020
FXUS62 KJAX 051134
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
734 AM EDT Sun Oct 5 2025

...New AVIATION...

.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

- Minor to Moderate Tidal Flooding Continues this Week. Coastal
  Flood Warning: Moderate Tidal Flood impacts within the St. Johns
  River Basin, Coastal Northeast FL & Intracoastal Waterway.
  Coastal Flood Advisory: Minor Tidal Flood impacts Coastal
  Southeast GA & Nassau Co.

- Dangerous Beach & Marine Conditions through Tuesday, Likely Returning
  Late this Week and Next Weekend. High Rip Current Risk, High
  Surf & Small Craft Advisory

- Locally Heavy Rainfall & Flood Risk on Monday. Isolated
  Thunderstorms on Sunday for North Central and Coastal Northeast
  FL. Localized Flood Risk on Monday at Coastal & Normally Flood
  Prone, Low-lying Locations

&&

.SYNOPSIS...
Issued at 414 AM EDT Sun Oct 5 2025

Overnight surface analysis depicts gradually weakening high
pressure (1025 millibars) now centered just offshore of the Mid-
Atlantic coast. This feature continues to wedge down the
southeastern seaboard, with a sharp coastal trough remaining
positioned over our near shore Atlantic waters to the south of
this surface ridge. Meanwhile, weak low pressure (1011 millibars)
was moving slowly westward across the northwestern Bahamas, with
this feature located along a warm front that was lifting slowly
northward across the FL Keys towards south FL. Otherwise, another
weak low pressure center (1009 millibars) was situated along this
same warm front in the Gulf to the south of coastal Louisiana.
Aloft...ridging was positioned over coastal VA and NC, while a
cutoff trough was located over the northern Gulf.

Latest GOES-East derived Total Precipitable Water imagery
indicates that tropical moisture has returned to locations south
of the Interstate 10 corridor, where PWATs have risen to around 2
inches. Meanwhile, PWATs were closer to early October climatology
across southeast GA, where values were generally in the 1.5 -
1.75 inch range. Coastal troughing continues to generate scattered
showers over the Atlantic coastal waters that were occasionally
moving onshore, with widely scattered light to moderate showers
extending inland to the U.S. Highway 301 corridor in southeast GA,
while only isolated showers were generally confined to the I-95
corridor in northeast FL. Multi-laytered cloudiness continues to
prevail throughout our region, with pockets of low stratus
cloudiness expanding in coverage early this morning across inland
locations that are along and north of I-10. Temperatures at 08Z
ranged from around 70 across inland portions of southeast GA and
the Suwannee Valley to the upper 70s along the northeast FL coast.
Dewpoints ranged from the mid 60s across inland portions of
southeast GA to the mid 70s at coastal locations.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 414 AM EDT Sun Oct 5 2025

Low level flow will veer to southeasterly today in between high
pressure situated off the Mid-Atlantic coast and lowering
pressures over the Gulf and southeast FL, with coastal troughing
remaining in place over our near shore waters. Meanwhile, ridging
aloft centered along the Carolina coast will direct the cutoff
trough over the northern Gulf slowly northward. This weather
pattern will allow for deeper tropical moisture to gradually
overspread our area through tonight, with strengthening isentropic
lift to the north of a lifting warm front and the presence of
persistent coastal troughing resulting in gradually increasing
rain chances by this afternoon and evening from south to north.
The deeper moisture advecting into our region could allow for a
few isolated thunderstorms to develop later today and tonight over
the northeast FL Atlantic waters and across north central FL.
Brisk low to mid level flow should keep activity moving at a 20-30
mph clip, likely limiting potential for heavy rainfall totals.
Onshore surface winds will remain breezy at coastal locations as a
tight local pressure gradient remains in place, keeping highs in
the low to mid 80s at coastal locations. Lower stratus ceilings
expanding early this morning across inland locations will lift by
the mid to late morning hours, with breaks in the multi-layered
cloud cover allowing inland highs to climb to the mid and upper
80s, with humid conditions this afternoon pushing heat index
values to the low and mid 90s across most of north central and
northeast FL.

Scattered convection over inland north central and northeast FL
this afternoon will shift to coastal locations tonight as brisk
onshore winds and the persistent coastal trough over our near
shore waters continues to generate scattered to numerous fast
moving showers. Lower stratus ceilings may once again expand at
inland locations during the overnight and predawn hours due to the
tropical air mass that will continue to overspread our area. Lows
will remain in the 70s area-wide.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 414 AM EDT Sun Oct 5 2025

High pressure pushes offshore along the mid Atlantic coast as
coastal troughing lingers over the local waters at the start of
the new week. Breezy northeasterly-easterly onshore flow will
continue to push in showers onshore through the day on Monday with
scattered to numerous showers highlighted in the forecast with
higher chances over NE FL. Elevated moisture levels with PWATs
around the 2" range could see some showers produce heavy downpours
which could lead to flooding in low lying and urban locations,
which could be problematic if any heavy downpours occurs over
locations which are already experiencing ongoing coastal flooding
due to the elevated onshore winds.

By Tuesday, precipitation chances will start to trend downward as
drier air begins to move into the area from the Atlantic as the
high pressure continues to move off into the Atlantic and the
coastal trough flattens. Enough lingering moisture will still
bring about isolated to scattered showers with higher chances
along the coast and inland NE FL, but chances of precipitation
will continue to trend downward through the overnight hours
Tuesday Night.

