Area Forecast Discussion
Issued by NWS Jacksonville, FL
FXUS62 KJAX 091639
Area Forecast Discussion
National Weather Service Jacksonville FL
1139 AM EST Fri Dec 9 2016
...Freeze Warning Tonight for all of Southeast Georgia and
portions of Inland Northeast Florida...
Late morning surface analysis depicts strong high pressure (1041
millibars) building southeastward from the Canadian prairies into
the Tennessee and lower Mississippi River Valleys. Aloft...broad
troughing covers most locations east of the Rockies, with a
subtropical jet in place across the southern Gulf of Mexico and
the Florida peninsula. Decks of mid and high altitude cloudiness
associated with this strong subtropical jet are now shifting
southward of our southern zones in Marion and Flagler Counties as
a deeper layer of colder and drier air advects into our region.
Temperatures have been slow to rise due to cold air advection
despite full sunshine over all but our far southern counties.
Breezy northerly winds prevail over the coastal counties. We
expect highs to reach the mid to upper 50s, which is between 9-13
degrees below climo for today.
High pressure well to our northwest will begin to weaken tonight,
allowing our local pressure gradient to slowly loosen. The
subtropical jet over the Florida peninsula may push periods of
high cloudiness over north central Florida overnight. Our low
level winds will begin to veer overnight, which will shut off cold
air advection. However, clear skies and decoupling winds will
ensure a light freeze over all but the immediate coast in
southeast Georgia. Subfreezing temperatures are expected along and
west of U.S. Highway 301 in northeast Florida and for locations
north of Gainesville in the Suwannee Valley. A light northerly
breeze will result in wind chills falling to the mid to upper 20s
in the freeze warning area, with near freezing wind chills
possible elsewhere inland. A developing onshore wind component
overnight will keep coastal lows in the upper 30s over southeast
Georgia and the low to mid 40s for coastal northeast Florida.
VFR conditions will prevail at the regional terminals. Northerly
surface winds will be sustained at 10-15 knots, with occasional
gusts of 20-25 knots at SGJ, SSI, and CRG through 22Z.
A small craft advisory remains in effect for the near shore waters
through 4 PM and offshore through 4 AM. Northerly winds sustained
near 20 knots will diminish somewhat near shore during the late
afternoon, with seas of 4-6 feet expected. Offshore seas will
remain in the 5-7 foot range offshore through late tonight. Winds
will gradually shift to a northeasterly direction overnight, with
speeds of 15-20 knots offshore and near 15 knots near shore. Seas
offshore will fall back to the 4-6 foot range on Saturday and 3-5
feet near shore. High pressure will shift over the Mid-Atlantic
states on Saturday night and offshore on Sunday, keeping onshore
winds in place through Sunday evening. Wind speeds and seas should
remain just below caution criteria in the offshore waters from
Saturday night through Sunday night. A cold front will enter the
southeastern states on Monday and will stall to the northwest of
our region, resulting in light offshore winds and gradually
diminishing seas offshore.
Rip Currents: Moderate risk for the northeast Florida beaches due
to easterly swells around 2 feet and a longshore current from
breezy northerly winds.
.PRELIMINARY POINT TEMPS/POPS...
AMG 54 30 56 37 / 0 0 0 0
SSI 55 39 56 48 / 0 0 0 10
JAX 57 35 59 46 / 0 0 0 10
SGJ 58 45 61 55 / 0 0 10 20
GNV 58 36 63 46 / 0 0 0 10
OCF 59 39 65 49 / 10 0 0 10
FL...Freeze Warning from 1 AM to 9 AM EST Saturday for Baker-Columbia-
GA...Freeze Warning from 1 AM to 9 AM EST Saturday for Appling-
Inland Camden-Inland Glynn-Jeff Davis-Pierce-Ware-Wayne.
AM...Small Craft Advisory until 4 AM EST Saturday for Waters from
Altamaha Sound GA to Fernandina Beach FL from 20 to 60 NM-
Waters from Fernandina Beach to St. Augustine FL from 20 to
60 NM-Waters from St. Augustine to Flagler Beach FL from 20
to 60 NM.
Small Craft Advisory until 4 PM EST this afternoon for Coastal
waters from Altamaha Sound to Fernandina Beach FL out 20 NM-
Coastal waters from Fernandina Beach to St. Augustine FL
out 20 NM-Coastal waters from St. Augustine to Flagler
Beach FL out 20 NM.