582
FXUS62 KJAX 162329
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
729 PM EDT Sun Jun 16 2024

...New UPDATE, AVIATION...

.UPDATE...
Issued at 729 PM EDT Sun Jun 16 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

No major updates needed on the forecast this evening, scattered
thunderstorms will linger west of I-75 for the next few hours.
With elevated onshore winds, very mild low temperatures are
forecast for the coast tonight, only dropping into the upper
70s/near 80 degrees.

&&

.SYNOPSIS...
Issued at 222 PM EDT Sun Jun 16 2024

Afternoon surface analysis depicts strengthening high pressure
(1027 millibars) centered over New England, with a decaying
frontal boundary wedging southward through the Carolinas and the
southern Appalachians. Aloft...stout ridging prevails over the
southeastern states, with the feature steering shortwave energy
around its western periphery from the southern Plains states
northeastward to the Great Lakes region. Latest GOES-East derived
Total Precipitable Water imagery indicates that a drier than
average air mass remains over most of our region, except for
locations near the Suwannee River, where values were in the 1.6 -
1.8 inch range, which is closer to climatology. PWAT values
elsewhere were generally in the 1.3- 1.5 inch range, with higher
PWATS just north of our region near the decaying frontal boundary.
Our local pressure gradient is tightening as high pressure wedges
down the southeastern seaboard, with breezy easterly winds now in
place for locations along and east of the St. Johns River, where
the Atlantic sea breeze was progressing fairly quickly westward.
Widely scattered convection was developing along both the inland
moving Gulf and Atlantic sea breeze boundaries, generally for
locations south of the I-10 corridor. Temperatures ranged from the
upper 80s to lower 90s at most locations, with dewpoints falling
through the 60s for locations west of the U.S. Highway 301
corridor, with 70s for locations behind the inland moving Atlantic
sea breeze boundary.

&&

.NEAR TERM...
(through Tonight)
Issued at 222 PM EDT Sun Jun 16 2024

Breezy easterly winds will overspread inland locations as the
afternoon progresses, with onshore winds increasing to the 15-20
mph range with occasional gusts up to 30 mph by late this
afternoon and early this evening along the Atlantic coast. The
strengthening surface ridge along the New England coast will
generally advect a dry and subsident air mass onshore, with the
Atlantic sea breeze progressing well inland towards the I-75
corridor by the late afternoon hours. This boundary will encounter
higher PWAT values located along and west of the Suwannee River,
as it encounters a pinned Gulf Coast sea breeze. with scattered to
numerous showers and thunderstorms expected to erupt by late
afternoon for locations along and west of I-75 in the Suwannee
Valley and north central FL.

Showers and thunderstorms developing along the I-75 corridor
during the mid to late afternoon hours will progress westward
across the Suwannee and Alapaha Rivers by sunset. Breezy and
convergent low level easterly flow may begin to advect isolated
showers developing over the Atlantic waters onshore along the
northeast FL coastal counties towards sunrise on Monday. The
onshore breeze will be slow to weaken along the coast overnight,
keeping lows in the upper 70s to around 80 for locations east of
I-95, while lows elsewhere fall to the low and mid 70s.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 222 PM EDT Sun Jun 16 2024

A persistent weather pattern is expected for this period as high
pressure centered south and east of New England will continue to
extend a ridge southwestward across the area. This will also
continue a brisk onshore flow featuring easterly winds in the
10-20mph range with gusts around 25-35mph, and an elevated risk of
rip currents at area beaches. Guidance is also in pretty good
agreement that stacked high pressure to our northeast will advect
some drier than normal air into the region aloft, and therefore
reduce chances for any significant convection. The highest rain
chances will likely be closer to the coast during this time frame
with some showers and possibly an isolated thunderstorm streaming
onshore. The secondary area where there may be some convective
coverage would be near or west of I-75 each day as the onshore
flow meets the pinned Gulf Coast seabreeze.

Expecting mainly mid to upper 80s for highs during this period,
with some low 90s likely for the western "half" of the CWA,
dropping into the low to mid 70s and upper 70s near the coast each
night.

