Jacksonville, Florida 7 Day Weather Forecast

Wx Forecast - Wx Discussion - Wx Aviation

821
FXUS62 KJAX 031615
AFDJAX

Area Forecast Discussion
National Weather Service Jacksonville FL
1115 AM EST Tue Dec 3 2024

...BREEZY AND COOL CONDITIONS THIS AFTERNOON...
...HARD FREEZE EXPECTED FOR INLAND SOUTHEAST GA AND THE SUWANNEE
VALLEY OVERNIGHT THROUGH EARLY WEDNESDAY MORNING...
...REINFORCING COLD FRONT ARRIVES ON THURSDAY NIGHT AND FRIDAY...

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

.UPDATE...
Issued at 1115 AM EST Tue Dec 3 2024

Late morning surface analysis depicts a reinforcing, dry cold
front that was pushing southward across the Interstate 10
corridor. Meanwhile, arctic high pressure (1038 millibars) was
building southeastward from the Ozarks and Tennessee Valley in the
wake of this reinforcing front. Aloft...deep troughing covers the
eastern half of the nation. Breezy north-northwesterly winds were
overspreading our region in the wake of the reinforcing, dry cold
front late this morning, with temperatures remaining in the 45-50
degree range at 16Z across southeast GA and 50-55 for most of
northeast and north central FL beneath sunny skies. Dewpoints at
16Z were falling through the 20s across southeast GA, while values
elsewhere were generally around 30.

Breezy north-northwesterly winds this afternoon will drive cold
air advection that will counter sunny skies and a dry air mass.
Highs will only climb to around 50 for locations north of
Waycross, ranging to around 60 for north central FL this
afternoon. Arctic high pressure will then build into the Deep
South this evening, setting up radiational cooling at inland
locations that will provide the coldest night of the season thus
far to our area. A Hard Freeze is expected across all of inland
southeast GA and the Suwannee Valley, where lows will fall to the
mid 20s. Temperatures at these locations will fall below freezing
towards midnight, and a heavy frost will accompany this hard
freeze. A light freeze and widespread, heavy frost will occur
elsewhere in northeast and north central FL for locations west of
the St. Johns River, where lows will fall to the upper 20s to
around 30. Areas to widespread frost will extend to coastal
locations in southeast GA and portions of northeast FL, including
locations along and west of Interstate 95, where lows will fall to
the lower 30s. A light northerly breeze overnight and some
incursion of marine stratocumulus from the Atlantic waters should
keep lows in the mid to upper 30s along the immediate coast and
urban areas in northeast FL, where patchy to areas of frost will
be possible during the overnight and early morning hours on
Wednesday.

&&

.SHORT TERM...
(Wednesday through Thursday night)
Issued at 332 AM EST Tue Dec 3 2024

Surface high pressure will migrate eastward across the area and
gradually develop northeastward off the Mid Atlantic coast by
Wednesday as the parent mid-level trough lifts and weak ridging
builds aloft. Winds will decrease through Tuesday and shift
onshore as the surface high builds toward the Atlantic. With the
shifting low level flow, increasing moisture will bring increasing
cloud cover and warmer temps to the coastal districts.

Cool drainage flow will keep temperatures below normal through
the period. Highs on Tuesday will struggle to reach the 70s
despite full sun. Temps will gradually rebound as onshore flow
develops Wednesday with highs spanning the 70s. Lows will fall to
the mid/upper 40s inland and mid/upper 50s at the coast Tuesday
night and warm about 5-8 degrees by Wednesday night.

&&

.LONG TERM...
(Friday through Monday)
Issued at 332 AM EST Tue Dec 3 2024

An inverted coastal trough will instigate showers over the
coastal waters through Thursday and spread moisture/cloud cover
inland as the next cold front begins to approach from the
northwest. The front is progged to sweep through the area on
Friday, though discrepancy in how quickly it pushes through
remains uncertain given a faster translation in the Euro versus
the GFS. Appears that there will be enough prefrontal moistening
to support scattered showers and storms ahead of and along the
front.

