Alert archive / Florida / Severe Thunderstorm Warnings in 1987

Severe Thunderstorm Warning 13, NWS Jacksonville, FL

June 23, 1987Saint Johns County, Florida

NWS Jacksonville, FL issued this severe thunderstorm warning at Jun 23, 1987, 4:26 PM EDT for Saint Johns County, Florida. It was in force for 64 min.

The area

The counties it named.

The facts

Issued
Jun 23, 1987, 4:26 PM EDT (20:26 UTC)
Expired
Jun 23, 1987, 5:30 PM EDT
In force
64 min
Issued by
NWS Jacksonville, FL
Area
Whole counties

County Saint Johns County, FL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Jacksonville, FL (KAYS), launched 12:00Z, 8.4 hours before the alert went out and 71 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 1987-06-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 799 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 1987-06-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 9 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
799 J/kg
Mixed-layer CIN
-21 J/kg
Mixed-layer LCL
733 m above ground
0-6 km bulk shear
22 kt
0-1 km storm-relative helicity
9 m²/s²
0-3 km storm-relative helicity
35 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KJAX 232026
SVRJAX
FLC109-232130-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED 
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE JACKSONVILLE FL
426 PM EDT TUE JUN 23 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A SEVERE THUNDERSTORM AND 
SPECIAL MARINE WARNING EFFECTIVE UNTIL 530 PM EDT FOR PEOPLE IN THE 
FOLLOWING COUNTY OF

NORTHEAST FLORIDA...ST JOHNS
...THIS WARNING ALSO INCLUDES THE ADJACENT COASTAL WATERS FOR THE
COUNTY JUST MENTIONED

RADAR INDICATED AN INTENSE THUNDERSTORM ALONG THE COAST NEAR
ST AUGUSTINE SHOWING VERY LITTLE MOVEMENT.

WHEN THUNDERSTORMS ARE OCCURRING..PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING. DO NOT STAND BY WINDOWS. DO NOT USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED. MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.

SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 60 MPH..
DESTRUCTIVE HAIL..DEADLY LIGHTNING AND VERY HEAVY RAIN. FOR YOUR
PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF YOUR
HOME OR BUSINESS. HEAVY RAINS FLOOD ROADS QUICKLY SO DO NOT DRIVE
INTO AREAS WHERE WATER COVERS THE ROAD.

 MARINE INTERESTS OPERATING IN THE COASTAL WATERS OFF
 ST AUGUSTINE SEEK SAFE HARBOR IMMEDIATELY.

Nearby

Severe Thunderstorm Warnings in Florida, 1987Every severe thunderstorm warning in 1987

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.