6 inches across much of the area except for a lingering high plume of 2 inches across parts of NE FL. This moisture combined with a weak east coast sea breeze triggered scattered to numerous storms across the I-95 corridor, St Johns River Basin and US 301 corridor in the afternoon and evening.
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 transition to a drier airmass in the mid/upper levels occurred with precipitable water amounts (PWAT) falling to 1.2-1.6 inches across much of the area except for a lingering high plume of 2 inches across parts of NE FL. This moisture combined with a weak east coast sea breeze triggered scattered to numerous storms across the I-95 corridor, St Johns River Basin and US 301 corridor in the afternoon and evening. Warm temperatures/weak lapse rates limited severe storm potential, but a few strong storms with wet downbursts did produce some damage.
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 Jul 11, 12:12 PM EST, 1 hour 17 minutes earlier.
Area Forecast Discussion
National Weather Service Jacksonville FL
112 PM EDT Sat Jul 11 2020
.AVIATION...
[Through 18Z Sunday]
Not much different in the thinking from the morning Aviation update.
with drier air coming in off the Continental U.S. and the upper
level trough axis centered over the KJAX AOR most convection
should be suppressed and what does form will move east-southeast
toward the coast. With high temperatures in the upper 90s expect a
few short lived storms will develop but at this point not
widespread enough to warrant more than a VCTS remark in the TAFs.
&&
.PREV DISCUSSION [732 AM EDT]...
.NEAR TERM [Through Sunday]...
Today...Trof axis ahead of frontal boundary and moisture available
in the atmosphere is still kicking off scattered showers and a
few storms over inland areas of NE FL/SE GA early this morning and
these should mostly fade by the mid morning hours. While this will
be a transition day in the upper levels of the atmosphere as drier
airmass pushes southward into inland SE GA, at the surface a hot
and humid west to northwest flow will quickly push temps into the
90s by mid-day and combined with humid airmass and dewpoints into
the mid/upper 70s this will push Heat Indices/Feels Like values
into the 107-111 degree range for most of the region and have
posted Heat Advisory for all of NE FL and most of SE GA, with only
a few counties across inland SE GA where some drier surface air
will mix dewpoints into the upper 60s and keep HI values closer to
105 degrees through the afternoon hours. The afternoon rainfall
forecast is a bit tougher as the transition to a drier airmass at
the mid/upper levels with Precipitable Water Amounts (PWATs)
falling to 1.2-1.6 inches across inland SE GA will basically shut
down convection there while across NE FL PWATS remaining closer to
2 inches and the weak East Coast Sea Breeze pushing inland will
once again trigger scattered to numerous storms across the I-95
corridor, St Johns River Basin and US 301 corridors. Temps still
too warm aloft to support severe storms but slow movement to
storms will continue locally heavy rainfall as the main threat.
Tonight...Drier Airmass aloft with trof axis at the surface will
bring PWATs down to the 1.0-1.5 range and this will lead to a
drier night with mostly clear skies developing. Drier airmass will
allow for Min Temps in the lower 70s across inland SE GA and
mid/upper 70s elsewhere.
Sunday...Mid level trof/dry airmass with widespread PWATs less
than 1.5 inches area-wide will basically shut down convection and
make for very hot conds with widespread temps into the mid/upper
90s, but enough of the drier airmass will mix down dewpoints into
the 60s and this should keep Heat Index/Feels Like values closer
to 105 degrees and slightly lower than Heat Advisory criteria.
Models suggesting only widely scattered showers/storms across
Flagler/Putnam/Marion counties during the afternoon hours.
.SHORT TERM [Sunday Night through Tuesday]...
Drier conditions caused by the settling air mass on Sunday will
result in fewer storms and showers for the remainder of the
weekend. Convection will become more widespread on Monday with
numerous thunderstorms forming ahead of a somewhat ragged frontal
boundary, with storms continuing overnight into early Tuesday
morning. High temperatures on Sunday are expected to reach up into
the upper 90s, close to 100 degrees, but with the lower humidity
levels keeping heat index values near 105 degrees. Temperatures
will be slightly lower on Monday and Tuesday, with highs in the
mid to upper 90s, but the heat index values will be much closer to
110 degrees due to the increase in moisture levels.
.LONG TERM [Wednesday Through Friday]...
Upper level ridging will start to build in by midweek leading to
a less organized surface wind field, making daily afternoon
convection become more driven by the diurnal sea breeze for the
remainder of the week. Temperatures will be slightly above the
seasonal average, reaching into the lower to mid 90s. Overnight
low temperatures will be in the mid to lower 70s.
.MARINE...
A trof axis will remain north of the waters along the SE US coast
through early next week and this continue a mainly offshore flow
at 10-15 knots with seas 2-4 ft. Local onshore sea breeze along
the coast during the afternoon hours.
Rip Currents: Low Risk continues in the mostly offshore flow
through the weekend with surf mainly 1-2 feet.
&&
.PRELIMINARY POINT TEMPS/POPS...
AMG 71 96 75 95 75 / 10 0 20 60 20
SSI 79 90 78 94 77 / 20 20 10 30 30
JAX 75 98 75 98 75 / 20 20 10 30 20
SGJ 76 95 75 95 75 / 20 20 0 20 20
GNV 74 95 73 95 75 / 30 10 10 30 20
OCF 75 95 74 93 75 / 30 20 0 20 10
&&
.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Heat Advisory until 6 PM EDT this evening for Baker-Bradford-
Central Marion-Clay-Coastal Duval-Coastal Flagler-Coastal
Nassau-Coastal St. Johns-Eastern Alachua-Eastern Marion-
Gilchrist-Hamilton-Inland Duval-Inland Flagler-Inland
Nassau-Inland St. Johns-Northern Columbia-Putnam-Southern
Columbia-Suwannee-Union-Western Alachua-Western Marion.
GA...Heat Advisory until 6 PM EDT this evening for Brantley-Clinch-
Coastal Camden-Coastal Glynn-Echols-Inland Camden-Inland
Glynn-Northeastern Charlton-Northern Ware-Pierce-Southern
Ware-Wayne-Western Charlton.
AM...None.
&&The Jacksonville radar (KJAX), 113 km away, was scanning. The volume nearest the first event began at 18:29 UTC.
2 thunderstorm wind, 1 heavy rain. Local standard time, as filed.
Small tree limbs were blown down with minor street flooding observed at Florida Park Drive and Palm Coast Parkway. The cost of damage was unknown, but estimated for Storm Data.
A tree fell on a home which caused roof damage near Fischer Lane and Flamingo Drive. The cost of damage was unknown but it was estimated for inclusion of the event in Storm Data.
The EM reported 1.79 inches was measured in 30 minutes in the Bulow area.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Florida in 2020Every state in 2020This day in weather historyWarnings in Florida, July 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: 897655, 897656, 897654.