169
FXUS62 KJAX 100812
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
412 AM EDT Mon Jun 10 2024

...NEAR RECORD HEAT CONTINUES TODAY FOR NORTHEAST FL...
...ELEVATED WILDFIRE DANGER FOR NORTHEAST AND NORTH CENTRAL FL...
...STRONG TO SEVERE THUNDERSTORMS LATE THIS AFTERNOON AND THIS
EVENING ACROSS PORTIONS OF SOUTHEAST GEORGIA...

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

.SYNOPSIS...
Issued at 412 AM EDT Mon Jun 10 2024

Early morning surface analysis depicts a slow moving frontal
boundary extending across the Deep South. Aloft...troughing
continues to dig southward from the Great Lakes and New England,
with ridging aloft migrating southward while flattening over the
southeast Gulf of Mexico and the FL peninsula. Latest GOES-East
derived Total Precipitable Water imagery indicates an unseasonably
dry and subsident air mass over the northeastern Gulf of Mexico
that was advecting across locations south of Interstate 10, where
PWAT values were generally below 1.3 inches at inland location.
Values elsewhere were generally around 1.5 inches, which is
slightly below mid-June climatology. Mostly thin cirrus clouds
were moving overhead, with convective activity along the frontal
boundary remaining well north of our region, or over east central
and northeast GA. Temperatures at inland locations were mostly in
the low to mid 70s as of 08Z, with dewpoints generally in the
60s. Meanwhile, an offshore breeze was keeping coastal
temperatures generally in the upper 70s to lower 80s.

&&

.NEAR TERM...
(Today and Tonight)
Issued at 412 AM EDT Mon Jun 10 2024

Troughing aloft will continue to dig southward towards our region,
with the frontal boundary slowly pushing into southeast GA late
this afternoon and evening. Meanwhile, a pocket of dry and
subsident air leftover from the flattening ridge that was in place
over our area this weekend will remain in place today across
northeast FL, while deeper tropical moisture over the Straits of
FL begins to advect northward through the FL Peninsula later
today. A narrow ribbon of deeper moisture accompanying the frontal
boundary will become positioned over southeast GA late this
afternoon and evening, triggering scattered to numerous
thunderstorms. Bulk west-southwesterly shear values will increase
to around 40 knots for locations north of Waycross later today,
with intense heating bringing ML CAPE values up to around 1,500
j/kg, setting the stage for potential strong to severe
thunderstorms. Stronger convection over southeast GA late this
afternoon and this evening will be capable of producing downburst
winds of 40-60 mph, hail, and frequent lightning strikes, and the
presence of a pinned Atlantic sea breeze boundary along the I-95
corridor could even present an isolated tornado/waterspout threat
for the Golden Isles. Otherwise, near record high temperatures can
be expected again today, as temperatures generally climb to the
95-100 degree range. The dry and subsident air mass over northeast
and north central FL should keep maximum heat index values around
100, while values climb to the 100-105 range this afternoon for
locations along and east of I-95 in coastal southeast GA, as
humidity values climb in the wake of a pinned Atlantic sea breeze.

Strong to severe thunderstorms may continue early this evening for
portions of inland southeast GA and the Golden Isles, with
activity struggling to progress southward due to the lingering
subsident air mass over northeast FL. This air mass will depart
after midnight as the digging trough aloft scoops up the deeper
tropical moisture over the FL peninsula and advects it towards
north central FL during the predawn hours on Tuesday. Showers and
possibly a lower topped thunderstorm or two could develop during
the predawn hours for Marion, Flagler, and southern Putnam
Counties, where PWATS will rapidly increase to near 2 inches
towards sunrise. Lows tonight will fall to the low and mid 70s
inland, with mid to upper 70s forecast at coastal locations.

&&

.SHORT TERM...
(Tuesday through Wednesday night)
Issued at 412 AM EDT Mon Jun 10 2024

A frontal boundary hanging over the local area will remain through
midweek, SW flow ahead of the boundary will work to bring
tropical moisture northward across much of the Florida peninsula.
The increase in moisture, with guidance suggesting PWAT values
ranging from 1.5" to 2.0" over north central Florida, will bring
higher chances of showers and thunderstorms mainly over the north
central FL counties during the afternoon hours on Tuesday and
Wednesday. Current estimates of 1.0" to 1.25" inches of rainfall
over north central FL. Daytime temperature highs will begin to
trend a bit lower as showers and cloud cover will keep the heat at
bay, but highs are still expected to be in the lower 90s for both
Tuesday and Wednesday. Overnight lows will sit in the lower
70s.

