061
FXUS62 KJAX 020617
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
217 AM EDT Tue Jul 2 2024

...New AVIATION...

.NEAR TERM...
Issued at 209 PM EDT Mon Jul 1 2024

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

Noon surface analysis depicts a cold front stretching from the
Ozarks eastward to the Carolinas that is decelerating as it pushes
into the Deep South. Meanwhile, strong high pressure (1030
millibars) was building over the Great Lakes region in the wake of
this frontal boundary. Aloft..."Heat Wave" ridging remains
centered along the Red River Valley of northern Texas, with this
feature continuing to expand into the southeastern states.
Otherwise, troughing was progressing southeastward towards the
Mid-Atlantic states and coastal New England. Latest GOES-East
derived Total Precipitable Water imagery indicates that deep
tropical moisture prevails throughout our region, with PWATS
generally in the 2 - 2.2 inch range, except for north central FL,
where values were in the 1.8 - 2 inch range. Slow moving, low-
topped showers were developing within this very humid air mass
along portions of the U.S. Highway 301 corridor in southeast GA,
while convection developing along the Gulf coast sea breeze along
the FL Big Bend and Nature Coasts remains nearly stationary over
Levy and Dixie Counties, while showers were developing ahead of
this sea breeze boundary across southern portions of the Suwannee
Valley early this afternoon. Temperatures at 16Z were mostly in
the low to mid 80s across southeast GA, with values rising to the
85-90 degree range elsewhere for northeast and north central FL.
Dewpoints were in the mid to upper 70s at most locations.

Our area will remain within a col region aloft during this
afternoon as "Heat Wave" ridging remains centered to the west of
our area and troughing progresses southeastward and offshore of
the Mid-Atlantic and New England coasts. The frontal boundary will
get pushed southward across the Altamaha River this evening before
support aloft wanes, as troughing exits into the Atlantic and
ridging aloft nudges eastward over the Lower Mississippi Valley.
Light winds within the aforementioned col region overhead will
result in slow moving downpours developing this afternoon, with
activity likely developing along a lingering low level trough that
is situated along U.S. Highway 84 in southeast GA, with additional
scattered convection being generated by the inland moving Atlantic
and Gulf sea breeze boundaries. Short-term, high resolution model
guidance continues to target the U.S. Highway 301 corridor in
southeast GA for excessive rainfall potential, where a quick 2-4
inches with locally higher totals will be possible in a corridor
from Nahunta and Blackshear northeastward to Jesup and Darien
through this evening. Mesoscale boundary collisions may shift
another axis of heavy downpours southward along the I-10 and I-75
corridors through the evening hours, where a widespread 1-2 inches
with locally higher amounts will be possible for locations such as
Macclenny, Lake City, Live Oak, and Gainesville. Some of this
activity will attempt to shift towards the I-95 corridor after
sunset before waning towards midnight.

The morning sounding at Jacksonville revealed a steep lapse rate
in the mid-levels, with a pocket of mild and dry air above this
layer. Strong to isolated severe thunderstorms will be possible
this afternoon through early this evening, with wet microbursts
potentially bringing wind gusts up to the 40-60 mph range, along
with frequent lightning strikes and slow moving downpours. High
temperatures will generally climb to the lower 90s this afternoon
before thunderstorm coverage increases. Convective coverage will
diminish towards midnight, with debris cloudiness thinning out
overnight across northeast and north central FL, while low
stratus clouds likely develop during the predawn and early morning
hours along the stalling frontal boundary across southeast GA.
Lows tonight will generally fall to the mid 70s inland and the
upper 70s at coastal locations.

&&

.SHORT TERM...
(Tuesday through Wednesday night)
Issued at 209 PM EDT Mon Jul 1 2024

Weakening frontal boundary draped across SE GA on Tuesday will
stall across the FL/GA state border and diffuse on Wednesday as
surface high pressure shifts off the mid-Atlantic coast.
Meanwhile, upper ridging builds over the SE US shifting flow to
north-northeasterly. Models have slightly delayed the influx of
drier air from the north allowing deep tropical moisture (PWATs
2.2-2.5 in.) to remain over the area through Wednesday. Scattered
to numerous showers and storms develop each day along the sea
breezes and the frontal boundary. This boundary and mesoscale
collisions will provide the focus for stronger convection, with
gusty winds and heavy rain as the main threats. Areas that have
received heavy rain over the past couple of days may be more
susceptible to flooding from slow-moving storms. High temperatures
will be in the 90s for most inland areas and in the upper 80s
along the coast and for areas behind the frontal boundary.
Overnight low temperatures will drop into the 70s.

&&

.LONG TERM...
(Thursday through Sunday)
Issued at 209 PM EDT Mon Jul 1 2024

Upper ridging remains over the SE US through the end of the week
before shifting southeastward as an upper trough digs into the
Plains this weekend. Daily chances for showers and storms along
the sea breezes continue into the weekend but convection becomes
more scattered with drier north-northeasterly flow. The greatest
chances for storms will be over north-central FL where PWATs
remain 2+ inches. Ridging and drier air will allow high
temperatures to quickly rise into the mid/upper 90s through the
weekend. Heat indices will likely rise into heat advisory criteria
by the weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 152 AM EDT Tue Jul 2 2024

MVFR and IFR ceilings will lift over TAF sites tonight. Ceilings
will be at VFR levels for most sites through Tuesday morning with
ceilings dropping below 3k feet for SSI and then lifting later in
the afternoon. Convection will develop at around 18-23z for
coastal and Jax Metro sites and extend to about 02-03z further
inland at GNV. Conditions will clear overnight with predominantly
VFR conditions returning along with mild winds.

&&

.MARINE...
Issued at 209 PM EDT Mon Jul 1 2024

A frontal boundary will approach our local waters from the north
tonight. Breezy south to southwest winds will prevail ahead of
this approaching frontal boundary through tonight. The frontal
boundary will stall over the Georgia waters on Tuesday and
dissipate, with increasing chances for mainly afternoon and
nighttime showers and thunderstorms across our local waters.
Prevailing winds will shift to east and southeast beginning on
Tuesday through Wednesday as high pressure builds down the
southeastern seaboard. Seas of 2-4 feet will prevail both near
shore and offshore during the next several days. High pressure
will then weaken as it shifts southward towards our local waters
later this week.

Rip Currents: Onshore winds developing in the wake of the inland
moving Atlantic sea breeze will combine with a persistent, long
period easterly ocean swell to create a lower end moderate rip
current risk at all area beaches through at least Tuesday.

&&

.HYDROLOGY...
Issued at 400 AM EDT Mon Jul 1 2024

Deep tropical moisture over the region will lead to heavy downpours
from convection especially along and ahead of an approaching frontal
boundary/trough from the north. WPC has placed SE GA in a slight
risk of excessive rainfall today. Localized areas could see rain
amounts of 3 inches, with higher amounts of 5 inches possible. A
Flood Watch was introduced for a few southeast GA counties for
this threat. Refinements to the watch may be needed later today.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  88  74  91  74 /  70  30  60  10
SSI  87  78  89  78 /  60  40  60  20
JAX  91  76  92  75 /  70  30  70  20
SGJ  91  78  91  77 /  60  30  60  20
GNV  92  74  92  73 /  70  40  70  10
OCF  93  76  93  75 /  70  40  70  20

&&

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

$$