219
FXUS62 KJAX 161340
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
935 AM EDT Fri Aug 16 2024

...DANGEROUS SURF AND RIP CURRENTS THROUGH THE WEEKEND...
...New UPDATE...

.UPDATE...
Issued at 935 AM EDT Fri Aug 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

The GOES imagery shows a nice swath of dry air over the forecast
area with a PWAT minimum down to near 1.03 inches, with higher
moisture well to the south over srn FL at 2 inches. Slightly higher
moisture noted over inland southeast GA, but still about 1.3 inches
and well below normal. Indeed, the 12z JAX sounding showed PWAT of
1.15 inches, about 1-2 tenths less than about the 10 percentile.
Temps and the moisture remain below average. Highs today upper 80s
around the coastal areas and lower 90s inland.

The current forecast looks on track and only minor adjustments were
made to the max temps and sky cover. Should see some daytime cumulus
develop but generally sunny to mostly sunny skies and continued
northeasterly winds up to 10-15 mph and breezy at times.

On the marine side, the forecast winds and seas appear to be on
track with little needing to be changed. Long period swell energy
from Ernesto began being registering at the nearshore buoys more so
after 06z this morning and will increase through tonight. High risk
of rip currents expected through at least Sunday.

&&

.NEAR TERM...
Issued at 313 AM EDT Fri Aug 16 2024

An unusually dry northeasterly flow has overspread the forecast
area this morning. The latest GOES derived precipitable water
values have fallen toward unseasonably low values, which are
hovering around the 10th percentile according to the sounding
climatology at JAX. Without typical moisture, a rain-free day is
expected. An elongated surface high stretched along southeastern
US will gradually slide eastward through today allowing the local
gradients to decompress. Breezy onshore winds through the morning
and afternoon will moderate afternoon high temperatures for
coastal communities today, highs reading int the mid/upper 80s.
Farther inland highs will be seasonal in the low 90s. Dewpoints
will mix out this afternoon, reducing the heat index (i.e. how hot
it feels). The breezy conditions will lighten up this evening and
temperatures will cool into the upper 60s and low 70s under clear
skies tonight.

With the lull in the typical summertime weather, the primary
concern today will be elevated surf and strong rip current at area
beaches over the next couple of days.

&&

.SHORT TERM...
(Saturday through Sunday night)
Issued at 313 AM EDT Fri Aug 16 2024

Pattern for dry weather will continue through Saturday as drier
air with PWAT values measuring less than 1 inch passes through the
area from out of the northeast. High pressure ridging over the
region is expected to push southward on Sunday followed by
unstable moist conditions ahead of an advancing cold front from
out of the north which will result in increased chances for
showers and storms by the end of the weekend, with developments
most likely to occur over southeast Georgia and adjacent areas of
northeast Florida. High temperatures for the weekend will be in
the lower to mid 90s with overnight low temperatures dropping down
into the lower to mid 70s. Heat index values will rise to be
above 100 on Sunday, however conditions are not expected to reach
heat advisory levels this weekend.

&&

.LONG TERM...
(Monday through Thursday)
Issued at 313 AM EDT Fri Aug 16 2024

The frontal boundary will press southward next week and is
expected to stall within the vicinity of the Georgia / Florida
border with drier weather expected over southeast Georgia, with
diurnal convective developments occurring south of the frontal
boundary and more widespread over north central Florida. The
remains of the frontal boundary over the region will diminish and
prevailing flow shifting to become more out of the southeast and
south as high pressure ridging builds in from out of the
southeast. High temperatures through midweek are expected to be
near and slightly above average with temps rising into the lower
to mid 90s. Conditions are not anticipated to reach heat advisory
levels during this period.

&&

.AVIATION...
(12Z TAFS)
Issued at 720 AM EDT Fri Aug 16 2024

VFR conditions expected to prevail today with few to scattered
cumulus developing by 15-16z. No convection is forecast to affect
the terminals due to a drier than normal airmass. Northeast winds
will increase to near 8-14 kt and gusty by midday.

&&

.MARINE...
Issued at 313 AM EDT Fri Aug 16 2024

A combination of breezy onshore and powerful swells emanating
from Hurricane will lead to hazardous combined seas offshore.
There may be a brief period of higher seas reaching the nearshore
waters late this afternoon. Small Craft Advisory will be in effect
today and tonight for those elevated seas. Onshore flow will
begin weakening this afternoon and continue through Saturday as
high pressure starts to shift east over the coastal waters. Later
this weekend winds will turn offshore ahead of an approaching cold
front that will work southward through the waters early next
week. Thunderstorm activity will be reignited ahead of and with
the cold frontal passage.

RIP CURRENTS: The surf will be particularly rough today. A
battering surf zone and a powerful long-period swell will lead to
substantial rip currents this afternoon. Dangerous rip currents
will persist through the entire weekend.

&&

.HYDROLOGY...
Issued at 313 AM EDT Fri Aug 16 2024

Ongoing moderate river flooding continues along portions of the
Santa Fe, St Marys, and Suwannee rivers; however, many points
along Suwannee and Santa Fe have already fallen to minor flood
levels. An unseasonable two-day bout of dry weather will allow
levels to fall farther with ongoing moderate flooding lowering
into minor levels by the end of the weekend or earlier.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  91  68  92  73 /   0   0  10  10
SSI  88  74  89  75 /  10   0   0   0
JAX  89  70  91  72 /   0   0   0   0
SGJ  87  73  88  72 /   0   0   0   0
GNV  90  67  91  70 /   0   0   0   0
OCF  91  68  92  70 /   0   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Sunday evening for FLZ124-125-133-
     138.

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

AM...Small Craft Advisory until 2 AM EDT Saturday for AMZ470-472-474.

&&

$$