Alert archive / Florida / Severe Thunderstorm Warnings in 2018

Severe Thunderstorm Warning 95, NWS Jacksonville, FL

June 15, 2018Clay County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Jun 15, 2018, 5:40 PM EDT for Clay County, Florida. It was in force for 23 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: Jun 15, 2018, 5:40 PM EDT (21:40 UTC)
Expired: Jun 15, 2018, 6:03 PM EDT
In force: 23 min
Issued by: NWS Jacksonville, FL
Area: Storm-based polygon
Hail: 1.0 in
Wind: 60.0 mph

County Clay County, FL

The radar

The Jacksonville radar (KJAX), 58 km from the middle of the area, began a volume at 21:40 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

Tallahassee Rgnl, FL (KTLH), launched 12:00Z, 9.7 hours before the alert went out and 239 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: 375 J/kg
Mixed-layer CIN: -29 J/kg
Mixed-layer LCL: 839 m above ground
0-6 km bulk shear: 6 kt
0-1 km storm-relative helicity: 20 m²/s²
0-3 km storm-relative helicity: 10 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 Jun 15, 4:59 PM EDT, 41 minutes earlier.

Area forecast discussion, Jun 15, 4:59 PM EDT, 41 minutes before

Area Forecast Discussion
National Weather Service Jacksonville FL
459 PM EDT Fri Jun 15 2018

.NEAR TERM.../Tonight and Saturday/

High pressure ridge over southern Florida continues to dictate the
predominant flow for the region as being out of the west/southwest
boosting the west coast sea breeze. A mid level low pressure
pressure system over Alabama and southwestern Georgia is helping
to maintain moisture in the low and mid levels north of I-10 and a
small line of storms has developed over the panhandle and is
following the flow into southeastern Georgia this afternoon.
Scattered storms are expected to develop with diurnal heating
throughout the day, with the west coast seabreeze reaching across
to just east of I-95, converging with the eastern sea breeze and
producing storms along the east coast, with some stronger storms
with heavy rainfall and gusty winds possible. Storms and showers
will dissipate and move off to the east after midnight.

The flow on Saturday will continue to be westerly but will be much
weaker than today's which will lead to the diurnal seabreeze
convergence taking place further inland about midway between the
eastern and western sides of the CWA. Convective activity can
potentially continue into the late evening as the frontal boundary
moves across the region, with thunderstorms persisting past
midnight.

.SHORT TERM.../Sunday through Monday/...

Winds will become more easterly over the course of the day on
Sunday which will result in the developing diurnal convection
developing earlier along the east coast and moving to the west
coast by late evening.

For Monday, high pressure will be building in from the east across
the forecast area behind the weak front which will produce more
isolated convection along the Atlantic seabreeze as it moves
inland.

.LONG TERM.../Tuesday night through Friday/...

High pressure will become more dominant as a ridge builds across
the region on Monday and Tuesday, suppressing convective
development again to just limited storms along the seabreezes.
Storm potential will increase on Wednesday and Thursday a low
pressure moves into the area, resulting in noticeably higher
temperatures ahead of the front and much stronger convective
growth through Friday.

&&

.AVIATION...
VFR conditions expected next 24 hours, except locally lower conditions
associated with TSRA. Greatest TSRA coverage expected to be
southern GA and I-10 corridor of ne FL...included a TEMPO for
TSRA in the 20z-00z period for the TAF sites along and N of
I-10....kept VCTS for KGNV/KSGJ and will monitor radar for TAF
updates.

&&

.MARINE...
A cold front will be moving south across area waters on Saturday
and through Saturday night. High pressure will build to the
northeast Sunday, then to the east early next week. Relatively low
winds and seas are expected over the next few days. Transition to
onshore flow will occur on Sunday and continues into early next
week.

Rip Currents: Light to Moderate risks of rip currents, with the
stronger currents more likely Sunday afternoon and evening.

&&

.PRELIMINARY POINT TEMPS/POPS...
AMG  72  89  72  90 /  20  30  30  40
SSI  76  86  76  86 /  40  20  20  20
JAX  73  91  74  89 /  40  20  20  30
SGJ  73  88  74  86 /  40  20  20  30
GNV  71  91  72  88 /  20  40  40  40
OCF  71  91  72  89 /  20  40  30  50

&&

.JAX WATCHES/WARNINGS/ADVISORIES...
FL...None.
GA...None.
AM...None.
&&

Corless/Elsenheimer/Bricker

In the hours before

Special weather statement, Jun 15, 5:05 PM EDT, 35 minutes before

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Special weather statement, Jun 15, 5:13 PM EDT, 27 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
513 PM EDT FRI JUN 15 2018

FLZ031-032-152200-
Bradford FL-Clay FL-
513 PM EDT FRI JUN 15 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHEASTERN BRADFORD AND
NORTHWESTERN CLAY COUNTIES UNTIL 600 PM EDT...

At 513 PM EDT, Doppler radar was tracking a strong thunderstorm near
Kingsley, or near Starke, moving east at 15 mph.

Excessive cloud-to-ground lightning and wind gusts of 45 to 55 mph
can be expected along with possible minor damage.

Locations impacted include...
Starke, Middleburg, Kingsley, Oakleaf Plantation, Camp Blanding,
Penney Farms, Lawtey and Asbury Lake.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2988 8211 3011 8214 3018 8182 2990 8176
TIME...MOT...LOC 2113Z 259DEG 13KT 2999 8206

HESS

Special weather statement, Jun 15, 5:14 PM EDT, 26 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
514 PM EDT FRI JUN 15 2018

FLZ033-037-038-133-138-152200-
Coastal Flagler FL-Coastal St. Johns FL-Putnam FL-Inland Flagler FL-
Inland St. Johns FL-
514 PM EDT FRI JUN 15 2018

...SIGNIFICANT WEATHER ADVISORY FOR FLAGLER...SOUTHEASTERN ST. JOHNS
AND EAST CENTRAL PUTNAM COUNTIES UNTIL 600 PM EDT...

