Severe Thunderstorm Warning 236, NWS Jacksonville, FL

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
154 PM EDT THU AUG 6 2009

.SHORT TERM...LATEST MSAS ANALYSIS SHOWS LOW PRESSURE OFF THE
CAROLINA COAST WITH A TROUGH EXTENDING THROUGH THE COASTAL PLAINS
AND THEN WESTWARD THROUGH SOUTH GEORGIA. MEANWHILE...HIGH PRESSURE
RIDGE AXIS EXISTS FROM JUST NORTH OF THE BAHAMAS THROUGH SOUTH
FLORIDA WHICH COMBINED WITH AFOREMENTIONED TROUGH...CONTINUES THE
LIGHT WESTERLY FLOW REGIME ACROSS THE AREA. TROUGH JUST OFF THE
COAST IS BEGINNING TO FORM AS SEABREEZE PUSHES INLAND...ESPECIALLY
ALONG THE FLORIDA COAST WHERE MAYPORT AND HAS ALREADY SEEN A SHIFT
TO THE EAST. PWATS TODAY CAME IN AT JUST BELOW 2 INCHES ON THE JAX
MORNING SOUNDING...VERY CLOSE TO THE PREVIOUS TWO DAYS WHILE MODEL
SOUNDINGS TO THE SOUTH INDICATE VALUES IN EXCESS OF 2 INCHES.
THIS...ALONG WITH THE PROGRESSION OF THE WEST COAST SEABREEZE HAS
ALLOWED FOR EARLY THUNDERSTORM DEVELOPMENT NEAR GNV WITH OTHER SCT
ACTIVITY ALONG THE INTERSTATE 75 CORRIDOR.

FOR THE REMAINDER OF THE EVENING HOURS...MODELS INDICATE SHORTWAVE
ACTIVITY WHICH IS APPARENT ON CURRENT WATER VAPOR IMAGERY TO
SLIDE SOUTHEAST SLIGHTLY AND PROVIDE ADDITIONAL LIFT FOR MAINLY
THE FLORIDA PORTION. WITH SEABREEZE PUSHING IN AGAINST WESTERLY
FLOW...WE SHOULD SEE STORMS DEVELOP IN WEAK STEERING CONDITIONS
WITH POTENTIAL FOR FLOODING LIKELY. WESTERLY FLOW ALOFT WILL ALSO
PROVIDE FOR GOOD PARTICLE SEPARATION AND ALTHOUGH LAPSE RATES
ALOFT ARE NOT VERY STEEP...HAIL AND MARGINALLY SEVERE WIND GUSTS
REMAIN POSSIBLE INTO THE LATE EVENING HOURS.

FOR FRIDAY...SURFACE TROUGH WEAKENS AND RIDGE AXIS SLIDES
NORTHWARD WITH A SOUTH FLOW QUICKLY TRANSITIONING TO EAST WITH AN
EARLY SEABREEZE ALONG THE ATLANTIC COAST. WILL ALSO SEE MID LEVEL
RIDGE TO THE EAST OF THE AREA STRENGTHEN SLIGHTLY WITH DRIER AIR
AT THE MID LEVELS NOTED FROM ST AUGUSTINE SOUTHWARD. THIS POINTS
TO AN OVERALL REDUCTION IN POPS WITH AXIS OF BEST RAIN CHANCES
SHIFTING INLAND SLIGHTLY.

THIS TREND WILL CONTINUE INTO SATURDAY AND SUNDAY OF OVERALL
DRYING OF THE COLUMN AND INCREASED EASTERLY FLOW WILL RESULT IN A
DECIDE LY INLAND DISTRIBUTION OF HIGHEST POPS ALTHOUGH ALL WILL BE
CAPPED IN THE SCATTERED RANGE.

.LONG TERM...MID LEVEL HIGH REMAINS OVER THE AREA FOR MOST OF THE
PERIOD WHILE SURFACE RIDGE AXIS REMAINS NEARLY STATIONARY OVER THE
AREA. THIS TYPE OF PATTERN SUPPORTS SCT POP DISTRIBUTION WHICH
CURRENT GRID FORECAST HANDLES WELL.

&&

.AVIATION...HAVE TEMPO TSRA BEG 18Z AT GNV AND 20Z IN DUVAL CO.
LOWER CHANCES FOR SSI AND WILL KEEP VCTS. WILL OPT FOR MIFG AT
VQQ AFTER MIDNIGHT INSTEAD OF TEMPO MVFR.

