[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 221302
SWODY1
SPC AC 221300

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
0800 AM CDT TUE AUG 22 2006

VALID 221300Z - 231200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS PARTS OF THE NRN
PLAINS...

...NRN PLAINS...
AN UPPER-LEVEL DISTURBANCE ON WATER VAPOR IMAGERY OVER SW MT WILL
MOVE INTO THE NRN PLAINS TODAY. IN RESPONSE TO THE DEVELOPING
SHORTWAVE TROUGH...A 35-40 KT LOW-LEVEL JET IS FORECAST TO
STRENGTHEN ACROSS SD RESULTING IN STRONG MOISTURE ADVECTION. THIS
WILL HELP MOVE A WARM FRONT NEWD ACROSS ERN SD INTO WRN MN AS A DRY
SLOT ADVECTS NEWD INTO SWRN SD. THE MOIST AXIS WITH 60 TO 65 F SFC
DEWPOINTS SHOULD SET UP FROM SRN ND EXTENDING SEWD INTO NE SD AND
SWRN MN. MODERATE INSTABILITY APPEARS LIKELY TO DEVELOP ALONG THE
MOIST AXIS BY AFTERNOON. HOWEVER...THE LOCATION AND TIMING OF
THUNDERSTORM INITIATION REMAINS HIGHLY UNCERTAIN. IT IS POSSIBLE
THAT THUNDERSTORMS WILL INITIATE LATE THIS AFTERNOON ALONG THE WARM
FRONT IN SCNTRL ND WHERE THE CAPPING INVERSION IS FORECAST TO BE
WEAKER. EVEN THOUGH WARM AIR ALOFT WILL BE IN PLACE BEHIND THE DRY
SLOT ACROSS SWRN SD...ISOLATED THUNDERSTORMS STILL MAY DEVELOP IN
THE HIGHER TERRAIN OF THE BLACK HILLS. THE GREATEST POTENTIAL FOR
THUNDERSTORM DEVELOPMENT APPEARS LIKELY TO OCCUR IN NE SD...SE ND
AND WRN MN ALONG THE MOIST AXIS AFTER DARK AS THE LOW-LEVEL JET
RAPIDLY STRENGTHENS THIS EVENING.

FORECAST SOUNDINGS ACROSS THE REGION THIS EVENING STRONGLY INCREASE
DEEP LAYER SHEAR AS THE SHORTWAVE TROUGH APPROACHES. THIS SHOULD
MAKE SUPERCELL DEVELOPMENT INCREASINGLY LIKELY AS STORM COVERAGE
INCREASES THIS EVENING. THE POTENTIAL FOR SUPERCELLS APPEARS MOST
LIKELY IN A CORRIDOR FROM NEAR FARGO ND EXTENDING EWD TO NEAR
MINNEAPOLIS MN LATE THIS EVENING. SUPERCELLS SHOULD BE CAPABLE OF
PRODUCING LARGE HAIL DUE TO THE STRONG DIRECTIONAL SHEAR AND STEEP
MID-LEVEL LAPSE RATES IN PLACE. IN ADDITION...LOW-LEVEL SHEAR
PROFILES WILL BE STRONG DUE TO THE LOW-LEVEL JET AND SUPERCELLS THAT
BECOME ROOTED IN THE BOUNDARY LAYER MAY HAVE AN ISOLATED TORNADO
POTENTIAL. WIND DAMAGE MAY ALSO OCCUR WITH CONVECTION THAT BECOMES
SFC-BASED.

...COASTAL CAROLINAS...
LATEST ANALYSIS SHOWS A NEARLY STATIONARY FRONT LOCATED ACROSS NRN
NC WITH A SFC LOW IN THE MTNS OF WRN NC. SOUTH OF THE
BOUNDARY...DEWPOINTS ARE IN THE LOWER 70S F AND THIS SHOULD ALLOW
MODERATE INSTABILITY TO DEVELOP ACROSS THE ERN CAROLINAS BY MIDDAY.
AS AN UPPER-LEVEL TROUGH MOVES EWD FROM THE SRN APPALACHIAN MTNS
INTO THE COASTAL PLAINS LATE THIS AFTERNOON...SCATTERED STRONG
THUNDERSTORMS APPEAR POSSIBLE. AS THE UPPER-TROUGH
APPROACHES...VERTICAL SHEAR PROFILES SHOULD INCREASE JUST ENOUGH FOR
STRONG AND POSSIBLE A FEW MARGINALLY SEVERE MULTICELLS. THE MAIN
THREAT WOULD BE WIND DAMAGE DUE TO THE UNIDIRECTIONAL WIND PROFILES
IN PLACE.

...ARIZONA...
LATEST ANALYSIS SHOWS A MOIST AXIS IN PLACE ACROSS SRN AND CNTRL AZ
WHERE DEWPOINTS ARE IN THE 60S F. AS SFC HEATING TAKES PLACE THIS
AFTERNOON...SCATTERED THUNDERSTORMS SHOULD INITIATE ALONG THE
MOGOLLON RIM. CONVECTIVE COVERAGE WILL LIKELY BE THE GREATEST THIS
EVENING AS STORMS MOVE WSWWD ACROSS SRN AND CNTRL AZ. STEEP
LOW-LEVEL LAPSE RATES MAY BE SUFFICIENT FOR A FEW DAMAGING WIND
GUSTS WITH THE STRONGER CELLS.

...UPSTATE NY/NH/VT/MAINE...
A COLD FRONT WILL MOVE SEWD INTO THE NERN U.S. TODAY PROVIDING A
FOCUS FOR ISOLATED THUNDERSTORM DEVELOPMENT. STEEP LAPSE RATES ARE
FORECAST TO BE IN PLACE AHEAD OF THE FRONT WHICH COMBINED WITH SFC
HEATING MAY BE ENOUGH FOR A FEW STRONG WIND GUSTS WITH THE MORE
ORGANIZED STORMS THIS AFTERNOON.

..BROYLES/GUYER.. 08/22/2006