AFD NWS Jacksonville

[TampaFl]

FXUS62 KJAX 230746
AFDJAX

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
345 AM EDT THU SEP 23 2004

.CURRENTLY...SFC ANALYSIS SHOWS HIGH PRES RIDGE TO OUR N OVER THE
APPALACHIANS. SFC MOISTURE CONVERGENCE AGAIN MAXIMIZED ALONG COASTAL
ZONES BUT ONLY VERY LIGHT SHOWER ACTIVITY NOTED ON RADAR LOOP.
LATEST TEMPS RANGED FROM NEAR 60 AT ALMA TO NEAR 80 AT THE NE FL
COAST. WATER VAPOR IMAGERY AND RUC MODEL SHOW MID-UPPER HIGH PRES
RIDGE OVER OHIO VALLEY WITH RIDGING TO SERN GA. NARROW UPPER TROUGH
NOTED FROM SW GA TO NRN BAHAMAS. HURRICANE JEANNE NEAR 25.6N69.3W AT
11 PM AND CONTS TO DRIFT WWD.

.FORECAST...WHILE THE NE FLOW HAS DECREASED OVER THE LAST COUPLE
OF DAYS STILL WILL BE ENOUGH COASTAL CONVERGENCE AND LOW LEVEL
MOISTURE TO MAINTAIN SOME SLIGHT POPS IN THE FORECAST...MAINLY ALONG
THE COAST IN MORNING HRS THEN SHIFTING INLAND IN THE AFTN. MODELS
HAVE TYPICALLY DONE POORLY DEPICTING COASTAL SHRA ACTIVITY...SO HAVE
CONTD TREND OF GOING A LITTLE ABOVE GUIDANCE. THE DEEP LAYER RIDGE
TO OUR N GRADUALLY WEAKENS THROUGH FRI AND MOVES OFFSHORE OF MID
ATLC STATES. AS HURRICANE JEANNE PRESSES FURTHER WWD THRU FRI...THE
PRES GRADIENT WILL TIGHTEN A BIT AND LOW LEVEL THICKNESSES DROP
SLIGHTLY. SO FOR TODAY EXPECT TEMPS JUST AS WARM IF NOT WARMER THAN
WED THEN 2-3 DEG COOLER ON FRI AS WINDS PICK UP. SW ALLOWING
TEMPS TO RISE BACK UP TO UPPER 80S. WEAK FRONTAL PASSAGE EXPECTED ON
WED AND THUS TEMPS MAY SHIFT TOWARD CLIMO. WILL KEEP SOME 20-30% POPS
IN THE FORECAST FOR TUE AND WED.
&&

.MARINE...LATEST OBS SHOW A 5 FOOT SWELL AT GRAYS REEF AS WELL AS JUST
OFFSHORE ST MARYS. A 9 FOOT SWELL WAS AT THE ST AUGUSTINE BUOY. THE
WAVE WATCH MODEL GRADUALLY DECREASES SEAS TODAY...BUT SWELLS WILL
STILL HIGH ENOUGH TO KEEP THE HIGH SURF ADVISORY GOING FOR ONE MORE DAY
AT LEAST. OTHERWISE...ALL EYES ON HURRICANE JEANNE WHICH IS FORECAST TO
PASS TO JUST EAST OF THE NE FL COAST SUNDAY BEFORE CURVING TO THE NE.LATEST NHC FORECAST
BRINGS JEANNE TOWARD THE NRN BAHAMAS SAT MORNING THEN THE TRACK
BEGINS TO BEND NW THROUGH SUN AND MON. AT 00Z MON JEANNE FCST PSN IS
ABOUT 50 MILES E OF ST AUGUSTINE. THUS HAVE MADE SOME SIGNIFICANT
CHANGES TO POPS IN THE SAT-MON TIME FRAME. FOR NOW WILL GO WITH
LIKELY POPS ALONG THE SERN ZONES EARLY SUN MORNING THEN LIKELY ON
REMAINDER OF SUN OVER ERN ZONES WHEN JEANNE'S TRACK IS CLOSE TO THE
NE FL/SE GA COASTS. GFS MODEL COMPARES FAVORABLY TO THE LATEST NHC
TRACK UNTIL AROUND 96 HRS WHEN IT IS SLOWER THAN THE NHC FCST. AS
JEANNE TRACKS NNE ON LATE MON AND TUE WINDS SHIFT TO W TO
THE MARGIN OF ERROR THIS FAR OUT IS LARGE...SO PERSONS NEED TO KEEP
ABREAST OF THE LATEST ADVISORIES BY THE NHC. WILL PUT HURRICANE
CONDITIONS POSSIBLE FOR SUNDAY IN THE COASTAL WATERS IN THE UPCOMING
FORECAST. WILL ALSO UPDATE MARINE FORECAST LATER AFTER NEXT NHC
ADVISORY.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 89 63 87 66 / 10 10 10 00
SSI 83 70 82 72 / 10 10 20 20
JAX 86 66 84 69 / 10 10 20 20
SGJ 84 72 82 74 / 20 10 30 20
GNV 87 65 86 67 / 20 10 20 20
OCF 88 65 87 67 / 20 10 20 20
&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...SCA FERNANDINA BEACH TO FLAGLER BEACH OUT 60NM.
HIGH SURF ADVISORY FLZ024-025-033-038.
GA...SCA ALTAMAHA SOUND TO FERNANDINA BEACH OUT 60NM.
HIGH SURF ADVISORY CAMDEN AND GLYNN.
&&

$$

ARS/PP