Graham, Georgia Weather Forecast Discussion

657
FXUS62 KJAX 181837
AFDJAX
Area Forecast Discussion
National Weather Service Jacksonville FL
237 PM EDT Thu Sep 18 2025
...New NEAR TERM, SHORT TERM, LONG TERM, AVIATION, 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
- Patchy to Areas of Fog Possible Inland Early on Friday Morning
- Moderate Rip Current Risk Continues at Area Beaches. High Risk Likely This Weekend
- Hazardous Marine Conditions this Weekend & Early Next Week
- Minor Coastal / Tidal Flooding Possible This Weekend & Early Next Week
- Isolated to Widely Scattered TStorms this Weekend & Next Week
.SYNOPSIS...
Issued at 230 PM EDT Thu Sep 18 2025
Early afternoon surface analysis depicts weak high pressure (1018
millibars) stretching across the Interstate 10 corridor in
northern FL. Aloft...broad troughing remains situated over the
southeastern states, with narrow ridging extending from Deep
South Texas northeastward across the Great Lakes. Per the morning
sounding at Jacksonville, deep southwesterly flow prevails
locally above a subsidence inversion based around 700 millibars
(around 10,000 feet). This southwesterly flow was transporting a
veil of thin cirrus across north central and coastal portions of
northeast FL. Otherwise, cutoff troughing prevails over the
Plains states and portions of the eastern / northern Rockies.
Latest GOES-East derived Total Precipitable Water imagery
indicates that the unseasonably dry air mass that has been in
place for at least the last week across our region was gradually
getting pinched from the north and south, with PWAT values
remaining in the 1 - 1.25 inch range along the Interstate 10
corridor, while values across inland southeast GA have increased
slightly to the 1.3 - 1.5 inch range. PWATs for locations south
of Gainesville and Palatka in north central FL generally remain in
the 1.4 - 1.6 inch range. A flat cumulus field was developing
beneath the thin cirrus layer in the slightly more moist
environment for locations south of Interstate 10, while fair skies
prevail elsewhere. Temperatures have soared to the upper 80s and
lower 90s at most inland locations as of 18Z, while a light
onshore breeze was keeping temperatures at coastal locations
generally in the mid 80s. Dewpoints ranged from the 60s inland to
around 70 in north central and coastal northeast FL.
&&
.NEAR TERM...
Issued at 230 PM EDT Thu Sep 18 2025
Isolated showers and possibly a brief thunderstorm may develop
late this afternoon and early this evening across north central FL.
This low-topped activity will generally develop along mesoscale
boundaries such as the Lake George breeze and the colliding
Atlantic and Gulf coast sea breezes. An overall dry and subsident
air mass in place across our area will make any rainfall that
manages to develop brief in duration. Otherwise, the cirrus shield
currently streaming across the FL peninsula and north central /
coastal northeast FL will again depart to the east overnight, with
fair skies and a gradually moistening air mass likely allowing for
at least patchy fog formation during the predawn hours, mostly at
inland locations. Areas of locally dense fog may develop towards
sunrise along the U.S. Highway 301 corridor in southeast GA. With
fair skies and decoupling winds setting up radiational cooling
after midnight, we have continued the trend of undercutting model
blends for low temperatures by a few degrees. Lows should fall to
the mid and upper 60s at most inland locations, ranging to the
low and mid 70s at coastal locations, where a light northeasterly
breeze should prevail towards sunrise.
&&
.SHORT TERM...
(Friday through Saturday night)
Issued at 230 PM EDT Thu Sep 18 2025
Weak surface high pressure ridging over the eastern U.S. down
through GA and into AL will gradually strengthen into Friday night
while weak troughing extends over the western Atlantic and into
the Bahamas and Cuba. This latter feature is associated with some
deep moisture, but remains east of the forecast area. Still some
adequate moisture levels near or just below normal, with PWATs of
about 1.5 inches or below. Some isolated showers or a storm
chances possible for inland southeast GA under some mid level
troughing and also a few coastal showers due to moist onshore
flow and convergence. This coastal chance of a brief shower
extends into Friday night as well. Breezy at times along the coast
due to the slightly tighter pressure gradient, but likely only
sustained about 15 mph coastal sections.
Saturday, some patchy fog and areas of low stratus expected in
the early morning mainly inland areas, but otherwise surface high
pressure ridge continues to wedge down into the eastern U.S.
through Sat night, across also GA and AL. This occurs while broad
low pressure troughing continues east of the area from the Bahamas
northeastward in the western Atlantic. The pressure gradient is a
little tighter so we can expect winds up to 15-20 mph on Saturday
for coastal areas and lower northeast wind speeds inland. Some
low chances for showers and a storm on Saturday mainly near and
east of the Highway 301 corridor in northeast FL and remaining
largely dry for southeast GA. A few showers possible in Saturday
evening for northeast FL but otherwise dry.
For temps, highs will be in the lower 90s well inland both days
and mid to upper 80s toward the coast. Lows 65-70 inland and around
70 to lower 70s coast. Skies mostly clear to partly cloudy with
most of the clouds being low to mid clouds- cumulus/stratocu each
day.
Coastal hazards build through Saturday and into Saturday Night,
including building surf and borderline high rip current risk.
Coastal/river levels may reach about 1 to 1.3 ft above MHHW which
will approach minor flooding thresholds for many of the usual low
lying trouble areas.
&&
.LONG TERM...
