970
FXUS62 KJAX 270554
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
154 AM EDT Mon May 27 2024

...New AVIATION...

.UPDATE...
Issued at 937 PM EDT Sun May 26 2024

Late evening surface analysis depicts weakening Atlantic ridging
extending its axis westward across the Florida peninsula.
Meanwhile, a cold front extends from Lake Michigan south-
southwestward across the Ozarks and the southern Plains states.
Aloft...ridging aloft centered over the Bay of Campeche
(southwestern Gulf of Mexico) continues to extend its axis east-
northeastward across the rest of the Gulf and across the FL
peninsula. Otherwise, a series of potent shortwave troughs
continue to migrate from the northern Rockies across the Great
Lakes states, with fast southwesterly flow in between these
troughs and the Gulf of Mexico ridge propelling shortwave energy
across the Ozarks and the Mid-Mississippi Valley, resulting in a
severe weather outbreak this evening near the confluence of the
Ohio and Mississippi Rivers. Closer to home, the Atlantic and Gulf
Coast sea breezes collided this evening just east of the U.S.
Highway 301 corridor, with subsidence and dry air aloft resulting
in only a narrow corridor of towering cumulus clouds, with
updrafts unable to sustain themselves for long enough to create
showers. Fair skies prevail elsewhere across our region, with
temperatures uniformly remaining in the 80-85 degree range
throughout our region, with dewpoints ranging from the mid 60s to
the mid 70s.

Troughing aloft will continue to dig southeastward from the Great
Lakes and the Upper Midwest towards the Ohio and Tennessee Valleys
on Monday, resulting in ridging aloft over the Gulf of Mexico
gradually flattening. This weather pattern will drive the cold
front into the southeastern states by Monday evening. Low level
west southwesterly flow will slowly increase overnight, which
could drive a stratus deck onshore from the northeast Gulf of
Mexico into the Suwannee Valley during the predawn and early
morning hours on Monday. Strengthening low level flow will likely
prevent dense fog formation, but patchy fog may develop beneath
the stratus deck along the I-75 corridor. Fair skies will prevail
elsewhere, with lows only falling to the 70-75 degree range at
most locations.

Any fog or low stratus that manages to develop during the predawn
and early morning hours on Memorial Day will quickly scour out
shortly after sunrise as west-southwesterly winds increase, with
breezy conditions expected area-wide by the late morning and early
afternoon hours. Multi-layered cloudiness will gradually increase
during the afternoon hours downstream of the digging trough and
approaching cold front, but plenty of morning sunshine and breezy
offshore winds will again boost highs into the low and mid 90s,
with the Atlantic sea breeze development delayed until the mid-
afternoon hours at coastal locations. Dewpoints will fall to the
60s during the afternoon hours as the dry and subsident air mass
holds on along the I-95 corridor, keeping maximum heat index
values around or just below 100.

Convection developing ahead of the cold front will begin to
encroach upon the Ocmulgee/upper Altamaha/Alapaha Rivers during
the late afternoon and early evening hours. Although bulk west-
southwesterly wind shear values will remain below 40 knots on
Monday evening across inland southeast GA, ML CAPE values around
1,000 j/kg may allow for a few storms to pulse and become strong
or even briefly severe towards sunset as activity moves into
inland portions of southeast GA. The primary threats with any
stronger convection will be damaging wind gusts of 40-60 mph,
frequent lightning strikes, and briefly heavy downpours. Most
activity will remain to the north and west of U.S. Highway 84 in
southeast GA during the early evening hours on Monday.

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 235 PM EDT Sun May 26 2024

By Wednesday the front will be sitting over central FL, bringing
chances of showers and storms for locations south of the I-10
corridor. On Thursday and Friday, the front looks to lift
northward as a warm front, bringing an increase in showers and
storms from NE FL and into SE GA during the afternoon each day.

