A strong pre-frontal squall line crossed the local area during the afternoon and into the early evening. Despite the limited instability, strong bulk shear of 50-60 kts and a strong low level jet produced widespread wind damage as a squall line crossed the local area.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS JAX wrote it up.
A strong pre-frontal squall line crossed the local area during the afternoon and into the early evening. Despite the limited instability, strong bulk shear of 50-60 kts and a strong low level jet produced widespread wind damage as a squall line crossed the local area. Wind gusts of 45-66 mph produced widespread tree and power line damage. Three QLCS tornadoes produced damage across NE FL where better surface based instability occurred during the afternoon ahead of the squall line.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Jacksonville, FL wrote its last area forecast discussion before the first event at Dec 24, 5:54 AM EST, 16 minutes earlier.
Area Forecast Discussion
National Weather Service Jacksonville FL
554 AM EST Thu Dec 24 2020
.AVIATION...
[Through 12Z Friday]
A strong cold front will pass across all sites today bringing a
brief period of thunderstorm activity with the associated squall
line. VFR conditions will continue through morning with a mix of low
and high clouds passing overhead on strengthening prefrontal
south/southwesterly flow. Gusty southerly winds will develop by
16/17z today with gusts up to 30 knots ahead of the front with a
leading line of thunderstorms will race across the region from WNW
to ESE between 21z/03z. Stronger thunderstorms will be capable of 40-
50 knot gusts. Brief MVFR to near IFR VSBY/CIG reductions are
possible with the squall line. Trailing stratiform showers will
persist behind the front as winds/gusts shift westerly. Conditions
will quickly improve late tonight.
&&
.PREV DISCUSSION [423 AM EST]...
.NEAR TERM [Through Christmas Eve]...
A strong cold front extending from a deepening surface centered in
the Great Lakes region is sliding eastward across the across the
Gulf states this morning. This frontal system, supported by a
dynamic, highly-amplified mid-level trough, will progress eastward
today and be accompanied by a strong line of thunderstorms along its
leading edge, with a few severe storms possible. The front and
associated storms are expected to reach the far western zones this
afternoon (between 4-5 PM) then race across the area, exiting into
the Atlantic late during the evening hours (9-11 PM).
Prior to the fronts arrival, surface and lower-tropospheric wind
fields will strengthen in response to pressure falls to the north.
Southerly surface winds will increase late this morning with speeds
ranging 15-25 mph and gusts between 25-35 mph; meanwhile, deep-layer
shear will also increase across the area to around 50-60 kts. Though
shear will be more than sufficient for organized convection along
the cold front, instability will be on the weaker side (classic high
CAPE/low shear scenario). These environments can favor a few
enhanced bowing segments capable of producing severe winds up to 60
MPH along the broader line of thunderstorms. Less pronounced storms
and showers will also be capable of strong gusts up to 50 MPH due
momentum transfer of stronger winds aloft.
Temperatures will be very warm for late December this afternoon with
highs reaching the low 70s across SE GA and the mid/upper 70s across
NE FL. Don't let the warmth fool you...big changes are on the way
tonight, with temperatures dropping nearly 35-40 degrees from the
afternoon highs as an arctic airmass surges in behind the front.
This cold blast will lead to a freeze tonight for the inland
counties and near-freezing temperatures (mid 30s) elsewhere,
including the beach communities. With winds remaining elevated,
frost development will be limited and wind chills will fall just
above wind chill advisory criteria - the low/mid 20s.
.SHORT TERM [Christmas Day through Saturday Night]...
The base of a deep and cold trough will pivot across our region on
Christmas Day, with breezy westerly winds adding to the chill that
will be over our region. High temperatures for the day will mostly
occur at midnight, with temperatures plunging into the 30s by sunrise
area-wide. Wind chill values during the morning hours will remain in
the mid to upper 20s across southeast GA and around or just below
freezing in northeast and north central FL. Despite full sunshine,
cold air advection will keep highs in the mid to upper 40s for
locations along and north of Interstate 10, with lower 50s expected
in north central FL. Wind chill values will remain in the 30s to
perhaps around 40 all afternoon long in southeast GA and the 40s
elsewhere as westerly winds remain sustained in the 15-25 mph range
with occasional gusts to 30-35 mph from the late morning through the
mid-afternoon hours.
