Macclenny, Florida Weather Forecast Discussion

764
FXUS62 KJAX 211723
AFDJAX
Area Forecast Discussion
National Weather Service Jacksonville FL
123 PM EDT Sun Sep 21 2025
...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, MARINE...
.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
- High Rip Current Risk at Northeast FL Beaches through Tuesday
- Minor Tidal Flooding St. Johns River Basin Monday - Thursday
- Daily Isolated Thunderstorm Risk Returns Monday
- Inland Heat Index 95-100F Wednesday & Thursday
&&
.NEAR TERM...
Issued at 123 PM EDT Sun Sep 21 2025
Breezy NNE winds continue over the coastal waters with the area
between high pressure ridging digging down the eastern seaboard
and an inverted coastal trough just offshore. Drier airmass (PWATs
1.2-1.4 in) and low level subsidence will suppress convection for
one last day. A few coastal showers will shift onshore mainly
between St. Augustine to Flagler Beach this afternoon. Highs will
continue to warm above normal well inland into the low 90s while
onshore flow keeps coastal locations more mild topping out in the
mid/upper 80s. The coastal trough begins to relax tonight causing
the flow to become more ENE lifting coastal showers up the coast
and into SE GA in the early Monday morning hours. Overnight lows
will range in the mid/upper 60s inland to low 70s along the coast.
&&
.SHORT TERM...
(Monday through Tuesday night)
Issued at 123 PM EDT Sun Sep 21 2025
A frontal boundary lifting across the FL peninsula will bring
tropical moisture into the local area during the start of the
new week as high pressure to the north retreats towards the
Atlantic waters.
Northeasterly flow will continue to usher in showers over the
local waters and towards coastal locations during the morning
hours on Monday with winds along the coast ranging from 10 to
15 mph. By Monday afternoon, isolated to scattered showers and
some embedded storms in the onshore flow and increased moisture
will bring activity further towards inland locations. Temperatures
highs in the 80s, with some locations along the I-75 corridor
potentially reaching into the lower 90s. Cooler temperatures along
the coast with the continuing onshore flow. By the evening,
showers and storms across the area will begin to clear. Overnight
lows in the upper 60s for far inland locations of SE GA and the
Suwannee Valley region of NE FL, with warmer lows in the low 70s
along the coast and north central FL continues.
By Tuesday, onshore winds will begin to trend lower as high
pressure shifts further towards the Atlantic. Likely will see
a similar pattern of isolated to scattered morning coastal showers,
with isolated showers and storms by the afternoon hours towards
inland locations. Greater chances of precipitation (40% to 50%)
over north central FL as moisture continues to filter into the
area from the south. Warmer temperatures on Tuesday will allow for
Highs to reach into the lower 90s for inland locations and the
upper 80s along the coast. Overnight lows in the upper 60s to low
70s.
&&
.LONG TERM...
(Wednesday through next Sunday)
Issued at 123 PM EDT Sun Sep 21 2025
Weak ridging midweek will bring drier air over most of the area,
with isolated to scattered showers and storms on limited to
locations in north central FL expected on Wednesday. With lower
sky coverage, highs will rise to the lower 90s with coastal
locations in the upper 80s as easterly onshore flow develops. An
mid/upper low over the central CONUS will begin to shift eastward
by the latter half of the week, with an associated cold front
shifting towards the SE CONUS. A return of scattered convection
area-wide by Thursday, with locations in northern SE GA
potentially seeing numerous showers and embedded storms on Friday
as the frontal boundary presses in from the northwest. As was
mentioned before, this rain will be beneficial for our inland
areas especially across the Suwannee River Valley that is
currently being highlighted for Moderate Drought (D1) conditions.
Scattered showers and storms chances continue on Saturday as the
frontal boundary begins to stall over the area.
Temperature Highs will begin to warm to the lower 90s through midweek,
trending above normal towards midweek. Temperature Highs begin to
drop to the upper 80s and lower 90s by the end of the week as the
frontal boundary enters the local area. Overnight lows will
continue to be low to mid 70s along the coast and north central
Florida, upper 60s over inland SE GA and the Suwannee Valley
Region of NE FL.
&&
.AVIATION...
(18Z TAFS)
Issued at 123 PM EDT Sun Sep 21 2025
NNE winds of sustained winds around 10 kts and gusts 18-25 kts
continue through 20-23Z. Scattered low level cumulus may stream
onshore with a low potential for brief MVFR restrictions through
the day at the coast. A stray shower may shift onshore and pass by
SGJ this afternoon and then SSI after 10Z. Winds calm tonight for
inland sites. Patchy fog and low stratus may develop at VQQ and
GNV lowering conditions to IFR/LIFR after 06Z.
&&
.MARINE...
Issued at 123 PM EDT Sun Sep 21 2025
Northeast winds strengthen to Caution levels today between high
pressure northeast of the local waters and a coastal trough
offshore. Isolated to scattered showers and isolated thunderstorms
will develop over the Florida Atlantic waters today, shifting
northward and expanding in coverage across Georgia Atlantic waters
tonight. Monday and Tuesday, winds begin to weaken as high pressure
settles southward down the U.S. eastern seaboard as the coastal
trough weakens offshore. Wednesday into Thursday, high pressure
extends across south Florida as a surface front approaches from the
west-northwest.
&&
.HYDROLOGY...
Issued at 159 AM EDT Sun Sep 21 2025
Forecast guidance continues to trend lower with peak tidal
flooding crests early this week, with now only the St. Johns River
basin south of downtown Jacksonville toward Welaka reaching
`action` stage around high tides Monday through Thursday. Peak
inundation values are generally < 1.25 ft MHHW, which is below
minor tidal flooding thresholds (generally less than 1.5 ft MHHW
for the St. Johns River basin) and a coastal flood advisory is not
expected at this time based on recent observations and forecast
trends.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG  65  88  67  90 /   0  20   0  10
SSI  70  83  73  84 /  20  30  10  20
JAX  69  87  70  89 /  20  40  10  30
SGJ  73  86  73  86 /  10  40  20  30
GNV  65  91  69  92 /   0  20  10  30
OCF  70  90  71  90 /   0  30  10  30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Tuesday evening for FLZ124-125-138-
     233-333.
GA...None.
AM...None.
&&
$$

NWS JAX Office Area Forecast Discussion