Tornadoes · United States · Florida · 2018

EF0 tornado, Saint Johns County, Florida, July 23, 2018

Name: EF0 tornado, Saint Johns County, Florida, July 23, 2018
Start: 2018-07-23T18:40:00.000Z
Location: Saint Johns County, Florida

This EF0 tornado ran 0.0 miles across Saint Johns County on July 23, 2018, touching down at 2:40 PM EDT and reaching 25 yards wide. It killed nobody.

The rating scale

Tracks are drawn in the color of the rating. The Enhanced Fujita scale rates the damage rather than measuring the wind: the speeds are what that damage is taken to imply.

EF065 to 85 mphthis tornado
Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.
EF186 to 110 mph
Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.
EF2111 to 135 mph
Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.
EF3136 to 165 mph
Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.
EF4166 to 200 mph
Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.
EF5over 200 mph
Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.
Unrated
The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

The record

Rating: EF0
Date: July 23, 2018
Touchdown: 2:40 PM EDT (18:40 UTC)
Path length: 0.0 miles (0.0 km)
Path width: 25 yards (23 m)
Deaths: 0
Injuries: 0
County: Saint Johns County
Touchdown point: 30.050, -81.370
Lift-off point: 30.050, -81.370
Record number: 1807231240-01

The warnings

No tornado warning for this county appears in the archive as in force at the moment the tornado touched down.

Issued (UTC)	Expired	Product	Office
18:38 UTC	19:45 UTC	Marine Warning	JAX

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The forecast that day

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 15:58 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

What forecasters said that day

The local office's own words before the tornado touched down, 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 tornado touched down at Jul 23, 8:43 AM EDT, 5 hours 57 minutes earlier.

Area forecast discussion, Jul 23, 8:43 AM EDT, 5 hours 57 minutes before

Area Forecast Discussion
National Weather Service Jacksonville FL
843 AM EDT Mon Jul 23 2018

.UPDATE...Radar is clear this morning, while satellite shows
partly cloudy skies over the area. Upper system continues to
slowly spin over the forecast area, but with somewhat drier air
both at the surface with lower dew points, and aloft. Morning
soundings indicate atmosphere will not be nearly as unstable as
yesterday, but still unstable enough to support scattered convection
during the afternoon. High-res models suggest greater coverage
will be western areas with gulf sea breeze 18-21z...then over
eastern areas 21-00z. Have adjusted hourly POP/Weather grids to
show this evolution. Dry air aloft will support strong downdrafts.
0-6km winds a little weaker than yesterday, suggesting less
organized convection. Current high temperature forecast looks
good.

&&

.AVIATION...VFR conditions expected next 24 hours...except
locally lower conditions within scattered afternoon TSRA. Kept
just VCTS in 12z TAFs due to just scattered coverage...will
evaluate need for TEMPO TSRA in 18z TAFs. Best chance of
TSRA will be 18z-21z KGNV and 20z-00z for other TAF sites.

&&

.MARINE...South to southwest flow expected during the week with
enhanced southerly flow today due to low pressure inland. Latest
guidance suggests 15kt winds offshore component given forecast
pressure gradient...just below SCEC conditions. Otherwise, speeds
generally in the 10-15 knot range. Seas 2-4 ft will peak near 4-6
ft for the offshore waters by Tuesday night.

Rip Currents: A low end moderate risk today due to southeast wind
seas and onshore flow in the aftn. Similar conditions expected for
Tuesday.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  90  72  90  73 /  40  40  50  40
SSI  88  77  88  77 /  50  30  50  50
JAX  91  73  91  74 /  50  30  50  40
SGJ  88  75  89  74 /  40  30  60  40
GNV  91  73  90  74 /  50  30  50  30
OCF  89  73  88  74 /  50  30  50  40

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

Wolf/Kennedy

In the hours before

Local storm report, Jul 23, 11:06 AM EDT, 3 hours 34 minutes before

PRELIMINARY LOCAL STORM REPORT...SUMMARY
National Weather Service Jacksonville FL
1106 AM EDT MON JUL 23 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

1105 AM     TSTM WND GST     VILANO BEACH            29.94N 81.30W
07/22/2018  M40.00 MPH       ST. JOHNS          FL   MESONET

            A WEATHER FLOW SITE MEASURED A WIND GUST OF 40 MPH.

