[SWODY2] SWODY2

[Severe Weather Outlook - Day 2]

ACUS02 KWNS 060535
SWODY2
SPC AC 060534

DAY 2 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1234 AM CDT FRI OCT 06 2006

VALID 071200Z - 081200Z

...NO SVR TSTM AREAS FORECAST...

...SYNOPSIS...
HIGHLY AMPLIFIED UPPER AIR PATTERN FCST THROUGH
PERIOD...CHARACTERIZED BY LARGE RIDGE OVER NERN PACIFIC...POSITIVELY
TILTED TROUGH FROM SASK SWWD ACROSS SRN CA...SYNOPTIC SCALE RIDGE
FROM ARKLATEX REGION TOWARD SRN QUE.  STRONG SHORTWAVE TROUGH -- NOW
EVIDENT IN MOISTURE CHANNEL IMAGERY AS OPEN-WAVE TROUGH OVER
MI/INDIANA/OH -- IS FCST TO DEEPEN AND CLOSE OFF AS IT APCHS
CAROLINAS/GA THROUGH DAY-1 INTO DAY-2. THIS IS SOMEWHAT FARTHER S
AND W OF EARLIER GUIDANCE...HOWEVER...06/00Z SHORT-RANGE
DETERMINISTIC PROGS AND 05/21Z SREF MEMBERS ARE IN REMARKABLY CLOSE
AGREEMENT.  CONFIDENCE THEREFORE IS STRONG IN SCENARIO OF NEARLY
CUT-OFF CYCLONE DRIFTING SWD OVER SC/GA COASTAL REGION DURING DAY-2.
 THIS PATTERN IS HIGHLY ANOMALOUS...BUT HAS A CLOSE 500 MB ANALOG
FROM SEP 19-20 1989.

AT SFC...WEAK/ELONGATED AREA OF LOW PRESSURE NOW ANALYZED OVER
CAROLINAS PIEDMONT IS EXPECTED TO DEEPEN CONSIDERABLY AND MOVE
OFFSHORE GA/SC COAST...IN RESPONSE TO APCHG UPPER LOW. FRONTAL ZONE
--- NOW ANALYZED FROM OFFSHORE OUTER BANKS WSWWD ACROSS NRN LA --
WILL MOVE SWD ACROSS MUCH OF CENTRAL/ERN GULF COAST IN RESPONSE TO
COASTAL CYCLOGENESIS.  WARM FRONTAL SEGMENT WILL REACH NEAR NC
COAST.

MEANWHILE...UPPER LOW NOW OVER COASTAL CA IS FCST TO EJECT NEWD FROM
YELLOWSTONE REGION ACROSS ND DAY-2...AS TROUGH NOW OVER ERN GULF OF
AK DIGS SEWD INTO NRN ROCKIES. IN RESPONSE...SFC
FRONTOGENESIS/CYCLOGENESIS IS FCST OVER NRN ROCKIES AND NRN HIGH
PLAINS...WITH LOW DEEPENING AND MOVING NEWD OVER ND DURING DAY. 
SECONDARY MID/UPPER SPEED MAX...DIGGING SWD INTO MEAN TROUGH
POSITION...WILL RESULT IN UPPER LOW RETROGRADING SWWD ACROSS SRN CA
IN WAKE OF EJECTING SYSTEM.

...ERN NC...
POTENTIAL FOR SFC-BASED CONVECTION WILL DEPEND STRONGLY ON WHETHER
FRONTAL ZONE STAYS OFFSHORE -- PER WRF GUIDANCE AND MOST SREF
MEMBERS -- OR REACHES COAST AS INDICATED BY OPERATIONAL
NGM/SPECTRAL.  CONSENSUS FCST SEEMS MOST REASONABLE ATTM FOR FRONT
TO REMAIN JUST OFFSHORE...WITH INTENSE/ELEVATED CONVEYOR OF
WARM/MOIST ADVECTION SUPPORTING GEN THUNDER POTENTIAL OVER NERN
QUADRANT OF DEEP-LAYER CYCLONE.  WRF FRONTAL POSITION DOES REACH
CLOSE ENOUGH TO COAST FOR EFFECTIVE PARCELS TO BE NEARLY SATURATED
AND SFC-BASED OVER IMMEDIATE SHORELINE AREAS...WITH LARGE LOW LEVEL
HODOGRAPHS.  SVR POTENTIAL OVER LAND APPEARS TOO
ISOLATED/CONDITIONAL FOR CATEGORICAL OUTLOOK ATTM...BUT WILL
INTRODUCE MRGL PROBABILITIES FOR IMMEDIATE COASTAL AREAS AND COASTAL
WATERS.

...AZ...
AS SECONDARY UPPER LOW TAKES SHAPE OVER SRN CA...VERTICAL SHEAR
PROFILES ARE EXPECTED TO REMAIN FAVORABLE FOR SUPERCELLS AND BOWS
ACROSS MUCH OF THIS REGION THROUGH DAY-2.  RELATED LOW LEVEL WAA
REGIME WILL CONTINUE TO YIELD RICH MOISTURE ACROSS THIS
REGION...THOUGH LOW-MIDLEVEL LAPSE RATES WILL BE WEAK WITHOUT
SUBSTANTIAL BOUNDARY LAYER HEATING.  MAIN UNCERTAINTY PRECLUDING
CATEGORICAL SVR OUTLOOK ATTM IS EXTENT OF DESTABILIZATION IN WAKE OF
ABUNDANT CLOUDS/PRECIP LIKELY BETWEEN NOW AND SATURDAY AFTERNOON.

...NRN HIGH PLAINS...NRN ROCKIES...
FCST SFC TRAJECTORIES FROM RELATIVELY DRY/CONTINENTAL AIR MASS OVER
UPPER MIDWEST SUGGEST MOISTURE WILL BE TOO SCANT FOR SFC-BASED
DEVELOPMENT ALONG FRONT OR IN WARM SECTOR.  HOWEVER.,..BAND OF
WIDELY SCATTERED TO SCATTERED TSTMS MAY OCCUR BEHIND SFC COLD FRONT.
 THIS AREA WILL BE IN REGION OF STG MIDLEVEL DPVA AND COOLING
ALOFT...WITH SOME POTENTIAL FOR AFTERNOON HEATING ALONG E RIM OF
CLOUD PLUME.  SFC TEMPS IN LOW 70S WOULD YIELD UP TO 700 J/KG MLCAPE
OVER ERN MT BY 07/21Z...BASED ON MODIFIED WRF SOUNDINGS.  STRONGEST
TSTMS MAY PRODUCE HAIL OR DAMAGING GUSTS.

..EDWARDS.. 10/06/2006