[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 131249
SWODY1
SPC AC 131247

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0647 AM CST SAT JAN 13 2007

VALID 131300Z - 141200Z

...NO SVR TSTM AREAS FORECAST...

...SRN PLAINS INTO THE LOWER OH RIVER VALLEY...
PAIR OF PROGRESSIVE SHORTWAVE TROUGHS CONTINUE TO EJECT OUT OF
BROADER WRN U.S. TROUGH THIS MORNING.  LEADING WAVE RESPONSIBLE FOR
CONSIDERABLE RAIN/ZR/IP ACROSS THE SRN PLAINS INTO THE LOWER OH
RIVER VALLEY WILL CONTINUE TO LIFT NEWD WITH DIMINISHING
THUNDERSTORM POTENTIAL.  SECOND IMPULSE APPEARED TO BE EJECTING
ACROSS THE SRN HIGH PLAINS EARLY THIS MORNING.  AT THE
SURFACE...ARCTIC COLD FRONT NOW EXTENDING FROM THE LOWER OH RIVER
VALLEY INTO THE ARKLATEX AND THE TX HILL COUNTRY AT 12Z.  MODEL
GUIDANCE INDICATES A WAVE WILL FORM ALONG THIS FRONT INTO SRN/SERN
AR THROUGH THE AFTERNOON.  LLJ WILL REMAIN ACROSS MOST OF ERN TX
INTO THE LOWER OH RIVER VALLEY TODAY...BEFORE REFORMING FARTHER WEST
OVERNIGHT IN RESPONSE TO MAIN UPPER TROUGH EXPECTED TO BEGIN
EJECTING ENEWD LATE IN THE PERIOD.

SIMILAR TO YESTERDAY...WARM SECTOR AIR MASS WILL BE SLOW TO
DESTABILIZE TODAY WITH EXTENSIVE CONVECTION ACROSS MUCH OF AREA
WITHIN PERSISTENT LOW LEVEL WAA.  HOWEVER...DEEP LAYER SHEAR WILL
REMAIN MORE THAN ADEQUATE FOR ROTATING STORMS UNDER MODERATE SWLY
FLOW ALOFT AS EVIDENCED BY 12Z SHV SOUNDING.  IN ADDITION...INFLUX
OF LOWER/MID 60F SURFACE DEW POINTS AND POSSIBLE SURFACE PRESSURE
FALLS FROM NERN TX INTO PORTIONS OF AR MAY SUPPORT STRONG TO
MARGINALLY SEVERE THUNDERSTORM POTENTIAL THIS AFTERNOON AND EVENING
ACROSS THIS AREA.

FARTHER WEST TOWARDS THE BIG BEND REGION...DEEP LAYER SHEAR IS
ALREADY QUITE STRONG ACCORDING TO 12Z SOUNDING AT DRT AND MID LEVEL
LAPSE RATES ARE MODERATELY STEEP.  HEATING WILL BE MODULATED BY MID
LEVEL CLOUDS/MOISTURE FEEDING OFF THE PACIFIC.  HOWEVER...LOW SEVERE
PROBABILITIES ARE WARRANTED SHOULD SURFACE BASED CAPE BE REALIZED
THIS AFTERNOON/EARLY EVENING AHEAD OF THE FRONT.

..EVANS.. 01/13/2007