1215 PM     TSTM WND GST     5 W EAST PALATKA        29.66N 81.69W
07/22/2018  M41.00 MPH       Putnam             FL   AWOS

            PALATKA AIRPORT AWOS SITE MEASURED A WIND GUST OF 41 MPH.

1230 PM     HAIL             PALATKA                 29.65N 81.66W
07/22/2018  E0.75 INCH       PUTNAM             FL   BROADCAST MEDIA

            MEDIA RELAYED A REPORT OF BETWEEN 0.5 AND 1.0 INCH SIZE
            HAIL FALLING IN PALATKA FROM A PUBLIC CITIZEN.

1230 PM     TSTM WND DMG     EAST PALATKA            29.65N 81.60W
07/22/2018                   PUTNAM             FL   911 CALL CENTER

            MULTIPLE TREES FELL DOWN FROM HIGH WINDS AND CAUSED A
            POWERLINE TRANSFORMER TO BLOW OUT.

1251 PM     TSTM WND GST     4 SE SAINT AUGUSTINE    29.86N 81.26W
07/22/2018  M39.00 MPH       AMZ454             FL   C-MAN STATION

            CMAN SAUF1 MEASURED A GUST TO 39 MPH/34 KNOTS.

1258 PM     TSTM WND DMG     9 SSW BUNNELL           29.34N 81.31W
07/22/2018                   Flagler            FL   TRAINED SPOTTER

            TREE DOWN IN CODYS CORNER

0108 PM     TSTM WND GST     FLAGLER BEACH           29.47N 81.13W
07/22/2018  M42.00 MPH       FLAGLER            FL   TRAINED SPOTTER

            WIND GUST OF 42 MPH MEASURED AT FLAGLER BEACH.

0110 PM     TSTM WND DMG     1 WNW BUNNELL           29.47N 81.27W
07/22/2018                   Flagler            FL   TRAINED SPOTTER

            WIRES DOWN ALONG HARDY STREET IN BUNNELL

0130 PM     TSTM WND DMG     3 NNW GAINESVILLE       29.71N 82.35W
07/22/2018                   Alachua            FL   EMERGENCY MNGR

            REPORT FROM EMERGENCY MANAGER IN ALACHUA COUNTY OF
            MULTIPLE TREES DOWN AND POWER OUT AT NORTHSIDE PARK NEAR
            GAINESVILLE.

0144 PM     TSTM WND DMG     2 WNW MACCLENNY         30.29N 82.16W
07/22/2018                   Baker              FL   911 CALL CENTER

            REPORT OF A TREE DOWN ON A POWER LINE ON N COUNTY ROAD
            125 AND CREWS ROAD.

0203 PM     HAIL             5 WNW DOWNTOWN JACKSONV 30.37N 81.72W
07/22/2018  E1.00 INCH       Duval              FL   TRAINED SPOTTER

            REPORT FROM A TRAINED SPOTTER OF QUARTER SIZE HAIL
            FALLING IN A PARKING LOT.

0858 PM     HAIL             4 ENE WILLACOOCHEE      31.37N 82.99W
07/22/2018  M0.75 INCH       Atkinson           GA   911 CALL CENTER

            REPORT OF DIME SIZED HAIL ON 135 N. TIME ESTIMATED FROM
            RADAR.

0906 PM     TSTM WND DMG     4 S DOUGLAS             31.45N 82.85W
07/22/2018                   Coffee             GA   PUBLIC

            PUBLIC REPORT OF NUMEROUS TREES AND POWERLINES DOWN NEAR
            US 441 SOUTH OF DOUGLAS.

