Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 18, NWS Jacksonville, FL

March 18, 2021Alachua County, Gilchrist County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Mar 18, 2021, 2:29 PM EDT for Alachua County, Gilchrist County, Florida. It was in force for 46 min. 4 reports came from inside the area while it was in force.

The area

The outline as issued, with what was reported inside it.

The facts

Issued
Mar 18, 2021, 2:29 PM EDT (18:29 UTC)
Expired
Mar 18, 2021, 3:15 PM EDT
In force
46 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Alachua County, FL, Gilchrist County, FL

The radar

The Jacksonville radar (KJAX), 142 km from the middle of the area, began a volume at 18:29 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.

What was reported inside it

TimeReportWhereRemark
Mar 18, 2:41 PM EDTTSTM WND DMG6 Nnw Newberry, FLPOSSIBLE TORNADO DAMAGE. DAMAGE TO TRACTOR NEAR CR 337 & CR 232.
Mar 18, 2:46 PM EDTTORNADO6 Nnw Newberry, FLCORRECTS PREVIOUS TSTM WND DMG REPORT FROM 6 NNW NEWBERRY. BRIEF EF-0 TOUCHDOWN NEAR CR 337 & CR 232. BARN FELL ON A TRACTOR.
Mar 18, 3:05 PM EDTTORNADO1 Nnw Alachua, FLCORRECTS PREVIOUS TSTM WND DMG REPORT FROM 1 NNW ALACHUA. ROOF PEELED OFF CARPORT AND MULTIPLE TREES DOWN, ONE OF WHICH FELL ON AND DAMAGED A CAR. EF-0 DAMAGE, ESTIMATED 81 MPH.
Mar 18, 3:08 PM EDTTSTM WND DMG1 Nnw Alachua, FLPOSSIBLE TORNADO DAMAGE. ROOF TORN OFF HOME AND VEHICLE DAMAGED.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

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, 6.5 hours before the alert went out and 143 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.

119 
WUUS52 KJAX 181829
SVRJAX
FLC001-041-181915-
/O.NEW.KJAX.SV.W.0018.210318T1829Z-210318T1915Z/

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

The National Weather Service in Jacksonville has issued a

* Severe Thunderstorm Warning for...
  Gilchrist County in northern Florida...
  Western Alachua County in northern Florida...

* Until 315 PM EDT.

* At 229 PM EDT, a severe thunderstorm was located near Trenton,
  moving east at 40 mph.

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

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Trenton, Alachua, High Springs, Archer and Newberry. 

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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

&&

LAT...LON 2964 8296 2970 8296 2988 8243 2953 8240
      2956 8266 2957 8271 2957 8276 2958 8276
      2958 8286 2959 8286 2959 8296 2963 8297
TIME...MOT...LOC 1829Z 251DEG 36KT 2961 8287 

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

NELSON
1 follow-up statement
158 
WWUS52 KJAX 181911
SVSJAX

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

FLC001-041-181920-
/O.EXP.KJAX.SV.W.0018.000000T0000Z-210318T1915Z/
Gilchrist FL-Alachua FL-
311 PM EDT Thu Mar 18 2021

...THE SEVERE THUNDERSTORM WARNING FOR GILCHRIST AND WESTERN ALACHUA
COUNTIES WILL EXPIRE AT 315 PM EDT...
    
The severe thunderstorm which prompted the warning has moved out of 
the warned area. Therefore, the warning will be allowed to expire.

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

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

Remember, a Tornado Warning still remains in effect for Alachua 
County.

LAT...LON 2964 8296 2970 8296 2988 8243 2953 8240
      2956 8266 2957 8271 2957 8276 2958 8276
      2958 8286 2959 8286 2959 8296 2963 8297
TIME...MOT...LOC 1910Z 242DEG 50KT 2979 8254 

$$

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, 2:40 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, 3:57 PM EDTSevere Thunderstorm WarningJAXBaker, Bradford, Clay, Duval36 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; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.