An arctic dome of high pressure will build over the FL panhandle late
on Friday night, allowing our local pressure gradient to gradually
loosen from west to east. Confidence is high enough to issue a Hard
Freeze Watch for most inland locations, where cold air advection and
diminishing winds after midnight will allow lows to fall into the mid
20s. This will likely be the first hard freeze for some inland
locations in northeast and north central since January 2018, which is
almost three years ago! Widespread frost will likely extend into
coastal locations, although winds will likely remain sustained in the
5-10 mph range at the immediate coast through sunrise on Saturday,
which could limit frost formation at area beaches somewhat. However,
confidence is high enough to include all coastal locations and the
sensitive agricultural locations of inland St. Johns and Flagler
Counties in a Freeze Watch at this time. Wind Chills will also likely
dip to the lower 20s at area beaches overnight.
Deep troughing will exit the U.S. eastern seaboard on Saturday morning,
with a deep and dry northwesterly flow pattern prevailing locally. Thin
cirrus will likely invade our skies shortly after sunrise, but despite
filtered sunshine and lighter northwesterly winds, highs will likely
struggle to reach 50 degrees at most locations, with a few lower 50s in
north central FL. Radiational cooling is expected on Saturday night as high
pressure gradually weakens and stretches out along the southeastern seaboard
and cirrus departs our area. Another long duration freeze is expected at all
inland locations, and Hard Freeze criteria may be met yet again for
locations west of I-95. Widespread frost is more likely at coastal areas as
winds become calm early in the evening.
.LONG TERM [Sunday through New Year's Eve]...
Temperatures will moderate on Sunday and Monday as another trough pivots
eastward from the Plains States across the Ohio Valley and Great Lakes
region, leaving a dry zonal flow pattern along the northern Gulf coast
and Deep South. High pressure will continue to extend its axis along
the southeastern seaboard, but low level flow will veer to southeasterly
by Sunday afternoon, possibly advecting marine stratocumulus onshore
along the I-95 corridor in northeast FL. Highs will generally rebound to
the 55-60 degree range on Sunday, except lower 60s in north central FL.
These temperatures are still about 5 degrees below late December climatology.
Low level flow will veer to southwesterly locally downstream of a weak
cold front that will be entering the southeastern states. However, the
lingering dry air mass and loose pressure gradient may again allow
radiational cooling to occur, with lows falling to the 30s for inland
locations north of I-10, along with some patchy frost potential. Warm
air advection will otherwise keep lows in the 40s. Deep-layer flow will
then veer to westerly on Monday as the moisture-starved frontal boundary
stalls over our region by the evening hours. Highs will climb to the mid
and upper 60s on Monday and Tuesday, with lows moderating through the
40s inland and remaining in the 50s for coastal northeast FL as low level
flow becomes onshore due to strong high pressure building into the Ohio
Valley.
Deep troughing progressing through the Rockies and the Desert Southwest
on Tuesday night will allow ridging aloft to take shape locally by
midweek. Strong surface ridging will shift off the Mid-Atlantic coast,
and a coastal trough may develop over our near shore waters that could
begin to generate isolated showers by Wednesday afternoon. Meanwhile,
low pressure emerging from the lee side of the Rockies on Tuesday night
will deepen over the Upper Midwest on Wednesday and will accelerate
towards the western Great Lakes, propelling another potentially strong
cold front eastward into the lower Mississippi Valley by Wednesday evening.
The coastal trough will lift northward as a warm front, with shower
coverage increasing along this boundary on Wednesday night over southeast
GA. Showers and thunderstorms will then sweep across our area along and
ahead of the cold front on New Year's Day, with highs warming back into the
70s for most locations.
