A coastal trough formed offshore of the local Atlantic coast. Increasing onshore flow triggered coastal showers, with a couple of funnel clouds observed near and offshore of the NE Florida Atlantic coast in cumulus lines.
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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 coastal trough formed offshore of the local Atlantic coast. Increasing onshore flow triggered coastal showers, with a couple of funnel clouds observed near and offshore of the NE Florida Atlantic coast in cumulus lines.
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 Oct 1, 2:30 AM EST, 4 hours 7 minutes earlier.
Area Forecast Discussion
National Weather Service Jacksonville FL
330 AM EDT Fri Oct 1 2021
.NEAR TERM [Through Tonight]...
Patchy fog is possible across the interior towards daybreak and
again tonight, especially interior southeast Georgia.
The early morning pattern begins with an upper level trough
moving off the northeastern conus, an upper level ridge extending
from the northwestern Gulf of Mexico northeastward across the
Southeast and into the Tennessee and Ohio Valleys, and an upper
low over the Four Corners region. Weak upper ridging will prevail
over the area through tonight. At the surface, high pressure was
settled over the lower Great Lakes and into the Ohio Valley.
Surface high pressure will slowly southeastward to the coast of
North Carolina by Saturday morning. Major Hurricane Sam will pass
well east of our area today, and then east of Bermuda tonight.
An inverted coastal trough will develop before daybreak and then
move inland this afternoon. A weak backdoor frontal boundary will
also move across the coastal waters, leading to an increase in low
level moisture. Precipitable water values around 1 inch this
morning will slowly increase to 1.3-1.5 inches tonight, highest
along the east coast. Isolated to widely scattered showers are
forecast for the coastal waters today, and an isolated shower is
possible for coastal areas this morning and across the interior
this afternoon as the inverted coastal trough and east coast sea
breeze move inland. Widely scattered coastal showers are possible
overnight as the low level moisture continues to slowly increase
in the easterly onshore flow.
Highs today will be in the upper 80s across the interior and mid
80s at the beaches. Overnight lows will be in the mid 60s to
around 70 across the interior and the low to mid 70s at the
beaches.
.SHORT TERM [Saturday Through Sunday]...
The frontal boundary will push its way southward over NE FL on
Saturday and gradually diminish as high pressure sinks SE from
the Mid Atlantic states towards the waters just off of the Outer
banks of NC. This will cause convergent low level onshore flow to
persist and keep moisture levels elevated to around 1.5 inches of
PWAT that will support isolated to scattered shower coverage over
the area, especially over NE FL where the most measurable
rainfall is expected. Sunday, the high will move eastward from
near the Outer Banks of NC to the western Atlantic waters NE of
our area. Shower activity will be cut down as drier air rotates
around the surface high pressure and moves onshore from the
Atlantic. Breezier winds at the coast around 15-20 mph will be
lower on Sunday to 10 to 15 mph as the pressure gradient relaxes
over the region as high pressure weakens over the Atlantic on
Sunday.
Both days will feature slightly cooler temperatures at the coast
in the low 80s and warmer near seasonal values over inland areas
west of I-95 in the mid to upper 80s.
.LONG TERM [Monday Through Friday]...
A mid/upper level shortwave trough over the upper midwest and
western Great Lakes region will dive south and east Monday with
the base of the shortwave separating into a cutoff low and moving
south from the mouth of the Ohio river into the lower Mississippi
valley on Tuesday. Deep layer ridging east of the region over the
Atlantic waters will support surface high pressure ridge axis
from near Bermuda westward to the Carolina coast. This pattern
will keep onshore southeasterly flow over the area early next week
with moisture levels increasing again Monday into Tuesday as a
cold front moves east through the deep south and approaches our
area late Tuesday.
Wednesday, the cold front will stall as it moves over the area as
a weak surface low near the northern Bahamas moves northward
east of our coastal waters. Unstable SW flow aloft with embedded
shortwave energy will kick of scattered to numerous showers and
isolated to scattered storms Wednesday as winds veer from easterly
in the low levels to southwesterly in the mid levels. Some
increase in dynamics are possible as a wave of low pressure may
form along the stalled front raising 0-6km wind shear values to
around 30 knots which may elevate potential for strong to severe
storms Wednesday into Wednesday night over NE FL and SE GA. This
elevated threat for strong to severe thunderstorms may persist
into Thursday depending on the evolution of the cutoff mid/upper
level low which the GFS and ECMWF models are showing it to move
slowly ENE from the deep south towards the Carolina coast by
Thursday night which may push the previously stalled front
eastward, clearing our area sometime on Thursday. This timing
difference will need to be resolved in upcoming forecasts, but for
now will keep likely pops over most of area with isolated,
embedded storm coverage.
Temperatures during the period will begin near seasonal Monday
through Tuesday and then cool to below seasonal values Wednesday
and Thursday due to increased cloud cover and shower coverage.
&&
.AVIATION...
[Through 06Z Saturday]
Patchy inland fog is possible at KGNV and KVQQ around daybreak.
Otherwise, VFR conditions will prevail through the period. A weak
frontal boundary/coastal trough will move inland today, and a few
showers could get near the TAF sites today. Light winds the rest
of the night will become easterly around 10 knots during the day.
&&
.MARINE...
High pressure builds down the SE US coastline behind the frontal
boundary and east winds increase to 10 to 15 knots today and
continue through the weekend. Combined seas are forecast to build
to 5 to 7 feet on Saturday as the onshore flow combines with
swells from distant Hurricane Sam. Combined seas decrease early
next week as high pressure builds off the coast and long period
swells from Sam subside and low level winds become more southeast
at 10 to 15 knots.
Rip Currents: High risk of rip currents at the area beaches
through the weekend.
&&
.HYDROLOGY...
Minor flooding continues on the Satilla and Santa Fe River
basins into the weekend. Water levels will slowly fall due to the
recent dry spell.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 87 66 85 64 86 / 20 20 20 0 10
SSI 85 73 83 71 83 / 20 20 20 0 10
JAX 86 72 85 69 86 / 20 20 30 10 10
SGJ 85 73 84 71 84 / 20 20 30 10 20
GNV 88 68 86 66 87 / 20 10 30 0 10
OCF 90 70 88 67 88 / 10 10 30 0 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through late tonight for Coastal Duval-
Coastal Flagler-Coastal Nassau-Coastal St. Johns.
GA...High Rip Current Risk through late tonight for Coastal Camden-
Coastal Glynn.
AM...None.
&&The Jacksonville radar (KJAX), 117 km away, was scanning. The volume nearest the first event began at 11:38 UTC.
2 funnel cloud. Local standard time, as filed.
A funnel cloud was observed about 8-10 miles NE of north 16t Street in Flagler Beach. Pictures were relayed to NWS Jacksonville.
A funnel cloud was observed near Neptune Beach.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2021Every state in 2021This day in weather historyWarnings in Florida, October 2021
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: 985683, 985682.