Tropical Storm in Florida, August 2 to 4, 2020

Name: Tropical Storm in Florida, August 2 to 4, 2020
Start: 2020-08-02T04:00
End: 2020-08-04T05:00
Location: Florida

August 2 to 4, 2020 · NWS JAX · 4 events in 4 counties and zones

Isaias tracked offshore of the local forecast area through the day August 3rd. Occasional rainbands moved onshore over the local area through the day with gusts of 20-40 mph.

Where it happened

Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
Crop damage: None recorded
Events: 4

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.

What happened

The episode as NWS JAX wrote it up.

Isaias tracked offshore of the local forecast area through the day August 3rd. Occasional rainbands moved onshore over the local area through the day with gusts of 20-40 mph.

What forecasters said that day

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 Aug 2, 12:24 AM EST, 3 hours 36 minutes earlier.

Area forecast discussion, Aug 2, 12:24 AM EST, 3 hours 36 minutes before

Area Forecast Discussion
National Weather Service Jacksonville FL
124 AM EDT Sun Aug 2 2020

.AVIATION...
[Through 06Z Monday]

Easterly winds will increase through the day as Tropical Storm Isaias
begins to approach the region from the south. All TAF sites could
have afternoon wind gusts around 20 kts. Gusts subside inland in
the evening but continue for coastal TAF sites (SGJ, CRG, SSI).
Winds and gusts at SGJ will continue to increase through the night
with Isaias. Some scattered showers and storms will come ashore
after 12Z first at the coast at CRG and SGJ then move inland and
north towards SSI. Have VCTS at all TAF sites after 15/16Z as
daytime heating enhances convection. MVFR ceilings are expected
as showers come ashore ahead of Tropical Storm Isaias as it gets
closer to the regional TAF sites.

&&

.PREV DISCUSSION [854 PM EDT]...

.Near Term.../through Tonight/...

As a ridge of high pressure moves north over forecast area, an
area of convergence has developed across forecast area roughly
along a line from around Lake City to Brunswick. The combination
of diurnal heating and this convergence will result in increased
convective chances near this line. Elsewhere isolated coverage
expected. With loss of daytime heating, convection will diminish
this evening. The ridge will slowly move to the north through
Tonight.

Temperatures will be near normal Tonight.

.Short Term.../Sunday through Monday/...

Hurricane Isaias is expected to affect region during this time
period. Headlines are in effect with respect to Isaias. Refer to
National Hurricane Center for updated track and timing
information.

At this time greatest impacts with this system expected to be at the
coast with surge, beach erosion, winds, and heavy rain. Flooding
also possible along the St Johns river basin, and intracoastal due
to storm surge.

Temperatures will trend near normal inland, and below normal near
the coast due to expected rainfall coverage.

.Long Term.../Monday night through Saturday/...

As the tropical system tracks further to the northeast Monday night,
surface high pressure will build to the southeast. The high will
build to the east Tuesday. This pattern will yield an increasingly
moist southerly flow. With the increased moisture scattered to
numerous storms will initiate with diurnal heating in the late
morning through the afternoon. This pattern will then persist
through Friday, with day time precipitation chances running above
normal. A trough of low pressure is expected to settle across the
southeastern US on Saturday, as the high sinks to the southeast with
numerous afternoon storms anticipated.

Temperatures will trend near to a little seasonal average this
period.

.Marine...

High pressure ridge will move north of the region through Tonight.
Area waters will be affected by Hurricane Isaias during the Sunday
to Monday timeframe. Headlines are in effect for this storm. High
pressure will build to the east southeast Tuesday into Wednesday.

Rip Currents: SE GA: High Risk through the weekend
              NE FL: High Risk through the weekend

&&

.PRELIMINARY POINT TEMPS/POPS...

AMG  95  75  91  73  95 /  20  30  60  20  30
SSI  89  79  88  77  92 /  50  70  70  40  40
JAX  91  77  91  75  96 /  50  70  70  30  40
SGJ  88  76  89  75  92 /  70  80  70  30  50
GNV  92  75  91  75  95 /  50  50  60  20  50
OCF  91  76  91  76  95 /  60  40  60  30  50

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...Tropical Storm Watch for Coastal Duval-Coastal Nassau-Inland
     Duval-Inland Nassau.

     High Rip Current Risk through late Monday night for Coastal
     Duval-Coastal Flagler-Coastal Nassau-Coastal St. Johns.

     Coastal Flood Advisory from 8 AM this morning to 2 AM EDT
     Tuesday for Clay-Coastal Duval-Coastal Nassau-Inland Duval-
     Putnam.

     Storm Surge Watch for Coastal Flagler-Coastal St. Johns.

     Tropical Storm Warning for Clay-Coastal Flagler-Coastal St.
     Johns-Inland Flagler-Inland St. Johns-Putnam.

