Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 21, NWS Jacksonville, FL

March 18, 20214 counties in Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Mar 18, 2021, 3:57 PM EDT for 4 counties in Florida. It was in force for 36 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Mar 18, 2021, 3:57 PM EDT (19:57 UTC)
Expired
Mar 18, 2021, 4:33 PM EDT
In force
36 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon
Tornado
Possible
Hail
0.75 in
Wind
60.0 mph

Counties Baker County, FL, Bradford County, FL, Clay County, FL, Duval County, FL

The radar

The Jacksonville radar (KJAX), 30 km from the middle of the area, began a volume at 19:58 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
Mar 18, 11:42 AM EDTTornado WatchSPC6 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 8.0 hours before the alert went out and 32 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Jacksonville, FL at 12:00Z on 2021-03-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 162 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 12:00Z on 2021-03-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 183 square meters per square second.19395878Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
162 J/kg
Mixed-layer CIN
-183 J/kg
Mixed-layer LCL
888 m above ground
0-6 km bulk shear
58 kt
0-1 km storm-relative helicity
183 m²/s²
0-3 km storm-relative helicity
220 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.5

Open this sounding in Storm Lab

The text

As transmitted.

027 
WUUS52 KJAX 181957
SVRJAX
FLC003-007-019-031-182045-
/O.NEW.KJAX.SV.W.0021.210318T1957Z-210318T2045Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Jacksonville FL
357 PM EDT Thu Mar 18 2021

The National Weather Service in Jacksonville has issued a

* Severe Thunderstorm Warning for...
  Northeastern Bradford County in northern Florida...
  Southeastern Baker County in northeastern Florida...
  Northern Clay County in northeastern Florida...
  Duval County in northeastern Florida...

* Until 445 PM EDT.

* At 356 PM EDT, a severe thunderstorm was located near Maxville, or
  10 miles northwest of Middleburg, moving northeast at 55 mph.

  HAZARD...60 mph wind gusts. Possible tornado.

  SOURCE...Radar indicated.

  IMPACT...Expect damage to roofs, siding, and trees.

* Locations impacted include...
  Jacksonville, Orange Park, Starke, Jacksonville International Arpt,
  Mandarin, Arlington, Middleburg, Baymeadows, Cisco Gardens and
  Ortega.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 600 PM EDT for northern and
northeastern Florida.

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3015 8146 3012 8157 3013 8160 3012 8168
      3008 8168 2995 8212 3010 8216 3012 8214
      3014 8214 3014 8217 3017 8218 3032 8200
      3051 8179 3051 8178 3053 8176 3054 8174
      3056 8172
TIME...MOT...LOC 1956Z 225DEG 47KT 3011 8206 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

NELSON
4 follow-up statements
285 
WWUS52 KJAX 182003
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
403 PM EDT Thu Mar 18 2021

FLC003-007-182012-
/O.CAN.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Bradford FL-Baker FL-
403 PM EDT Thu Mar 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHEASTERN BRADFORD AND
SOUTHEASTERN BAKER COUNTIES IS CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 600 PM EDT for northern and
northeastern Florida.

LAT...LON 3012 8157 3013 8160 3012 8168 3008 8168
      3007 8169 2998 8203 3003 8205 3028 8205
      3056 8172 3015 8146
TIME...MOT...LOC 2002Z 246DEG 38KT 3007 8197 

$$

FLC019-031-182045-
/O.CON.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Clay FL-Duval FL-
403 PM EDT Thu Mar 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR NORTHERN CLAY AND DUVAL COUNTIES...

At 402 PM EDT, a severe thunderstorm was located near Middleburg,
moving northeast at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Jacksonville, Orange Park, Jacksonville International Arpt, Mandarin,
Arlington, Middleburg, Baymeadows, Cisco Gardens, Ortega and Oakleaf
Plantation.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 600 PM EDT for northern and
northeastern Florida.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3012 8157 3013 8160 3012 8168 3008 8168
      3007 8169 2998 8203 3003 8205 3028 8205
      3056 8172 3015 8146
TIME...MOT...LOC 2002Z 246DEG 38KT 3007 8197 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

AK
170 
WWUS52 KJAX 182023
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
423 PM EDT Thu Mar 18 2021

FLC019-182032-
/O.CAN.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Clay FL-
423 PM EDT Thu Mar 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHERN CLAY COUNTY IS
CANCELLED...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning has been cancelled.

A Tornado Watch remains in effect until 600 PM EDT for northeastern
Florida.

LAT...LON 3018 8168 3019 8168 3019 8182 3035 8197
      3056 8172 3024 8152
TIME...MOT...LOC 2022Z 225DEG 46KT 3022 8176 

$$

FLC031-182045-
/O.CON.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Duval FL-
423 PM EDT Thu Mar 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR CENTRAL DUVAL COUNTY...

At 422 PM EDT, a severe thunderstorm was located near
Bellair-Meadowbrook Terrace, or near Orange Park, moving northeast at
55 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Jacksonville, Jacksonville International Arpt, Arlington, Baymeadows,
Cisco Gardens, Ortega, Nas Jax, Normandy, San Marco and Riverside.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 600 PM EDT for northeastern
Florida.

