Alert archive / Florida / Severe Thunderstorm Warnings in 2021

Severe Thunderstorm Warning 11, NWS Jacksonville, FL

February 9, 2021Clay County, Duval County, Saint Johns County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Feb 9, 2021, 10:58 AM EST for Clay County, Duval County, Saint Johns County, Florida. It was in force for 32 min. 5 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: Feb 9, 2021, 10:58 AM EST (15:58 UTC)
Expired: Feb 9, 2021, 11:30 AM EST
In force: 32 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Tornado: Possible
Hail: 1.0 in
Wind: 50.0 mph

Counties Clay County, FL, Duval County, FL, Saint Johns County, FL

The radar

The Jacksonville radar (KJAX), 48 km from the middle of the area, began a volume at 15:59 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

Time	Report	Where	Remark
Feb 9, 11:02 AM EST	HAIL 0.5	4 Nw Middleburg, FL
Feb 9, 11:04 AM EST	HAIL 0.88	2 Nw Middleburg, FL	ABOUT 1.5 INCHES OF RAIN. REPORT RELAYED VIA SOCIAL MEDIA. RADAR ESTIMATED TIME.
Feb 9, 11:06 AM EST	HAIL 0.7	Middleburg, FL	RADAR ESTIMATED TIME. REPORT RELAYED VIA SOCIAL MEDIA.
Feb 9, 11:23 AM EST	HAIL 0.25	Fleming Island, FL	RADAR ESTIMATED TIME.
Feb 9, 11:25 AM EST	HAIL 0.75	4 Wsw Switzerland, FL	REPORT RELAYED VIA SOCIAL MEDIA. RADAR ESTIMATED TIME.

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, 4.0 hours before the alert went out and 49 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

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.

Mixed-layer CAPE: 636 J/kg
Mixed-layer CIN: -23 J/kg
Mixed-layer LCL: 523 m above ground
0-6 km bulk shear: 65 kt
0-1 km storm-relative helicity: 87 m²/s²
0-3 km storm-relative helicity: 68 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.5

Open this sounding in Storm Lab

The text

As transmitted.

552 
WUUS52 KJAX 091558
SVRJAX
FLC019-031-109-091630-
/O.NEW.KJAX.SV.W.0011.210209T1558Z-210209T1630Z/

BULLETIN - IMMEDIATE BROADCAST REQUESTED
Severe Thunderstorm Warning
National Weather Service Jacksonville FL
1058 AM EST Tue Feb 9 2021

The National Weather Service in Jacksonville has issued a

* Severe Thunderstorm Warning for...
  Northwestern St. Johns County in northeastern Florida...
  Northern Clay County in northeastern Florida...
  Southwestern Duval County in northeastern Florida...

* Until 1130 AM EST.

* At 1058 AM EST, a severe thunderstorm was located near Middleburg,
  moving east at 40 mph.

  HAZARD...Quarter size hail.

  SOURCE...Radar indicated.

  IMPACT...Damage to vehicles is expected.

* Locations impacted include...
  Orange Park, Green Cove Springs, Middleburg, Mandarin, Fruit Cove,
  Fleming Island, Baymeadows, Oakleaf Plantation, Bellair-Meadowbrook
  Terrace and Switzerland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2998 8204 3018 8204 3025 8156 2997 8152
TIME...MOT...LOC 1558Z 261DEG 36KT 3006 8199 

TORNADO...POSSIBLE
HAIL...1.00IN
WIND...<50MPH
 
$$

AK

3 follow-up statements

187 
WWUS52 KJAX 091608
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
1108 AM EST Tue Feb 9 2021

FLC019-031-109-091630-
/O.CON.KJAX.SV.W.0011.000000T0000Z-210209T1630Z/
St. Johns FL-Clay FL-Duval FL-
1108 AM EST Tue Feb 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 AM EST
FOR NORTHWESTERN ST. JOHNS...NORTHERN CLAY AND SOUTHWESTERN DUVAL
COUNTIES...

