Area Forecast Discussion
Issued by NWS Jacksonville, FL

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50
000
FXUS62 KJAX 180150
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
950 PM EDT Sun Mar 17 2024

...New UPDATE...

.UPDATE...
Issued at 948 PM EDT Sun Mar 17 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

Initial wave of showers and isolated thunderstorms has moved into
the area this evening ahead of a wave of low pressure traveling east
along a frontal boundary that stretches from near the mouth of
the St mary`s river westward along the coast of the FL panhandle
into the northern Gulf of Mexico. Showers are more organized over
SE GA at this hour while coverage is more scattered over NE FL as
a decaying MCS has been waning with eastward extent into the
area. However, another round or two of showers is expected to
redevelop from the NE Gulf into NE FL areas after midnight through
the early morning hours with low stratus clouds developing along
and just behind the front as the boundary slowly sinks to I-10
overnight and south of I-10 into the rest of NE FL by the morning
hours.

Lows will be above normal overnight with low to mid 60s over NE FL
and upper 50s to near 60 degrees just north of the cold front over
much of SE GA.


Rain showers will continue to stretch across north central to
portions of NE FL south of I-10 on Monday. An isolated strong to
severe thunderstorm is still not out of the question over north
central Fl, mainly Marion county southward where some elevated
instability ahead of the southward moving front along with mid
level lapse rates near 6.0-6.5 C/km and 40-50 knots of 0-6km bulk
shear could combine for a more favorable storm to produce wind
gusts 50 to 60 mph. Otherwise clouds will begin to clear from NW
to SE in the afternoon and showers end just behind the cold front
as it sinks south of the area by late afternoon with winds
increasing from the northwest 10-15 mph.

Highs Monday will be near 70 over inland SE GA to the mid 70s
over NE FL and upper 70s over north central FL and the southern St
Johns river basin.

&&

.NEAR TERM...(through Tonight)

Main period of weather will occur this evening and through the
overnight hours as a wave of low pressure tracks northeastward from
the GOMEX east-northeastward along the stationary front that will
wobble back toward the I-10 corridor as said wave approaches. CAMs
have been a bit wishy-washy in the intensity of the associated
convection as it crosses NE FL this evening. However, the potential
for strong and possibly marginally severe storms will exist,
particularly for areas south of I-10 where HREF probs maintain
about a 40-50% chance of at least 500 j/kg of SBCAPE through
midnight.

The main concern will be the threat of strong or locally damaging
winds with stronger embedded t`storms as the wave tracks across.
Behind the wave a trailing cold front will begin to push
southeastward through SE GA late tonight. Enough convergence along
the frontal edge will support a secondary round of showers and
isolated storms through sunrise and likely most of the morning
monday as it slowly sinks south. Overall, rain amounts aren`t
expected to be significant, with accumulations expected to stay
below an inch at any given location.

Another warm, near-record day in terms of high temperatures will
lead to another mild night as skies trend to overcast and the
stationary boundary becomes situated essentially along I-10. Lows in
SE GA (on the cool side) will be in the upper 50s while NE FL zones
will read more so in the mid 60s. Though there could be some
localized lowered visibility due to showers, the boundary layer will
likely remain stirred up enough to limit any significant fog
development.

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

&&

.SHORT TERM...(Monday through Wednesday night)

Moisture will continue to stream northeast along the frontal
boundary, as it slowly moves off to the southeast Monday. The best
energy moves off with the front, so will end thunderstorm mention
with frontal line itself, while precipitation may trail its passage.
Highs on Monday will range from the mid 60s inland SE GA, which will
be on the northwest side of the front in the morning, to the mid
70s over north central FL where frontal passage will be later.

A strong pressure gradient will set up behind the front for Monday
night as high pressure builds from the northwest. With subsidence
from the building high, it will be a dry night. With the subsidence
and tightened gradient it will be a somewhat gusty night, especially
at the coast. A surge of winds is expected to move south down the
coastal waters overnight, which will lead to even higher winds along
the coast. Beach front communities will likely experience wind gusts
around 35 mph overnight Monday night, with gusts to around 25 mph
more common inland. Temperatures will drop quickly Monday
night, with about a 30 degree diurnal swing from highs on Monday.
Lows in the mid 30s across SE GA will be common, to lower 40s over
NE FL. The expected wind will provide enough mixing to keep frost
from becoming an issue, but wind chills due to the wind and
temperature will dip to at or below freezing for many inland
locations.

