931
FXUS62 KJAX 111745
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
145 PM EDT Tue Jun 11 2024

...New AVIATION...

.SYNOPSIS...
Issued at 423 AM EDT Tue Jun 11 2024

Early morning surface analysis depicts a stalling frontal
boundary that was situated near the FL/GA border. Aloft...deep
troughing continues to dig over the eastern third of the nation,
with ridging in place from the Southern Plains northward through
the Mississippi Valley and the western Great Lakes. Otherwise,
cutoff troughing was located over the Texas and Oklahoma
panhandles. Latest GOES-East derived Total Precipitable Water
imagery indicates that the much anticipated surge of deep
tropical moisture is nudging into north central FL, with PWATS of
around 2 inches in place along the Interstate 4 corridor, while
values elsewhere across our region remaining around or just below
1.5 inches, which is below climatology for June 11th.
Southwesterly flow on the northern periphery of the tropical
moisture surge are developing low-topped convection along the
Nature coast, with a few showers also developing over Marion
County. Otherwise, low stratus ceilings were developing for
locations near the Altamaha River in southeast GA following late
evening convection, while mostly mid and high altitude cloudiness
in place elsewhere across our region. Temperatures were in the 70s
for inland locations as of 08Z, ranging to around 80 along the
northeast FL coast. Dewpoints generally ranged from the mid 60s to
lower 70s.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 423 AM EDT Tue Jun 11 2024

Troughing over the eastern U.S. will tend to gradually fill today
and tonight, with northwesterly flow keeping a drier air mass in
place to the north of a stalled frontal boundary for inland
southeast GA. This drier air mass should quickly erode low stratus
ceilings that are developing near the Altamaha River by the mid-
morning hours. Meanwhile, deep tropical moisture residing over
the FL peninsula will struggle to lift into northeast FL, with
PWATS finally rising above 1.5 inches by late afternoon. Values
over north central FL should approach 2 inches by early afternoon,
fostering increasing chances for beneficial showers and embedded
thunderstorms through the afternoon hours. Scattered convection is
expected to develop along the inland moving Atlantic sea breeze
boundary by late afternoon along the I-95 corridor, and the
moistening atmosphere should allow for convective outflows to
develop additional showers and thunderstorms for the rest of
northeast FL through around sunset, with coverage likely remaining
isolated over the Suwannee Valley, where a pocket of drier and
more subsident air will be stubborn to erode. Filtered sunshine
should boost highs to the low and mid 90s, except upper 80s along
the southeast GA coast, where breezy onshore winds will develop
earlier in the afternoon, and also for far southern portions of
north central FL, where thicker multi-layered cloudiness will
prevail to the north of widespread convection that will be ongoing
for locations along and south of the I-4 corridor. The drier air
mass over inland southeast GA and the Suwannee Valley should allow
dewpoints to fall through the 60s this afternoon, while dewpoints
remain in the lower 70s across north central FL and at coastal
locations today.

Low level flow will become more southerly overnight, while the
filling trough along the U.S. eastern seaboard keeps the frontal
boundary stalled near the FL/GA border, with weak cyclogenesis
progged along this boundary near the northeast FL coast towards
sunrise. Gradually deepening moisture should allow for scattered
showers and possibly a few thunderstorms to continue overnight for
northeast and north central FL, while a drier air mass finally
begins to retreat northward and away from southeast GA after
midnight. Thickening multi-layered cloud cover from south to north
overnight should keep lows in the lower 70s for most inland
locations, with upper 70s expected along the Atlantic coast.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 423 AM EDT Tue Jun 11 2024

A weakening frontal boundary will slowly trek through the area on
Wednesday and Thursday. The SW flow ahead of the frontal boundary
will continue to bring tropical moisture into our southern
locations of NE FL, PWAT values near 2". Chances of showers and
thunderstorms increase into the afternoon on Wednesday from north
central FL towards the FL/GA border. Thursday, we can expect a
similar story in terms of spread of showers and storms for NE FL
and SE GA, with the highest chances over the north central FL
counties. A Marginal risk for excessive rainfall currently in
place which includes north central FL on Wednesday and Thursday,
with the risk of spreading a bit north on Thursday just south of
the JAX metro area.

