Alert archive / Florida / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 199, NWS Jacksonville, FL

August 17, 20184 counties in Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 17, 2018, 3:50 PM EDT for 4 counties in Florida. It was in force for 12 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued: Aug 17, 2018, 3:50 PM EDT (19:50 UTC)
Expired: Aug 17, 2018, 4:02 PM EDT
In force: 12 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
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), 46 km from the middle of the area, began a volume at 19:50 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 nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 7.8 hours before the alert went out and 48 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: 1013 J/kg
Mixed-layer CIN: -67 J/kg
Mixed-layer LCL: 870 m above ground
0-6 km bulk shear: 11 kt
0-1 km storm-relative helicity: 8 m²/s²
0-3 km storm-relative helicity: -8 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

What forecasters said that day

The local office's own words before this severe thunderstorm warning went out, 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 this severe thunderstorm warning went out at Aug 17, 9:22 AM EDT, 6 hours 28 minutes earlier.

Area forecast discussion, Aug 17, 9:22 AM EDT, 6 hours 28 minutes before

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In the hours before

Special weather statement, Aug 17, 2:40 PM EDT, 1 hour 10 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
240 PM EDT FRI AUG 17 2018

FLZ040-171915-
Marion FL-
240 PM EDT FRI AUG 17 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN MARION COUNTY UNTIL
315 PM EDT...

At 240 PM EDT, Doppler radar was tracking a strong thunderstorm near
Fort McCoy. This storm was nearly stationary.

Wind gusts of up to 40 can be expected along with frequent lightning.

Locations impacted include...
Fort McCoy and Burbank.

LAT...LON 2946 8201 2946 8178 2927 8178 2927 8201
TIME...MOT...LOC 1840Z 208DEG 2KT 2936 8189

MCGINNIS

Special weather statement, Aug 17, 2:59 PM EDT, 51 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
259 PM EDT FRI AUG 17 2018

FLZ036-171930-
Alachua FL-
259 PM EDT FRI AUG 17 2018

...SIGNIFICANT WEATHER ADVISORY FOR EAST CENTRAL ALACHUA COUNTY UNTIL
330 PM EDT...

At 258 PM EDT, Doppler radar was tracking a strong thunderstorm over
Newnans Lake, or 7 miles east of Gainesville, moving northwest at 10
mph.

Wind gusts up to 50 mph can be expected along with frequent
lightning.

Locations impacted include...
Gainesville, Gainesville Airport, Newnans Lake and University Of
Florida.

LAT...LON 2968 8212 2963 8213 2959 8219 2966 8241
      2982 8230
TIME...MOT...LOC 1858Z 112DEG 9KT 2966 8221

MCGINNIS

Special weather statement, Aug 17, 3:14 PM EDT, 36 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
314 PM EDT FRI AUG 17 2018

FLZ025-032-171945-
Inland Duval FL-Clay FL-
314 PM EDT FRI AUG 17 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN CLAY COUNTY UNTIL
345 PM EDT...

At 314 PM EDT, Doppler radar was tracking a strong thunderstorm near
Middleburg, moving northwest at 10 mph.

Wind gusts up to 50 mph can be expected along with locally heavy
rainfall.

Locations impacted include...
Middleburg, Doctors Inlet, Lakeside, Kingsley, Oakleaf Plantation,
Camp Blanding, Bellair-Meadowbrook Terrace, Penney Farms and Asbury
Lake.

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 3001 8175 2994 8187 2995 8205 3019 8205
      3019 8175
TIME...MOT...LOC 1914Z 137DEG 26KT 3003 8185

MCGINNIS

Special weather statement, Aug 17, 3:41 PM EDT, 9 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
341 PM EDT FRI AUG 17 2018

FLZ023-025-031-032-172015-
Inland Duval FL-Baker FL-Bradford FL-Clay FL-
341 PM EDT FRI AUG 17 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BRADFORD...
SOUTHEASTERN BAKER...NORTHWESTERN CLAY AND SOUTHWESTERN DUVAL
COUNTIES UNTIL 415 PM EDT...

At 340 PM EDT, Doppler radar was tracking a strong thunderstorm near
Maxville, or 7 miles northwest of Middleburg, moving north at 10 mph.

Wind gusts up to 50 mph can be expected along locally heavy rainfall.

Locations impacted include...
Middleburg, Macclenny, Glen St. Mary, Maxville, Baldwin and Lawtey.

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 3000 8199 2999 8208 3011 8215 3012 8214
      3014 8214 3014 8217 3026 8224 3031 8205
      3027 8205 3033 8198 3034 8196 3005 8188
TIME...MOT...LOC 1940Z 161DEG 24KT 3011 8202

MCGINNIS

Special weather statement, Aug 17, 3:44 PM EDT, 6 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
344 PM EDT FRI AUG 17 2018

FLZ032-033-172015-
Clay FL-Inland St. Johns FL-
344 PM EDT FRI AUG 17 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN ST. JOHNS AND
NORTHEASTERN CLAY COUNTIES UNTIL 415 PM EDT...

At 343 PM EDT, Doppler radar was tracking a strong thunderstorm near
Green Cove Springs, moving north at 10 mph.

Wind gusts up to 50 mph can be expected along with locally heavy
rainfall.

Locations impacted include...
Green Cove Springs, Fruit Cove, Fleming Island and Switzerland.

