Alert archive / Florida / Tornado Warnings in 1997

Tornado Warning 7, NWS Jacksonville, FL

April 23, 1997Nassau County, Florida

NWS Jacksonville, FL issued this tornado warning at Apr 23, 1997, 4:59 AM EDT for Nassau County, Florida. It was in force for 31 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: Apr 23, 1997, 4:59 AM EDT (08:59 UTC)
Expired: Apr 23, 1997, 5:30 AM EDT
In force: 31 min
Issued by: NWS Jacksonville, FL
Area: Whole counties

County Nassau County, FL

What was reported inside it

Time	Report	Where	Remark
Apr 23, 5:10 AM EDT	Thunderstorm Wind	Callahan, FL	Large 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 watch it was issued in

The SPC watch in force over the same counties when this warning went out.

Issued	Product	Office	Lasted
Apr 23, 3:00 AM EDT	Tornado Watch	SPC	6 hr

The nearest sounding before it

Jacksonville, FL (KJAX), launched 00:00Z, 9.0 hours before the alert went out and 14 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: 814 J/kg
Mixed-layer CIN: -147 J/kg
Mixed-layer LCL: 1303 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 123 m²/s²
0-3 km storm-relative helicity: 147 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 0.7

Open this sounding in Storm Lab

The text

As transmitted, in the capitals the NWS used until 2016.

000 
TTAA00 KJAX 230859 RRA
TORJAX
FLC089-230930-
 
BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE JACKSONVILLE FL
459 AM EDT WED APR 23 1997
 
THE NATIONAL WEATHER SERVICE IN JACKSONVILLE HAS ISSUED A
TORNADO WARNING EFFECTIVE UNTIL  530 AM EDT
FOR PERSONS IN THE FOLLOWING LOCATIONS...
 
IN NORTH FLORIDA
 
   ...NASSAU COUNTY
 
AND THE ADJOINING COASTAL WATERS.
 
AT 555 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
POSSIBLE TORNADO WEST OF US 301 MOVING NORTHEAST. THIS STORM SHOULD MOVE
INTO THE CALLAHAN AREA BY 520 AM. PERSONS IN THE WARNED AREA SHOULD SEEK
SHELTER.
 
IF YOU LIVE IN A HOME OR APARTMENT...SEEK SHELTER IN THE
INNERMOST PORTION OF THE BUILDING ON THE LOWEST FLOOR.  GET TO
A BASEMENT IF ONE IS AVAILABLE.  AVOID WINDOWS AND PROTECT YOUR
BODY FROM FLYING DEBRIS WITH CUSHIONS...BLANKETS...OR PILLOWS.
 
SANDRIK
&

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 23, 5:29 AM EDT	Severe Thunderstorm Warning	JAX	Duval	61 min
Apr 23, 7:29 AM EDT	Severe Thunderstorm Warning	JAX	Clay	31 min
Apr 23, 7:38 AM EDT	Severe Thunderstorm Warning	JAX	Columbia, Suwannee	37 min
Apr 23, 7:46 AM EDT	Severe Thunderstorm Warning	JAX	Saint Johns	44 min
Apr 23, 7:57 AM EDT	Tornado Warning	JAX	Clay, Putnam	33 min
Apr 23, 8:13 AM EDT	Tornado Warning	JAX	Alachua	47 min
Apr 23, 8:31 AM EDT	Tornado Warning	JAX	Bradford, Clay	59 min
Apr 23, 8:43 AM EDT	Flash Flood Warning	JAX	Alachua	4 hr
Apr 23, 9:41 AM EDT	Severe Thunderstorm Warning	JAX	Flagler	49 min
Apr 23, 9:56 AM EDT	Tornado Warning	JAX	Marion	64 min
Apr 23, 10:08 AM EDT	Flash Flood Warning	JAX	Putnam	4 hr
Apr 23, 10:31 AM EDT	Severe Thunderstorm Warning	JAX	Flagler	29 min
Apr 23, 11:39 AM EDT	Severe Thunderstorm Warning	JAX	Alachua	36 min
Apr 23, 11:50 AM EDT	Severe Thunderstorm Warning	JAX	Clay	40 min

Nearby

Tornado Warnings in Florida, 1997 Every tornado warning in 1997 Tornadoes in 1997

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.