Area Forecast Discussion
Issued by NWS Jacksonville, FL

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FXUS62 KJAX 060204

Area Forecast Discussion
National Weather Service Jacksonville FL
1004 PM EDT Mon Jun 5 2023


Issued at 1005 PM EDT Mon Jun 5 2023

Late evening surface analysis depicts weakening high pressure
(1014 millibars) centered over the southeastern states. Aloft...a
highly amplified weather pattern prevails, with cutoff troughing
positioned over coastal New England and the Canadian Maritime
Region that was creating a drier westerly flow across our region.
Meanwhile, stout ridging continues across the Upper Midwest
continues to gradually retrograde westward, with weak troughing
trapped beneath this ridge over the lower Mississippi Valley and
western and central portions of the Gulf of Mexico. Thin cirrus
cloud cover was streaming across southeast GA and western portions
of the Suwannee Valley, with fair skies elsewhere. Unseasonably
pleasant weather prevails across our area, with temperatures at
02Z falling through the upper 60s and lower 70s, while dewpoints
generally in the low to mid 60s.

Radiational cooling overnight will allow lows to fall to the lower
60s at inland locations, ranging to the mid to upper 60s along the
immediate coast. These values are about 4-7 degrees below early
June climatology. Surface ridging will then slide south of our
area by the late morning hours on Tuesday, allowing for a gradual
return of deeper moisture during the afternoon and evening hours
from south to north. PWAT values will rise above 1.5 inches before
sunset across north central and northeast FL, possibly developing
isolated to widely scattered convection where the Atlantic and
Gulf coast sea breezes collide during the late afternoon and early
evening hours, mainly along the U.S. Highway 301 corridor. Plenty
of morning and early afternoon sunshine will allow highs to climb
back to near climatology, with highs around 90 inland and the mid
80s at coastal locations.


(00Z TAFS)
Issued at 807 PM EDT Mon Jun 5 2023

Periods of MVFR visibilities will be possible at VQQ overnight
through around sunrise on Tuesday. Otherwise, VFR conditions will
prevail at the regional terminals. Isolated to widely scattered
showers and possibly a thunderstorm will develop near the
northeast FL terminals after 18Z on Tuesday afternoon. Confidence
was too low to include any mention of vicinity thunderstorm
coverage at this time, but may be added to the GNV terminal in
future TAF issuances. East to northeasterly surface winds
sustained around 5 knots will diminish before 06Z Tuesday. Light
south to southwesterly surface winds will then develop shortly
after sunrise on Tuesday, with speeds increasing to 5-10 knots
towards 15Z. The Atlantic sea breeze boundary will then develop
near the coastal terminals after 17Z, resulting in surface winds
shifting to east-southeasterly and increasing to around 10 knots
by 19Z at SGJ and SSI. This boundary will gradually progress
across the rest of the Duval County terminals by 22Z.


Issued at 1005 PM EDT Mon Jun 5 2023

Elevated seas throughout our local waters will continue to
gradually subside overnight as winds diminish. Small Craft should
exercise Caution if venturing into the near shore waters as well
ad the offshore waters adjacent to southeast GA tonight, where
seas of 4-6 feet will prevail, while Small Craft Advisory level
seas of 6-8 feet over the offshore waters adjacent to northeast
FL will subside to 5-7 feet after midnight. Seas are expected to
fall below Caution levels shortly after sunrise on Tuesday.

Otherwise, weak high pressure situated over our region will
gradually shift southward on Tuesday, resulting in prevailing
southerly winds that will shift to southwesterly by Wednesday.
Evening wind surges and afternoon sea breezes will result in
mostly brief periods of Caution level speeds of 15-20 knots
across our local waters through midweek. Seas will continue to
gradually subside, with 2-4 foot seas expected both near shore and
offshore by Wednesday.

Meanwhile, a cold front will shift southward down the southeastern
seaboard by Wednesday night and Thursday, resulting in increasing
chances for showers and thunderstorms, mainly during the late
afternoon and evening hours. This front is expected to stall
across our local waters by late Friday and Saturday. This front
will then lift back northward as a weak warm front by late in the
upcoming weekend.

Rip Currents: A long period northeasterly swell and elevated surf
conditions on Tuesday will likely keep a high-end moderate to
possibly high risk of rip currents in place at the northeast FL
beaches, with a moderate risk expected at the southeast GA
beaches. The northeasterly swell will fade on Wednesday, and
prevailing offshore winds should result in a lower-end moderate
risk at area beaches.


Issued at 1005 PM EDT Mon Jun 5 2023

Surface and transport winds will shift to westerly across inland
southeast GA shortly after sunrise on Tuesday, with these winds
combining with elevated mixing heights to create good to
marginally high daytime dispersion values. Lighter south-
southwesterly surface and transport winds will prevail for
locations south of Interstate 10, where fair to good daytime
dispersion values are forecast on Tuesday. A dry air mass will
prevail at inland locations, where minimum relative humidity
values will fall to the 30-35 percent range on Tuesday afternoon.
Strengthening southwesterly surface and transport winds on
Wednesday will create high daytime dispersion values across most
of southeast GA on Wednesday, with good to marginally high value
forecast for most of northeast and north central FL.


Issued at 1005 PM EDT Mon Jun 5 2023

Another round of minor tidal flooding is expected along the
immediate coast, the Intracoastal Waterway, and within the St.
Johns River Basin during the overnight high tide cycle. Therefore,
a Coastal Flood Advisory will remain in effect through late
tonight along the Atlantic coast, with minor flooding possibly
continuing through midweek within portions of the St. Johns River
basin, as elevated astronomical tides only gradually allow water
to drain from the basin. Water levels will generally peak in the
1 to 1.5 feet (MHHW) range later this evening along the Atlantic
coast and through at least Tuesday night within the St. Johns
River basin.


AMG  61  91  66  91 /   0  10  10  30
SSI  67  86  72  89 /   0  10  10  40
JAX  62  89  66  90 /   0  10  10  60
SGJ  66  86  70  89 /   0  10  10  60
GNV  62  90  66  88 /   0  30  30  40
OCF  63  89  66  88 /   0  30  20  30


FL...Coastal Flood Advisory until 6 AM EDT Wednesday for FLZ033-038-

     Coastal Flood Advisory until 6 AM EDT Tuesday for FLZ124-125-133-

     High Rip Current Risk until 6 AM EDT Tuesday for FLZ124-125-133-

GA...Coastal Flood Advisory until 6 AM EDT Tuesday for GAZ154-166.

     High Rip Current Risk until 6 AM EDT Tuesday for GAZ154-166.

AM...Small Craft Advisory until 6 AM EDT Tuesday for AMZ472-474.


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