A `cooling` trend begins as high pressure builds in from the
northwest on Wednesday after the cold front`s passage. Morning
lows in the 60s for the latter half of next week. Highs will begin
in the 90s across the area on Wednesday and begin to trend
downward as Highs will get into the upper 80s for SE GA and the
lower 90s in NE FL from Thursday and into next weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 150 AM EDT Mon May 27 2024

VFR prevails at this time, but some potential for low stratus 0clouds
to filter in from the west, moving toward GNV and possibly VQQ by
12z. Otherwise, after any stratus dissipates by 13z-14z, VFR
clouds through today with increasing mid to high clouds in the
aftn as a weak cool front moves into the region. Scattered deep
convection expected to develop over southeast GA and then shift
east to southeast late aftn and into the late evening and
overnight hours. The only site where we introduced a low prob of
convection was at SSI for late in the TAF period. Further additions
will likely needed in the 06z-12z time period when convective
debris clouds and VCSH or VCTS. Sfc winds will be light southwest
through 12z and increase to about 10G16kt by late morning and
early aftn. Atlantic sea breeze will impact SGJ, CRG, and SSI
this aftn, later occurrence than on prior days due to breezier
west-southwest winds.

&&

.MARINE...
Issued at 937 PM EDT Sun May 26 2024

Atlantic ridging will continue to extend its axis westward across
the Florida peninsula through Memorial Day, with prevailing west
southwesterly winds resuming overnight and again on Monday night
following afternoon sea breezes and southerly evening wind surges.
Speeds should mostly remain below Caution levels during the
evening wind surges, although speeds will likely increase to
around 15 knots offshore on Monday evening. Seas of 2-3 feet will
prevail both near shore and offshore during the next several days.

High pressure will slide eastward on Monday afternoon ahead of a
frontal boundary that will be entering the southeastern states.
This front will stall across our local waters on Tuesday and
Tuesday night, bringing increased chances for scattered showers
and thunderstorms beginning late Monday night. The front will then
gradually weaken and dissipate over the northeast Florida waters
on Wednesday and Thursday, with winds becoming onshore by late
this week as high pressure builds southeastward from the Great
Lakes region.

Rip Currents: Breezy onshore winds developing on Monday afternoon
will create a lower-end moderate rip current risk at the northeast
FL beaches. A low risk is expected to continue at the southeast GA
beaches during the next several days.

&&

.FIRE WEATHER...
Issued at 937 PM EDT Sun May 26 2024

West-southwesterly transport winds will strengthen early on Monday
morning, with these breezy winds combining with elevated mixing
heights to create high to very high daytime dispersion values
across much of southeast GA and for locations east of Interstate
75 in northeast and north central FL. A hot and dry air mass will
result in afternoon relative humidity values falling to around 35
percent for location east of Interstate 75 in northeast and north
central FL. Transport winds will shift to west-northwesterly and
will remain breezy on Tuesday, with continued elevated mixing
heights resulting in high to very high daytime dispersion values
area-wide. A drier air mass will filter into inland portions of
southeast GA on Tuesday, resulting in minimum relative humidity
values falling to the 30-35 percent range for locations north of
Waycross during the afternoon hours. Transport winds will then
shift to northwesterly by Wednesday, with speeds diminishing
slightly. However, elevated mixing heights should create good to
marginally high daytime dispersion values nearly area-wide. A
drier air mass will continue to filter into our area by midweek,
possibly dropping relative humidity values to near critical
thresholds across inland southeast GA on Wednesday afternoon, with
values elsewhere expected to fall to the 30-35 percent range for
locations west of the I-95 corridor.

&&

.HYDROLOGY...
Issued at 937 PM EDT Sun May 26 2024

Water levels continue to slowly rise along lower portions of the
Santa Fe River due to backwater flooding caused by a wave of minor
flooding working its way down the lower Suwannee River. A brief
period of moderate flooding may be possible next weekend along the
lower Santa Fe River near the Three Rivers Estates gauge. Minor
flooding will be possible towards midweek for the lower Santa Fe
River near the gauge at Hildreth. Otherwise, water levels have
crested along lower portions of the Satilla River near the gauge
at Atkinson, where minor flooding is expected to continue into
next weekend.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  92  71  90  67 /  50  70  20   0
SSI  91  75  90  72 /  10  40  20  10
JAX  94  73  93  69 /  10  20  40  10
SGJ  92  75  90  72 /   0  30  40  20
GNV  93  73  93  68 /   0  30  50  10
OCF  93  72  92  70 /   0  30  50  10

&&

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

$$