&&

.MARINE...NO HEADLINES. WRN ATLANTIC HIGH GRADUALLY BUILDS
RESULTING IN WINDS SHIFTING TO E TO SE THIS WEEKEND...BUT SHIFTING
AGAIN TO S TO SW MON/TUE AS A SFC TROUGH MOVES TO ERN SEABOARD.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  69  95  70  95 /  30  30  10  30
SSI  75  90  76  89 /  30  20  10  20
JAX  73  92  73  92 /  30  40  20  20
SGJ  74  91  74  91 /  30  40  20  20
GNV  70  92  70  92 /  40  60  40  30
OCF  71  91  71  92 /  30  60  50  30

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...NONE.
GA...NONE.
AM...NONE.
&&

DEESE/TRABERT/MCALLISTER

HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE JACKSONVILLE FL
320 AM EDT THU AUG 6 2009

FLZ020>025-030>033-035>038-040-GAZ132>136-149>154-162>166-071000-
HAMILTON-SUWANNEE-COLUMBIA-BAKER-NASSAU-DUVAL-UNION-BRADFORD-CLAY-
ST JOHNS-GILCHRIST-ALACHUA-PUTNAM-FLAGLER-MARION-COFFEE-
JEFF DAVIS-BACON-APPLING-WAYNE-ATKINSON-WARE-PIERCE-BRANTLEY-
INLAND GLYNN-COASTAL GLYNN-ECHOLS-CLINCH-CHARLTON-INLAND CAMDEN-
COASTAL CAMDEN-
320 AM EDT THU AUG 6 2009

THIS OUTLOOK IS FOR NORTHEAST FLORIDA AND SOUTHEAST GEORGIA.

.DAY ONE...TODAY AND TONIGHT...

SCATTERED TO NUMEROUS THUNDERSTORMS ARE EXPECTED ONCE AGAIN THIS
AFTERNOON AND EVENING. THE SLOW MOVEMENT OF THE STORM ACTIVITY
WILL PROMOTE LOCALLY HEAVY RAINFALL AND MINOR FLOODING CONCERNS. A
FEW OF THE STORMS WILL BECOME STRONG WITH EXCESSIVE LIGHTNING AND
GUSTY WINDS. STORM MOTION WILL BE TOWARD THE EAST AROUND 5 TO 10
MPH.

.DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY...

SCATTERED TO NUMEROUS THUNDERSTORMS ARE FORECAST EACH DAY WITH A
FEW STRONG THUNDERSTORMS POSSIBLE IN THE AFTERNOON AND EVENING. A
GRADUAL DECREASE IN THUNDERSTORM CHANCES IS EXPECTED ACROSS THE
AREA INTO THE WEEKEND.

.SPOTTER INFORMATION STATEMENT...

SPOTTER ACTIVATION IS NOT REQUESTED AT THIS TIME.

FOR ADDITIONAL INFORMATION...VISIT THE NATIONAL WEATHER SERVICE
IN JACKSONVILLE WEBSITE ON THE INTERNET AT WEATHER.GOV/JAX.

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
151 PM EDT THU AUG 6 2009

FLZ040-061830-
MARION-
151 PM EDT THU AUG 6 2009

...A SIGNIFICANT WEATHER ALERT HAS BEEN ISSUED FOR CENTRAL MARION
COUNTY FOR STRONG WINDS AND EXCESSIVE LIGHTNING VALID UNTIL 230 PM
EDT...

AT 151 PM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STRONG THUNDERSTORM CENTERED 5 MILES WEST OF SANTOS...OR 6 MILES
SOUTHWEST OF OCALA...MOVING EAST AT 10 MPH. THIS STRONG THUNDERSTORM
WILL AFFECT AREAS AROUND OCALA AIRPORT...OCALA...SANTOS...
BELLEVIEW...SILVER SPRINGS SHORES...MOSS BLUFF...LYNNE...FORT MCCOY
AND BURBANK THROUGH 230 PM EDT. EXCESSIVE CLOUD-TO-GROUND LIGHTNING
AND GUSTY WINDS OF 45 TO 55 MPH CAN BE EXPECTED ALONG WITH POSSIBLE
MINOR DAMAGE.

REPORT DAMAGE TO THE NEAREST LAW ENFORCEMENT AGENCY OR YOUR COUNTY
EMERGENCY MANAGEMENT.

LAT...LON 2937 8196 2907 8183 2900 8221 2918 8227
TIME...MOT...LOC 1751Z 253DEG 10KT 2912 8214

CARROLL