175
FXUS62 KJAX 070548
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
148 AM EDT Mon Oct 7 2024

...New AVIATION...

.UPDATE...
Issued at 1057 PM EDT Sun Oct 6 2024

Late evening surface analysis depicts strengthening Hurricane
Milton (977 millibars) located over the southwestern Gulf of
Mexico, which was moving slowly eastward. Meanwhile, a frontal
boundary extends across central and eastern portions of the Gulf
of Mexico and across central FL, with a low pressure center (1007
millibars) positioned about 250 miles due south of Pensacola.
Otherwise, high pressure (1018 millibars) was wedging down the
southeastern seaboard ahead of a cold front that was pushing
across the Ohio and Tennessee Valleys. Aloft...troughing was
digging into the southeastern states, with ridging positioned over
the Desert Southwest and west Texas. Latest GOES-East derived
Total Precipitable Water imagery indicates that a much drier air
mass was slowly filtering southward across central portions of
Georgia, with a tight moisture gradient in place across the
Altamaha River basin. Stratiform, mainly light rainfall continues
across most of our area to the south of this moisture gradient,
with somewhat stronger isentropic lift / overrunning producing
some pockets of heavier downpours across coastal southeast GA.
Temperatures at 03Z were generally in the 70-75 range, with
dewpoints ranging from the upper 60s across inland southeast GA to
the lower 70s elsewhere.

The drier air mass will continue to gradually filter southward
across inland portions of southeast GA overnight, shifting the
shield of mostly stratiform rainfall towards the FL/GA border and
the I-95 corridor in coastal southeast GA during the predawn
hours. Pockets of heavier downpours will remain possible
overnight, with the focus shifting towards coastal northeast FL.
Breaks in the mid and high altitude cloudiness over inland
southeast GA will allow lows to fall to the mid and upper 60s for
locations from Waycross northward. Lows may drop just below 70 for
inland locations along the FL/GA border, with lower 70s forecast
elsewhere, except along the coast, where an onshore breeze around
10 mph will keep lows generally in the mid 70s.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 300 PM EDT Sun Oct 6 2024

Another dry frontal boundary drops southward across most of
Georgia during the day on Monday, slowing and stalling over
Central GA as it runs into the moisture boundary currently
overhead. This "surge" will push some drier air aloft into
southern GA through Monday as well as at least the start of
Tuesday, creating an even sharper moisture gradient across the
region. As a result, persistent shower activity over the area as
seen over the past several days will become generally confined to
northeast FL, and especially southeastern areas of the CWA. Some
very isolated thunder remains possible, though the airmass will be
mostly stable. Less cloud cover and lower rainfall chances for
most will allow temps to bump up a bit, especially over interior
southeast GA. Generally in the mid 80s north and low 80s south.

Pressure gradient over the area starts to increase for the second
half of Tuesday and into Tuesday Night, as well as layer moisture
as Hurricane Milton approaches from the southwest. Any significant
impacts look to hold off for the short term period, though
increasing moisture flowing towards a stationary boundary over
southeast GA will as well as outer bands from Milton will likely
increase rain chances Tuesday evening and Tuesday Night over
northeast FL. This will certainly be dependent on the exact track
of Milton, though at this time it looks as though majority of
showers and embedded t`storms will be generally from FL HWY 301 to
the coast, with the strongest winds generally south and towards
the coast and St. Johns River Basin. Low to mid 80s will be common
on Tuesday.

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 300 PM EDT Sun Oct 6 2024

Confidence is increasing that Milton will greatly affect the
Wednesday into Thursday time frame. There is still some
uncertainty as to the track and speed of the system, but still
expecting landfall on the west coast of FL Wednesday, then track
east northeast across the peninsula Wednesday night. At this point
interests in NE FL and SE GA should continue to monitor for the
latest updates on this system, as adjustments to forecast track
and timing can be expected, and make necessary precautions. At
this time, at least tropical storm conditions will be expected
across northeast FL and especially at the coast and St. Johns
River Basin, with potential for strong tropical storm conditions
and gusts to hurricane force. Over interior southeast GA, tropical
storm winds and/or gusts will be possible, with most of the heavy
rain threat remaining further south.

Milton pulls away from the area to the east and Northeast Thursday
and Thursday night, also transitioning into a extratropical
system as it does so. High pressure builds from the north
northwest in its wake as it pulls a front southward through the
area. Drier and cooler air will advect across the area throughout
the night, with this air mass lingering into Friday and perhaps
even the start of the weekend, with very limited rain chances
across the region. Any chances for showers will likely be confined
towards the coast of Northeast FL. Temperatures will be below
normal this period.