Remain alert for a possible tornado! Tornadoes can develop quickly
from severe thunderstorms. If you spot a tornado go at once into the
basement or small central room in a sturdy structure.

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3018 8168 3019 8168 3019 8182 3035 8197
      3056 8172 3024 8152
TIME...MOT...LOC 2022Z 225DEG 46KT 3022 8176 

TORNADO...POSSIBLE
HAIL...<.75IN
WIND...60MPH
 
$$

AK
235 
WWUS52 KJAX 182030
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
430 PM EDT Thu Mar 18 2021

FLC031-182045-
/O.CON.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Duval FL-
430 PM EDT Thu Mar 18 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 445 PM EDT
FOR CENTRAL DUVAL COUNTY...

At 430 PM EDT, a severe thunderstorm was located over San Marco, or
near Jacksonville, moving northeast at 45 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

IMPACT...Expect damage to roofs, siding, and trees.

Locations impacted include...
Jacksonville, Arlington, Nas Jax, Ortega, Normandy, San Marco,
Riverside and Tallyrand.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Tornado Watch remains in effect until 600 PM EDT for northeastern
Florida.

A tornado watch remains in effect for the warned area. Tornadoes can
develop quickly from severe thunderstorms. Although a tornado is not
immediately likely, if one is spotted act quickly and move to a place
of safety inside a sturdy structure, such as a basement or small
interior room.

For your protection move to an interior room on the lowest floor of a
building.

Torrential rainfall is occurring with this storm, and may lead to
flash flooding. Do not drive your vehicle through flooded roadways.

&&

LAT...LON 3019 8172 3030 8177 3045 8165 3027 8154
      3020 8167 3019 8168
TIME...MOT...LOC 2030Z 235DEG 40KT 3028 8167 

HAIL...<.75IN
WIND...60MPH
 
$$

AK
819 
WWUS52 KJAX 182033
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
433 PM EDT Thu Mar 18 2021

FLC031-182043-
/O.CAN.KJAX.SV.W.0021.000000T0000Z-210318T2045Z/
Duval FL-
433 PM EDT Thu Mar 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR CENTRAL DUVAL COUNTY IS
CANCELLED...
                
The storm which prompted the warning has weakened below severe
limits, and no longer poses an immediate threat to life or property.
Therefore, the warning has been cancelled.  However gusty winds and
heavy rain are still possible with this thunderstorm.

A Tornado Watch remains in effect until 600 PM EDT for northeastern
Florida.

To report severe weather, contact your nearest law enforcement
agency. They will relay your report to the National Weather Service
Jacksonville.

LAT...LON 3019 8172 3030 8177 3045 8165 3027 8154
      3020 8167 3019 8168
TIME...MOT...LOC 2030Z 225DEG 47KT 3030 8164 

$$

AK

The office that day

Everything else NWS Jacksonville, FL issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Mar 18, 2:31 AM EDTWind AdvisoryJAXAlachua, Baker, Bradford, Duval, Flagler, Gilchrist and 4 more15 hr
Mar 18, 11:53 AM EDTSpecial Weather StatementJAXHamilton, Suwannee82 min
Mar 18, 12:55 PM EDTSpecial Weather StatementJAXGilchrist, Suwannee50 min
Mar 18, 1:16 PM EDTSpecial Weather StatementJAXHamilton29 min
Mar 18, 1:33 PM EDTSpecial Weather StatementJAXColumbia, Suwannee42 min
Mar 18, 1:41 PM EDTSevere Thunderstorm WarningJAXColumbia, Gilchrist, Suwannee49 min
Mar 18, 2:02 PM EDTSpecial Weather StatementJAXGilchrist43 min
Mar 18, 2:09 PM EDTSpecial Weather StatementJAXBaker, Bradford, Union66 min
Mar 18, 2:29 PM EDTSevere Thunderstorm WarningJAXAlachua, Gilchrist46 min
Mar 18, 2:40 PM EDTTornado WarningJAXAlachua, Gilchrist35 min
Mar 18, 2:58 PM EDTSevere Thunderstorm WarningJAXAlachua, Bradford, Union47 min
Mar 18, 3:07 PM EDTTornado WarningJAXAlachua, Bradford, Union23 min
Mar 18, 3:22 PM EDTSevere Thunderstorm WarningJAXBaker, Bradford, Clay, Duval, Union38 min
Mar 18, 3:40 PM EDTSpecial Weather StatementJAXDuval, Nassau50 min
Mar 18, 3:59 PM EDTSpecial Marine WarningJAX91 min
Mar 18, 4:10 PM EDTTornado WarningJAXClay, Duval11 min
Mar 18, 4:41 PM EDTSpecial Weather StatementJAXSaint Johns19 min
Mar 18, 4:49 PM EDTSpecial Weather StatementJAXCitrus56 min
Mar 18, 4:52 PM EDTSpecial Marine WarningJAX83 min
Mar 18, 5:31 PM EDTSpecial Weather StatementJAXDuval44 min
Mar 18, 6:07 PM EDTSpecial Weather StatementJAXDuval23 min
Mar 18, 6:10 PM EDTSpecial Marine WarningJAX2 hr
Mar 18, 7:09 PM EDTSpecial Weather StatementJAXSaint Johns51 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021Every severe thunderstorm warning in 2021

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.