831
FXUS62 KJAX 091111
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
711 AM EDT Sun Jun 9 2024

...New AVIATION...

.SYNOPSIS...
Issued at 404 AM EDT Sun Jun 9 2024

Overnight surface analysis depicts weak high pressure (1016
millibars) centered over the eastern Gulf of Mexico. Meanwhile, a
frontal boundary was sinking southward across the Ohio and Mid-
Mississippi Valleys. Aloft...stout ridging was centered along the
northern Gulf coast and was building eastward towards our region.
Otherwise, troughing was gradually digging east-southeastward from
the Great Lakes states and southeastern Canada towards New England
and the Ohio Valley. Shortwave energy moving east-southeastward in
between these two features was triggering Mesoscale Convective
Systems (MCSs) over the southern Plains, the Ozarks, and the
Tennessee Valley. Fair skies prevailed region-wide, with a dry,
subsident air mass and decoupling winds allowing temperatures and
dewpoints to fall to the low and mid 60s for locations northwest
of Waycross in southeast GA, with mid to upper 60s extending into
western portions of the Suwannee Valley. Temperatures and
dewpoints elsewhere remain in the 70s as of 08Z, except along the
immediate coast, where temperatures remain around 80 degrees.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 404 AM EDT Sun Jun 9 2024

The subsident air mass may promote radiation fog development,
especially for locations within a more humid environment in the
Suwannee Valley and north central FL during the predawn and early
morning hours. A few patches of locally dense fog cannot be ruled
out early this morning. Any fog that develops will dissipate
before the mid-morning hours.

Ridging aloft to our west will begin to flatten today as troughing
amplifies over the Great Lakes, Ohio Valley, New England, and the
Mid-Atlantic states. This amplifying trough will drive a frontal
boundary into the southeastern states tonight. A dry air mass
will prevail area-wide today, with prevailing westerly winds
likely delaying the development of the Atlantic sea breeze
boundary to the early to mid afternoon hours, with this boundary
only slowly moving inland towards the I-95 corridor late this
afternoon. Some thin cirrus emanating from convection well
upstream from our region will drift across our skies this
afternoon and tonight, but plenty of sunshine and strong
subsidence will only allow for a paltry, flat cumulus field to
develop this afternoon along mesoscale boundaries such as the St.
Johns River breeze and the inland moving Gulf and Atlantic sea
breezes.

Dewpoints crashing through the 50s this afternoon across inland
southeast GA and locations north of I-10 and the 60s elsewhere
away from the immediate coast will foster near record high
temperatures region-wide today (see Climate section below for
details), as inland temperatures approach 100 degrees. The late
development of the Atlantic sea breeze will result in coastal
highs soaring to the mid and upper 90s before cooling back towards
90s degrees as this boundary moves slowly inland late this
afternoon. The dry air mass will keep maximum heat index values in
check today despite the near record actual temperatures, with
values generally topping out in the 100-105 range for coastal
southeast GA and most of northeast and north central FL, with
values around or just under 100 degrees for inland southeast GA.

Cirrus cloud cover may begin to thicken somewhat overnight as
convection traverses the southeastern states along and ahead of
the approaching frontal boundary. This cloud cover may remain thin
enough for some patchy fog to develop across inland portions of
north central FL during the predawn and early morning hours on
Monday. Lows tonight will generally fall to the 70-75 degree
range, except mid to upper 70s at coastal locations.

&&

.SHORT TERM...
(Monday through Tuesday night)
Issued at 404 AM EDT Sun Jun 9 2024

Moisture slowly begins to fill in ahead of a cold front
approaching the area from the North Monday morning. Showers and
thunderstorms kick off for the week beginning Monday afternoon
with highest chances for precip in SE GA with values of 50-60%
while NE FL will see chances in the 40-50% range. Daytime
temperatures should be slightly cooler for areas behind the cold
front in SE GA with values in the low to mid 90s. Areas ahead of
the front will be in the mid to upper 90s range. The cold front
will continue to slowly push its way through the region by Tuesday
morning, cooling temperatures overnight into the low 70s inland
with temps in the mid to upper 70s along the coast. Tuesday,
expect rain and isolated thunderstorms chances area wide with
chances increasing in the afternoon. Highest percentages will be
focused on NE FL. Daytime temperatures will be in the low to mid
90s.