Daytime highs will be in 80s with warmer temps away from the
coast, slightly warmer temps on Tuesday. Overnight lows in the 70s
with warmer temps along coastal locations Monday Night. Tuesday
Night, upper 60s over inland SE GA and the Suwannee Valley Region
of NE FL, lower 70s along the coast and inland locations of NE FL
aside from the Suwannee Valley Region.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 414 AM EDT Sun Oct 5 2025

Dry air will continue to limit the amount of precipitation across
the area midweek, with isolated to scattered chances for the
southern and coastal locations of NE FL. By Thursday, an
approaching frontal boundary will begin to shift over the
northern portions of SE GA. Northeast onshore flow begins to ramp
up once again ahead of the frontal boundary. As this will still
coincide with the Full Moon and higher tides, the onshore
northeasterly flow will likely continue the risk of coastal
hazards of rip currents, coastal flooding, dangerous maritime
boating conditions, and rough surf during the back half of the
upcoming week and next weekend.

&&

.AVIATION...(12Z TAFS) Issued at 729 AM EDT Sun Oct 5 2025

Northeasterly flow shifts easterly this morning, becoming
gusty (up to 25 knots) at the coastal airfields again. One change
worth noting will be the increasing thunderstorm chance versus
strictly showers. Best chances for t`storm development will be
inland toward I-75 and KGNV late this morning and early afternoon.
Once limited stratus lifts by 13z, VFR conditions prevail as quick-
moving showers continue to move inland from the Atlantic. Late
afternoon and evening break in the showers appears likely before
another coastal trough develops, igniting another round showers
during the predawn hours Monday. Increasing showers at the coast
will coincide with inland stratus development, with high-IFR (25%
chance) or low-MVFR (50% chance) ceilings.

&&

.MARINE...
Issued at 414 AM EDT Sun Oct 5 2025

High pressure centered along the Mid-Atlantic coast will continue to
wedge down the southeastern seaboard, while coastal troughing
remains situated over our near shore waters through Tuesday.
Gusty easterly winds and Small Craft Advisory conditions featuring
rough, elevated seas will continue across our local waters
through Tuesday. Seas of 6-9 feet through tonight will build to
7-11 feet on Monday and Monday night as easterly winds increase to
20-30 knots. Meanwhile, waves of showers and a few embedded
thunderstorms will increase in coverage by Sunday night and Monday
as weak low pressure traversing the Bahamas moves towards
southeast Florida. High pressure will then shift further offshore
of the Mid-Atlantic coast by Tuesday night and Wednesday, allowing
coastal troughing to weaken over our local waters. Onshore winds
and seas will gradually subside, briefly falling back to Caution
levels of 15-20 knots and 4-6 foot seas on Wednesday and Wednesday
night. A cold front entering the southeastern states on Wednesday
will then shift slowly southward across our local waters by
Thursday night and Friday. Strong northeasterly winds will
redevelop late this week as another high pressure center building
over New England wedges down the southeastern seaboard.

&&

.HYDROLOGY...
Issued at 414 AM EDT Sun Oct 5 2025

Persistent onshore winds will continue to "trap" tides within the
St. Johns River basin, with an increasingly astronomical influence
to local tides this week due to Tuesday`s "Harvest" Full Moon,
with minor to moderate tidal flooding continuing throughout the
upcoming week.

Coastal Flood Warning: includes the St. Johns River Basin,
Intracoastal Waterway (ICWW) and the northeast FL coast from
Mayport to Flagler Beach. Tidal levels will continue to crest
generally between 2 to 2.5 ft above Mean Higher High Water (MHHW)
within the St. Johns River basin, with values around 2 feet above
MHHW and along the Atlantic coast south of Mayport and within the
ICCW. Moderate tidal flooding impacts include flooding of low-
lying roads and water surrounding some vulnerable structures.

Coastal Flood Advisory: includes coastal Nassau County and coastal
southeast GA. Water levels of 1.5 - 2 feet above MHHW around times
of high tide will mainly cause minor tidal flooding impacts,
including flooding of some boat ramps, docks, over-topping of
bulkheads and some tidal-prone roads in low-lying areas.

This will be and extended duration coastal / tidal flood 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 into
next weekend for the St. Johns River basin and possibly along
portions of coastal northeast FL.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  84  70  85  68 /  50  10  30  10
SSI  82  73  83  74 /  50  30  40  20
JAX  85  73  84  72 /  60  30  60  20
SGJ  84  74  84  75 /  60  40  70  40
GNV  88  72  87  72 /  50  20  60  20
OCF  86  73  86  73 /  60  20  60  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 5 PM EDT Tuesday for FLZ124.

     High Rip Current Risk through Tuesday afternoon for FLZ124-125-
     138-233-333.

     High Surf Advisory until 5 PM EDT Tuesday for FLZ124-125-138-233-
     333.

     Coastal Flood Warning until 5 PM EDT Tuesday for FLZ125-132-137-
     138-225-233-325-333-633.

GA...Coastal Flood Advisory until 5 PM EDT Tuesday for GAZ154-166.

     High Rip Current Risk through Tuesday afternoon for GAZ154-166.

AM...Small Craft Advisory until 5 PM EDT Tuesday for AMZ450-452-454-
     470-472-474.

&&

$$