GA...Tropical Storm Watch for Coastal Camden-Coastal Glynn-Inland
     Camden-Inland Glynn.

     High Rip Current Risk through late Monday night for Coastal
     Camden-Coastal Glynn.

     Coastal Flood Advisory from 8 AM this morning to 2 AM EDT
     Tuesday for Coastal Camden-Coastal Glynn.

AM...Hurricane Warning for Coastal waters from Fernandina Beach to
     St. Augustine FL out 20 NM-Coastal waters from St.
     Augustine to Flagler Beach FL out 20 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.

     Hurricane Watch for Coastal waters from Altamaha Sound to
     Fernandina Beach FL out 20 NM-Waters from Altamaha Sound GA
     to Fernandina Beach FL from 20 to 60 NM.

&&

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

4 tropical storm. Local standard time, as filed.

Tropical Storm, Coastal St. Johns

When: August 2, 4:00 AM EST to August 4, 4:00 AM EST
Where: Coastal St. Johns forecast zone
Reported by: Official NWS Observations

TS Isaias tracked north, offshore of the local coast. Broken rain bands moved onshore with brief squalls. At 5:27 am on 8/3, the AWOS at St. Augustine airport measured a peak wind of 21 mph from the north. A peak gust of 32 mph from the NNE was measured at 5:59 am. The St. Augustine C-Man station measured peak winds at 6:10 am with sustained 33 mph and a gust to 41 mph. Rainfall was minimal across the area with measured totals 1.02 inches at a few locations across western parts of the county per a CoCoRaHS station. Otherwise, rainfall was less than 1 inch with several areas near St. Augustine measuring around 0.50 inches. Storm surge was up to 2 ft inundation, most locations were 1.5 ft above dry ground or less. The only damage reported was from the National Park Service who stated that there was minor beach erosion at Fort Matanzas.

Tropical Storm, Coastal Duval

When: August 2, 4:00 AM EST to August 4, 5:00 AM EST
Where: Coastal Duval forecast zone
Reported by: Official NWS Observations
Coordinates: 30.335, -81.648 (the zone’s center; the record gives no point)

Tropical Storm Isaias tracked northward and remained offshore of the local Atlantic coast and produced with broken squalls moving onshore over the local area. Impacts to the county were minimal and confined to the immediate coast where Jacksonville Beach lost about 5 feet of sand in some locations. The peak wind across the county was measured with a WeatherFlow mesonet station at Jacksonville Beach Pier and was sustained 35 mph with a peak gust of 41 mph on Aug. 3rd at 3:27 pm. Gusts in squalls generally ranged between 30-40 mph elsewhere across the county. Rainfall was minimal and the peak value across the county was measured at the NWS Jacksonville office of 0.53 inches. Peak storm surged was 1.44 ft above ground level (MHHW) at Mayport on Aug 3rd at 9:54 pm. The surge reached 1.23 ft MHHW at the Dames Point Bridge at 11 pm on Aug 3rd. Within the St Johns River basin peak surge reach 0.88 ft MHHW at the Southbank Riverwalk in downtown Jacksonville on Aug 3rd at 11:45 pm and 0.80 ft MHHW at the Buckman Bridge on Aug 4th at 12:45 am.

Tropical Storm, Coastal Nassau

When: August 2, 4:00 AM EST to August 4, 4:00 AM EST
Where: Coastal Nassau forecast zone
Reported by: Official NWS Observations
Coordinates: 30.611, -81.771 (the zone’s center; the record gives no point)

Minimal impacts occurred to the county. The peak wind measured at the Fernandina Beach AWOS was 20 mph with a gust to 29 mph on Aug. 3rd at 2:35 pm. Measured rainfall was less than 0.50 inches across the county. The peak surge at Fernandina Beach was 1.59 ft MHHW on Aug. 3rd at 10:18 pm.

Tropical Storm, Coastal Flagler

When: August 2, 4:00 AM EST to August 4, 4:00 AM EST
Where: Coastal Flagler forecast zone
Reported by: Official NWS Observations
Coordinates: 29.471, -81.293 (the zone’s center; the record gives no point)

There was no significant damage to the county. The peak wind gust was 41 mph at the Marineland WeatherFlow station on August 3rd at 3:23 am. Peak measured storm total rainfall was 0.63 inches about 1 mile SE of Flagler Beach by a COCORaHS observer. Peak storm surge was 1.22 ft MHHW at Mantanzas River Bings Landing on August 4th at 1 am.

What these are

Tropical Storm: A tropical cyclone with sustained winds of 34 to 63 knots (39 to 73 mph).

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Florida in 2020 Every state in 2020 This day in weather history Warnings in Florida, August 2020 The 2020 hurricane season

Sources

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: 907777, 908141, 908160, 908164.