FXUS62 KJAX 111857
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
257 PM EDT WED APR 11 2007

.SHORT TERM ...AT 130 PM EDT...SATELLITE IMAGERY INDICATED MOSTLY 
SUNNY SKIES SKIES ACROSS MOST OF JAX CWA. MSAS ANALYSIS 
INDICATED A WEAKENING SURFACE LOW OFFSHORE GEORGIA WITH SURFACE 
RIDGE EXTENDING FROM THE MID-ATLANTIC STATES SOUTHWEST TO NORTHERN 
GEORGIA. SURFACE COLD FRONT EXTENDS OVER THE MISSISSIPPI VALLEY 
REGION...AND IN VICINITY OF UPPER LOW. A MODERATE WESTERLY FLOW 
ALOFT CONTINUES OVER THE LOCAL AREA.

WIDESPREAD FOG EARLY THIS MORNING LED TO CONSIDERABLE LOW CLOUDS
THROUGH MID-MORNING. THIS HAS KEPT TEMPS SLIGHTLY COOLER...WITH
CURRENT TEMPS GENERALLY BETWEEN 75 TO 80 DEGREES (BUT MUCH WARMER
THAN WAS REALIZED THIS TIME YESTERDAY).

WELL BE HARD PRESSED TO GET ACTIVITY UNTIL LATE THIS AFTERNOON/
EARLY EVENING AS 12Z KJAX SOUNDING VALIDATED NICE SUBSIDENCE
INVERSION AROUND 800 MB...WITH DRY ADIABATIC FLOW BETWEEN 700 MB
TO NEAR 800 MB.

BEGINNING LATE THIS AFTERNOON/EVENING...MEAN LAYER RIDGE POSITIONED
OVER FLORIDA PENINSULA AND SOUTH GEORGIA WILL BEGIN TO TRANSLATE
EAST IN RESPONSE TO UPSTREAM UPPER LOW AND ATTENDANT SURFACE LOW
MIGRATING EAST. AS WAS ALLUDED TO IN EARLIER DISCUSSION...STRONGEST
DYNAMICS WILL HOLD WELL NORTH OF THE AREA...AND DO NOT ANTICIPATE
MORE THAN SCATTERED SHOWERS AS WEAKENING SOUTHERN EXTENSION OF
WEATHER SYSTEM APPROACHES. HAVE REMOVED THUNDERSTORM WORDING FOR
TONIGHT AS LOW LEVEL INSTABILITY LOOKS MARGINAL AND INSTABILITY/ 
DYNAMICS ALOFT APPEAR EVEN LESS FAVORABLE DUE TO WARM WESTERLY FLOW 
REGIME.

SHOWER ACTIVITY WILL GENERALLY END ACROSS THE AREA AROUND MIDNIGHT 
AND ANTICIPATE PATCHES OF FOG DEVELOPMENT PRIOR TO COLD FRONTAL 
PASSAGE BETWEEN MIDNIGHT AND SUNRISE. AT THIS TIME...DO NOT 
ANTICIPATE MORE THAN PATCHES OF FOG DEVELOPMENT AS MODERATE BOUNDARY 
LAYER WINDS SHOULD PROVIDE SUFFICIENT TURBULENT MIXING.

DRY AND STABLE CONDITIONS WILL ENSUE...UNTIL LATE SATURDAY AFTERNOON
WHEN A VIGOROUS LOW PRESSURE SYSTEM MOVES RAPIDLY EAST ACROSS THE
SOUTHEAST UNITED STATES. GIVEN THE EVENT IS SEVERAL DAYS AWAY...IT
IS DIFFICULT TO DETERMINE THUNDERSTORM COVERAGE AND INTENSITY...BUT 
LATEST MODEL RUNS SUGGEST A SQUALL LINE MOVING ACROSS THE AREA LATE 
SATURDAY AFTERNOON INTO SATURDAY EVENING. 

.LONG TERM (SUN THRU WED)...POTENT WEATHER SYSTEM WILL LIKELY CLEAR
THE AREA SUNDAY MORNING AND HAVE INCLUDED MORNING POPS FOR MAINLY
COASTAL AREAS. MODERATE TO POSSIBLY STRONG NORTHWEST WINDS WILL
ESTABLISH BY MID-MORNING...USHERING MUCH DRIER AND COOLER
CONDITIONS INTO THE AREA.

GRADIENT WILL RELAX LATE SUNDAY AFTERNOON/EARLY EVENING AS POST-
FRONTAL HIGH NEARS FROM THE WEST. COOLEST TEMPS WILL OCCUR MONDAY
MORNING...WITH LOWS IN THE LOWER TO MID 40S COMMON ACROSS THE
INTERIOR. A DRY AND STABLE PATTERN WILL CONTINUE THROUGH EARLY
NEXT WEEK. A PROGRESSIVE PATTERN WILL LIKELY BRING NEXT FRONTAL
SYSTEM INTO THE AREA AROUND MID-WEEK.

&&

.AVIATION...MAY SEE SOME ISOLATED STORMS EARLY THIS EVE.
THEN MVFR/IFR LATER TONIGHT BETWEEN 06Z AND 12Z. LLWS 
AFTER 06Z. 

&&

.MARINE...NO HEADLINES FOR THE SHORT TERM. WILL SEE SCA 
CONDITIONS DEVELOP SATURDAY WITH THE APPROACH OF THE NEXT
COLD FRONT. A SQUALL LINE MAY BE MOVING OFFSHORE SAT NITE.
SCA CONDITIONS EXPECTED INTO EARLY NEXT WEEK AS MUCH COOLER
AND DRIER AIR SWEEPS DOWN ACROSS THE WATERS BEHIND THE FRONT.  

&&

.FIRE WEATHER...MUCH DRIER AIRMASS MOVES IN TONIGHT AS COLD
FRONT MOVES THROUGH. HAVE UPGRADED PVS WATCH TO A RED FLAG.
SIMILAR CONDITIONS EXPECTED FRI SO HAVE POSTED A WATCH.   

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  58  81  45  82 /  30  10  10  10 
SSI  63  79  53  74 /  30  10  10  10 
JAX  62  83  49  80 /  40  10  10  10 
SGJ  64  81  54  77 /  30  10  10  10 
GNV  62  85  49  84 /  40  10  10  10 
OCF  64  86  50  85 /  40  10  10  10 

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING 
     FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-
     HAMILTON-MARION-NASSAU-PUTNAM-SUWANNEE-UNION.

     RED FLAG WARNING FROM 12 PM TO 8 PM EDT THURSDAY FOR ALACHUA-
     BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-HAMILTON-
     NASSAU-SUWANNEE-UNION.

GA...RED FLAG WARNING FROM 1 PM TO 7 PM EDT THURSDAY FOR APPLING-
     ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-ECHOLS-JEFF 
     DAVIS-PIERCE-WARE-WAYNE.

     FIRE WEATHER WATCH FROM FRIDAY AFTERNOON THROUGH FRIDAY EVENING 
     FOR APPLING-ATKINSON-BACON-BRANTLEY-CHARLTON-CLINCH-COFFEE-
     ECHOLS-JEFF DAVIS-PIERCE-WARE-WAYNE.

AM...NONE.

&&

$$

ZAPPE/PETERSON