Beach, Georgia Weather Forecast Discussion

505
FXUS62 KJAX 030804
AFDJAX
Area Forecast Discussion
National Weather Service Jacksonville FL
404 AM EDT Fri Oct 3 2025
...New SYNOPSIS, NEAR TERM, SHORT TERM, LONG TERM, MARINE, HYDROLOGY...
.KEY MESSAGES...
For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf
- Coastal Flood Warning for the St. Johns River Basin and the
  Northeast FL Atlantic Coast Beginning Late this Afternoon.
  Coastal Flood Advisories for the Southeast GA and Nassau County
  Coasts Beginning Late this Afternoon.
- Dangerous Beach & Marine Impacts into Early Next Week. High Rip
  Current Risk, High Surf & Small Craft Advisories Remain Posted.
  Moderate to Major Beach Erosion Possible. Wind Gusts at Coastal
  Locations of 30 to 40 mph Later this Morning through this
  Evening.
- Locally Heavy Rainfall & Isolated Embedded Thunderstorms at
  Coastal Locations this Weekend and Early Next Week. Localized
  Flooding will be Possible.
&&
.SYNOPSIS...
Issued at 404 AM EDT Fri Oct 3 2025
Overnight surface analysis depicts strong high pressure (1032
millibars) anchored along the New England and Mid-Atlantic
coasts, with this feature wedging down the southeastern seaboard.
Meanwhile, coastal troughing remains positioned over the near
shore portion of our local Atlantic waters, with this feature
helping to generate widely scattered light to moderate showers
that were being steered quickly westward across our area, with
the intensity of these showers waning once they reach the U.S.
Highway 301 corridor. Otherwise, a stationary frontal boundary
located over the Straits of Florida and extending eastward across
the northwestern Bahamas was poised to lift slowly northward
towards southern FL. Aloft...a complex pattern prevails over the
southeastern states, as ridging prevails over the southern
Appalachians and the Carolinas, while troughing was in place over
the Bahamas and south FL. Latest GOES-East derived Total
Precipitable Water imagery indicates that a seasonably dry air
mass was located for areas north of Waycross in southeast GA,
where PWAT values were generally around 1.25 inches. A seasonably
moist air mass prevails elsewhere, with PWAT values generally
between 1.5 - 1.75 inches. Pockets of lower stratus clouds have
developed for locations along and west of the U.S. Highway 301
corridor, with marine stratocumulus otherwise overspreading our
region from east to west during the predawn hours. Temperatures
range from the mid and upper 60s for locations along and west of
the U.S.-301 corridor to the 70s along the northeast FL coast,
where breezy onshore winds were keeping dewpoints in the mid to
upper 60s. Dewpoints have fallen to around 60 for interior
portions of southeast GA as of 08Z.
&&
.NEAR TERM...
(Today and Tonight)
Issued at 404 AM EDT Fri Oct 3 2025
Strong high pressure anchored along the New England and Mid-
Atlantic coasts will be slow to weaken today, with this feature
continuing to wedge down the southeastern seaboard and keeping a
tight local pressure gradient in place. Coastal troughing will
also remain in place over our near shore waters, with this feature
expected to generate scattered showers over the coastal waters
today that will occasionally move onshore and impacting locations
along and east of the U.S. Highway 301 corridor in southeast GA
and for locations west of the I-75 corridor in northeast and north
central FL. The tight local pressure gradient will keep strong
northeasterly winds in place along coastal locations into
tonight, with speeds increasing to the 20-25 mph range with
occasional gusts of 30-40 mph possible for locations along and
east of I-95. We`ll let the day shift assess whether gusts will
be frequent enough at coastal locations to warrant the issuance of
a Wind Advisory. Breezy winds will expand inland by late this
morning and early afternoon, with marine stratocumulus
overspreading our area and keeping high temperatures generally in
the 80-85 degree range today area-wide, except upper 70s along the
southeast GA coast.
Weak low pressure may develop along a frontal boundary that will
be lifting slowly northward towards southern FL tonight. This
feature should shift low level flow from northeasterly to easterly
after midnight, with this subtle wind change and a sharp coastal
trough likely generating a higher coverage of showers and possibly
an isolated thunderstorm or two over the Atlantic waters, with
this activity pushing onshore towards or just after midnight.
