[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 080436
SWODY1
SPC AC 080434

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1134 PM CDT SAT OCT 07 2006

VALID 081200Z - 091200Z

...THERE IS A SLGT RISK OF SVR TSTMS ACROSS SERN AZ AND WRN NM...

...SYNOPSIS...
MORE OF A SPLIT FLOW REGIME WILL DEVELOP ACROSS NRN/CNTRL U.S THIS
PERIOD AS NRN STREAM REMAINS QUITE PROGRESSIVE...AND SRN STREAM
RETAINS SOME AMPLITUDE. STRONGEST HEIGHT FALLS WITH THE NRN STREAM
SHORT WAVE TROUGH NOW CROSSING NRN PLAINS WILL SPREAD EAST ACROSS
SRN CANADA. HOWEVER...WEAK HEIGHT FALLS ASSOCIATED WITH THIS FEATURE
WILL ACT TO DAMPEN THE UPPER RIDGE AXIS FROM THE GREAT LAKES TO THE
NORTHEAST. A BROAD BELT OF DEEP LAYER SWLY FLOW WILL PERSIST IN THE
WAKE OF THE NRN STREAM IMPULSE...FROM THE SOUTHWEST TO THE UPPER MS
VALLEY/GREAT LAKES. AS STRONGER FORCING PULLS AWAY FROM THE
PLAINS... ASSOCIATED TRAILING COLD FRONT WILL BE ALIGNED WITH THE
DEEP LAYER SWLY FLOW. THEREFORE THE FRONT WILL MAKE ONLY GRADUAL
EWD/SEWD PROGRESS ACROSS THE UPPER MS AND MO VALLEYS THIS PERIOD...
AND SHOULD EXTEND FROM LOWER MI TO KS BY EARLY MONDAY. HIGH PLAINS
SEGMENT OF THE COLD FRONT IS FORECAST TO SURGE SWD FROM ERN CO AND
ACROSS THE TX PNHDL TODAY AND TONIGHT WITH LIFT ACROSS THIS BOUNDARY
LIKELY BEING ENHANCED BY A LOW AMPLITUDE IMPULSE EMANATING OUT OF
THE SRN STREAM.

UPPER LOW ACROSS SRN CA WILL BEGIN TO BE SHUNTED EWD ACROSS THE
LOWER CO RIVER VALLEY THROUGH THIS PERIOD AS A NRN STREAM
DISTURBANCE SPREADS SEWD ACROSS THE INTERIOR NORTHWEST. OTHER SRN
STREAM CLOSED LOW...OVER THE SOUTHEAST...WILL CONTINUE TO FILL AND
DRIFT ACROSS THE GA/NRN FL COASTLINE LATER THIS AFTERNOON.

...AZ/NM...
DYNAMIC FORCING FOR ASCENT ASSOCIATED WITH THE SRN CA UPPER LOW WILL
SPREAD EAST ATOP A RELATIVELY MOIST AND INCREASINGLY UNSTABLE AIR
MASS ACROSS PARTS OF SERN AZ THIS AFTERNOON. MODEL GUIDANCE
INDICATES STRONG CONVECTION WILL DEVELOP AS THE LIFT ASSOCIATED WITH
THE TROUGH COMBINES WITH DIURNAL HEATING AND UPSLOPE FLOW. DEEP
LAYER SHEAR IS ALSO EXPECTED TO STRENGTHEN COINCIDENT WITH TSTM
DEVELOPMENT AND SHOULD SUPPORT STORM ORGANIZATION. LINES OR 
CLUSTERS OF STORMS AND PERHAPS A FEW SUPERCELLS APPEAR POSSIBLE AND
COULD BE ACCOMPANIED BY HAIL AND LOCALLY HIGH WINDS FROM SERN AZ
EWD/NEWD INTO PORTIONS OF WRN NM.

...SRN HIGH PLAINS...
ANOTHER AREA OF DEEP CONVECTION MAY EVOLVE AS A LOW AMPLITUDE
MID/UPPER WAVE DEVELOPS NNEWD FROM SRN/CNTRL NM ACROSS SERN CO AND
THE TX/OK PNHDLS LATER TODAY. THIS FEATURE IS EMBEDDED WITHIN
TROPICAL MOISTURE CONNECTION BUT LIMITED LOW LEVEL MOISTURE AND
POTENTIAL FOR ABUNDANT CLOUD COVER ACROSS THE SRN HIGH PLAINS MAY
LIMIT GREATER SURFACE-BASED DESTABILIZATION. IF HEATING AND WEAK
DESTABILIZATION CAN OCCUR AHEAD OF THE FRONTAL SURGE DEVELOPING
ACROSS THESE AREAS LATER TODAY...LIFT AND SHEAR APPEAR ADEQUATE FOR
A COUPLE OF SEVERE STORMS. ANY SURFACE-BASED ACTIVITY MAY BE QUICKLY
UNDERCUT BY THE COLD FRONT BUT COULD STILL POSE A THREAT OF
MARGINALLY SEVERE HAIL. GIVEN UPPER FORCING AND LIFT ACROSS THE
ADVANCING FRONT...A SMALL MCS MAY EVOLVE FROM THE INITIAL ACTIVITY
AND DEVELOP EAST ACROSS THE TX PNHDL THROUGH SUNDAY NIGHT. MARGINAL
HAIL AND GUSTY WINDS MAY ACCOMPANY THIS SYSTEM BUT AREAL EXTENT OF
SEVERE POTENTIAL AND LEVEL OF UNCERTAINTY AT THIS TIME DO NOT
WARRANT HIGHER SEVERE PROBABILITIES.

...SOUTHEAST COAST/FL...
MOIST ONSHORE FLOW ACROSS ERN CAROLINAS BENEATH COLD POOL AND LIFT
ASSOCIATED WITH MID/UPPER LEVEL LOW MAY BE ENOUGH FOR A COUPLE OF
TSTMS. INSTABILITY...HOWEVER...WILL LIKELY BE WEAK AND LITTLE SEVERE
THREAT IS CURRENTLY ANTICIPATED. FURTHER SOUTH...OVER FL...GREATER
SURFACE-BASED INSTABILITY MAY DEVELOP ACROSS THE ECNTRL PART OF THE
PENINSULA. FORCING AND STEEPER LAPSE RATES ASSOCIATED WITH THE UPPER
SYSTEM WILL BRUSH THE EAST COAST AS SEA-BREEZE CONVECTIVE
DEVELOPMENT OCCURS DURING THE AFTERNOON. PRIOR NAM-WRF FORECASTS
WERE VERY ACCURATE IN DEPICTING THE ISOLATED DEVELOPMENT THAT
OCCURRED SATURDAY EVENING. LATEST NAM-WRF SUGGESTS A SIMILAR
ENVIRONMENT AND SCENARIO APPEAR POSSIBLE SUNDAY AFTERNOON AND
EVENING. THUS...LOW SEVERE PROBABILITIES FOR WIND/HAIL...AND AN
ISOLATED TORNADO...WILL BE INTRODUCED FOR PARTS OF ERN FL TODAY.

..CARBIN/GRAMS.. 10/08/2006