FXUS62 KJAX 180806

Area Forecast Discussion
National Weather Service Jacksonville FL
305 AM EST Fri Jan 18 2019

.SHORT TERM...Today and Tonight...Surface ridge sinking south into
central Fl with a zonal flow aloft will result in light sw winds
and mild temperatures today. A return flow over the Fl panhandle
into sw Ga will produce weak isentropic lift and a slight chance
of showers over se Ga this afternoon and evening. A seabreeze
will form at the coast this afternoon keeping coastal areas a
little cooler as winds become onshore. Temperatures will continue
to moderate with lows tonight in the lower 50s.


Saturday, a cold front will be west of the area with warm southerly
flow in advance of the system. Increasing moisture/cloudiness
expected to move in through the day with an increased chance of
showers expected over the wrn zones, mainly west of Highway 301, as
the day progresses. Latest guidance shows moisture advection ahead
of the front sped up so have increased POPs for Saturday with this
forecast. Temps should easily manage to reach mid to upper 70s as
south-southwest winds increase to near 15-20 mph.

Saturday night, precip associated with strong cold front will be
moving into the region as deep moisture pushes in with PWATS progged
to be about 1.5 inches and dewpoints climbing to the upper 50s and
lower 60s. Models continue to indicate weak instability with MLCAPE
of about 100-250 J/kg, with a chance of values up to 300-400 J/kg
over parts of northeast FL. Best chance of t-storms will be across
the Suwannee Valley area into extreme southeast GA based on NAM and
GFS MOS guidance. With eastward extent, instability will be weaker.
SPC has indicated an isolated severe storm is possible for the wern
zones with an isolated damaging wind gust possible. Widespread
precip with rainfall totals around the 0.5 to 1 inch range. Between
about 09z and 12z, precip expected to be pushing offshore as cooler
air arrives when front passes through most of the area. Min temps
may dip into the upper 40s northwest zones behind the front, with
50s elsewhere.

Sunday, some light precip possible in the morning over ern zones
with lingering low level moisture and mostly cloudy condition, then
clearing skies in the mid to late aftn. Much cooler with highs only
in the 50s to near 60. Gusty northwest winds of about 15-20 mph are
expected. Cold temps expected Sunday night dropping into the 30s and
with a northwest wind of near 10 and up to 15 mph under mostly clear
skies. A light freeze appears likely for portions of the inland


Monday morning starts out cold with northerly winds about 10 mph and
temps in the 30s and only warms to the 50s in the aftn under sunny
skies. Wind chills in the 20s are likely through about 9 am. High
pressure ridge north of the area Monday will quickly move east and
southeast into Tuesday while low level flow veers. This will allow
for quick moderation in temps. While the highs on Monday will be in
the lower to mid 50s (a good 10 deg below normal), max temps on
Tuesday will be close to climatology.

Onshore flow on Tuesday will bring moisture return to the area with
skies becoming partly cloudy. Another cold front approaches from the
west early Wed. GFS and ECMWF models diverge on the timing of this
next front passing over the forecast area but general consensus is
late Wed-Wed night, followed by cooler and dry air pushing in on
Thursday. Temperatures are expected to be near or above normal
Tuesday and Wednesday, then below normal for Thursday.


.AVIATION...VFR conditions expected today with ceilings in 5000 to
10000 foot range. Light sw winds today...becoming se this
afternoon near the east coast as a weak seabreeze forms.


.MARINE...Light and variable wind today will become southerly
tonight and then increase to Exercise Caution levels(15-20kts) on
Saturday. Advisory conditions expected to develop Saturday
evening as winds and seas increase ahead of a cold front. Strong
cold front will move across the waters late Saturday night with
widespread rain and isolated thunderstorms. Advisory conditions
expected to continue through Sunday night. Winds and seas will
decrease early next week.

Rip Currents: Low risk today...becoming moderate on Saturday as
winds increase.


AMG 66 53 72 48 / 30 10 20 90
SSI 64 53 69 51 / 10 10 10 80
JAX 69 52 76 51 / 0 0 10 80
SGJ 69 53 76 53 / 0 0 10 80
GNV 71 50 76 52 / 0 0 20 80
OCF 72 49 77 54 / 0 0 10 80




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