[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 041629
SWODY1
SPC AC 041628

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1128 AM CDT FRI AUG 04 2006

VALID 041630Z - 051200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY ACROSS NE ND INTO NRN
MN....

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON FROM ERN VA
ACROSS THE CAROLINAS TO GA/FL....

...FL PENINSULA THIS AFTERNOON...
A MID LEVEL LOW OVER CENTRAL FL WILL MOVE SLOWLY WWD THROUGH THE
PERIOD.  THE 12Z SOUNDING FROM TBW REVEALS 6.5-7 C/KM LAPSE RATES
THROUGH THE LOWER TO MIDDLE TROPOSPHERE...AND A 500 MB TEMPERATURE
OF -9 TO -10 C IN ASSOCIATION WITH THIS MID LEVEL LOW. AFTERNOON
TEMPERATURES NEAR 90 F AND DEWPOINTS IN THE LOW-MID 70S WILL SUPPORT
MLCAPE VALUES AOA 3000 J/KG.  THUNDERSTORMS WILL LIKELY DEVELOP BY
EARLY AFTERNOON...AND THE STRONGER STORMS WILL BE CAPABLE OF
PRODUCING DAMAGING WINDS WITH WET MICROBURSTS AND MARGINALLY SEVERE
HAIL. 

...SE ATLANTIC STATES THIS AFTERNOON...
A MID LEVEL DEFORMATION ZONE EXISTS INVOF THE SRN
APPALACHIANS...BETWEEN THE SRN FRINGE OF THE WLYS OVER THE OH
VALLEY...AND THE MID LEVEL LOW IN THE ELYS OVER FL.  A SURFACE COLD
FRONT IS MOVING SEWD ACROSS THE CENTRAL/SRN APPALACHIANS...AND A
PRE-FRONTAL TROUGH EXTENDS ALONG THE SE ATLANTIC COASTAL PLAINS FROM
VA TO SE GA.  SCATTERED THUNDERSTORMS ARE EXPECTED THIS AFTERNOON
ALONG BOTH SURFACE BOUNDARIES AND OVER THE HIGHER TERRAIN OF THE WRN
CAROLINAS.  THE STRONGER INSTABILITY IS EXPECTED OVER THE COASTAL
PLAINS WHERE AFTERNOON TEMPERATURES WILL REACH THE MID-UPPER 90S
WITH DEWPOINTS IN THE 70S.  STEEP LOW-LEVEL LAPSE RATES...MLCAPE OF
3000-4000 J/KG...DCAPE IN EXCESS OF 1000 J/KG...AND MINIMAL VERTICAL
SHEAR WILL SUPPORT A FEW PULSE-TYPE STORMS CAPABLE OF PRODUCING WET
MICROBURSTS WITH DAMAGING WINDS.  

...NRN PLAINS THROUGH TONIGHT...
AN ONGOING CLUSTER OF THUNDERSTORMS ALONG THE INTERNATIONAL BORDER
WILL LIKELY PERSIST INTO THIS AFTERNOON ACROSS NE ND AND NRN MN. 
THIS CONVECTION APPEARS TO BE BASED IN THE 850-700 MB LAYER...IN
ASSOCIATION WITH LOW-LEVEL WAA AND STEEP MID LEVEL LAPSE RATES
SAMPLED IN THE 12Z BIS SOUNDING.  CLOUDS ACROSS THE AREA WILL SLOW
SURFACE HEATING...THOUGH THE CONVECTION COULD BECOME ROOTED NEAR THE
GROUND WITH TEMPERATURES IN THE LOWER 80S.  MARGINALLY SEVERE HAIL
AND ISOLATED DAMAGING GUSTS WILL BE THE PRIMARY SEVERE THREATS.

FARTHER W...STRONG SURFACE HEATING /AFTERNOON TEMPERATURES IN THE
LOW-MID 90S/ WILL RESULT IN DEEP INVERTED-V PROFILES NEAR THE LEE
CYCLONE IN WRN ND.  THOUGH LOW-LEVEL MOISTURE IS SOMEWHAT LIMITED
THIS AREA AND STORM COVERAGE MAY BE RATHER SPARSE...THE STEEP
LOW-LEVEL LAPSE RATES MAY SUPPORT VERY ISOLATED STRONG OUTFLOW WINDS
LATER THIS AFTERNOON/EVENING.  A PRONOUNCED MID LEVEL TROUGH NOW
OVER SE BRITISH COLUMBIA WILL APPROACH THE NRN HIGH PLAINS LATE IN
THE PERIOD...THOUGH MARGINAL MOISTURE AND INCREASING CONVECTIVE
INHIBITION WILL TEND TO LIMIT THE THREAT FOR OVERNIGHT STORMS. 

...SE ID THIS AFTERNOON...
WATER VAPOR IMAGERY SHOWS A WEAK MID LEVEL WAVE MOVING NNEWD FROM
ERN NV/NW UT TOWARD SE ID.  SHORT TERM FORECAST SOUNDINGS...AND THE
12Z SLC SOUNDING MODIFIED FOR SURFACE HEATING...SHOW THE POTENTIAL
FOR GUSTY OUTFLOW WINDS AND PERHAPS SMALL HAIL.

...CENTRAL OK TO CENTRAL AR THIS AFTERNOON...
A QUASI-STATIONARY FRONT IS LOCATED NEAR I-40. STRONG SURFACE
HEATING ALONG AND S OF THE FRONT WILL RESULT IN THE DEVELOPMENT OF
MODERATE INSTABILITY AND A RELATIVELY DEEP BOUNDARY LAYER THIS
AFTERNOON.  WIDELY SCATTERED THUNDERSTORMS WILL LIKELY FORM ALONG
THE FRONT BY MID AFTERNOON...A FEW OF WHICH WILL PRODUCE STRONG
DOWNBURST WINDS.

..THOMPSON/TAYLOR.. 08/04/2006