Alert archive / Florida / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 321, NWS Jacksonville, FL

August 8, 1998Clay County, Duval County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Aug 8, 1998, 1:08 PM EDT for Clay County, Duval County, Florida. It was in force for 62 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 8, 1998, 1:08 PM EDT (17:08 UTC)
Expired
Aug 8, 1998, 2:10 PM EDT
In force
62 min
Issued by
NWS Jacksonville, FL
Area
Whole counties

Counties Clay County, FL, Duval County, FL

The radar

The Jacksonville radar (KJAX), 37 km from the middle of the area, began a volume at 17:10 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 8, 1:30 PM EDTThunderstorm WindMarietta, FLLarge trees and power lines were blown down.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Jacksonville, FL (KJAX), launched 12:00Z, 5.1 hours before the alert went out and 38 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 1998-08-08Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1188 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Jacksonville, FL at 12:00Z on 1998-08-08The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 18 square meters per square second.1939Sfc1 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
1188 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
849 m above ground
0-6 km bulk shear
7 kt
0-1 km storm-relative helicity
18 m²/s²
0-3 km storm-relative helicity
14 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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 8, 9:45 AM EDT, 3 hours 23 minutes earlier.

Area forecast discussion, Aug 8, 9:45 AM EDT, 3 hours 23 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE JACKSONVILLE FL
945 AM EDT SAT AUG 8 1998

PLENTY OF CONVECTION WELL OFFSHORE THIS MRNG...WITH ISOLATED ACTIVITY
JUST N OF MY CWA AND MOVING N. WITH THIS MUCH ACTIVITY OFFSHORE WILL
SEE IT TRANSLATE TO A BUSY AFTRN/EVE ACROSS THE CWA AND CONVECTION
DEVELOPS INLAND DURING THIS TIME. PRECIPITABLE WATER OVER 2 INCHES AT
JAX AND THIS MOISTURE SHOWS UP WELL ON WATER VAPOR SATELLITE PIX OVER
THE AREA IN WAKE OF UPPER LOW OVER NE GA/W NC AND W SC WHICH IS MOVING
NNE. BECAUSE OF SUCH A HIGH MOISTURE CONTENT WILL SEE HEAVY RAINS IN
MANY AREAS THIS AFTRN/EVE. SEVERE THREA IS SMALL...BUT WITH CAPE OVER
3000 AND LI -6 WILL HAVE SOME PULSE SEVERE TSTMS JUST LIKE YESTERDAY.

WILL LEAVE POPS AS IS IN NE FL...BUT WILL MENTION AS MOSTLY INLAND FOR
COASTAL COUNTIES AS SEA BREEZE PUSHES WELL INLAND. ATL MAY WANT TO
CONSIDER BUMPING POPS UP TO 50 OR 60% WITH SUCH HIGH MOISTURE.

H8 TEMPS AT JAX DOWN 1.5 DEGREES CELCIUS SINCE 12Z FRI MRNG SO TEMPS
NO HIGHER THAN YESTERDAY. WITH ONSHORE WIND WILL SEE A RANGE FROM
COAST TO INLAND.

ONLY A SLIGHT CHANCE OF RIP CURRENTS TODAY AS SWELLS ARE TOO SMALL AT
LESS THAN 2 FEET. NO CHANGES IN CWF.

MOHLIN

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 8, 2:24 PM EDTSevere Thunderstorm WarningJAXBradford, Union61 min
Aug 8, 2:47 PM EDTSevere Thunderstorm WarningJAXAlachua33 min
Aug 8, 2:47 PM EDTTornado WarningJAXAlachua33 min
Aug 8, 2:52 PM EDTSevere Thunderstorm WarningJAXMarion63 min
Aug 8, 2:56 PM EDTSevere Thunderstorm WarningJAXGilchrist64 min
Aug 8, 3:18 PM EDTSevere Thunderstorm WarningJAXSuwannee62 min
Aug 8, 3:22 PM EDTSevere Thunderstorm WarningJAXAlachua63 min
Aug 8, 3:57 PM EDTSevere Thunderstorm WarningJAXMarion63 min
Aug 8, 4:24 PM EDTSevere Thunderstorm WarningJAXSuwannee61 min
Aug 8, 5:39 PM EDTTornado WarningJAXMarion46 min
Aug 8, 6:35 PM EDTFlash Flood WarningJAXMarion3 hr
Aug 8, 2:01 PM EDTSevere Thunderstorm WarningJAXCharlton34 min
Aug 8, 3:28 PM EDTSevere Thunderstorm WarningJAXClinch, Ware62 min
Aug 8, 4:32 PM EDTSevere Thunderstorm WarningJAXAtkinson, Coffee63 min

Nearby

Severe Thunderstorm Warnings in Florida, 1998Every severe thunderstorm warning in 1998

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.