At 514 PM EDT, Doppler radar was tracking a strong thunderstorm over
Andalusia, moving east at 15 mph.

Nickel size hail and wind gusts of 45 to 55 mph can be expected along
with possible minor damage.

Locations impacted include...
Palm Coast, Bunnell, Crescent City, East Palatka, Andalusia, San
Mateo and Espanola.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2943 8112 2941 8115 2939 8116 2937 8142
      2940 8142 2940 8143 2938 8145 2937 8148
      2966 8162 2976 8127
TIME...MOT...LOC 2114Z 259DEG 13KT 2948 8143

HESS

Local storm report, Jun 15, 5:19 PM EDT, 21 minutes before

PRELIMINARY LOCAL STORM REPORT
National Weather Service Jacksonville FL
519 PM EDT FRI JUN 15 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND GST     1 E FORT CAROLINE       30.39N 81.48W
06/15/2018  M41 MPH          Duval              FL   MESONET

            A WEATHER FLOW SITE MEASURED A PEAK WIND GUST OF 41
            KNOTS.

&&

RBRICKER

Local storm report, Jun 15, 5:21 PM EDT, 19 minutes before

PRELIMINARY LOCAL STORM REPORT...CORRECTED
National Weather Service Jacksonville FL
521 PM EDT FRI JUN 15 2018

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0440 PM     TSTM WND GST     1 E FORT CAROLINE       30.39N 81.48W
06/15/2018  M41.00 MPH       Duval              FL   MESONET

            A WEATHER FLOW SITE MEASURED A PEAK WIND GUST OF 41 MPH.

&&

RBRICKER

Special weather statement, Jun 15, 5:23 PM EDT, 17 minutes before

Special Weather Statement
National Weather Service Jacksonville FL
523 PM EDT FRI JUN 15 2018

FLZ036-152200-
Alachua FL-
523 PM EDT FRI JUN 15 2018

...SIGNIFICANT WEATHER ADVISORY FOR NORTHWESTERN ALACHUA COUNTY UNTIL
600 PM EDT...

At 523 PM EDT, Doppler radar was tracking a strong thunderstorm over
Alachua, or 10 miles southwest of Worthington Spring, moving east at
10 mph.

Wind gusts of 40 to 50 mph can be expected along with possible minor
wind damage.

Locations impacted include...
Gainesville, Alachua, High Springs, University Of Florida and La
Crosse.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

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

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 2990 8254 2985 8229 2984 8228 2985 8227
      2984 8223 2957 8239 2979 8266
TIME...MOT...LOC 2123Z 291DEG 9KT 2979 8250

HESS

The office that day

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

Issued	Product	Office	Counties	Lasted
Jun 14, 8:11 PM EDT	Special Weather Statement	JAX	Duval	49 min
Jun 14, 8:18 PM EDT	Special Marine Warning	JAX		87 min
Jun 15, 2:57 PM EDT	Special Weather Statement	JAX	Flagler	33 min
Jun 15, 3:51 PM EDT	Special Weather Statement	JAX	Duval, Nassau	54 min
Jun 15, 4:10 PM EDT	Special Weather Statement	JAX	Saint Johns	50 min
Jun 15, 4:17 PM EDT	Special Weather Statement	JAX	Flagler	43 min
Jun 15, 4:20 PM EDT	Special Weather Statement	JAX	Alachua	40 min
Jun 15, 4:24 PM EDT	Special Marine Warning	JAX		96 min
Jun 15, 4:32 PM EDT	Special Weather Statement	JAX	Duval	43 min
Jun 15, 4:36 PM EDT	Areal Flood Advisory	JAX	Duval	114 min
Jun 15, 4:42 PM EDT	Special Weather Statement	JAX	Duval	48 min
Jun 15, 4:44 PM EDT	Special Weather Statement	JAX	Saint Johns	46 min
Jun 15, 4:51 PM EDT	Special Weather Statement	JAX	Duval	24 min
Jun 15, 5:13 PM EDT	Special Weather Statement	JAX	Clay	47 min
Jun 15, 5:14 PM EDT	Special Weather Statement	JAX	Flagler	46 min
Jun 15, 5:23 PM EDT	Special Weather Statement	JAX	Alachua	37 min
Jun 15, 5:43 PM EDT	Special Weather Statement	JAX	Flagler, Saint Johns	47 min
Jun 15, 5:53 PM EDT	Special Marine Warning	JAX		67 min
Jun 15, 5:57 PM EDT	Severe Thunderstorm Warning	JAX	Flagler, Saint Johns	24 min
Jun 15, 6:01 PM EDT	Special Weather Statement	JAX	Duval	44 min
Jun 15, 6:10 PM EDT	Areal Flood Advisory	JAX	Bradford, Clay	95 min
Jun 15, 6:22 PM EDT	Special Weather Statement	JAX	Saint Johns	38 min
Jun 15, 6:57 PM EDT	Special Weather Statement	JAX	Putnam	33 min
Jun 15, 7:48 PM EDT	Areal Flood Advisory	JAX	Marion	87 min
Jun 15, 3:38 PM EDT	Special Weather Statement	JAX	Atkinson	37 min
Jun 15, 3:49 PM EDT	Special Weather Statement	JAX	Brantley	41 min
Jun 15, 4:45 PM EDT	Special Weather Statement	JAX	Ware	45 min
Jun 15, 5:05 PM EDT	Special Weather Statement	JAX	Pierce	25 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.