Winter Storm in Georgia, January 3, 2018

Area Forecast Discussion
National Weather Service Jacksonville FL
340 AM EST Wed Jan 3 2018

...SIGNIFICANT SNOW AND ICE ACCUMULATIONS EXPECTED TODAY ACROSS
SOUTHEAST GEORGIA AND INLAND NORTH FLORIDA...
...WIDESPREAD HARD FREEZE EXPECTED TONIGHT WITH POSSIBLE BLACK
ICE IN SOME LOCATIONS...

.NEAR TERM /Today-Tonight/...
Today...No change to ongoing forecast package as Significant
Snow/Ice event for SE GA and inland North FL (N and W of JAX) still
on track as strong low pressure system develops near the Bahamas and
tracks rapidly Northward. Shortwave aloft coming in from the West
from the GOMEX is already triggering precip across NE FL south of
GNV-JAX for now in an area that is above freezing.
Expect this to shift northward and expect Snow/Ice onset in the
4am-6am time frame over inland areas. Main axis of significant ice
accumulation around 0.25" still on track from Live Oak/Lake City
NE across the FL/GA border through Waycross and Jesup with lesser
amounts as you move closer to the coast. Further inland on the NW
portion of precip shield to the NW of Waycross, still have the
potential for significant snow accumulations of 2-4 inches. Some
higher totals may be possible but the system will be tracking away
from the area so quickly this should keep any Max Totals likely
less than 6 inches. Will leave Winter Storm Warning as-is and
Winter Weather Advisory on the SE edge of Warning from GNV-JAX
still looks like borderline event as possible start as frozen pcpn
likely to changeover to all-Rain event as is expected for the rest
of NE FL towards the coast and southward to Marion County. The
back-side of the shortwave aloft and wind shift to the NW at the
end of precip event will allow for enough colder air to push in to
possible mix some areas with snow briefly in the JAX metro area.
Max temps will still be near Record Low levels with only lower to
middle 30s expected from the I-10 corridor northward through SE GA
with only brief window of temps above freezing to help with the
roadways but still expect likely accumulation of ice/snow on other
surfaces. Across the rest of NE FL temps in the cold rain will
likely only push to around 40 degrees with some of the current
readings along the NE FL coast in the 40s this morning actually
falling/steady the rest of the day as the winds shift NW behind
the system late in the Day. The brisk north winds will generally
be in the 15-20G30 mph over inland areas and closer to 20-30G35-40
mph at the coast and will issue Wind Advisory for the gusty winds
at the coast through the day. Will keep current brief Freeze/Hard
Freeze warnings as-is this morning and also extend the Wind Chill
Advisories through the day as north winds will combine with much
below normal high temps to keep wind chills indices in the upper
teens and 20s through much of the day.

Tonight...Precip event should taper off quickly during the mid-
late afternoon hours with temps falling below freezing quickly
after sunset as skies become clear with gusty NW winds at 10-20G30
mph at times as low departs into the Carolinas. Temps will plummet
into the 20s area-wide as NW flow pushes the cold airmass all the
way to the coast. Hard Freeze Warning has been posted for all
areas with lows near 20 inland SE GA, lower 20s coastal SE GA,
lower to middle 20s inland from the NE FL coast and upper 20s at
the beaches of NE FL. The lingering impact from todays precip
event will be the possibility of wet roadways re-freezing as temps
fall below freezing so quickly this evening and while the gusty NW
winds will tend to dry out roadways, there is the potential for
black ice, especially across SE GA where snowfall/ice event
impacts will linger with lesser chances of Black Ice across NE FL
where it will likely mainly impact bridges and other elevated
roadways. Have also extended Wind Chill Advisory for all locations
and expect Wind Chills as low as 10 degrees across SE GA and in
the teens/lower 20s across the rest of the area.

.SHORT TERM /Thursday through Friday night/...
Deep troughing will prevail over the eastern half of the nation
throughout the short term period, with rapidly deepening low
pressure accelerating northward from just east of the the Mid-
Atlantic coast early on Thursday and approaching the Canadian
Maritime region by Thursday night. Despite full sunshine, highs will
only reach the 40-45 range in southeast Georgia and the mid to upper
40s for northeast and north central Florida on Thursday, which is 15-
20 degrees below early January climo. Our local pressure gradient
will begin to slowly loosen on Thursday night as arctic high
pressure begins to build southward from the western Great Lakes into
the Tennessee and lower Mississippi Valleys. Northwesterly winds
will fall back to the 5-8 mph range inland and 9-13 mph at the
coast. Another long duration hard freeze nearly area-wide, with lows
approaching daily record values once again. Lows over inland
southeast Georgia and the northern Suwannee Valley will fall to
around 20, with lower 20s for most of inland northeast Florida and
coastal southeast Georgia. Lows over north central Florida will
plunge into the mid 20s, with mid to upper 20s at the immediate
coast in northeast Florida. Wind chill values will fall into the
teens area-wide during the overnight hours and into early morning on
Friday.

