000
FXUS62 KJAX 250951
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
551 AM EDT Thu Apr 25 2024

...New AVIATION...

For the latest NE FL and SE GA Daily Key Messages please visit:
https://www.weather.gov/media/jax/briefings/nws-jax-briefing.pdf

.AVIATION...
(12Z TAFS)
Issued at 551 AM EDT Thu Apr 25 2024

A brief period of MVFR visibilities will be possible through
around 12Z at VQQ and GNV. Confidence was not high enough to
indicate a sustained period of MVFR conditions at this time.
Otherwise, periods of broken ceilings around 6,000 feet will be
possible at SSI today, with this cloud cover then expanding
southward to the northeast FL terminals this afternoon and evening.
Light westerly surface winds early this morning will increase to
5-10 knots before 15Z. The Atlantic and Gulf coast sea breezes
will develop towards noon and will push inland more quickly
than prior days, resulting in surface winds shifting to westerly
at GNV following the passage of the Gulf coast sea breeze, with
sustained speeds increasing to around 10 knots towards 20Z.
Surface winds will shift to easterly at SGJ following the passage
of the Atlantic sea breeze boundary shortly after noon, with
sustained speeds increasing to 10-15 knots during the early to mid
afternoon hours. Surface winds elsewhere will shift to easterly
or southeasterly during the early to mid afternoon hours, with
speeds increasing to around 10 knots, except at GNV, where this
wind shift will likely not occur until around sunset as the
Atlantic and Gulf sea breeze boundaries collide around U.S.
Highway 301. Surface winds will then shift to southeasterly or
southerly by the mid-evening hours at the regional terminals, with
speeds diminishing to 5-10 knots.

&&

.SYNOPSIS...
Issued at 358 AM EDT Thu Apr 25 2024

Overnight surface analysis depicts a weakening cold front
extending from the Mid-Atlantic coast southwestward across the
southern Appalachians, with this boundary then becoming stationary
further westward across the lower Mississippi Valley and the
southern Plains states. Meanwhile, high pressure (1021 millibars)
was located to the south of this cold front along the northern
Gulf coast and the FL peninsula, while a stronger high pressure
center (1029 millibars) was building over the Great Lakes region
in the wake of the cold front. Aloft...troughing was progressing
across New England and the Mid-Atlantic states, while ridging was
building over the Plains states, which were positioned downstream
of a potent trough that was progressing eastward from southern
California towards the Desert Southwest. Mid-level cloud cover
associated with the approaching cold front was located to the
north of Waycross in southeast GA, with fair skies prevailing
elsewhere across our region. Temperatures at 08Z were generally in
the 55-60 degree range at inland locations, while coastal and
temperatures were mainly in the 60-65 degree range. Dewpoints were
in the 50s area-wide.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 358 AM EDT Thu Apr 25 2024

Patchy fog developing over the Suwannee Valley overnight may
expand northeastward into the Okefenokee Swamp towards sunrise,
with this fog bank unlikely to extend east of the U.S. Highway 301
corridor. Fog at these locations should then dissipate during the
early morning hours as sunshine quickly warms and mixes the lower
troposphere.

Ridging aloft over the Plains states will build eastward as
troughing slides off the Mid-Atlantic and New England coasts,
allowing for heights to rise as ridging builds eastward from the
Plains states. This weather pattern will leave little in the way
of support for the frontal boundary that will be moving slowly
across the southeastern states today and tonight, with this
boundary crossing inland southeast GA this afternoon and then
decelerating as it approaches the FL/GA border this evening. Mid-
level cloud cover will continue to gradually increase this morning
ahead of the approaching boundary across southeast GA, with this
cloud cover then shifting over northeast FL this afternoon.
Weakening high pressure to the south of the approaching cold front
will leave our area within a weak local pressure gradient today,
allowing for the Gulf and Atlantic sea breezes to develop towards
noon at coastal locations, followed by these boundaries moving
more quickly inland this afternoon when compared to previous days.
A collision of these boundaries seems to be likely along the U.S.
Highway 301 corridor towards sunset, but a dry and increasingly
subsident air mass will only allow for mid-level cloudiness to be
generated by these inland moving mesoscale boundaries this
afternoon. This dry air mass and rising heights aloft will allow
highs to climb to the mid 80s at most inland locations this
afternoon, while developing breezy onshore winds this afternoon
after the passage of the sea breeze boundary keeps coastal highs
closer to 80.

Mid-level cloud cover generated by the weakening cold front will
shift over northeast and north central FL tonight. Clearing skies
over southeast GA could result in at least patchy fog development
along the U.S. Highway 301 corridor towards sunrise on Saturday.
Otherwise, light winds and a lingering dry air mass should allow
lows to fall to the upper 50s at most inland locations, ranging to
the low and mid 60s at coastal locations.