Daytime temperature highs will begin to trend a bit lower as
showers and cloud cover will keep the heat at bay, but highs are
still expected to be in the lower 90s for far inland locations of
NE FL and SE GA, with highs in the upper 80s along the coast and
north central FL. Overnight lows will sit in the lower 70s, but in
the upper 70s along the coast and the St Johns River.

&&

.LONG TERM...
(Friday through Monday)
Issued at 423 AM EDT Tue Jun 11 2024

By Friday, the front is expected to move to sit just over north
central FL. This will bring drier air to filter into the area
behind the frontal boundary, lowering chances of showers and
storms over SE GA, with best chances of showers and storms again
over north central FL during the afternoon hours into Monday.
Daytime temperature highs will begin in the mid 90s over SE GA to
the lower 90s over inland NE FL during the end of the work week.

Saturday, daytime temperatures will rise to the mid to upper 90s,
with warmer temperatures expected over SE GA as most showers will
be over NE FL. Heading into the upcoming week, daytime
temperatures will sit in the lower 90s. Temperature lows expected
to sit in the lower to mid 70s from late this week into the
upcoming weekend, with warmer temperatures in the upper 70s along
coastal locations.

&&

.AVIATION...
(18Z TAFS)
Issued at 141 PM EDT Tue Jun 11 2024

Showers and storms initially building across north central Florida
will develop over northeast Florida as the afternoon progresses,
with heaviest developments occurring south of the I-10 corridor.
Vicinity showers and storms are likely for most sites with GNV and
potentially SGJ experiencing more abundant thunderstorm activity
by around 21-22z. Developments near the coast are possible in
association with the diurnal sea breeze. Convection will dissipate
overnight with low level cloud decks building in more densely
over GNV and VQQ by around 06-08z on Wednesday with convection
beginning to redevelop by the end of the forecasted period for
areas west of the I-95 corridor, with winds building in from out
of the west.

&&

.MARINE...
Issued at 423 AM EDT Tue Jun 11 2024

A frontal boundary will stall across our local waters today, with
showers and thunderstorms initially over central Florida gradually
spreading northward towards our area this afternoon. Weak low
pressure will then develop along this stalled boundary tonight
over the northeast Florida waters, with this feature moving slowly
northeastward through Friday. Southerly winds will likely surge to
Caution levels of 15-20 knots for the offshore waters this
evening before gradually diminishing after midnight. Seas of 2-4
feet will prevail both near shore and offshore today, with seas
offshore building to the 3-5 foot range offshore tonight and
Wednesday.

Onshore winds may briefly strengthen late this week as weak low
pressure center moves further away from our local waters. Periods
of showers and thunderstorms will remain possible across through
the upcoming weekend as the frontal boundary remains stalled. Seas
of 2 to 4 feet are expected to prevail throughout our local waters
from Wednesday night through at least Saturday. A stronger high
pressure center will build southeastward from the eastern Great
Lakes region this weekend, with another surge of onshore winds
possible by Sunday and Monday as this feature wedges down the
southeastern seaboard.

Rip Currents: Developing onshore winds this afternoon will combine
with a south-southeasterly ocean swell to create a low-end
moderate rip current risk at area beaches. This lower end moderate
risk will likely continue during the next few days.

&&

.FIRE WEATHER...
Issued at 423 AM EDT Tue Jun 11 2024

A dry air mass will continue today for inland locations along and
north of the Interstate 10 corridor, where minimum relative
humidity values will fall to around 35 percent this afternoon.
Light northwesterly transport winds will prevail across inland
southeast GA today, with breezy south-southwesterly transport
winds for locations south of the I-10 corridor. Breezy onshore
surface winds are expected to develop outside of shower and
thunderstorm activity for locations along the I-95 corridor this
afternoon. Elevated mixing heights will result in generally good
daytime dispersion values today. Surface and transport winds will
then shift to easterly on Wednesday and northeasterly on Thursday.
Fair to good daytime dispersion values are forecast on Wednesday,
with good to marginally high values possible on Thursday as
transport winds become breezy by the afternoon hours.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  70  92  70  92 /  20  10  10  20
SSI  79  87  76  87 /  20  20  10  30
JAX  73  90  72  90 /  30  40  10  40
SGJ  77  89  75  88 /  40  50  30  60
GNV  73  91  71  91 /  40  80  30  50
OCF  73  90  72  90 /  40  80  60  60

&&

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

$$