Lighter northwesterly winds will prevail on Friday, but cold air
advection will continue and high cloudiness may increase from the
west during the afternoon hours. Highs on Friday will again only
climb to the 40-45 range in southeast Georgia, the mid 40s along the
Interstate 10 corridor, and the upper 40s in north central Florida.
Arctic high pressure will become centered over the Ohio Valley by
late Friday night, with inland winds decoupling and allowing for
another long duration hard freeze for all of southeast Georgia and
all of inland northeast and north central Florida. A N-NW breeze
around 10 mph keeping the immediate coastal locations in northeast
Florida from experiencing another hard freeze, with lows in the
upper 20s to near 30 and  wind chills in the lower 20s.

.LONG TERM /Saturday through Wednesday/...
Deep troughing aloft over the eastern third of the nation early on
Saturday will pivot northeastward off the New England coast by late
Saturday night. The arctic high pressure center will continue to
progress slowly eastward from the Ohio/ Tennessee Valleys early in
the day to the Carolina coast by early Sunday. Low level winds will
veer to a more northerly direction on Saturday, keeping cold air
advection going with interludes of high cloudiness advecting
eastward through our region. Highs on Saturday will again only reach
the mid 40s, with upper 40s to near 50 elsewhere, except lower 50s
in north central Florida. Low level winds then continue to veer to a
northeasterly direction by Saturday night, finally signaling the
demise of cold air advection over our region. Coastal lows will
remain above freezing, with a light freeze anticipated for inland
northeast and north central Florida as well as coastal southeast
Georgia. Decoupling winds over inland southeast Georgia may allow
for one more hard freeze into early Sunday morning.

High cloudiness will likely increase over our area on Sunday
downstream of a shortwave trough that will be digging into the
Midwest and southern Plains states. Flow aloft will become zonal
locally, with surface winds veering to an easterly direction as high
pressure nudges eastward and off the Carolina coast by the evening
hours. Highs will rebound into the mid 50s for southeast Georgia,
upper 50s along the I-10 corridor and low/mid 60s in north central
Florida. While these temperatures will feel balmy following a full
week of arctic cold temperatures, these highs will still be about 3-
6 degrees below early January climo. An isolated shower or two may
advect westward over the St. Johns and Flagler County coastal areas
by late Sunday afternoon or evening. Lows will rebound to slightly
above climo on Sunday night thanks to veering low level winds, an
increasing stratocumulus field advecting westward from the Atlantic
waters, and a cirrus shield overhead, with 40s inland and upper 40s
to lower 50s at the coast.

A shortwave trough will dig southeastward into the lower Mississippi
Valley on Monday, with deep southwesterly flow developing locally
and transporting increasing moisture northeastward from the Gulf of
Mexico by late in the day. Scattered showers will develop during the
afternoon hours over inland southeast Georgia and the Suwannee
Valley, with isolated showers possible along coastal locations
towards sunset. Highs will reach the upper 60s to near 70 for inland
southeast Georgia, with mid 60s expected along the coast. Highs will
generally climb to the lower 70s for inland northeast Florida,
except upper 60s along the coast and mid 70s for north central
Florida. Numerous showers will then traverse our region along and
ahead of a cold front on Monday night and early Tuesday, with the
front clearing southeast Georgia and the Suwannee Valley shortly
after midnight. Lows in these locations behind the front will cool
back to the upper 40s to near 50, while low to mid 50s are expected
ahead of the front. Rainfall is currently progged to exit coastal
locations early in the day, with cool air advection on the heels of
breezy northwesterly winds keeping highs in the 60-65 range, except
upper 60s in north central Florida. Cool high pressure will then
build over the Ohio and Tennessee Valleys on Tuesday night and
Wednesday, with northwesterly surface winds Tuesday night veering to
northerly on Wednesday. Inland lows will fall back into the 30s,
with 40s for coastal locations and north central Florida. Near or
slightly below climo highs are currently forecast for next Wednesday.

&&

.AVIATION...
Widespread MVFR CIGS at the moment expected to drop to IFR/LIFR
CIGS and VSBYS with the onset of precipitation btwn 06-12z time
frame. Have included some mention of FZRA at JAX/VQQ/SSI/GNV
around 12z based on forecast but will watch temps trends to see if
this will still be needed. Some changeover to a mix of rain and
snow will be possible at JAX/VQQ TAF sites briefly this afternoon
otherwise SSI will have the best chances of seeing mixed precip of
FZRA/PL/SN as it changes back over from rainfall to mixed precip
there. Improvement to VFR expected in the 21z-00z time frame for
all TAF sites as precip ends and winds become NW.

&&

.MARINE...
Have upgraded Gale Watch to a Warning for the offshore waters as
strong north flow expected on the back-side of low pressure
tracking north with winds 25-35 knots expected with seas 8-12 ft
developing once again. For now will keep SCA for the nearshore
waters but will be close with occasional gusts to gale force.
Strong North flow becomes NW tonight and remains strong with gale
force gusts then a decreasing trend on Thursday with winds/seas
falling below SCA criteria Thu Night and then North flow 15 knots
or less Fri/Sat becoming NE less than 15 knots on Sunday.