The gradient will slowly relax through the day Tuesday, as the high
pressure ridge builds across the area. Tuesday will be a bright
sunny day, but cooler than normal due to cold advection on north
northwest flow. Highs Tuesday in the lower to mid 60s will be
common, which is now about 10 degrees cooler than seasonal averages.

High pressure will be the prevailing weather feature for Tuesday
night through Wednesday night, continuing the dry weather, and fair
skies. Temperatures will begin a moderating trend, but still remain
below normal.

&&

.LONG TERM...(Thursday through next Sunday)

The high pressure ridge will lift off to the northeast Thursday,
making away for a low pressure system developing over the Gulf to
affect the region. The low will track northeast across the Gulf
Thursday night, with precipitation overspreading the region from
southwest to northeast. The low center is then expecting to cross
the area during the day on Friday.

Depending on the strength of this wave, there is the potential for a
few strong to severe storms, along with heavy rainfall Thursday
night through Friday.

The low pressure system is expected to lift northeast of the region
in time for the weekend, with it currently looking like a dry
weekend.

Temperatures will trend near to a little below seasonal levels for
this period.

&&

.AVIATION...
(00Z TAFS)
Issued at 752 PM EDT Sun Mar 17 2024

A wave of low pressure along a stalled cold front near the Florida
and Georgia state line will bring rounds of rain and isolated
thunderstorms into the regional terminals through the first 6
hours of the TAF period starting by 02Z at GNV/VQQ/JAX/SSI and
spreading to CRG and SGJ by 03Z-04Z. This round may bring and MVFR
restrictions gusty winds to 25 knots at SSI due to stronger
storms currently trekking east across southern Georgia. As the
shield of showers moves over the TAF sites from 02Z-06Z ceilings
will lower to MVFR levels between 1.5 to 2.5 kft. The initial
round of showers and embedded thunderstorms will move off into the
Atlantic waters late tonight with less rain shower coverage for
SSI while light showers should prevail at the other sites through
early to mid morning Monday and ceilings will lower to IFR levels
by 07Z-10Z time frame, potentially to LIFR restrictions at GNV.

Thereafter, another round of showers should develop as the cold
front sinks southward over Northeast Florida just after sunrise
with Ceilings slowly improving back to low end MVFR 13Z-17Z, then
high end MVFR levels 17-21Z as showers slip away to the southeast
with VFR conditions returning after 21Z for most TAF sites with
northwest winds after sunrise elevating to near 10 knots in the
afternoon as the front exits the area and high pressure begin to
build in from the northwest. Breezier winds from the northwest
are anticipated Monday night after the end of the period due to
the tightening local pressure gradient.

&&

.MARINE...

Tranquil maritime conditions this afternoon while a stalled
frontal boundary extends across the waters. A wave of low pressure
moving along the boundary this evening will bring scattered
showers and thunderstorms into the waters before midnight. Behind
the low pressure, a cold front will begin to sweep southeastward
across the waters through Monday and be trailed by a strong surge
of northwesterly winds. Small Craft Advisory conditions will
overspread the waters Monday evening. Given the likelihood for
frequent gale force gusts offshore Monday night, a Gale Watch has
been issued. Winds will lighten and conditions improve Tuesday
afternoon as high pressure to the west shifts over the waters.
High pressure will be the dominant weather feature until the next
weather disturbance arrives Thursday night.

Rip Currents: Low risk through Monday.

&&

.FIRE WEATHER...

An elevated fire danger is forecast for Tuesday and Wednesday due
to dry conditions.

A cold front will cross the region Tonight, providing chances for
Thunderstorms. High pressure will build from the northwest
Monday. This high will be the predominant weather feature over the
area through Thursday. An area of low pressure will lift
northeast out of the Gulf Thursday night into Friday, bringing
another round of showers and storms. High pressure will then build
for next weekend.

&&

.HYDROLOGY...
Issued at 335 AM EDT Sun Mar 17 2024

On the Altamaha River, moderate flooding is occurring at Baxley
and is forecast at Charlotte and Everett City, with rest of river at
minor flooding. Minor flooding is also forecast for Satilla River
at Atkinson. Additional rainfall through the weekend will keep
these rivers elevated into early to the middle of next week.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  59  70  37  61 / 100  30   0   0
SSI  61  72  41  61 /  90  50   0   0
JAX  63  72  40  64 /  80  70   0   0
SGJ  65  75  43  61 /  50  80   0   0
GNV  65  74  40  65 /  60  80   0   0
OCF  66  77  42  65 /  60  80   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...Gale Watch from Monday evening through Tuesday morning for
     AMZ470-472-474.

&&

$$


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.