&&

.SHORT TERM...
(Friday through Saturday night)
Issued at 358 AM EDT Thu Apr 25 2024

Weak, dry cold front becomes more diffuse and dissipates on Friday
over northeast FL, while sfc high pressure ridging strengthens to
the northeast of the area. Anticipate light southeast winds Friday
morning turning more to the east during the afternoon up to near
10-15 mph and gusty as the sea breeze moves in quickly. PWATs near
1.2 inches and sufficient low level moisture looks to support low
rain chances at only 10-15 percent.

Friday night through Saturday night, high pressure continues to
dominate to the northeast of the area with prevailing easterly
flow, breezy during the daytime, and breezy at night near the
coast. A couple of showers can`t be ruled out over the marine
zones given the fairly moist low levels and some convergent bands.

Skies will be mostly clear to partly cloudy given a mix of mostly
daytime cumulus and scattered to broken high clouds. Max temps
expected in the lower to mid 80s Friday and around 80-85 deg
Saturday. Warmest temps will be inland given the prevailing east
flow. Lows near normal from upper 50s and lower/mid 60s.

&&

.LONG TERM...
(Sunday through Wednesday)
Issued at 358 AM EDT Thu Apr 25 2024

Mostly dry and warm conditions this period. A strong mid/upper
level ridge will be across the east coast Sunday, but will break
down while moving east. A weak mid level trough will move into GA
Monday night into Tuesday, but ridging is still dominate in the
mid levels that will keep our area in a stable pattern. A sfc high
pressure system near 1028 mb starts out off the Mid Atlantic
states and will drift southward through Wednesday. Breezy east to
southeast winds Sunday and Monday will gradually ease by Tuesday
and Wednesday as the pressure gradient relaxes. Mostly clear to
partly cloudy each day. There may be some slight chance for
convection across inland southeast GA by Wednesday as a weak pre-
frontal trough triggers a couple of showers.

Fairly seasonal max temperatures around 80-85 deg anticipated
Sunday, but a warming trend commences Monday through Wednesday.
Temperatures will steadily increase into the upper 80s to near 90
by mid week inland zones, and generally lower 80s coastal areas.
Lows will be near normal.

&&

.MARINE...
Issued at 358 AM EDT Thu Apr 25 2024

A weak cold front entering the southeastern states will nudge
southward today, crossing the GA waters tonight and then becoming
stationary over the northeast FL waters by Friday evening before
dissolving during the weekend. Seas of 2 to 4 feet will prevail
today near shore, with 3-5 foot seas expected offshore. Meanwhile,
strong high pressure building over the eastern Great Lakes in the
wake of this cold front will shift eastward over New England on
Friday, with this feature then wedging down the southeastern
seaboard from Friday afternoon through early Sunday. Onshore winds
will strengthen beginning on Friday afternoon, with speeds and
seas likely reaching Caution levels of 15-20 knots by late
afternoon. Small Craft Advisory conditions are becoming
increasingly likely for the offshore waters adjacent to northeast
FL from early Saturday evening through at least Sunday morning,
where seas will build to 5-7 feet. Caution conditions will persist
for the near shore waters adjacent to northeast FL during this
period, as seas build to 4-6 feet. High pressure will then
gradually weaken as it shifts southward late this weekend, with
this feature then becoming anchored off the Carolina coast by
early next week. Onshore winds and seas will gradually diminish
throughout our local waters late this weekend and early next week.

Rip Currents: A long period northeasterly ocean swell will combine
with breezy onshore winds this afternoon to create a high end
moderate rip current risk at all area beaches, with breakers of
2-4 feet expected. Onshore winds will then strengthen to 15-20 mph
on Friday afternoon, keeping at least a high-end moderate rip
current risk in place, with a possible high risk at the northeast
FL beaches. Onshore winds will then strengthen to around 20 mph
during the weekend, with building and increasingly rough surf
resulting in a high rip current risk at all area beaches.

&&

.HYDROLOGY...
Issued at 358 AM EDT Thu Apr 25 2024

Moderate flooding along lower portions of the Santa Fe River near
the Three Rivers Estates gauge will continue through the weekend,
with water levels then gradually falling, but remaining in minor
flood for much of next week. Water levels near the gauge at
Hildreth on the lower Santa Fe will also gradually subside late
this weekend, with minor flooding expected to continue through at
least the middle portions of next week. Water levels are gradually
falling along upper portions of the Suwannee River near the gauge
at Suwannee Springs, where minor flooding will likely continue
through Friday morning. Minor flooding will otherwise continue
along most of the lower Suwannee River through the weekend.
Elsewhere, water levels are expected to fall below flood stage
along lower portions of the Satilla River near the gauge at
Atkinson towards sunrise on Saturday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  84  58  84  62 /   0   0  10   0
SSI  82  63  78  67 /   0   0  10   0
JAX  85  60  82  64 /   0   0  10   0
SGJ  81  62  82  67 /   0   0  10  10
GNV  86  59  85  62 /   0   0  10   0
OCF  86  58  86  63 /   0   0  10   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

$$