&&

AK

Special weather statement, Jul 23, 2:35 PM EDT, 5 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
235 PM EDT MON JUL 23 2018

FLZ125-133-231900-
Coastal St. Johns FL-Coastal Duval FL-
235 PM EDT MON JUL 23 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN ST. JOHNS AND
SOUTHEASTERN DUVAL COUNTIES UNTIL 300 PM EDT...

At 235 PM EDT, Doppler radar was tracking a strong thunderstorm over
Guana River State Park, or 12 miles northwest of Saint Augustine,
moving east at 10 mph.

Doppler radar has indicated weak rotation within this storm.
Tornadoes may develop with little or no advanced warning.

Locations impacted include...
Durbin, Nocatee, South Ponte Vedra, Guana River State Park and Vilano
Beach.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

Frequent cloud to ground lightning is occurring with this storm.
Lightning can strike 10 miles away from a thunderstorm. Seek a safe
shelter inside a building or vehicle.

&&

LAT...LON 2995 8144 2997 8145 3013 8148 3017 8132
      2994 8124
TIME...MOT...LOC 1835Z 263DEG 9KT 3005 8139

ELSENHEIMER

The air that afternoon

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

Jacksonville, FL (KJAX), 12:00Z

6.7 hours before the tornado, 59 km from the path. July 23, 2018.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km. RM and LM are the right and left moving storms Bunkers' method gives; the shaded area is the 0 to 1 km storm-relative helicity.

Mixed-layer CAPE: 314 J/kg
Mixed-layer CIN: -152 J/kg
Surface CAPE: 18 J/kg
Mixed-layer LCL: 1014 m above ground
0-6 km bulk shear: 21 kt
0-1 km bulk shear: 13 kt
0-1 km storm-relative helicity: 23 m²/s²
0-3 km storm-relative helicity: 18 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 4.2 K/km

Open this sounding in Storm Lab

Jacksonville, FL (KJAX), 00:00Z

5.3 hours after it, 59 km from the path. July 24, 2018.

Skew-T log-p

Temperature in red, dew point in green, the mixed-layer parcel dashed. The warm shading is its CAPE, the cool shading the inhibition it has to break through.

Hodograph

Mixed-layer CAPE: 1268 J/kg
Mixed-layer CIN: -37 J/kg
Surface CAPE: 1849 J/kg
Mixed-layer LCL: 1013 m above ground
0-6 km bulk shear: 19 kt
0-1 km bulk shear: 2 kt
0-1 km storm-relative helicity: 3 m²/s²
0-3 km storm-relative helicity: 35 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0
0-3 km lapse rate: 6.5 K/km

Open this sounding in Storm Lab

The surface observations

St Augustine Airpt (SGJ), 11 km from the path, in the two hours either side.