Instability will be the one factor that may limit potential for
strong or severe storms with the passing front. However, if
moistening occurs faster than current guidance suggests, there
will be sufficient shear to support the potential for strong or
marginally severe isolated t`storms.

Benign weather will return this weekend as dry, cool northwest
flow sets up in the wake of the departing front. Temperatures will
gradually warm and trend near normal by Friday before another
period of cooler than normal temps this weekend.

&&

.AVIATION...
(12Z TAFS)
Issued at 608 AM EST Tue Dec 3 2024

VFR conditions will be in place throughout the forecast period.
Northwesterly winds will pick up in the afternoon by around 17-19z
and then diminish in the evening and overnight hours, becoming
more mild and variable through Wednesday morning.

&&

.MARINE...
Issued at 1115 AM EST Tue Dec 3 2024

North-northwesterly winds will strengthen early this afternoon as
a reinforcing, dry cold front passes southward across our local
waters. Small Craft Advisory conditions are expected over the
offshore waters through late this afternoon as speeds increase to
around 20 knots, with Caution level wind speeds of 15-20 knots
expected near shore this afternoon. Seas will build to 5-7 feet by
late this afternoon for the offshore waters adjacent to northeast
FL, with 4-6 foot seas for the offshore waters adjacent to
southeast GA, while seas near shore build to 3-5 feet. Small
Craft Advisory level seas will linger into the early evening
hours tonight for the offshore waters adjacent to northeast
Florida before diminishing to Caution levels of 4-6 feet, while
3-5 foot seas prevail elsewhere.

Winds and seas will diminish tonight and Wednesday as high
pressure settles directly over our local waters. Westerly winds
will then strengthen late on Wednesday night and Thursday ahead of
another strong cold front that will pass across our area on
Thursday evening. Speeds will increase to Caution levels for the
offshore waters late Wednesday night and Thursday before shifting
to northerly in the wake of this dry frontal passage late on
Thursday night and Friday. Winds and seas will then gradually
diminish this weekend as another high pressure center builds
directly over our local waters.

Rip Currents: A persistent easterly ocean swell will create a
lower-end moderate rip current risk at area beaches this
afternoon. A low risk is expected on Wednesday and Thursday as
winds and seas initially diminish, followed by offshore winds
developing on Thursday.

&&

.FIRE WEATHER...
Issued at 1115 AM EST Tue Dec 3 2024

Breezy north-northwesterly surface and transport winds this
afternoon will create good daytime dispersion values area-wide.
Transport and surface winds will diminish towards sunset this
evening and will shift to northeasterly overnight. Surface and
transport winds will then become southwesterly on Wednesday
afternoon, with light speeds resulting in low daytime dispersion
values inland and poor daytime dispersion values at coastal
locations on Wednesday. Minimum humidity values will fall to the
30-35 percent range this afternoon, with critically low humidity
values possible across inland southeast GA and the Suwannee Valley
on Wednesday afternoon. Red Flag conditions are not expected due
to light winds. West-southwesterly surface and transport speeds
will then increase on Thursday, with fair daytime dispersion
values forecast across inland southeast GA and good daytime
dispersion values expected elsewhere.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  50  24  56  37 /   0   0   0   0
SSI  52  33  56  39 /   0   0   0   0
JAX  56  28  59  36 /   0   0   0   0
SGJ  58  38  60  44 /   0   0   0   0
GNV  59  29  62  38 /   0   0   0   0
OCF  61  30  63  39 /   0   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Freeze Warning from 11 PM this evening to 9 AM EST Wednesday for
     FLZ021-023-024-030-031-035-120-136-220-232-236-237-240-322-
     340-422-425-522.

     Frost Advisory from 11 PM this evening to 9 AM EST Wednesday for
     FLZ033-038-124-125-132-137-140-225-325.

GA...Freeze Warning from 11 PM this evening to 9 AM EST Wednesday for
     GAZ132>136-149-151>154-162-163-165-166-250-264-350-364.

AM...Small Craft Advisory until 5 PM EST this afternoon for AMZ470.

     Small Craft Advisory until 8 PM EST this evening for AMZ472-474.

&&

$$