLAINS.  THE
GFS TAKES THIS FEATURE E INTO THE LOWER MO VALLEY...WITH THE NAM/WRF
THE FARTHEST S AND THE ECMWF INDICATING LITTLE MOVEMENT THROUGH THE
PERIOD.  SIMILARLY...DIFFERENCES EXIST IN LOCATION AND TRACK OF
ATTENDANT SURFACE LOW AND SURFACE FRONT...WITH LOW SEVERE
PROBABILITIES ASSIGNED TO ROUGHLY A MEAN COLD FRONTAL POSITION AT
THE TIME OF PEAK HEATING.

...CNTRL/SRN PLAINS...

GIVEN THESE DIFFERENCES...CONSIDERABLE UNCERTAINTY EXISTS IN THE
INITIATION AND EVOLUTION OF DIURNAL TSTM DEVELOPMENT SUNDAY
AFTERNOON AND EVENING. IT DOES APPEAR THAT FAIRLY WIDESPREAD CLOUDS
AND PRECIPITATION WILL LIMIT AIR MASS DESTABILIZATION AHEAD OF
SURFACE LOW AND COLD FRONT OVER KS.  FARTHER TO THE S...DEWPOINTS IN
MID 50S TO LOWER 60S COUPLED WITH ANTICIPATED STRONGER DIABATIC
HEATING SHOULD CONTRIBUTE TO THE DEVELOPMENT OF MODERATE AFTERNOON
INSTABILITY AHEAD OF FRONT FROM PORTIONS OF THE TX PNHDL AND S
PLAINS EWD INTO WRN AND PERHAPS CNTRL OK WITH MLCAPES OF 1000-1500
J/KG.

TSTMS ARE EXPECTED TO BECOME INCREASINGLY LIKELY BY AFTERNOON AS
FRONT ENCOUNTERS THIS STRONGER INSTABILITY.  THOUGH AMBIENT WIND
FIELDS WILL NOT BE PARTICULARLY STRONG...FORECAST SOUNDINGS INDICATE
PRONOUNCED VEERING THROUGH THE LOWEST 3 KM AGL WITH 30-35 KTS OF
EFFECTIVE BULK SHEAR.  THIS COMBINATION OF MODEST INSTABILITY AND
SHEAR SHOULD SUPPORT AT LEAST A FEW ORGANIZED STORMS CAPABLE OF
LOCALLY STRONG WIND GUSTS AND SEVERE HAIL THROUGH THE AFTERNOON AND
EVENING HOURS.

..MEAD.. 09/09/2006