802
FXUS62 KJAX 191753
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
153 PM EDT Sat Oct 19 2024

...WINDY CONDITIONS CONTINUE AT COASTAL LOCATIONS THROUGH SUNDAY...
...DANGEROUS SURF CONDITIONS PREVAIL AT ALL AREA BEACHES...
...MODERATE TIDAL FLOODING CONTINUES ACROSS SOUTHERN PORTIONS OF
THE ST. JOHNS RIVER BASIN...

...New NEAR TERM, SHORT TERM, LONG TERM, MARINE, HYDROLOGY...

.NEAR TERM...
Issued at 152 PM EDT Sat Oct 19 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

Sprawling high pressure is expected to dip southward into the TN
River Valley during the overnight hours into Sunday setting the
stage for a stronger pressure gradient resulting in slightly
stronger NELY winds tomorrow, particularly near the coast. Deep
ridging resides over the eastern half of the CONUS, with
subtropical ridge building westward from the Bahamas across south
FL. Today, north of I-10 precipitable water values will run well
below an inch with PWs around 1 inch along the First Coast south
of Ponte Vedra.

Periods of thicker marine stratocumulus will occasionally move
onshore today across northeast FL, with this cloud cover extending
westward across southern portions of the Suwannee Valley and
north central FL. Shallow showers have to develop across the
local Atlantic waters, with activity moving onshore. These
isolated and sparse showers are forecast to continue through
tonight,  primarily impacting areas along the coast, particularly
south of Ponte Vedra.

Despite these clouds and windy conditions, ridging aloft will
allow highs to climb to the mid and upper 70s. Winds along coastal
locations should remain sustained in the 15-20 mph range
throughout the day and evening hours, with occasional gusts 30-35
mph.  Fair skies will prevail tonight for inland locations north of
I-10, with decoupling winds overnight allowing lows to again fall
to the upper 40s and lower 50s. A northeasterly breeze will keep
coastal lows in the 60s, while inland lows for locations south of
I-10 falling to the 55-60 degree range, except lower 60s in north
central FL.

&&

.SHORT TERM...
(Sunday through Monday night)
Issued at 152 PM EDT Sat Oct 19 2024

Surface high pressure remains strong and stationary north of the
area with a southward extending ridge interacting with a broad
coastal trough off the east coast of Florida. These features will
promote persistent onshore winds, creating breezy conditions along
the coast and St. Johns river, dangerous rip currents, coastal
flooding concerns, along with scattered showers moving onshore in
northeast Florida. Highs will remain below normal on Sunday, in
the mid 70s to lower 80s, increasing a few degrees area-wide on
Monday.

&&

.LONG TERM...
(Tuesday through next Saturday)
Issued at 152 PM EDT Sat Oct 19 2024

The high pressure across the eastern United States will begin to
broaden, easing onshore flow mid-week. Overall, dry conditions and
near normal temperatures are forecast for the week, with high
temperatures ranging from the upper 70s to mid 80s. A dry cold
front will move through the area Thursday into Friday, leaving
high pressure to build to the northeast again.

&&

.AVIATION...
(18Z TAFS)
Issued at 1243 PM EDT Sat Oct 19 2024

Brief period of lowered ceilings will be possible at SGJ as
patches of lower marine have pushed onshore. Ceilings of 2.5 to
3.5 kft are then expected to prevail the afternoon hours at SGJ as
a few showers have pushed onshore from the nearby Atlantic
waters. Included -RA at SGJ through 22z. Lower stratocumulus
clouds and a few showers could extend as far inland as GNV during
the mid to late afternoon hours, but confidence was too low to
indicate MVFR conditions at this time. Ceilings are then expected
to lower to MVFR at the Duval County terminals during the late
afternoon and early evening hours as stratocumulus expands
northward, possibly accompanied by a few brief showers or
sprinkles. VFR conditions should prevail at SSI. Gusty
northeasterly surface winds will continue where speeds around 15
knots with occasional gusts to 22-27 knots possible through the
afternoon hours. Surface speeds will remain sustained at 5-10
knots overnight, with northeasterly winds then increasing to 10-15
knots and gusty during the late morning or early afternoon hours.
Winds and stratocu will once again increase Sunday morning for FL
coastal TAF sites with the onset of northeast winds at 15 knots
with some gusts to 20 knots around 15z.

&&

.MARINE...
Issued at 152 PM EDT Sat Oct 19 2024

An area of high pressure will remain north of the region through
this weekend and into early next week then weaken mid week. The
resulting northeast to east-northeast pressure gradient will support
wind speeds 15-25 knots with gusts occasionally up to 30 knots.
In addition, the long fetch of east northeast winds across the
Atlantic waters will produce elevated seas across the local Atlantic
waters which has resulted in SCAs. Pretty solid Small Craft Advisory
(SCA) conditions are occurring across all the local Atlantic waters
this morning and are forecast to continue into early next week. So
the SCA continues through Mon aftn. Meanwhile, coastal troughing
situated over our near shore waters will sharpen tonight,
with showers occasionally pushing onshore along the northeast Florida
coast. Seas of 6-9 feet will prevail both near shore and offshore
through the weekend, with seas slowly subsiding to 5-7 feet by Monday.

The winds will continue to slowly taper Wednesday as the high weakens
but onshore flow will continue 10-15 knots.  Another dry frontal
boundary will then move across our local waters by late in
the upcoming week.

Rip Currents / High Surf / Beach Erosion: Breakers of 4-6 feet
will prevail at the northeast FL beaches throughout the weekend,
with 3-5 foot breakers expected at the southeast GA beaches. This
rough, pounding surf will keep a high risk of deadly rip currents
at all area beaches through at least Monday, with astronomically
high tides adding to the danger, especially during the outgoing
tide during the late morning and early afternoon hours. Minor to
moderate each erosion is likely during each high tide cycle
through the early portions of next week.

&&

.HYDROLOGY...
Issued at 152 PM EDT Sat Oct 19 2024

Tidal Flooding: A Coastal Flood Warning has been extended through
Sunday Night for the St. Johns River basin in eastern Flagler and
western Putnam Counties, where `Moderate` level tiding flooding
will occur around times of high tide. Moderate flooding for this
section of the St. Johns occurs around 2 ft above Mean Higher High
Water (MHHW) and can cause inundation of some structures and
roads. A Coastal Flood Advisory has also been extended through
Sunday Night for the St. Johns River basin within Clay and Duval
counties as well as the Intracoastal Waterway and local northeast
FL Atlantic coast, as persistent onshore flow and elevated
astronomical tides continue `Minor` mainly nuisance tidal flooding
around times of high tide.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  49  77  50  79 /   0   0   0   0
SSI  64  74  62  76 /   0   0   0   0
JAX  58  76  61  79 /  10  10   0  10
SGJ  69  76  68  79 /  40  10   0  10
GNV  60  78  59  80 /  10   0   0   0
OCF  62  79  63  82 /  10   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Coastal Flood Advisory until 6 AM EDT Monday for FLZ033-124-125-
     132-133-138-225-325.

     Coastal Flood Warning until 6 AM EDT Monday for FLZ038-137.

     High Rip Current Risk through late Sunday night for FLZ124-125-
     133-138.

GA...High Rip Current Risk through late Sunday night for GAZ154-166.

AM...Small Craft Advisory until 6 AM EDT Monday for AMZ450-452-454.

     Small Craft Advisory until 6 AM EDT Tuesday for AMZ470-472-474.

&&

$$