&&

.AVIATION...
(06Z TAFS)
Issued at 148 AM EDT Mon Oct 7 2024

Radar shows areas of light rain continuing across the
area...expected to continue the remainder of the night. Likely to
be associated with areas of MVFR/IFR CIGs. Latest guidance
suggests improving conditions Monday with 8-12kt northeasterly
winds.

&&

.MARINE...
Issued at 1057 PM EDT Sun Oct 6 2024

Breezy northeasterly winds will continue on Monday as high
pressure along the New England coast slowly weakens but continues
to wedge down the southeastern seaboard. Small Craft Advisory
conditions will continue for the offshore waters, where seas of
6-8 feet will prevail through Tuesday. Caution conditions
overnight for the near shore waters will deteriorate to Small
Craft Advisory conditions by Monday morning, as seas build to 5-7
feet. Meanwhile, a wave of non-tropical low pressure located
along a frontal boundary in the eastern Gulf of Mexico, or about a
few hundred miles south of Pensacola, is expected to push
eastward in advance of Hurricane Milton on Monday, crossing the FL
peninsula on Monday night and then emerging near the northwestern
Bahamas by sunrise on Tuesday. This feature will tighten our
local pressure gradient, resulting in gradually strengthening
northeasterly winds on Tuesday and Tuesday night. Seas near shore
will build to 7-9 feet by Tuesday night, while offshore seas build
to 8-10 feet.

Official forecasts from the National Hurricane Center continue to
delay direct impacts from what will likely be Major Hurricane
Milton until later on Wednesday and Wednesday night, with tropical
storm or possible hurricane conditions possibly extending into
Thursday morning. Strong winds will likely continue on the back
side of Milton as it accelerates across the Atlantic waters late
this week.

Rip Currents / High Surf: A high risk of deadly rip currents and
very rough surf will continue for much of the upcoming week, with
long period swells from distant Hurricane Kirk adding to the
dangerous surf conditions on Monday and Tuesday. A High Surf
Advisory may be required on Monday and Tuesday in advance of
Milton for coastal northeast FL, where breakers of 6-7 feet are
forecast.

&&

.HYDROLOGY...
Issued at 1057 PM EDT Sun Oct 6 2024

Rivers: Major river flooding is ongoing along the Alapaha River
near the gauge at Statenville, where a crest is forecast on
Monday. The Altamaha River at the Charlotteville, Baxley and
Doctortown gauges continues to slowly fall, but minor flooding
will continue through late this week. Minor flooding is beginning
along the Altamaha River near the gauge at Everett City, where a
crest just below Moderate Flooding is expected on Tuesday or
Wednesday. Minor flooding is forecast to begin along lower
portions of the Satilla River near the gauge at Atkinson on Monday
night. As flood waters travel down the Suwannee River, backwater
flooding has resulted in water levels rising to minor flooding
along lower portions of the Santa Fe River near the Three Rivers
Estates gauge, and further rises will continue this week, with
moderate flooding forecast by next weekend.

Tidal Flooding: The combination of persistent onshore flow and the
approach of the annual high Spring Tides mid-month will continue
to elevate local water level departures for tidal locations this
week. A Coastal Flood Advisory remains in effect for the St. Johns
River basin from downtown JAX to Lake George through Monday
evening due to Minor, mainly nuisance type, tidal flooding around
times of high tide. Water levels will continue to rise as tides
are trapped within the St. Johns basin this week, and there
increasing chances that water levels could reach the "Moderate"
stage within the River basin and coastal locations towards midweek
as Milton approaches.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  84  63  84  64 /   0   0   0   0
SSI  82  71  80  72 /  10   0  20  10
JAX  83  70  83  72 /  40  10  40  30
SGJ  81  74  82  73 /  60  30  60  50
GNV  79  69  83  71 /  40  10  30  30
OCF  79  71  83  72 /  60  30  40  40

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 8 PM EDT Tuesday for FLZ033-038-132-
     137-325.

     High Rip Current Risk through Tuesday evening for FLZ124-125-133-
     138.

GA...High Rip Current Risk through Tuesday evening for GAZ154-166.

AM...Small Craft Advisory from 8 AM this morning to 6 AM EDT Tuesday
     for AMZ450-452-454.

     Small Craft Advisory until 10 AM EDT Tuesday for AMZ470-472-474.

&&

$$