&&

.LONG TERM...
(Wednesday through Saturday)
Issued at 404 AM EDT Sun Jun 9 2024

The cold front from the beginning of the week rebounds through the
area as a stationary front Wednesday night and hangs around SE
GA and the FL/GA line into the weekend. This stationary front will
aid in bringing in more moisture to the area, increasing PWAT
values to over 2 inches for NE FL by Thursday morning and SE GA by
Thursday afternoon and into the weekend. Expect showers and
thunderstorms for the rest of the week with the highest chances
occurring each afternoon.

&&

.AVIATION...
(12Z TAFS)
Issued at 703 AM EDT Sun Jun 9 2024

Prevailing VFR conditions today and dry weather expected at all
terminals. Diurnally enhanced cumulus will develop with bases 5-7
kft with mid and high clouds increase from the NW late afternoon
and overnight tonight.

Light westerly land breeze winds 5-7 kts at the coast. Westerly
winds increase late morning into the 5-9 kt range, with stronger
winds today delaying the inland sea breeze by 1-2 hrs compared to
yesterday and slowing its inland progression. Indicate SSE winds
trailing the east coast sea breeze at SSI, CRG and SGJ between
19-21z then not reaching JAX/VQQ until 23-01z time frame.

Another round of shallow ground fog will be possible after 06z
tonight, mainly near GNV and VQQ. Will include MVFR after 09z for
VQQ given MAV, MET, NBH and SREF consensus.

&&

.MARINE...
Issued at 404 AM EDT Sun Jun 9 2024

A weak pressure pattern will prevail across our local waters
through Monday morning, with prevailing offshore winds becoming
onshore by late this afternoon over the near shore waters. A
southerly evening wind surge may bring speeds up to Caution levels
of 15-20 knots tonight, especially for the offshore waters. Seas
of 2-4 feet will prevail both near shore and offshore through at
least midweek.

A frontal boundary entering the southeastern states on
Monday will stall across our local waters by late Tuesday. Strong
to isolated severe thunderstorms will be possible across the
Georgia waters late on Monday afternoon, with this activity
weakening as it pushes across the northeast Florida waters on
Monday evening. A surge of tropical moisture will then lift
northward from the Caribbean Sea and the Gulf of Mexico by
midweek, resulting in waves of widespread showers and
thunderstorms impacting our local waters into next weekend. Weak
low pressure may develop over the Gulf of Mexico late this week,
potentially resulting in strengthening southerly winds.

Rip Currents: Prevailing offshore winds and low wave heights
should keep the risk low at all area beaches through Tuesday.

&&

.FIRE WEATHER...
Issued at 404 AM EDT Sun Jun 9 2024

A hot and unseasonably dry air mass will prevail area-wide today,
with long durations of critically low relative humidity values for
most inland locations and near critical values by early afternoon
at coastal locations. Drying fuels and breezy westerly transport
winds will present an Elevated Fire Danger for northeast and north
central FL, with marginally high to high daytime dispersion
values forecast area-wide today. Surface wind speeds will remain
just below critical thresholds this afternoon, precluding Red Flag
Conditions. Westerly transport winds will increase a little on
Monday and will combine with elevated mixing heights to create
high to very high daytime dispersion values at most locations on
Monday. Strong to isolated severe thunderstorms will be possible
for locations along and north of the Interstate 10 corridor late
on Monday afternoon and evening. Breezy westerly transport winds
and elevated mixing heights will continue on Tuesday, with
marginally high to high daytime dispersion values forecast,
especially across northeast and north central FL. Widespread,
significant rainfall chances increase beginning on Wednesday
across our region.

&&

.CLIMATE...
Issued at 404 AM EDT Sun Jun 9 2024

Record high temperatures for today and Monday at our official
local climate sites:

                June 9      June 10
              -----------------------
Jacksonville   101/1872     100/1954
Gainesville    99/1907      99/1899
Alma, GA       99/1993      103/1954
Craig Airport  97/2006      99/2006

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  98  73  94  71 /   0  10  60  50
SSI  97  78  94  74 /   0   0  60  60
JAX 100  72  98  73 /   0   0  50  40
SGJ  97  76  98  73 /   0   0  40  50
GNV 100  72  96  71 /   0   0  40  40
OCF  99  72  96  73 /   0   0  50  50

&&

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

$$