[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 151617
SWODY1
SPC AC 151615

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1115 AM CDT TUE AUG 15 2006

VALID 151630Z - 161200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
PRIMARY WESTERLIES REMAIN ACROSS NRN TIER OF CONUS WITH PROGRESSIVE
LARGE SCALE FEATURES.  TROUGH MOVING EWD THRU NERN STATES WHILE SOME
AMPLIFICATION OCCURS UPSTREAM WITH TROUGH ENTERING PAC NW.  BROAD
RIDGE SHIFTS EWD ACROSS NRN PLAINS/UPPER MS VALLEY THIS FORECAST
PERIOD.  S/WV IMPULSE RIDING ACROSS RIDGE LOCATED WY/SRN MT WILL
CROSS NRN PLAINS TONIGHT.

COLD FRONT WILL MOVE OFF NERN COAST THIS AFTERNOON TRAILING WSWWD
THRU DELMARVA TO TN/MID MS VALLEY.  WWD ACROSS SRN PLAINS FRONT WILL
BEGIN LIFTING NWD AS LEE TROUGH DEVELOPS E OF ROCKIES.

...NRN HIGH PLAINS...
RATHER ACTIVE OVERNIGHT HIGH BASED CONVECTION NOTED WITH S/WV NOW
CROSSING WY/SRN MT.  THIS FEATURE WILL PROVIDE SOME DYNAMIC SUPPORT
ALONG WITH ENHANCED DEEP LAYER SHEAR FOR POTENTIAL OF STRONG/SEVERE
THUNDERSTORMS THIS AFTERNOON.  WITH STEEP LAPSE RATES IN PLACE AND
LOW LEVEL MOISTURE SPREADING NWD THRU HIGH PLAINS E OF LEE
TROUGH...EXPECT AT LEAST ISOLATED SEVERE STORMS TO DEVELOP BY MID
AFTERNOON WITH PRIMARY THREAT LARGE HAIL AND DOWNBURST WINDS.  WHILE
SHEAR OF 35-40KT SUGGESTS AN UPGRADE COULD BE NEEDED...THERE IS
SUFFICIENT DOUBT AS TO AVAILABLE MOISTURE/INSTABILITY TO SUPPORT THE
STORM COVERAGE NEED FOR A SLIGHT RISK ATTM.  PORTION OF HIGH PLAINS
COULD BE UPGRADED IN AFTERNOON UPDATE.

FARTHER W STEEP LAPSE RATES AND STRONG HEATING WILL SUPPORT
REDEVELOPMENT OF HIGH BASED STORMS FROM SERN ID ACROSS NRN WY/SRN
MT. PRIMARY THREAT WOULD BE ISOLATED STRONG WINDS.

...MID ATLANTIC STATES WWD TO LOWER MS VALLEY...
AIR MASS S OF FRONTAL ZONE REMAINS MOIST AND POTENTIALLY VERY
UNSTABLE.  WHILE WEAK SHEAR PROFILES SUPPORT PRIMARILY PULSE
STORMS...MLCAPES UPWARDS TO 2000 J/KG AND STEEP LOW LEVEL LAPSE
RATES SUPPORT WET DOWNBURSTS.  SEVERE THREAT WILL BE HIGHLY DIURNAL 
DIMINISHING BY SUNSET.

..HALES/GUYER.. 08/15/2006