A cold front shifted southward down the SE GA coast with convergence between this boundary and a weak trough and high moisture extending across the area on the east side of Hurricane Sally across the north central Gulf of Mexico. Stronger low level convergence and training bands of rainfall produced very high daily rainfall amounts of 5-8 across parts of Glynn county near Brunswick.
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 cold front shifted southward down the SE GA coast with convergence between this boundary and a weak trough and high moisture extending across the area on the east side of Hurricane Sally across the north central Gulf of Mexico. Stronger low level convergence and training bands of rainfall produced very high daily rainfall amounts of 5-8 across parts of Glynn county near Brunswick.
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 Sep 14, 8:23 PM EST, 2 hours 37 minutes earlier.
Area Forecast Discussion
National Weather Service Jacksonville FL
923 PM EDT Mon Sep 14 2020
...MINOR COASTAL FLOODING EXPECTED BY TUE EVENING...
.UPDATE...
A drier evening compared to recent days with drier low/mid level
air nosing across the area from the ENE keeping convection fairly
sparse and focus toward the Gulf Coast region on the eastern
periphery of Hurricane Sally.
Expect a few passing showers mainly west of Highway 301 through
the night, with more limited coverage toward the Atlantic coast
until more activity develops offshore and then approaches the
coast early tomorrow morning through sunrise where convergence
will increase between an approaching 'backdoor' front sliding SE
down the SE Atlantic coast and a trough axis across central FL
extending east of Sally, which will be pivoting northward through
the night. Scattered showers and isolated early morning storms
will focus along the local coast through daybreak, with locally
heavy rainfall potential and gusty winds. Latest Hi-Res guidance
indicates best potential for this band of early morning rainfall
will focus along the SE GA coast to north of St. Augustine.
Farther inland tonight, more drier air will let enable some
partial clearing with low stratus and shallow ground fog possible.
Temperatures will continue to trend above normal with low in the
mid/upper 70s to near 80 coast under partly to mostly cloudy
skies.
&&
.MARINE...
Easterly winds 10-15 kts tonight with elevated combined seas of
4-7 ft composed of swells running about 3-4 ft. Current advisory
looks on track for the outer waters, with NE wind surge increasing
over the GA waters into Tuesday afternoon with winds 15-20 kts.
Rip Currents: Long period easterly swells with 12-14 sec periods
and onshore flow will continue a high rip current risk Tuesday.
&&
.HYDROLOGY...
Water levels rising to Action Stage within the St. Johns River
basin with high tide this evening with the approach of the new
moon on the 17th, persistent onshore flow and seasonally high King
tides. By tomorrow evening, many locations along the local coast,
ICWW and St. Johns River basin are expected to rise into Minor
Flooding with tidal departures up to 2 ft MHHW (above normally dry
ground). A coastal flood advisory will likely be needed by
Tuesday.
These elevated water levels in concert with training bands of rainfall
within coastal convergent bands will pose an elevated concern for
localized flooding rainfall over the next 48 hrs due to poor drainage,
especially in our normally flood prone coastal areas including Brunswick,
JAX Beach & St. Augustine.
&&
.PREV DISCUSSION [748 PM EDT]...
.NEAR TERM [Through Tonight]...
A few outermost rain bands from Sally will continue rotate across
primarily our srn/wrn counties through early evening. Latest
guidance suggests a break in rain chances late evening through
pre-dawn hours, then new shower development over coastal waters
spreading toward our coastal counties mainly N of St. Johns around
dawn. Greatest coverage expected to be through 00z over interior
northeast FL counties into our southern interior se GA counties.
Low temperature forecast Tonight looks good.
.SHORT TERM [Tuesday through Wednesday Night]...
Interesting pattern sets up for Tue/Tue Night. As Sally approaches
the Gulf Coast, models show a NE flow surge coming down GA coast,
with weak low forming just offshore SE GA. A more E-to-W rain
band could set up over or just N of FL/GA border and put down
significant rain thru Tue Night...could see 1-3 inches of rain,
though likely not enough for any significant flooding threat.
May be some break, more scattered nature of showers, on Wed. By
Wed night, could see some eastern rainbands from Sally affect our
western counties as Sally moves over southern Alabama.