Lower stratus ceilings may again develop at inland locations
during the predawn hours on Saturday. Breezy onshore winds at
coastal locations will keep lows in the 70s, while breaks in the
stratocumulus and a drier air mass allow lows to fall to the mid
and upper 60s inland. The bigger weather story later this
afternoon and tonight will be increasing coastal and tidal
flooding along the northeast FL Atlantic coast and within the St.
Johns River basin (see "Coastal Flooding" section below for more
details).
&&
.SHORT TERM...
(Saturday through Sunday night)
Issued at 404 AM EDT Fri Oct 3 2025
The mid/upper level ridging will remain stubborn along the east
coast of the US this weekend as an upper level wave shifts from
the NW Bahamas into the FL peninsula. Strong high pressure near
the Delmarva peninsula will wedge SSW along the lee side of the
central/southern Appalachian mountains with a coastal trough
persisting off of the Florida and southeast coast. The local
pressure gradient will remain tight between these two surface
features and breezy ENE winds 15-25 mph with gusts approaching
40 mph at the beaches may bring near wind advisory conditions
for the immediate coast, but not inland.
Saturday, waves of showers and isolated embedded T`storms will
move onshore the NE FL coast and diminish in coverage with inland
extent to isolated showers over the Suwannee Valley and dry
conditions north and west of Alma over far inland SE GA.
Sunday, the upper level wave will turn winds aloft more southerly
as the feature moves NW into central FL, spurring a weak surface
low along a developing west to east frontal boundary over the
peninsula. Lift from surface boundary just south of the area and
additional shortwave energy will focus more numerous to widespread
convergent coastal showers and embedded T`storms along the Atlantic
coast that will push well inland. Surface winds will become more
easterly 15-20 mph with gusts to 30-35 at the coast and 10-15 mph
inland gusting to 25 mph as high pressure shifts more NE of the
region over the western Atlantic east of the Mid Atlantic coast.
Abundant clouds and onshore flow will keep highs along the coast
in the low 80s, warming to the mid 80s west of highway 301 Saturday,
but higher shower coverage Sunday will limit highs predominantly
into the low 80s area wide, slightly below normal. Lows, however
will remain slightly above normal around 70 inland and the low
70s at the coast.
&&
.LONG TERM...
(Monday through Thursday)
Issued at 404 AM EDT Fri Oct 3 2025
Monday and Tuesday, ridging aloft will will move off the east coast
of the U.S. as an upper level wave moves NW of the area. Surface
high pressure will shift to the northeast over the western Atlantic
waters NW of Bermuda with a weak frontal boundary over south and
central FL with easterly moist onshore flow producing scattered to
numerous showers and isolated to scattered afternoon T`storms as
coastal showers push onshore. Easterly winds will not be as strong
as this weekend due to a decreasing pressure gradient over the area
about 10-15 mph gusting to 25 mph at the coast.
Wednesday, drier air will rotate into the region from Atlantic high
pressure that will limit shower chances to isolated inland and more
scattered near the coast. By Thursday, a deepening upstream trough
will swing through the NE U.S. and support a surface cold front
sliding through the southeast states and into the area by late in
the day. As the front moves through, winds will increase from the
NE as strong high pressure begin to build from the eastern great
lakes down the east coast. Coastal showers will be limited to
primarily the coastal counties.
Temperatures will begin the period with near normal highs in the
low/mid 80s at the coast and the mid/upper 80s inland. Lows will
be above normal in the low 70s along the coast and slightly above
normal inland with lows in the mid/upper 60s.
&&
.AVIATION...
(06Z TAFS)
Issued at 151 AM EDT Fri Oct 3 2025
Periods of showers and MVFR ceilings are expected at the regional
terminals throughout the period. Brief periods of IFR conditions
will be possible during heavier showers, and longer periods of VFR
conditions are expected in between waves of showers. Confidence in
timing of heavier showers and MVFR/IFR conditions remains low, as
we used vicinity coverage overnight through Friday morning and
PROB30 groups on Friday afternoon, with activity more likely to
impact the SSI and SGJ coastal terminals shortly after 16Z, with
activity then quickly progressing inland. East-northeasterly
surface winds sustained around 15 knots and gusty at SGJ overnight
will increase to 15-20 knots by 16Z, with frequent gusts around 30
knots expected. Northeasterly surface winds sustained at 5-10
knots elsewhere will increase to 10-15 knots and gusty by 15Z and
then around 15 knots by 18Z, with frequent gusts of 20-30 knots
likely. Surface winds at the inland terminals will diminish to
around 10 knots towards 00Z Saturday, while sustained speeds at
the coastal terminals remain sustained at 10-15 knots and gusty.