.MARINE...
A strong, fast-moving cold front approaching from the west will
reach the coastal waters this evening bringing a line of
thunderstorms with it, some of which may be strong. The back edge of
the frontal squall line should exit the coastal waters by midnight.
Southerly winds will strengthen today ahead of the front resulting
in Small Craft Advisory conditions by mid morning. Winds will shift
offshore behind the front and remain strong through most of
Christmas Day. Frequent gusts to Gale force are possible across the
offshore waters with the strong winds ahead of and behind the front.
Winds will gradually subside and conditions will improve by Saturday
as cold high pressure builds from west.
RIP CURRENTS: NE FL - High Risk Today; Moderate Risk Friday
SE GA - Moderate Risk Today; Low Risk Friday
.FIRE WEATHER...
Breezy southerly transport winds early this morning will rapidly
strengthen shortly after sunrise and will shift to southwesterly
by the mid-afternoon hours ahead of a squall line of strong to
severe thunderstorms that will move quickly east-southeastward
across our region during the late afternoon and early evening
hours. Light southerly surface winds around sunrise will become
breezy by the late morning hours, with windy conditions expected
this afternoon area-wide that will create high dispersion values.
A much colder and drier air mass will then plunge into our region
overnight, with gusty westerly surface and transport winds on
Friday creating marginally high dispersion values area-wide.
Minimum relative humidity values will fall to near 30 percent on
Friday and Saturday afternoons. A Hard Freeze Watch has been
issued for most inland locations in southeast GA, northeast and
north central FL for Friday night and early Saturday morning, with
a Freeze Watch in effect for all coastal locations. Widespread
frost is expected nearly area-wide on Friday and Saturday nights.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 72 31 44 24 47 / 80 70 0 0 0
SSI 73 35 47 29 49 / 90 90 0 0 0
JAX 76 34 48 26 49 / 90 90 0 0 0
SGJ 77 35 50 31 50 / 30 80 0 0 0
GNV 76 33 51 26 50 / 90 90 0 0 0
OCF 78 36 52 27 51 / 60 80 0 0 0
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Freeze Watch from late tonight through Friday morning for Baker-
Bradford-Eastern Alachua-Gilchrist-Hamilton-Inland Nassau-
Northern Columbia-Southern Columbia-Suwannee-Union-Western
Alachua.
Hard Freeze Watch from late Friday night through Saturday
morning for Baker-Bradford-Central Marion-Clay-Eastern
Alachua-Eastern Marion-Gilchrist-Hamilton-Inland Duval-
Inland Nassau-Northern Columbia-Putnam-Southern Columbia-
Suwannee-Union-Western Alachua-Western Marion.
Freeze Watch from late Friday night through Saturday morning for
Coastal Duval-Coastal Flagler-Coastal Nassau-Coastal St.
Johns-Inland Flagler-Inland St. Johns.
High Rip Current Risk from 10 AM EST this morning through this
evening for Coastal Duval-Coastal Flagler-Coastal Nassau-
Coastal St. Johns.
GA...Freeze Watch from late tonight through Friday morning for
Appling-Atkinson-Bacon-Brantley-Clinch-Coffee-Echols-Inland
Camden-Inland Glynn-Jeff Davis-Northeastern Charlton-
Northern Ware-Pierce-Southern Ware-Wayne-Western Charlton.
Hard Freeze Watch from late Friday night through Saturday
morning for Appling-Atkinson-Bacon-Brantley-Clinch-Coffee-
Echols-Inland Camden-Inland Glynn-Jeff Davis-Northeastern
Charlton-Northern Ware-Pierce-Southern Ware-Wayne-Western
Charlton.
Freeze Watch from late Friday night through Saturday morning for
Coastal Camden-Coastal Glynn.
AM...Small Craft Advisory from 10 AM this morning to 7 PM EST this
evening 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 from 7 AM to 10 PM EST Friday 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 PM this evening to 7 AM EST Friday 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 from 10 AM this morning to 1 PM EST Friday
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.
