[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 271640
SWODY1
SPC AC 271638

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1138 AM CDT SUN AUG 27 2006

VALID 271630Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF
THE DELMARVA....

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EVENING
ACROSS PARTS OF THE LOWER OHIO VALLEY...

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON AND EARLY
TONIGHT ACROSS THE CENTRAL HIGH PLAINS....

...SYNOPSIS...
MID/UPPER LEVEL LOW OVER THE CENTRAL ROCKIES WILL MOVE INTO NEB
DURING THE PERIOD.  TROUGH ASSOCIATED WITH THIS LOW WILL DRAG EWD
THRU THE CENTRAL AND NRN PARTS OF THE SRN PLAINS.  LATEST SURFACE
ANALYSIS SHOWS A SERIES OF CONVECTIVE BOUNDARIES THAT REACH FROM
CENTRAL IND WSWWD ACROSS SRN MO INTO NERN AND S CENTRAL OK INTO W
CENTRAL TX.  IN ADDITION...THERE IS A QUASI STATIONARY FRONT THAT
LIES FROM SRN NJ WWD ACROSS THE MD/WV PANHANDLE INTO CENTRAL OH. 
LOOKS AT THIS TIME THAT THE STRONGEST ACTIVITY TODAY AND EARLY
TONIGHT WILL FOCUS ON THESE AREAS WHERE THERMAL GRADIENTS WILL
PROVIDE THE MORE FAVORABLE THERMODYNAMICS FOR STRONG/ISOLATED SEVERE
THUNDERSTORMS.

...PARTS OF THE DELMARVA REGION FROM SRN PA/MD AND NRN VA INTO DE...


LATEST VISIBLE IMAGERY SHOWS SRN EDGES OF CLOUD COVER FROM DE/MD
INTO NRN VA THEN SWWD ACROSS SERN WV.  AREAS S OF THIS CLOUD COVER
DELINEATION WILL BE LOCATION OF BETTER DAYTIME HEATING/
THERMODYNAMICS.  ISOLATED STRONG/SEVERE THUNDERSTORMS ARE POSSIBLE
AS THERE WILL BE FAVORABLE SHEAR /STORM RELATIVE HELICITY AROUND 200
M2/S2/ DUE TO LOW LEVEL WARM ADVECTION.  LOOKS LIKE STRONG GUSTY
WINDS MAY BE THE MAIN THREAT LATER THIS AFTERNOON INTO THIS EVENING.


...PARTS OF THE LOWER OHIO VALLEY...

REMNANT OF COLD FRONTAL BOUNDARY EXTENDS FROM LOW OVER SERN ONTARIO
SWWD THRU SWRN IND INTO CENTRAL KS.  CONSIDERABLE CLOUDINESS COVERS
MUCH OF THESE REGION FROM PREVIOUS CONVECTION. THUS...ONCE AGAIN
WILL LOOK FOR WHERE THERMAL GRADIENTS MAY SET UP THE BEST FOR
AFTN/EVE THUNDERSTORM DEVELOPMENT.  BOTH THE NAM AND GFS DEVELOPS
CONVECTION ALONG THE SRN FRINGES OF THE CLOUD COVER FROM THE CENTRAL
MO/AR BORDER ENEWD INTO N CENTRAL KY.  SBCAPE IS FORECAST TO BE
BETWEEN 2000-3000 J/KG BY LATER TODAY. THUS...STRONG/ISOLATED
SEVERE THUNDERSTORMS ARE POSSIBLE ACROSS THESE AREA WITH THE THREAT
BEING STRONG GUSTY WINDS AND SOME HAIL.

...CENTRAL HI PLAINS...

MID/UPPER LEVEL LOW WILL BE MOVING OUT OF THE CENTRAL ROCKIES BY MID
AFTN.  WHILE THE AIR MASS LOOKS WORKED OVER ACROSS THE CENTRAL
PLAINS FROM CONVECTION OVER THE PAST FEW DAYS...BEST THERMAL
GRADIENT EXTENDS FROM SWRN/CENTRAL TX NEWD INTO SERN OK.  MID LEVEL
COOLING IS EXPECTED TO MOVE ACROSS ERN CO BY MID AFTN AND THIS
SHOULD AID IN INITIATING CONVECTIVE DEVELOPMENT WITH DAYTIME HEATING
ALONG THE WRN EDGES OF THE EXISTING CLOUD COVER OVER ERN CO. 
DAYTIME HEATING WITH UPSLOPE COMPONENT TO THE FLOW SHOULD BE
SUFFICIENT IN DEVELOPING STRONG/POSSIBLE SEVERE THUNDERSTORMS ACROSS
ERN CO THIS AFTN WITH SBCAPE BETWEEN 1000-1500 J/KG.  MAIN THREAT
AGAIN WILL BE HAIL AND DAMAGING WINDS. MID/UPPER LEVEL FLOW IS
EXPECTED TO BE SUFFICIENT FOR DEEP LAYER SHEAR TO 40 KT WHICH WILL
BE ENOUGH TO SUPPORT UPDRAFTS/ISOLATED SUPERCELLS.

..MCCARTHY/GRAMS.. 08/27/2006