[SWODY1] SWODY1

[Severe Weather Outlook Day 1]

ACUS01 KWNS 270521
SWODY1
SPC AC 270520

DAY 1 CONVECTIVE OUTLOOK  
NWS STORM PREDICTION CENTER NORMAN OK
1220 AM CDT FRI OCT 27 2006

VALID 271200Z - 281200Z

...THERE IS A SLGT RISK OF SVR TSTMS OVER PORTIONS OF THE CNTRL AND
ERN GULF COASTAL AREA INTO PARTS OF NWRN FL...

...SYNOPSIS...

POSITIVELY TILTED SHORTWAVE TROUGH PRESENTLY OVER OK WILL MOVE ESEWD
THROUGH THE LOWER MS VALLEY AND SERN STATES FRIDAY...REACHING THE
CAROLINAS LATE FRIDAY NIGHT. SURFACE LOW AND COLD FRONT WILL ATTEND
THIS FEATURE. THE LOW SHOULD BE OVER THE WRN TN VALLEY WITH A COLD
FRONT EXTENDING SWD THROUGH THE LOWER MS VALLEY AT THE START OF THIS
PERIOD. THE LOW WILL SHIFT ENEWD INTO ERN KY WITH TRAILING FRONT
THROUGH ERN TN...WRN GA AND INTO THE ERN GULF EARLY FRIDAY EVENING.
BY THE END OF THIS PERIOD...THIS BOUNDARY SHOULD EXTEND FROM EXTREME
ERN VA/NC SWWD THROUGH NRN FL.

...CNTRL AND ERN GULF COASTAL AREA THROUGH NWRN FL...

HEIGHT FALLS ACCOMPANYING THE UPPER TROUGH WILL CONTRIBUTE TO A
STRONG SWLY 60+ KT LOW LEVEL JET THAT WILL SHIFT EWD THROUGH THE
SERN STATES DURING THE DAY AS SURFACE LOW ADVANCES THROUGH THE TN
VALLEY. THIS SHOULD RESULT IN ADVECTION OF NEAR 70 DEWPOINTS INTO
SRN PORTIONS OF GULF COASTAL STATES. HOWEVER...NWD RECOVERY OF
AIRMASS WILL BE LIMITED BY WIDESPREAD RAIN EXPECTED WITHIN PLUME OF
DEEPER MOISTURE ALONG WARM CONVEYOR BELT OVER THE SERN STATES. NEAR
THE COAST WHERE RICHER MOISTURE ADVECTS INLAND...MLCAPE FROM 500 TO
1000 J/KG WILL BE POSSIBLE WITHIN THE MOIST...WEAK LAPSE RATE
ENVIRONMENT.

STORMS WILL LIKELY CONTINUE DEVELOPING IN ZONE OF ASCENT WITHIN THE
PRE-FRONTAL WARM SECTOR AND SHIFT EWD THROUGH THE SERN STATES DURING
THE DAY. STRONGER STORMS ARE EXPECTED JUST INLAND OF THE COAST FROM
SERN LA THROUGH SRN AL...SWRN GA AND THE FL PANHANDLE WHERE INFLOW
FROM HIGHER THETA-E AIR WILL EXIST. THE INTENSIFYING LOW LEVEL JET
WILL RESULT IN LARGE LOW LEVEL HODOGRAPHS. THIS ALONG WITH STRONG
SHEAR THROUGH A DEEPER LAYER WILL BE SUPPORTIVE OF ORGANIZED STORM
STRUCTURES INCLUDING BOW ECHOES AND SUPERCELLS CAPABLE OF PRODUCING
DAMAGING WIND AND ISOLATED TORNADOES. OVERALL THREAT MAY BE TEMPERED
SOMEWHAT BY THE MARGINAL THERMODYNAMIC ENVIRONMENT.

...COASTAL CAROLINAS...

NEAR SURFACE TRAJECTORIES WILL EMANATE FROM CP HIGH PRESSURE OFF THE
ATLANTIC SEABOARD IN THIS REGION UNTIL FRIDAY AFTERNOON AND EVENING
WHEN THE FLOW SHOULD VEER TO SLY IN ADVANCE OF SURFACE LOW. THIS
WILL ALLOW MODIFYING BOUNDARY LAYER AIR WITH DEWPOINTS IN THE 60S TO
ADVECT NWD TOWARD THE COASTAL CAROLINAS OVERNIGHT. THE RICHER
MOISTURE WILL LIKELY RESIDE S OF A COASTAL BOUNDARY THAT COULD MOVE
INLAND LATER FRIDAY NIGHT. LOW LEVEL AND MID LEVEL WIND FIELDS WILL
STRENGTHEN SIGNIFICANTLY AS THE UPPER TROUGH AND ATTENDANT LOW LEVEL
JET MOVE TOWARD THE CAROLINAS.

WITH RAIN EXPECTED TO SPREAD EWD INTO THE COOL AIRMASS ALREADY IN
PLACE OVER THE CAROLINAS BY EARLY FRIDAY...INLAND RECOVERY WILL BE
DIFFICULT EXCEPT POSSIBLY NEAR THE COASTAL AREAS. THE THREAT FOR
ISOLATED TORNADOES OR DAMAGING WIND MAY INCREASE IN VICINITY OF THE
COASTAL BOUNDARY FRIDAY NIGHT AS SHEAR PROFILES INCREASE AND HIGHER
THETA-E AIR ADVECTS INLAND. HOWEVER...GIVEN THE POTENTIAL LIMITING
FACTORS UPON THE THERMODYNAMIC ENVIRONMENT...LOW SEVERE
PROBABILITIES WILL BE MAINTAINED AT THIS TIME. AN UPGRADE TO SLIGHT
RISK MIGHT BE NECESSARY IN LATER OUTLOOKS IF IT BEGINS TO APPEAR
MORE INSTABILITY WILL DEVELOP THAN CURRENTLY ANTICIPATED.

..DIAL/GRAMS.. 10/27/2006