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 2993 8156 2994 8166 3012 8176 3013 8169
      3012 8168 3013 8163 3013 8160 3012 8157
      3012 8154 3010 8154 3010 8152 2996 8148
TIME...MOT...LOC 1943Z 163DEG 14KT 3001 8160

MCGINNIS

The office that day

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

Issued	Product	Office	Counties	Lasted
Aug 17, 2:35 PM EDT	Areal Flood Advisory	JAX	Marion	85 min
Aug 17, 2:40 PM EDT	Special Weather Statement	JAX	Marion	35 min
Aug 17, 2:59 PM EDT	Special Weather Statement	JAX	Alachua	31 min
Aug 17, 3:14 PM EDT	Special Weather Statement	JAX	Clay	31 min
Aug 17, 3:41 PM EDT	Special Weather Statement	JAX	Bradford	34 min
Aug 17, 3:44 PM EDT	Special Weather Statement	JAX	Clay	31 min
Aug 17, 3:54 PM EDT	Special Weather Statement	JAX	Duval	36 min
Aug 17, 3:57 PM EDT	Special Weather Statement	JAX	Alachua	33 min
Aug 17, 3:59 PM EDT	Special Weather Statement	JAX	Gilchrist	31 min
Aug 17, 4:01 PM EDT	Areal Flood Advisory	JAX	Duval	89 min
Aug 17, 4:08 PM EDT	Areal Flood Advisory	JAX	Gilchrist	97 min
Aug 17, 4:08 PM EDT	Special Weather Statement	JAX	Alachua	37 min
Aug 17, 4:11 PM EDT	Special Weather Statement	JAX	Duval	34 min
Aug 17, 4:23 PM EDT	Areal Flood Advisory	JAX	Alachua	82 min
Aug 17, 4:30 PM EDT	Severe Thunderstorm Warning	JAX	Alachua	13 min
Aug 17, 4:31 PM EDT	Special Weather Statement	JAX	Columbia	29 min
Aug 17, 4:34 PM EDT	Severe Thunderstorm Warning	JAX	Columbia, Gilchrist, Suwannee	26 min
Aug 17, 4:39 PM EDT	Severe Thunderstorm Warning	JAX	Columbia, Suwannee	16 min
Aug 17, 4:45 PM EDT	Areal Flood Advisory	JAX	Columbia, Gilchrist, Suwannee	90 min
Aug 17, 4:50 PM EDT	Special Weather Statement	JAX	Union	25 min
Aug 17, 4:53 PM EDT	Severe Thunderstorm Warning	JAX	Columbia, Union	20 min
Aug 17, 5:06 PM EDT	Special Weather Statement	JAX	Columbia	39 min
Aug 17, 5:12 PM EDT	Special Weather Statement	JAX	Putnam	33 min
Aug 17, 5:23 PM EDT	Areal Flood Advisory	JAX	Columbia	97 min
Aug 17, 5:26 PM EDT	Special Weather Statement	JAX	Columbia	34 min
Aug 17, 5:29 PM EDT	Severe Thunderstorm Warning	JAX	Nassau	46 min
Aug 17, 5:47 PM EDT	Areal Flood Advisory	JAX	Putnam, Saint Johns	88 min
Aug 17, 6:01 PM EDT	Areal Flood Advisory	JAX	Columbia	89 min
Aug 16, 8:22 PM EDT	Special Weather Statement	JAX	Pierce	23 min
Aug 16, 8:48 PM EDT	Special Weather Statement	JAX	Bacon	27 min
Aug 16, 9:34 PM EDT	Areal Flood Advisory	JAX	Appling, Bacon, Ware	86 min
Aug 16, 9:37 PM EDT	Areal Flood Advisory	JAX	Wayne	83 min
Aug 17, 5:09 PM EDT	Special Weather Statement	JAX	Charlton	36 min
Aug 17, 5:48 PM EDT	Special Weather Statement	JAX	Camden	42 min
Aug 17, 5:57 PM EDT	Special Weather Statement	JAX	Echols	33 min
Aug 17, 6:08 PM EDT	Special Weather Statement	JAX	Brantley	37 min
Aug 17, 6:15 PM EDT	Special Weather Statement	JAX	Clinch	30 min
Aug 17, 6:36 PM EDT	Special Weather Statement	JAX	Ware	39 min
Aug 17, 6:43 PM EDT	Special Weather Statement	JAX	Wayne	32 min
Aug 17, 6:52 PM EDT	Special Weather Statement	JAX	Ware	38 min
Aug 17, 7:01 PM EDT	Severe Thunderstorm Warning	JAX	Ware	29 min
Aug 17, 7:03 PM EDT	Areal Flood Advisory	JAX	Ware	87 min
Aug 17, 7:05 PM EDT	Areal Flood Advisory	JAX	Ware	85 min
Aug 17, 7:11 PM EDT	Special Weather Statement	JAX	Glynn	19 min
Aug 17, 7:20 PM EDT	Special Weather Statement	JAX	Pierce	25 min
Aug 17, 7:27 PM EDT	Areal Flood Advisory	JAX	Glynn, Wayne	93 min
Aug 17, 7:32 PM EDT	Areal Flood Advisory	JAX	Pierce	88 min
Aug 17, 7:33 PM EDT	Areal Flood Warning	JAX	Ware	117 min
Aug 17, 7:42 PM EDT	Special Weather Statement	JAX	Wayne	48 min

Nearby

Severe Thunderstorm Warnings in Florida, 2018 Every severe thunderstorm warning in 2018

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.