&&The Jacksonville radar (KJAX), 51 km away, was scanning. The volume nearest the first event began at 11:07 UTC.
26 thunderstorm wind, 3 tornado. Local standard time, as filed.
A large pine tree was blown onto power lines at 9848 County Road 139 in Glen St. Mary.
Trees were blown down between Branford and Lake City.
A tree was blown down onto a home which caused major damage. Injuries were not reported.
Multiple trees were blown down in Lake City.
Numerous trees were reported south of County Road 232. The time of damage was based on radar.
A tree branched punctured a home wall in Lake Butler due to strong winds. No injuries were reported.
A large tree was blown down with a lot of tree debris as well as roof shingles at a condo complex near UF. The time of damage was based on radar.
A tree was blown down onto power lines at 6288 Chestnut Road and at 6238 George Hodges Road. The time of damage was based on radar.
A weak tornado touched down just SW of Stark around 6:16 pm. The vortex damaged trees, fences, and roofs on manufactured homes along its 4 mile path. Four people were displaced on Christmas Eve by the tornado. Two people were taken to the hospital as a precaution and later released. The tornado was 100 yards at its widest point with peak winds of 105 mph.
A tree was blown down across State Road 121 near the Baker-Union county line.
A tree was blown down across State Road 121 at 13490 N SR 121 near the weigh station. It blocked both lanes. A car crashed into the tree, but no injuries occurred. Occupants were trapped inside due to a power line on the vehicle.
A tree fell down through a residence at 60 Milton Street. No injuries were reported.
Power lines and trees were blown down at 12417 N State Road 121. Power lines were also blown down across State Road 121. The time of damage was based on radar.
A power line was blown down and hanging in the parking lot at 391 West Macclenny Ave.
Multiple trees and power lines were blown down in East Hampton. Holiday decor was blown out of yards.
Multiple trees and power lines were blown down in Melrose. A large tree was blown down and blocked Price Road near the solar plant.
Just before 7 pm, at QLCS tornado touched down just south of I-295 in Mandarin from the shore of the St. Johns River near Tacito Trail and ended near Scott Circle East. The tornado damaged trees and caused minor damage to the roof of one home due to a tree falling on it. Another tree fell on a transformer which caused it to blow out and ignite the tree on fire. The tornado had peak winds of 105 mph.
A tree was blown down near Southside and I-295.
Several trees were blown down in the Bardin area. The time of damage was based on radar.
Shortly before 7 pm on Christmas Eve, a QLCS tornado touched down just south of Baymeadows Blvd in the Baymeadows Subdivision. The tornado damaged trees. Peak winds were estimated at 105 mph.
A power line was blown down across the road south of Green Cove Springs.
A small tree was blown down near Southside and Interstate 95.
A light pole was blown down in the Winn-Dixie parking light in Baymeadows.
A large tree was blown down on Central Parkway, just north of the UNF Campus.
A power sports dealer in East Palatka suffered roof damage from strong winds. The cost of damage was unknown and estimated for inclusion in Storm Data. The time of damage was based on radar.
A tree was blown down at Seagate Lane and Puryear Street.
A tree was blown down across the road on US-1 in St. Augustine. A car hit the downed tree. No injuries were reported.
Major wind damage to homes occurred in Starke and families are displaced. Possible tornado damage.
A tree was blown down on Fellowship Drive in Palm Coast. The time of damage was bsed on radar. The cost of damage was estimated.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2020Every state in 2020This day in weather historyThe tornado archive for Florida, 2020Warnings in Florida, December 2020
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 928603, 928399, 928400, 928402, 928401, 928403, 928404, 928602, 928427, 928405, 928406, 928621, 928622, 928623, 928407, 928408, 928616, 928409, 928599, 928619, 928410, 928411, 928412, 928413, 928601, 928414, 928415, 928418, 928417.