&&

.LONG TERM...
(Wednesday through next Sunday)
Issued at 222 PM EDT Sun Jun 16 2024

Wednesday/Thursday: Eyes for the this period will be primarily
focused on a tropical wave east of the Bahamas on Wednesday, and
the potential for further tropical organization/development as it
moves west-northwestward towards our area through Thursday. It is
still too far out to determine if the system will organize into a
tropical cyclone, or pass near the area as a tropical wave/trough.
In addition to strength and organization of the disturbance,
guidance is also shaky with regards to the track, which has varied
from moving towards as far north as the GA/SC border to as far
south as south of Cape Canaveral, pending the strength and
position of the strong steering ridge impacting the area this
week. Main points to drive home as of now will be: 1. this area
should pass close enough to increase rain chances area wide,
including some localized heavy rain and flooding potential 2.
gusty onshore conditions are likely to continue through at least
the end of the week, with hazardous beach conditions also likely
to persist.

Friday through Sunday: Aforementioned high pressure will start to
drift further south into the western Atlantic into next weekend,
with ridging overhead weakening a bit in the wake of the departing
disturbance. This should shift our flow more towards the southeast
for the weekend and return a more normal sea breeze convection
type of regime.

Temperatures: Tending near to slightly below average for the start
of the long term period with more unsettled weather, returning
closer to normal or even slightly above normal for next weekend.

&&

.AVIATION...
(00Z TAFS)
Issued at 729 PM EDT Sun Jun 16 2024

Overall, VFR conditions with the exception of low, early morning
visibilities at VQQ are expected. Gusty easterly winds will pick
up after sunrise tomorrow impacting all sites, with vicinity
showers in place as well for showers moving onshore. Thunderstorm
potential is limited for tomorrow so have not place that in the
TAFs at this time until confidence increases.

&&

.MARINE...
Issued at 222 PM EDT Sun Jun 16 2024

High pressure centered over New England will strengthen as it
moves slowly offshore this evening. This feature will result in
strengthening easterly winds late this afternoon and evening
throughout our local waters, with winds and seas continuing to
gradually increase early this week. Small Craft will need to
Exercise Caution if venturing into our local waters on Monday and
Monday night, as easterly winds strengthen to 15-20 knots and seas
build to 3-5 feet on Monday and 4-6 feet by Monday evening. Small
Craft Advisory conditions are expected to begin offshore on
Tuesday and near shore by Tuesday night, as onshore winds
strengthen to around 20 knots and seas build to 5-7 feet.

A low pressure center is expected to develop over the southwestern
Atlantic Ocean early this week, with this feature gradually
organizing  around midweek as it moves westward across the
Bahamas, with a low risk for tropical development as this system
approaches our local waters on Thursday and Thursday night.
Coverage of showers and thunderstorms will gradually increase
across our local waters towards midweek, with widespread activity
likely by late week. Seas will continue to build, with near shore
seas climbing to the 8-11 foot range by Thursday, while seas
offshore build to 9-13 feet.

Rip Currents: Strengthening easterly winds will result in building
and increasingly rough surf, especially during the outgoing tide
late this afternoon and early this evening. A High Risk of rip
currents is expected by late afternoon at the northeast FL
beaches, with a high end moderate risk for the southeast GA
beaches, where wave heights should remain around 2 feet or less
today. A high risk of rip currents is expected for the upcoming
work week at all area beaches due to gradually strengthening
onshore winds and building seas.

&&

.FIRE WEATHER...
Issued at 1119 AM EDT Sun Jun 16 2024

Easterly surface and transport winds will become breezy this
afternoon, creating good to marginally high daytime dispersion
values for locations along and north of the Interstate 10
corridor. Generally fair dispersion values are expected for north
central FL this afternoon. A dry air mass will prevail for inland
locations across southeast GA and also for northern portions of
the Suwannee Valley today and again on Monday, where afternoon
humidity values will fall to the 30-35 percent. Breezy easterly
transport winds will prevail area-wide on Monday and Tuesday, with
windy surface conditions expected along the I-95 corridor during
the afternoon and early evening hours. Good to high daytime
dispersion values are forecast throughout our region for the
early to middle portions of this week.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  72  92  70  90 /   0  10  10  10
SSI  80  87  77  87 /  10  30  30  40
JAX  74  89  73  88 /  10  30  30  30
SGJ  79  88  76  87 /  10  40  30  40
GNV  73  91  70  89 /  10  20  20  20
OCF  73  92  72  92 /  20  20  20  20

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late Wednesday night for FLZ124-
     125-133-138.

GA...None.
AM...None.
&&

$$