Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 151, NWS Jacksonville, FL

August 23, 2021Charlton County, Georgia; Duval County, Nassau County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 23, 2021, 1:39 PM EDT for Charlton County, Georgia; Duval County, Nassau County, Florida. It was in force for 36 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
Aug 23, 2021, 1:39 PM EDT (17:39 UTC)
Expired
Aug 23, 2021, 2:15 PM EDT
In force
36 min
Issued by
NWS Jacksonville, FL
Area
Storm-based polygon
Hail
0.75 in
Wind
60.0 mph

Counties Duval County, FL, Nassau County, FL, Charlton County, GA

The radar

The Jacksonville radar (KJAX), 18 km from the middle of the area, began a volume at 17:39 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
Aug 23, 2:00 PM EDTTSTM WND DMG2 Ese Ratliff, FLDELAYED REPORT OF POWER LINE DOWN AT 13941 NEW KINGS RD.
Aug 23, 2:00 PM EDTTSTM WND DMG5 Sse Hilliard, FLDELAYED REPORT OF TREE DOWN AT OLD DIXIE HWY AND BETHEL CHURCH RD. RADAR ESTIMATED TIME.
Aug 23, 2:10 PM EDTTSTM WND GST 48Jacksonville Internatio, FLWIND GUST OF 48 MPH RECORDED AT THE JACKSONVILLE INTERNATIONAL AIRPORT.
Aug 23, 2:23 PM EDTTSTM WND DMG7 Nw Yulee, FLDELAYED REPORT OF TREE DOWN ALONG I-95 SOUTHBOUND AT MILE MARKER 377.

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

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 5.7 hours before the alert went out and 18 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 2021-08-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1299 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 2021-08-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -30 square meters per square second.193958Sfc1 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
1299 J/kg
Mixed-layer CIN
-34 J/kg
Mixed-layer LCL
823 m above ground
0-6 km bulk shear
10 kt
0-1 km storm-relative helicity
-30 m²/s²
0-3 km storm-relative helicity
-27 m²/s²
Significant tornado parameter
0.0
Supercell composite
-1.0

Open this sounding in Storm Lab

The text

As transmitted.

125 
WUUS52 KJAX 231739
SVRJAX
FLC031-089-GAC049-231815-
/O.NEW.KJAX.SV.W.0151.210823T1739Z-210823T1815Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Jacksonville FL
139 PM EDT Mon Aug 23 2021

The National Weather Service in Jacksonville has issued a

* Severe Thunderstorm Warning for...
  Nassau County in northeastern Florida...
  Central Duval County in northeastern Florida...
  Southeastern Charlton County in southeastern Georgia...

* Until 215 PM EDT.

* At 139 PM EDT, a severe thunderstorm was located near Bryceville,
  or 10 miles southwest of Callahan, moving east at 35 mph.

  HAZARD...60 mph wind gusts.

  SOURCE...Radar indicated.

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

* Locations impacted include...
  Jacksonville, Hilliard, Callahan, Jacksonville International Arpt,
  Cisco Gardens, Nassau Village-Ratliff, Ratliff, St. George,
  Bryceville and Whitehouse Air Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Large hail and damaging winds and continuous cloud to ground
lightning is occurring with this storm. Move indoors immediately.
Lightning is one of nature's leading killers. Remember, if you can
hear thunder, you are close enough to be struck by lightning.

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

&&

LAT...LON 3032 8168 3034 8205 3036 8205 3036 8207
      3037 8213 3036 8217 3068 8211 3075 8169
      3074 8168 3075 8168 3075 8167
TIME...MOT...LOC 1739Z 269DEG 30KT 3045 8196 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NELSON
2 follow-up statements
741 
WWUS52 KJAX 231757
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
157 PM EDT Mon Aug 23 2021

GAC049-231807-
/O.CAN.KJAX.SV.W.0151.000000T0000Z-210823T1815Z/
Charlton GA-
157 PM EDT Mon Aug 23 2021

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

LAT...LON 3032 8168 3034 8205 3036 8205 3037 8204
      3044 8204 3047 8202 3052 8202 3056 8201
      3060 8201 3061 8203 3065 8204 3069 8204
      3075 8171 3074 8168 3075 8167 3074 8167
TIME...MOT...LOC 1757Z 260DEG 20KT 3048 8190 

$$

FLC031-089-231815-
/O.CON.KJAX.SV.W.0151.000000T0000Z-210823T1815Z/
Nassau FL-Duval FL-
157 PM EDT Mon Aug 23 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 215 PM EDT
FOR NASSAU AND CENTRAL DUVAL COUNTIES...

