[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 091628
SWODY1
SPC AC 091627

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1127 AM CDT FRI JUN 09 2006

VALID 091630Z - 101200Z

...THERE IS A SLGT RISK OF SVR TSTMS TODAY INTO TONIGHT FROM ERN WY
EWD TO IA....

...THERE IS A SLGT RISK OF SVR TSTMS THROUGH THIS EVENING FOR NE
NV...NW UT...SRN ID....

...THERE IS A SLGT RISK OF SVR TSTMS THIS AFTERNOON ACROSS PARTS OF
CENTRAL AND ERN PA....

...CENTRAL PLAINS AREA THROUGH TONIGHT...
A REMNANT LEE CYCLONE OVER N CENTRAL NEB THIS MORNING WILL MOVE
TOWARD SE NEB BY LATE TONIGHT...ALONG A QUASI-STATIONARY BAROCLINIC
ZONE WHICH SHOULD REMAIN NEAR THE MO RIVER.  MORNING SURFACE AND
UPPER AIR ANALYSES REVEAL A CONTINUATION OF THE RELATIVELY POOR
LOW-LEVEL MOISTURE IN THE WARM SECTOR...WITH A SKIN LAYER 60-64 F
DEWPOINTS IN A NARROW CORRIDOR ALONG THE SURFACE FRONT AND IN THE
WARM SECTOR ACROSS MO/ERN KS.  12Z SOUNDINGS SUGGEST THAT CONVECTIVE
INHIBITION WILL BE MINIMIZED FOR AFTERNOON TEMPERATURES OF 95-100 F
IN THE WARM SECTOR...WITH MEAN BOUNDARY LAYER DEWPOINTS LIKELY TO
DECREASE INTO THE 40S AND 50S IN AREAS WHERE TEMPERATURES GET THIS
WARM AND DEEP MIXING OCCURS.  THE POOR MOISTURE AND STEEP LAPSE
RATES WILL SUPPORT ONLY MODEST INSTABILITY /MLCAPE VALUES NEAR 1000
J/KG/ IN THE DEEPLY MIXED WARM SECTOR...AND SOMEWHAT GREATER
INSTABILITY IN AREAS N OF THE SURFACE FRONT THAT ARE SHELTERED FROM
DEEP MIXING /MLCAPE VALUES OF 1500-2000 J/KG/. 

THE MORE PROBABLE AREA FOR CONVECTIVE INITIATION THIS
AFTERNOON/EVENING WILL BE NEAR THE TRIPLE POINT IN EXTREME NE NEB/SE
SD WHERE INSTABILITY AND LOW-LEVEL ASCENT WILL BE MAXIMIZED. 
FORECAST HODOGRAPHS APPEAR FAVORABLE FOR SUPERCELLS WITH THE INITIAL
CONVECTION...AND STORMS SHOULD EVOLVE INTO AN MCS TONIGHT ACROSS IA
IN ASSOCIATION WITH STRONG WAA N OF THE SURFACE FRONT. A TORNADO
COULD OCCUR THIS EVENING WITH THE INITIAL STORMS...BUT THE MAIN
SEVERE THREATS SHOULD BE SCATTERED LARGE HAIL AND DAMAGING WINDS
LATE THIS EVENING INTO TONIGHT.

FARTHER W...THUNDERSTORMS MAY FORM LATE THIS AFTERNOON OVER THE HIGH
TERRAIN OF ERN WY...IN ADVANCE OF A MID LEVEL WAVE MOVING ENEWD FROM
SW WY AND WRN CO.  CONVECTION FORMING IN THIS AREA MAY PERSIST AND
MOVE E WITHIN THE RESIDUAL MOISTURE AXIS TO THE N OF THE SFC
FRONT...INTO WRN AND NRN NEB.  ISOLATED LARGE HAIL/DAMAGING WINDS
WILL BE POSSIBLE WITH THESE STORMS...SOME OF WHICH MAY DEVELOP
SUPERCELL STRUCTURES. 

...NRN INTERMOUNTAIN REGION...
A CLOSED MID LEVEL LOW WILL DRIFT EWD SLOWLY OVER WA...WHILE
EMBEDDED SHORTWAVE TROUGHS ROTATE EWD FROM ORE TOWARD WRN ID...AND
NEWD FROM NV TOWARD NW UT AND SRN ID.  RELATIVELY MOIST PROFILES IN
12Z SOUNDINGS AND ONGOING CONVECTION SUGGEST THAT STORMS WILL
CONTINUE THROUGH THE DAY...WHICH MAY IMPACT THE DEGREE OF
DESTABILIZATION THIS AFTERNOON.  STILL...CLOUD BREAKS ACROSS
SRN/SERN ID MAY ALLOW SUFFICIENT SURFACE HEATING/DESTABILIZATION FOR
A ISOLATED STORMS WITH LARGE HAIL AND DAMAGING WINDS. 

...CENTRAL/ERN PA AREA THIS AFTERNOON...
ISOLATED THUNDERSTORMS ARE FORMING ACROSS CENTRAL PA AS OF MIDDAY. 
THIS AREA IS DOWNSTREAM FROM A MID LEVEL TROUGH AXIS OVER WRN
PA...WHERE SURFACE HEATING AND WEAK ASCENT WILL PROMOTE ADDITIONAL
THUNDERSTORM DEVELOPMENT THROUGH THE AFTERNOON.  STEEP LOW-MID LEVEL
LAPSE RATES AND COOL TEMPERATURE PROFILES WILL CONTRIBUTE TO THE
THREAT FOR MARGINALLY SEVERE HAIL WITH THE STRONGER STORMS.

..THOMPSON/CROSBIE.. 06/09/2006