[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 060532
SWODY1
SPC AC 060531

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1231 AM CDT FRI OCT 06 2006

VALID 061200Z - 071200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER ERN NV...MUCH OF AZ AND
UT...

...SYNOPSIS...
LARGE SCALE OMEGA BLOCK PATTERN WILL CONTINUE ACROSS THE LOWER 48
STATES THIS PERIOD WITH STRONG TROUGHS ALONG EACH COAST...AND A
LARGE SCALE RIDGE DOMINATING THE CNTRL U.S. FROM TX TO THE GREAT
LAKES. A SIGNIFICANT SHORT WAVE IMPULSE ACCOMPANIED BY 70KT MID
LEVEL FLOW WILL EJECT FROM THE BASE OF THE DEEP WEST COAST TROUGH
AND MOVE FROM THE LOWER CO RIVER VALLEY...NEWD ACROSS THE GREAT
BASIN...AND THEN OVER THE NRN ROCKIES THROUGH EARLY SATURDAY. 
DOWNSTREAM FROM THE CNTRL STATES UPPER RIDGE...A VIGOROUS SHORT WAVE
TROUGH...CURRENTLY CROSSING THE OH VALLEY...WILL DIG SSEWD ACROSS
THE CAROLINAS WHILE EVOLVING INTO A COMPACT COLD CORE VORTEX OVER NC
THROUGH LATE TODAY.

...SOUTHWEST/GREAT BASIN...
STRONG DEEP LAYER SLY FLOW CONTINUES TO TRANSPORT ABUNDANT MOISTURE
NWD AHEAD OF THE STRONG SLOW MOVING UPPER LOW OVER CA. LOW LEVELS
HAVE ALSO MOISTENED THROUGH A COMBINATION OF ADVECTION AND DIABATIC
EFFECTS. WHILE FORCING FOR ASCENT IS EXPECTED TO INCREASES FURTHER
TODAY WITH THE NEWD ACCELERATION OF SHORT WAVE IMPULSE OUT OF SRN
CA...OVERALL DESTABILIZATION WILL PROBABLY REMAIN MARGINAL GIVEN
POTENTIAL FOR WIDESPREAD CLOUDINESS AND PRECIPITATION.
HOWEVER...RELATIVELY STEEP LAPSE RATES MAINTAINED BY ADIABATIC
COOLING/STRONG ASCENT SHOULD CONTRIBUTE TO CAPE ON THE ORDER OF
200-500 J/KG WHICH WILL ADEQUATELY FUEL RELATIVELY LOW-TOPPED
CONVECTION. GIVEN THE PRESENCE OF VERY STRONG EFFECTIVE SHEAR...AND
FOCUSED FORCING ON THE NOSE OF 70 KT MID LEVEL JET STREAK SPREADING
ACROSS SRN NV/WRN AZ THROUGH THE AFTERNOON... EXPECT AN INCREASE IN
SEVERE STORM POTENTIAL. FAST-MOVING LINES/BANDS OF STORMS AND A FEW
SUPERCELLS APPEAR POSSIBLE AS THE STRONG ASCENT ACCOMPANYING THE MID
LEVEL IMPULSE ACTS ON MOIST/UNSTABLE AIR MASS. IN ADDITION TO HAIL
AND HIGH WINDS...AN ISOLATED TORNADO CANNOT BE RULED OUT. ORGANIZED
ACTIVITY AND SEVERE THREAT SHOULD SPREAD NEWD FROM ERN NV/AZ AND
INTO UT THROUGH LATE AFTERNOON/EVENING.

...MID ATLANTIC/SOUTHEAST COASTS...
SURFACE FRONT SHOULD STRENGTHEN AND SURGE SEWD INTO WARM/MOIST AIR
MASS ALONG THE COASTAL PLAIN AS VIGOROUS MID LEVEL CYCLOGENESIS
COMMENCES OVER SRN VA/NC THIS AFTERNOON. WHILE STRONGER DEEP SHEAR
IS FORECAST TO LAG THE FRONTAL LIFT...INCREASINGLY STRONG FORCING
ACROSS THE REGION COULD AID TSTM DEVELOPMENT ALONG THE FRONT AS IT
MOVES EAST. A COUPLE OF SEVERE STORMS WITH STRONG TO DAMAGING WINDS
APPEAR POSSIBLE OVER A RELATIVELY SMALL REGION. ISOLATED AND 
MARGINALLY SEVERE HAIL MAY ALSO OCCUR BENEATH THE DEVELOPING MID
LEVEL LOW CENTER OVER ERN NC THROUGH EVENING.

...NRN ROCKIES TO NRN PLAINS...
CONVECTION IS FORECAST TO INCREASE IN A SW-NE BAND FROM NRN NV
ACROSS ID...AND INTO PARTS OF MT...FROM LATE AFTERNOON INTO THE
NIGHT AS STRENGTHENING MID LEVEL DEFORMATION ZONE ACTS ON NWRN
PERIPHERY OF DEEP MOISTURE PLUME. INSTABILITY AND SHEAR ARE EXPECTED
TO REMAIN MARGINAL WITHIN THIS AXIS...BUT LAPSE RATES AND FORCING
APPEAR SUFFICIENT FOR A COUPLE OF HAIL STORMS OVER THE NRN ROCKIES.

LOW-AMPLITUDE SHORT WAVE IMPULSE AND INCREASING LOW LEVEL SLY FLOW
MAY COMBINE TO PRODUCE A FEW ELEVATED STORMS ACROSS THE WRN DAKOTAS
THROUGH EARLY SATURDAY. A LOW PROBABILITY OF HAIL WILL EXIST WITH
THIS ACTIVITY.

..CARBIN/EVANS.. 10/06/2006