000
FXUS62 KJAX 200805
AFDJAX
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
300 AM EST THU NOV 20 2008
...FREEZING TEMPS EXPECTED THIS MORNING...
...ANOTHER COLD BLAST EXPECTED FOR SATURDAY...
.SHORT TERM...LATEST MSAS ANALYSIS SHOWS SURFACE HIGH PRESSURE HAS
SETTLED INTO THE EAST GULF OF MEXICO...CENTERED JUST OFFSHORE THE
NATURE COAST OF FLORIDA. WITH NO EXTENSIVE RIDGE AXIS EMANATING
FROM THIS FEATURE...A GRADIENT IS REALIZED AT VERY LITTLE DISTANCE
FROM THE HIGH`S CENTER. RESULTANT FLOW OVER THE AREA IS LIGHT
WESTERLY...BUT ENOUGH TO ALLEVIATE RAPID TEMPERATURE DROP SEEN
EARLIER WITH MORE IDEAL RADIATIONAL COOLING CONDITIONS. ALTHOUGH
MOST AREAS HAVE LEVELED OUT IN THE MID 30S...EXPECT A SLOWER DROP
TO COMMENCE THROUGH SUNRISE AND A LIGHT FREEZE FOR THE COASTAL
COUNTIES AND AROUND 30 FOR INLAND AREAS REMAINS ON TRACK.
HIGH PRESSURE WILL GET SHUNTED SOUTH THROUGH THIS
AFTERNOON...MAINTAINING THE DRY WESTERLY FLOW ACROSS THE AREA.
MODERATING TEMPS WILL RESULT IN AFTERNOON HIGH TEMPS IN THE MID TO
UPPER 60S ACROSS THE AREA UNDER CLEAR SKIES.
ANOTHER AREA OF VERY STRONG HIGH PRESSURE IS EXPECTED TO DROP INTO
THE CENTRAL PLAINS STATES THU NIGHT WITH A FRONTAL BOUNDARY
EXPECTED TO RACE INTO THE AREA BETWEEN 06Z AND 12Z. ALTHOUGH
PASSAGE WILL OCCUR OVER THE GA PORTION PRIOR TO SUNRISE...COLD AIR
ADVECTION WILL BE LIMITED INITIALLY AND SHOULD KEEP ALL AREAS ABOVE
FREEZING...IF ONLY BY A FEW DEGREES.
STRONG COLD AIR ADVECTION PATTERN IN PLACE FOR FRIDAY AFTERNOON
WILL ALLOW FOR STRUGGLING TEMPS AND HIGHS ONLY IN THE UPPER 50S.
ALTHOUGH 1040MB HIGH IS IMPRESSIVE FOR THIS TIME OF YEAR...MID
LEVEL TROUGH FOR THIS OUTBREAK IS NOT QUITE AS DEEP AND THEREFORE
WILL SEE HIGH TRANSLATE MORE EAST THAN SOUTH THIS TIME AROUND.
WITH HIGH SETTLING OVER THE CAROLINAS FRIDAY NIGHT INTO SAT
MORNING...AN ADVECTIVE TYPE FREEZE WILL BE IN STORE WITH HINTS OF
AN ONSHORE FLOW FOR COASTAL FLORIDA AREAS PERHAPS CURBING THE
EXPECTED TEMPERATURE DROP. STILL...COLD AIR IS FORMIDABLE AND
EXPECT FREEZE WARNINGS FOR A GOOD PORTION OF INLAND AREAS.
.LONG TERM...WITH STRONG HIGH REMAINING OVER THE MID ATLANTIC...A
MODERATE EASTERLY FLOW REGIME WILL BE IN STORE FOR EARLY NEXT
WEEK. SURFACE MOISTURE DOES NOT INCREASE APPRECIABLY UNTIL SAT
MORNING AND SHOULD ONLY RESULT IN LOW CLOUDS OVER THE MAINLAND
AND ISOLATED SHOWERS OVER THE MARINE ENVIRONMENT. NEXT BEST RAIN
CHANCES WILL BE ON TUE WITH ANOTHER COLD FRONT TO PUSH THROUGH.
PREP TIME AHEAD OF THIS FEATURE WITH MOIST EASTERLY FLOW SHOULD BE
SUFFICIENT TO ALLOW FOR SCT POPS WITH THE FRONTAL PASSAGE.
&&
.AVIATION...OTHER THAN SOME PATCHY GROUND FOG NEAR SUNRISE AND SOME
LINGERING SMOKE NEAR KJAX...NO SIGNIFICANT WX EXPECTED WITH VFR
CONDITIONS CONTINUING.
&&
.MARINE...SMALL CRAFT ADVISORY CRITERIA EXPECTED IN THE OFFSHORE
WATERS AFTER MIDNIGHT TONIGHT AND WILL ADD ADVISORY TO THIS PACKAGE.
THINK WINDS MAY STAY JUST BELOW ADVISORY CRITERIA IN THE NEAR SHORE
WATERS...BUT LATER SHIFTS CAN PIN THIS DOWN. SEAS IN THE NEAR SHORE
AREA WILL STAY BELOW 7 FT UNTIL LATE FRI NIGHT OR EARLY SAT WHEN
FLOW BECOMES MORE ONSHORE. SEAS 7 FT OR GREATER WILL LIKELY CONTINUE
IN THE OFFSHORE WATERS THRU SAT NIGHT.
&&
.FIRE WEATHER...WITH LIGHT W FLOW AND CONTINUED DRY AIR IN PLACE...
MOST OF NE FL SHOULD SEE RED FLAG CONDITIONS TODAY. THINK THE
COMBINATION OF DRY AIR BEHIND NEXT FRONT AND SUSTAINED DAYTIME WINDS
NEAR 15 MPH WILL NECESSITATE A FIRE WX WATCH FOR MOST OF NE FL FOR
FRI.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 66 33 58 26 / 0 0 0 0
SSI 64 41 59 36 / 0 0 0 0
JAX 67 39 58 32 / 0 0 0 0
SGJ 66 44 61 40 / 0 0 0 0
GNV 67 38 60 30 / 0 0 0 0
OCF 67 40 63 34 / 0 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...RED FLAG WARNING FROM 11 AM THIS MORNING TO 5 PM THIS
AFTERNOON FOR ALACHUA-BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-
FLAGLER-GILCHRIST-HAMILTON-MARION-NASSAU-PUTNAM-ST JOHNS-
SUWANNEE-UNION.
FREEZE WARNING UNTIL 8 AM THIS MORNING FOR ALACHUA-BAKER-
BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-HAMILTON-MARION-
NASSAU-PUTNAM-SUWANNEE-UNION.
FROST ADVISORY FROM 4 AM TO 8 AM THIS MORNING FOR FLAGLER-ST
JOHNS.
FIRE WX WATCH FROM LATE FRI MORNING THRU FRI AFTN FOR ALACHUA-
BAKER-BRADFORD-CLAY-COLUMBIA-DUVAL-GILCHRIST-HAMILTON-MARION-
NASSAU-PUTNAM-SUWANNEE-UNION.
FIRE WX WATCH FOR FRI AFTN FOR DUVAL-FLAGLER-NASSAU-ST JOHNS.
GA...NONE.
AM...SMALL CRAFT ADVISORY FROM 4 AM FRI TO 10 PM SAT FOR ALTAMAHA
SOUND GA TO FLAGLER BEACH FL 20 NM TO 60 NM OFFSHORE.
&&
$$
DEESE/CARROLL