&&

.LONG TERM...
(Thursday through Sunday)
Issued at 412 AM EDT Mon Jun 10 2024

Tropical moisture is expected to remain over most of the Florida
peninsula, current model guidance suggests PWAT values ranging
from 1.5" to 2.0" over north central FL counties during the end of
the upcoming work week. As such, a Marginal risk for excessive
rainfall has been placed by the WPC for the north central FL
counties in our area. Daily precipitation chances will continue
into the upcoming weekend, but guidance suggests the tropical
moisture over the local area will be much lower from the previous
few days. Temperature highs will begin in the lower 90s during the
later half of the week, dropping to the upper 80s across most of
the local area by the end of the weekend. Temperature lows
expected to sit in the lower to mid 70s from late this week into
the upcoming weekend.

&&

.AVIATION...
(06Z TAFS)
Issued at 225 AM EDT Mon Jun 10 2024

VFR conditions will prevail through at least 21Z at the regional
terminals. Showers and thunderstorms are expected to approach the
SSI terminal from the northwest after 21Z, with a strong or
isolated severe thunderstorm possible through around 01Z Tuesday.
We included a PROB30 group for wind gusts up to 30 knots and MVFR
conditions during heavier downpours. Otherwise, an isolated shower
could develop during the late afternoon or early evening hours
near the SGJ terminal, but confidence remains too low to include
anything other than vicinity coverage at this time. West-
southwesterly winds sustained around 5 knots or less at the inland
terminals and 5-10 knots at the coastal terminals will increase
after sunrise, with sustained speeds expected to climb to around
10 knots before 16Z. Surface winds will shift to southeasterly at
10-15 knots at SGJ after 19Z following the passage of the Atlantic
sea breeze boundary, while surface winds shift to southerly at
10-15 knots at SSI. Outside of thunderstorm activity, surface
winds will then shift to southwesterly at 5-10 knots after 01Z
Tuesday.

&&

.MARINE...
Issued at 412 AM EDT Mon Jun 10 2024

A frontal boundary over the southeastern states will move
southward, stalling over the Georgia waters tonight. Strong to
severe thunderstorms will be possible late this afternoon and
early this evening, mainly closer to the frontal boundary over the
Georgia waters. Severe thunderstorms late this afternoon and early
this evening over the Georgia waters will be capable of producing
strong wind gusts, hail, waterspouts, and frequent lightning.
Outside of thunderstorm activity, southerly winds will likely
surge to Caution levels of 15-20 knots over the offshore waters
this evening. Seas of 2-3 feet both near shore and offshore today
will build to 3-5 feet offshore tonight.

Waves of showers and thunderstorms will then overspread our local
waters from south to north on Tuesday and Wednesday as the
frontal boundary remains stalled over our region. Prevailing
onshore winds are expected late this week and into the weekend as
weak low pressure potentially develops over the Gulf of Mexico.
Waves of showers and thunderstorms will continue to impact our
local waters through the weekend. Seas of 2-4 feet will prevail
both near shore and offshore from Tuesday through the upcoming
weekend.

Rip Currents: Prevailing offshore winds and low wave heights
should keep the rip current risk low at all area beaches through
Tuesday. Prevailing onshore winds developing on Wednesday should
result in a moderate risk at area beaches by late this week.

&&

.FIRE WEATHER...
Issued at 412 AM EDT Mon Jun 10 2024

An Elevated Fire Danger will continue today across northeast and
north central FL, where long durations of critically low relative
humidity values will be possible at inland locations as
temperatures soar to the mid to upper 90s. Otherwise, breezy
westerly transport winds will combine with elevated mixing heights
to create high to very high daytime dispersion values nearly
area-wide today. Surface wind speeds should remain just below Red
Flag Warning criteria this afternoon across northeast and north
central FL. Strong to severe thunderstorms will be possible across
southeast GA late this afternoon through the evening hours. A
drier air mass will briefly move over inland portions of southeast
GA on Tuesday, where transport winds will shift to northwesterly.
Otherwise, breezy southwest to westerly transport winds will
combine with elevated mixing heights to create good daytime
dispersion values nearly area-wide on Tuesday. Transport winds
will then shift to east and southeasterly on Wednesday, with
increasing chances for showers and thunderstorms spreading from
south to north.

&&

.CLIMATE...
Issued at 412 AM EDT Mon Jun 10 2024

Record high temperatures at official local climate sites today:

         June 10
                ----------
Jacksonville     100/1954
Gainesville      99/1899
Alma, GA         103/1954
Craig Airport    99/2006

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  94  71  91  70 /  50  50  30  10
SSI  95  77  89  76 /  30  40  50  30
JAX  98  73  93  72 /  10  10  70  30
SGJ  96  76  92  73 /  20  20  70  40
GNV  97  73  93  71 /  10  20  70  30
OCF  95  73  91  72 /  10  50  70  40

&&

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

$$