Somewhat cooler temperatures expected over Srn GA compared to Nrn FL.
High temperatures Tue/Wed should be in the lower-mid 80s Srn GA, with
mid-upper 80s to near 90 ne FL.
.LONG TERM [Thursday through Sunday]...
Tricky situation sets up this period. Sally works slowly northward
over Srn MS/AL Wed, with apparent boundary/pseudo-front setting
up ESE toward our SE GA coast to weak surface low off SE GA coast.
On Thursday/Thursday Night, this pseudo-front lifts N to Ctrl GA,
while what's left of Sally shifts more eastward along this
boundary to Ctrl GA. Could see some very slow moving bands of
heavy rain with this boundary and around what's left of Sally
extending into our wrn/nrn GA counties Thursday, possibly into
Friday. Its possible that a nearly stationary band sets up E/S of
Sally track...setting up over our wrn/nrn GA counties.
Another northeasterly surge comes down coast Saturday as high
pressure sets up well N of the area. This surge maintains itself
over our coastal counties through the weekend. Some guidance
suggesting potential for nearly stationary bands of heavy rain
setting up from coastal waters over our coastal counties around
JAX metro area or just S during the weekend. Given access to
tropical moisture from Sally, a significant flood threat could
develop. Will need to monitor this closely in later guidance
through the week.
Should see a cooldown in high temperatures from the 85-90 range
Thu/Fri to the upr 70s/lwr 80s Sat/Sun.
.AVIATION...
[Through 00Z Wednesday]
Prevailing VFR conditions this evening with TEMPO MVFR possible in
passing showers that could impact FL terminals over the next few
hours. Expect a general lull in rainfall potential around midnight
through the pre-dawn hours with some drier air in the mid levels
bringing partial clearing and enabling some patchy ground fog to
form through sunrise with MVFR conditions advertised at GNV, VQQ
and JAX through 12z. VCSH advertised for coastal terminals early
Tue morning under onshore flow. By afternoon, breezy NE winds expected
to push down the coast impacting SSI first with prevailing MVFR
ceilings and showers as weak trough axis slides southward down the
SE Atlantic coast. Best TS potential near GNV and VQQ mid-afternoon
where VCTS was advertised.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 74 84 72 82 73 / 10 80 40 70 40
SSI 79 84 77 84 77 / 30 90 70 80 50
JAX 76 87 75 86 75 / 30 90 50 80 40
SGJ 78 87 75 88 75 / 20 50 40 70 30
GNV 74 89 73 88 74 / 30 60 30 70 30
OCF 74 89 74 89 74 / 40 50 30 70 30
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...High Rip Current Risk through Tuesday evening for Coastal Duval-
Coastal Flagler-Coastal Nassau-Coastal St. Johns.
GA...High Rip Current Risk through Tuesday evening for Coastal Camden-
Coastal Glynn.
AM...Small Craft Advisory until 4 PM EDT Tuesday for 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 4 PM EDT Tuesday for Waters
from Altamaha Sound GA to Fernandina Beach FL from 20 to 60
NM.
&&The national radar mosaic for the moment the first event began.
4 heavy rain, 1 flood. Local standard time, as filed.
A mesonet site near Brunswick CW0041 measured a daily rain total of 5.41 inches as of 1605.
A Weather Underground Station measured 7.34 inches of daily rainfall.
A mesonet station CW0041 near Brunswick measured 7.21 inches of rainfall since late morning.
A Weather Underground station KGABRUNS52 measured 5.88 inches since 1300.
At 1710, Glynn County EM reported road closures due to flood water near Brunswick Golden Isles Airport including Canal Road and Georgia Spur 25. Several rain gauges near this area measured near 7 inches of rainfall thus far since midnight. Around 1748, the public submitted social media images of up to 6 inches of flood water covering yards and neighborhood streets near the Intersection of Gene Court and Jill Trace. The cost of flood damage was unknown and is likely greatly under-estimated for inclusion of this event in Storm Data.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Georgia in 2020Every state in 2020This day in weather historyWarnings in Georgia, September 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: 921573, 921575, 921576, 921574, 921572.