[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 100522
SWODY2
SPC AC 100521

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1221 AM CDT SUN SEP 10 2006

VALID 111200Z - 121200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...

LATEST SHORT-RANGE MODEL GUIDANCE HAS COME INTO MUCH BETTER
AGREEMENT IN EVOLUTION OF MID/UPPER-LEVEL TROUGH OVER THE MIDWEST
INTO UPPER MS VALLEY.  THIS FEATURE...CURRENTLY COMPOSED OF SEVERAL
SMALLER PERTURBATIONS OVER KS AND NEB...IS FORECAST TO PHASE WITH
NRN BRANCH IMPULSES OVER BRITISH COLUMBIA AND
SASKATCHEWAN/MANITOBA...EFFECTIVELY FORMING A LARGER-SCALE TROUGH
DURING THE DAY TWO PERIOD.  IN THE LOW-LEVELS...ATTENDANT SURFACE
LOW WILL DEVELOP GENERALLY EWD ACROSS CNTRL MO INTO CNTRL IL WHILE
TRAILING COLD FRONT PUSHES SWD INTO THE LOWER MS VALLEY AND CNTRL
TX.  A WEAK WARM OR STATIONARY FRONT WILL EXTEND EWD FROM THIS LOW
ACROSS THE OH VALLEY.

...OH VALLEY INTO OZARK PLATEAU...

IT APPEARS CONSIDERABLE CLOUDS AND PRECIPITATION WILL LIKELY PERSIST
THROUGH MUCH OF THE PERIOD FROM VICINITY OF SURFACE LOW EWD ALONG
WARM FRONT OWING TO STRONG DEEP-LAYER FORCING VIA LOW-LEVEL WAA AND
DCVA AHEAD OF EVOLVING UPPER TROUGH.  BETTER POTENTIAL FOR AIR MASS
DESTABILIZATION WILL LIKELY OCCUR ACROSS PRE-COLD FRONTAL WARM
SECTOR --I.E. CNTRL/SRN PARTS OF MO/IL-- WHERE STRONGER DIABATIC
HEATING WILL COMBINE WITH DEWPOINTS IN THE 60S TO SUPPORT MLCAPES OF
1000-1500 J/KG.

EXPECT TSTMS TO INCREASE IN COVERAGE AND INTENSITY THROUGH THE
AFTERNOON AS FORCING ASSOCIATED WITH UPPER TROUGH AND SURFACE FRONT
ENCOUNTER DESTABILIZING AIR MASS.  NEITHER VERTICAL SHEAR NOR
MID-LEVEL LAPSE RATES ARE FORECAST TO BE PARTICULARLY STRONG AND
THIS SHOULD TEND TO LIMIT UPDRAFT STRENGTH/STORM ORGANIZATION. 
STILL...THE PRESENCE OF RELATIVELY STEEP LOW-LEVEL LAPSE RATES AND
MODEST INSTABILITY MAY SUPPORT A FEW MARGINALLY SEVERE STORMS
CAPABLE OF STRONG WINDS AND SOME HAIL.

STRONGER LOW AND DEEP-LAYER SHEAR WILL LIKELY EXIST NEAR SURFACE LOW
EWD ALONG WARM FRONT.  HOWEVER...IT APPEARS THAT INSTABILITY WILL
REMAIN QUITE MARGINAL OWING TO THE PERSISTENT CLOUDS/PRECIPITATION.

...SRN PLAINS...

DIURNAL STRONG STORMS WILL BE POSSIBLE MONDAY AFTERNOON INTO EVENING
BOTH ALONG COLD FRONT AS WELL AS IN POST-FRONTAL UPSLOPE OVER
CNTRL/ERN NM WITHIN UNSTABLE AIR MASS WITH MLCAPES OF 500-1500 J/KG.
HERE TOO...VERTICAL SHEAR WILL REMAIN RELATIVELY WEAK...WITH THE
EXCEPTION BEING OVER CNTRL/ERN NM WHERE BACKED LOW-LEVEL WINDS WILL
RESULT IN EFFECTIVE BULK SHEAR APPROACHING 30 KTS.  LOCALLY STRONG
WIND GUSTS WILL BE POSSIBLE WITH THE MOST INTENSE STORMS OVER THE
LOWER ELEVATIONS...WHILE THE THREAT OF MARGINALLY SEVERE HAIL WILL
EXIST WITH THE STRONGER CELLS DEVELOPING OVER THE HIGH PLAINS.

..MEAD.. 09/10/2006