At 157 PM EDT, a severe thunderstorm was located near Ratliff, or
near Callahan, moving east at 25 mph.

HAZARD...60 mph wind gusts.

SOURCE...Radar indicated.

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

Locations impacted include...
Jacksonville, Hilliard, Callahan, Jacksonville International Arpt,
Cisco Gardens, Nassau Village-Ratliff, Ratliff, Bryceville and
Whitehouse Air Field.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

Continuous cloud to ground lightning is occurring with this storm.
Move indoors immediately. Lightning is one of nature's leading
killers. Remember, if you can hear thunder, you are close enough to
be struck by lightning.

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

&&

LAT...LON 3032 8168 3034 8205 3036 8205 3037 8204
      3044 8204 3047 8202 3052 8202 3056 8201
      3060 8201 3061 8203 3065 8204 3069 8204
      3075 8171 3074 8168 3075 8167 3074 8167
TIME...MOT...LOC 1757Z 260DEG 20KT 3048 8190 

HAIL THREAT...RADAR INDICATED
MAX HAIL SIZE...<.75 IN
WIND THREAT...RADAR INDICATED
MAX WIND GUST...60 MPH

$$

NELSON
944 
WWUS52 KJAX 231808
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
208 PM EDT Mon Aug 23 2021

FLC031-089-231818-
/O.EXP.KJAX.SV.W.0151.000000T0000Z-210823T1815Z/
Nassau FL-Duval FL-
208 PM EDT Mon Aug 23 2021

...THE SEVERE THUNDERSTORM WARNING FOR NASSAU AND CENTRAL DUVAL
COUNTIES WILL EXPIRE AT 215 PM EDT...
                
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 will be allowed to expire.  However gusty
winds and heavy rain are still possible with this thunderstorm.

LAT...LON 3032 8168 3034 8205 3036 8205 3037 8204
      3044 8204 3047 8202 3052 8202 3056 8201
      3060 8201 3061 8203 3065 8204 3069 8204
      3075 8171 3074 8168 3075 8167 3074 8167
TIME...MOT...LOC 1808Z 269DEG 30KT 3048 8181 

$$

HESS

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 23, 2:04 PM EDTSpecial Weather StatementJAXCamden26 min
Aug 23, 2:32 PM EDTSpecial Weather StatementJAXCamden28 min
Aug 23, 3:07 PM EDTSpecial Weather StatementJAXGlynn23 min
Aug 23, 3:21 PM EDTSpecial Weather StatementJAXBrantley39 min
Aug 23, 3:32 PM EDTSpecial Weather StatementJAXGlynn28 min
Aug 23, 3:51 PM EDTAreal Flood WarningJAXGlynn84 min
Aug 23, 4:09 PM EDTSpecial Weather StatementJAXWayne36 min
Aug 23, 4:47 PM EDTSpecial Weather StatementJAXWayne58 min
Aug 23, 5:07 PM EDTAreal Flood WarningJAXWayne113 min
Aug 23, 5:31 PM EDTSpecial Weather StatementJAXCoffee29 min
Aug 23, 6:12 PM EDTSpecial Weather StatementJAXCoffee63 min
Aug 23, 6:46 PM EDTAreal Flood WarningJAXCoffee119 min
Aug 23, 12:57 PM EDTSpecial Weather StatementJAXBaker48 min
Aug 23, 1:25 PM EDTSpecial Weather StatementJAXNassau50 min
Aug 23, 1:42 PM EDTSpecial Marine WarningJAX93 min
Aug 23, 2:06 PM EDTSpecial Weather StatementJAXDuval, Nassau39 min
Aug 23, 2:14 PM EDTSpecial Weather StatementJAXClay46 min
Aug 23, 2:15 PM EDTSpecial Weather StatementJAXMarion30 min
Aug 23, 2:48 PM EDTSpecial Weather StatementJAXMarion27 min
Aug 23, 3:03 PM EDTSpecial Marine WarningJAX87 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021Severe Thunderstorm Warnings in Georgia, 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.