At 1108 AM EST, a severe thunderstorm was located over Middleburg,
moving east at 45 mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Orange Park, Green Cove Springs, Middleburg, Mandarin, Fruit Cove,
Fleming Island, Baymeadows, Oakleaf Plantation, Bellair-Meadowbrook
Terrace and Switzerland.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 2998 8192 3019 8197 3025 8156 2997 8152
TIME...MOT...LOC 1608Z 263DEG 37KT 3006 8185 

HAIL...1.00IN
WIND...<50MPH
 
$$

AK

569 
WWUS52 KJAX 091616
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
1116 AM EST Tue Feb 9 2021

FLC019-031-109-091630-
/O.CON.KJAX.SV.W.0011.000000T0000Z-210209T1630Z/
St. Johns FL-Clay FL-Duval FL-
1116 AM EST Tue Feb 9 2021

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 1130 AM EST
FOR NORTHWESTERN ST. JOHNS...NORTHEASTERN CLAY AND SOUTH CENTRAL
DUVAL COUNTIES...

At 1116 AM EST, a severe thunderstorm was located over Fleming
Island, or 7 miles northwest of Green Cove Springs, moving east at 40
mph.

HAZARD...Quarter size hail.

SOURCE...Radar indicated.

IMPACT...Damage to vehicles is expected.

Locations impacted include...
Orange Park, Green Cove Springs, Mandarin, Fruit Cove, Fleming
Island, Baymeadows, Oakleaf Plantation, Bellair-Meadowbrook Terrace,
Switzerland and Nas Jax.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

&&

LAT...LON 3025 8156 2998 8152 2997 8168 2998 8185
      3020 8188
TIME...MOT...LOC 1616Z 261DEG 36KT 3007 8175 

HAIL...1.00IN
WIND...<50MPH
 
$$

AK

872 
WWUS52 KJAX 091626
SVSJAX

Severe Weather Statement
National Weather Service Jacksonville FL
1126 AM EST Tue Feb 9 2021

FLC019-031-109-091636-
/O.EXP.KJAX.SV.W.0011.000000T0000Z-210209T1630Z/
St. Johns FL-Clay FL-Duval FL-
1126 AM EST Tue Feb 9 2021

...THE SEVERE THUNDERSTORM WARNING FOR NORTHWESTERN ST. JOHNS...
NORTHEASTERN CLAY AND SOUTH CENTRAL DUVAL COUNTIES WILL EXPIRE AT
1130 AM EST...
                
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 small hail
and heavy rain are still possible with this thunderstorm.

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

LAT...LON 3025 8156 2998 8152 2997 8168 2998 8185
      3020 8188
TIME...MOT...LOC 1626Z 261DEG 36KT 3008 8168 

$$

AK

The office that day

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

Issued	Product	Office	Counties	Lasted
Feb 9, 4:22 AM EST	Dense Fog Advisory	JAX	Alachua, Baker, Bradford, Duval, Flagler, Gilchrist and 3 more	6 hr
Feb 9, 4:25 AM EST	Marine Dense Fog Advisory	JAX		9 hr
Feb 9, 8:28 AM EST	Special Weather Statement	JAX	Baker	32 min
Feb 9, 8:47 AM EST	Special Weather Statement	JAX	Duval	43 min
Feb 9, 9:31 AM EST	Special Weather Statement	JAX	Columbia, Union	44 min
Feb 9, 10:11 AM EST	Special Weather Statement	JAX	Bradford, Union	49 min
Feb 9, 10:46 AM EST	Special Weather Statement	JAX	Duval	44 min
Feb 9, 11:27 AM EST	Special Weather Statement	JAX	Duval	33 min
Feb 9, 11:52 AM EST	Special Marine Warning	JAX		53 min
Feb 9, 11:54 AM EST	Special Weather Statement	JAX	Saint Johns	21 min
Feb 9, 12:18 PM EST	Special Marine Warning	JAX		87 min
Feb 9, 1:25 PM EST	Special Weather Statement	JAX	Baker	35 min

Nearby

Severe Thunderstorm Warnings in Florida, 2021 Every 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.