(Sunday through next Thursday)
Issued at 230 PM EDT Thu Sep 18 2025
Similar situation to start off Sunday with high pressure ridging
to the north over the Appalachians area with troughing extending
from the Bahamas northeastward. The pressure gradient continues to
tighten so a breezier day is on tap for both Sunday and Monday
with northeast winds up to 15-20 mph gusting to about 30 mph along
coastal counties and 10-15mph, G20-25mph inland. However, winds
may be slightly lower on Monday. Precip chances (20-35 percent)
mainly confined for the coastal areas of northeast FL on Sunday
and then spreading further inland on Monday with chances rising up
to 20-40 percent.
A change in the pattern does begin by late Monday as the high
pressure ridge weakens and shift towards more northeast of the
region by the Tuesday/Wednesday time frame, which will help to
break the brief northeasterly event and also shift the low level
flow more towards the southeast to south, bringing in deeper layer
moisture as well as the return of slightly more normal diurnal
convection. A cold front will approach the area from the northwest
on Thursday that may support a higher chance of showers and
storms. Uncertain on weather on more specific weather details for
Wed night into late Thu time frame with model guidance differing
in regard to placement and intensity of mid/upper level low over
the lower to mid MS valley and therefore how strong the cold
front will be as it begins to move into the southeast U.S.
Temps will start near to slightly above climo for the beginning
of next week, though trending above normal with a more southerly
flow component towards the middle of next week.
&&
.AVIATION...
(18Z TAFS)
Issued at 230 PM EDT Thu Sep 18 2025
VFR conditions will prevail through at least 05Z Friday at the
regional terminals. IFR to LIFR conditions are expected to develop
at VQQ towards 05Z, with MVFR to IFR conditions likely at GNV
towards 09Z. Periods of LIFR conditions will also be possible at
GNV during the predawn and early morning hours on Friday. MVFR
visibilities are expected to develop after 09Z at JAX and CRG and
are possible at the coastal terminals as well. Confidence was too
low to indicate MVFR conditions at SSI and SGJ coastal terminals
at this time, as a light north or northwesterly breeze develops
towards sunrise. Fog and low stratus ceilings that develop
overnight through early Friday morning are expected to dissipate
before 14Z, with VFR conditions then prevailing afterwards. Marine
stratocumulus may increase at the coastal terminals on Friday
afternoon, with ceilings generally between 3,500 - 4,500 feet.
Easterly surface winds will increase to around 10 knots at the
regional terminals this afternoon, with winds shifting to
southeasterly while gradually diminishing this evening.
Northeasterly surface winds will then develop towards 14Z, with
speeds quickly increasing to around 10 knots at the inland
terminals and 10-15 knots at the coastal terminals.
&&
.MARINE...
Issued at 230 PM EDT Thu Sep 18 2025
Weak high pressure will remain situated over our region through
tonight. Seas of 2-3 feet will prevail both near shore and
offshore. Strong high pressure will then build southeastward from
Hudson Bay, Canada on Friday, with this feature then shifting
over New England by Saturday as it wedges down the southeastern
seaboard. Coastal troughing will sharpen over our near shore
waters this weekend, resulting in strengthening onshore winds,
building seas, and a gradual increase in showers and
thunderstorms. Seas will begin to build to the 3-4 foot range by
Friday evening throughout our local waters, peaking in the 5-6
foot range this weekend and early next week. Northeasterly winds
will increase to Caution levels of 15-20 knots by early Saturday,
with these speeds likely continuing through Monday. Small Craft
Advisory conditions will be possible from Saturday night through
Monday, as sustained speeds approach 20 knots and seas potentially
build to around 7 feet. Weak low pressure may develop over our
local waters early next week, with this feature then expected to
move slowly northward towards the coastal Carolinas. This feature
will likely keep chances for showers and thunderstorms in place
through the middle portion of next week.
Rip Currents: Strengthening northeasterly winds on Friday will
begin to build breakers up to the 3-4 foot range at the northeast
FL beaches, where either a higher end moderate risk or possibly a
high risk is expected to develop by the afternoon hours. A
moderate risk is anticipated at the southeast GA beaches on
Friday, where breakers will gradually build to around 2 feet
during the afternoon hours. A high rip current risk is anticipated
at all area beaches this weekend through early next week, as
persistent northeasterly winds build surf heights to the 4-5 foot
range at the northeast FL beaches and 2-3 feet at the southeast GA
beaches.
&&
.HYDROLOGY/TIDAL FLOODING...
Issued at 230 PM EDT Thu Sep 18 2025
Strengthening northeasterly winds from Friday afternoon through
the weekend will gradually increase water levels along the
Atlantic coast and within the St. Johns River basin, but less of
an astronomical influence during this local nor`easter may keep
tide levels around or just under what is considered to be a minor
flood. Nuisance type flooding in the normal low-lying locations
can be expected, with water levels possibly climbing to 1-2 feet
above Mean Higher High Water (MHHW) around times of high tide this
weekend and early next week, especially for locations from
downtown Jacksonville southward within the St. Johns River basin.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG  65  90  66  89 /   0  20  10  10
SSI  72  85  72  84 /   0  10  10  10
JAX  67  89  70  87 /   0  10  10  20
SGJ  72  87  73  86 /  10  20  10  30
GNV  66  92  68  90 /   0  10   0  10
OCF  67  90  70  89 /   0  20   0  20
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&
$$

NWS JAX Office Area Forecast Discussion