Rip Currents: High Risk Today with strong North Flow Today then
becoming Moderate on Thursday with strong offshore flow.

&&

.HYDROLOGY...
Will keep Coastal Flood Advisory in place for the Atlantic Coast
as North Winds will combine with another Full Moon High Tidal
Cycle during the morning High Tide Cycle to produce another round
of Minor Tidal Flooding.

&&

.CLIMATE...
With significant measurable snowfall expected near Alma, GA (AMG).
Here are there daily snowfall records since 1948...
4.4" Snowfall on 02-10-1973
2.3" Snowfall on 12-23-1989
0.5" Snowfall on 02-08-1968

Daily record low maximum temperatures for today at our
designated climate sites (January 3rd):

Jacksonville........38 (1979)
Gainesville.........39 (1900)
Alma................35 (1979)
St. Simons Island...36 (1979)

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  36  20  40  20 / 100   0   0   0
SSI  36  25  42  23 / 100   0   0   0
JAX  36  25  44  23 / 100   0   0   0
SGJ  45  27  46  28 / 100   0   0   0
GNV  40  24  46  23 / 100   0   0   0
OCF  43  26  48  24 / 100   0   0   0

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Hard Freeze Warning from 6 PM this evening to 11 AM EST Thursday
     for Alachua-Baker-Bradford-Clay-Coastal Duval-Coastal
     Nassau-Columbia-Flagler-Gilchrist-Hamilton-Inland Duval-
     Inland Nassau-Marion-Putnam-St. Johns-Suwannee-Union.

     Winter Storm Warning until 5 PM EST this afternoon for Baker-
     Columbia-Gilchrist-Hamilton-Inland Nassau-Suwannee-Union.

     Wind Chill Advisory until 11 AM EST Thursday for Alachua-Baker-
     Bradford-Clay-Columbia-Gilchrist-Hamilton-Inland Duval-
     Inland Nassau-Suwannee-Union.

     Coastal Flood Advisory until 1 PM EST this afternoon for Coastal
     Duval-Coastal Nassau-Flagler-St. Johns.

     High Rip Current Risk through this evening for Coastal Duval-
     Coastal Nassau-Flagler-St. Johns.

     Wind Advisory until 7 PM EST this evening for Coastal Duval-
     Coastal Nassau-Flagler-St. Johns.

     High Surf Advisory until 1 PM EST this afternoon for Coastal
     Duval-Coastal Nassau-Flagler-St. Johns.

     Wind Chill Advisory from 7 PM this evening to 11 AM EST Thursday
     for Coastal Duval-Coastal Nassau-Flagler-Marion-Putnam-St.
     Johns.

     Winter Weather Advisory until 5 PM EST this afternoon for
     Alachua-Bradford-Clay-Coastal Nassau-Inland Duval.

     Freeze Warning until 1 PM EST this afternoon for Baker-Columbia-
     Gilchrist-Hamilton-Inland Nassau-Suwannee-Union.

GA...Hard Freeze Warning from 6 PM this evening to 11 AM EST Thursday
     for Appling-Atkinson-Bacon-Brantley-Charlton-Clinch-Coastal
     Camden-Coastal Glynn-Coffee-Echols-Inland Camden-Inland
     Glynn-Jeff Davis-Pierce-Ware-Wayne.

     Winter Storm Warning until 5 PM EST this afternoon for Appling-
     Atkinson-Bacon-Brantley-Charlton-Clinch-Coastal Camden-
     Coastal Glynn-Coffee-Echols-Inland Camden-Inland Glynn-Jeff
     Davis-Pierce-Ware-Wayne.

     Wind Chill Advisory until 11 AM EST Thursday for Appling-
     Atkinson-Bacon-Brantley-Charlton-Clinch-Coastal Camden-
     Coastal Glynn-Coffee-Echols-Inland Camden-Inland Glynn-Jeff
     Davis-Pierce-Ware-Wayne.

     Coastal Flood Advisory until 1 PM EST this afternoon for Coastal
     Camden-Coastal Glynn.

     High Rip Current Risk through this evening for Coastal Camden-
     Coastal Glynn.

     Wind Advisory until 7 PM EST this evening for Coastal Camden-
     Coastal Glynn.

     Hard Freeze Warning until 9 AM EST this morning for Appling-
     Atkinson-Bacon-Coffee-Jeff Davis-Wayne.

AM...Small Craft Advisory until 7 AM EST this morning 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.

     Gale Warning from 7 AM this morning to 7 AM EST Thursday 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 7 AM EST Thursday 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.

&&

Hess/Nelson

PRELIMINARY LOCAL STORM REPORT
National Weather Service Jacksonville FL
438 AM EST WED JAN 03 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0418 AM     FREEZING RAIN    LAKE CITY               30.19N 82.64W
01/03/2018  U0.00 INCH       COLUMBIA           FL   PUBLIC

            PUBLIC REPORT OF RAIN STARTING TO FREEZE ON VEGETATION
            AND VEHICLES IN LAKE CITY. REPORT VIA SOCIAL MEDIA.

&&

BNELSON