Time (UTC)	Temp (°F)	Dew point (°F)	Wind	Gust (kt)	Pressure (mb)	Weather
16:40 UTC			190° 4 kt		1010.2
16:45 UTC			210° 5 kt		1010.2
16:50 UTC			200° 5 kt		1010.2
16:55 UTC			230° 5 kt		1010.2
16:56 UTC	85	75	230° 5 kt		1010.2
17:00 UTC			180° 6 kt		1010.2
17:03 UTC	84.2	75.2	180° 6 kt		1010.2
17:05 UTC			210° 8 kt		1010.2
17:10 UTC			190° 5 kt		1010.2
17:15 UTC			220° 6 kt		1010.2
17:20 UTC			200° 7 kt		1009.8
17:25 UTC			210° 6 kt		1009.8
17:30 UTC			230° 5 kt		1009.5
17:31 UTC	87.8	75.2	220° 4 kt		1009.5
17:35 UTC			130° 6 kt		1009.5
17:39 UTC	87.8	75.2	130° 4 kt		1009.1
17:40 UTC			140° 3 kt		1009.1
17:45 UTC			170° 4 kt		1009.1
17:50 UTC			190° 5 kt		1009.1
17:55 UTC			200° 3 kt		1009.1
17:56 UTC	85	73	4 kt		1009.1
18:00 UTC			210° 5 kt		1009.1
18:05 UTC			90° 8 kt		1008.8
18:10 UTC			11 kt		1008.8
18:15 UTC			15 kt		1008.5
18:20 UTC			120° 13 kt		1008.8
18:24 UTC	86	75.2	110° 12 kt		1008.8	VCTS
18:25 UTC			13 kt		1008.8
18:30 UTC			140° 7 kt		1009.5
18:35 UTC			12 kt		1009.5
18:40 UTC			13 kt		1009.8
18:45 UTC			12 kt	17	1009.8	-RA
18:50 UTC			12 kt		1009.5	+RA
18:52 UTC	73.4	69.8	310° 12 kt	17	1009.5	TSRA
18:55 UTC			300° 8 kt		1009.8	-RA BR
18:56 UTC	73	69	300° 8 kt	17	1009.8	-TSRA BR
19:00 UTC			340° 8 kt		1009.8	RA BR
19:03 UTC	73.4	69.8	350° 9 kt		1009.8	VCTS -RA BR
19:05 UTC			350° 8 kt		1009.8	+RA BR
19:10 UTC			360° 8 kt		1009.8	+RA BR
19:15 UTC			10° 6 kt		1009.8	-RA BR
19:20 UTC			10° 5 kt		1009.5	-RA BR
19:21 UTC	75.2	71.6	360° 4 kt		1009.5	-RA BR
19:25 UTC			40° 5 kt		1009.5	-RA BR
19:30 UTC			100° 4 kt		1009.5	BR
19:32 UTC	77	71.6	4 kt		1009.1	VCTS HZ
19:35 UTC			40° 4 kt		1009.1	HZ
19:40 UTC			0° 0 kt		1009.1	HZ
19:45 UTC			0° 0 kt		1009.1	HZ
19:50 UTC			40° 3 kt		1009.1	HZ
19:55 UTC			0° 0 kt		1009.5	HZ
19:56 UTC	77	71	3 kt		1009.5	VCTS HZ
20:00 UTC			200° 7 kt		1009.5
20:05 UTC			190° 8 kt		1009.5	-RA
20:10 UTC			180° 8 kt		1009.5	-RA
20:15 UTC			160° 7 kt		1009.1	-RA BR
20:20 UTC			120° 7 kt		1009.1	-RA BR
20:25 UTC			110° 6 kt		1008.8	-RA BR
20:30 UTC			110° 5 kt		1008.8	-RA BR
20:30 UTC	75.2	71.6	110° 5 kt		1008.8	-RA BR
20:35 UTC			140° 8 kt		1009.1	BR

From the Iowa Environmental Mesonet's archive of airport observations.

The radar

The Jacksonville radar (KJAX), 58 km away, was scanning. The volume nearest the touchdown began at 18:40 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

What was reported nearby

Local storm reports within 60 km of the path, in the three hours either side.

Time (UTC)	Report	Where	County	Remark
18:40 UTC	TORNADO 0	3 Ssw Guana River State	St. Johns, FL	NWS STORM SURVEY...SUPPORTED BY A PUBLIC VIDEO OF THE EVENT...DETERMINED THAT A BRIEF EF-0 TORNADO TOUCHED DOWN ALONG RIO DEL NORTE ROAD ALONG THE INTRACOASTAL WATERWAY IN THE PALENCIA NEIGHBORHOOD ON MONDAY AFTERNOON. M

From the Iowa Environmental Mesonet's archive of National Weather Service local storm reports.

This ground now

The live radar over the track Every 2018 tornado in Florida Every tornado in Florida since 1950 Warnings in force in Florida now The forecast where you are

The other tornadoes of July 23, 2018

3 more were confirmed in the United States that day.

Date	Time	Rating	Where	Path (mi)	Width (yd)	Damage
July 23	1:25 PM EDT	EF0	Horry, SC	0.1	15	$500
July 23	2:15 PM EDT	EF1	Tioga, PA	2.1	100	$10,000
July 23	3:46 PM MDT	EF0	Park, CO	0.0	50

What this means

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

Sources

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.