&&
.MARINE...
Issued at 404 AM EDT Fri Oct 3 2025
Strong high pressure stretching along the Mid-Atlantic and New
England coasts will continue to wedge down the southeastern
seaboard, with this feature expected to gradually weaken on Friday
night. Strong northeasterly winds and Small Craft Advisory
conditions will continue across our local waters, with occasional
wind gusts to Gale Force and rough, elevated seas expected. Seas
of 8-11 feet will prevail both near shore and offshore today and
tonight, followed by seas near shore falling slightly to the 6-9
foot range this weekend. Meanwhile, coastal troughing positioned
over our local waters will continue to generate waves of moderate
to heavy showers, with a few embedded thunderstorms possible.
Otherwise, weak low pressure may develop along a frontal boundary
over southern Florida later tonight and Saturday. This frontal
boundary will lift slowly northward this weekend, resulting in
increasing coverage of showers and thunderstorms. Prevailing winds
will shift to easterly this weekend as high pressure shifts off
the Mid- Atlantic coast, with Small Craft Advisory conditions and
rough, elevated seas extending through at least Monday night.
Rip Currents / Beach Erosion: High risk of rip currents and high
surf advisory conditions, along with moderate to severe beach
erosion will continue at Atlantic beachfront locations through
the weekend and into early next week. Surf/breakers into the 5-8
ft range will continue through the weekend. Moderate to severe
beach erosion is expected at Atlantic beachfront locations during
times of high tide.
&&
.HYDROLOGY...
Issued at 404 AM EDT Fri Oct 3 2025
Water levels peaked at moderate flooding within the St. Johns
River basin at many gauges south of downtown Jacksonville on
Thursday night. With persistent, strong onshore winds continuing
to "trap" tides within the St. Johns River basin combining with
the approach of Tuesday`s "Hunter" Full Moon, we expect a more
widespread moderate flood event to occur with the late afternoon,
evening, and overnight high tide cycle on Friday, with water
levels potentially touching moderate flood levels, or around 2 to
2.5 feet above Mean Higher High Water (MHHW), or above normally
dry ground, along the Atlantic Coast and within the Intracoastal
Waterway (ICCW) from Mayport southward through Flagler Beach.
A Coastal Flood Warning has thus been issued for these locations
along the Atlantic Coast in northeast FL and for the entire St.
Johns River basin, where water levels will likely peak in the 2-3
foot range above MHHW, or above normally dry ground. Before this
evening`s higher tide cycle, we expect Minor flooding to occur
around high tide during the morning and early afternoon hours.
Minor tidal / coastal flooding will then expand into Nassau County
and coastal southeast GA beginning tonight, where Coastal Flood
Advisories will go into effect. This will be an extended duration
coastal / tidal flooding event, as astronomical tides will not
peak until the mid to late part of next week. With brisk onshore
flow continuing through Monday and then potentially re-
strengthening late next week, we can expect Coastal Flood
Advisories / Watches / Warnings to continue during at least the
next week and possibly longer.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG  82  65  83  69 /  10  10  10  20
SSI  78  72  81  73 /  40  70  40  50
JAX  81  70  83  72 /  40  60  60  60
SGJ  81  72  83  73 /  50  60  70  70
GNV  84  69  85  71 /  30  30  40  40
OCF  83  70  83  72 /  30  30  40  40
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 5 AM EDT Monday for FLZ124.
High Rip Current Risk through late Sunday night for FLZ124-125-
     138-233-333.
High Surf Advisory until 5 AM EDT Monday for FLZ124-125-138-233-
     333.
Coastal Flood Advisory until 5 PM EDT this afternoon for FLZ125-
     132-137-138-225-233-325-333-633.
Coastal Flood Warning from 5 PM this afternoon to 5 AM EDT
     Monday for FLZ125-132-137-138-225-233-325-333-633.
GA...Coastal Flood Advisory until 5 AM EDT Monday for GAZ154-166.
High Rip Current Risk through late Sunday night for GAZ154-166.
High Surf Advisory until 5 AM EDT Monday for GAZ154-166.
AM...Small Craft Advisory until 5 AM EDT Monday for AMZ450-452-454-
     470-472-474.
&&
$$

NWS JAX Office Area Forecast Discussion