Alert archive / Florida / Tornado Warnings in 1987

Tornado Warning 3, NWS Jacksonville, FL

June 17, 1987Saint Johns County, Florida

NWS Jacksonville, FL issued this tornado warning at Jun 17, 1987, 3:15 PM EDT for Saint Johns County, Florida. It was in force for 30 min.

The area

The counties it named.

The facts

Issued
Jun 17, 1987, 3:15 PM EDT (19:15 UTC)
Expired
Jun 17, 1987, 3:45 PM EDT
In force
30 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, 7.3 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 1987-06-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1568 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 1987-06-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 42 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
1568 J/kg
Mixed-layer CIN
-6 J/kg
Mixed-layer LCL
608 m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
42 m²/s²
0-3 km storm-relative helicity
73 m²/s²
Significant tornado parameter
0.0
Supercell composite
1.3

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 tornado warning went out, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

In the hours before

Special weather statement, Jun 17, 12:46 PM EDT, 2 hours 29 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
1245 PM EDT WED JUN 17 1987

AT 1240 PM EDT RADAR INDICATED VERY STRONG THUNDERSTORMS EXTENDING
FROM FERNANDINA BEACH SOUTHWEST THROUGH THE WESTSIDE OF JACKSONVILLE
TO GAINESVILLE. THESE THUNDERSTORMS CONTAIN HEAVY RAINS FREQUENT
LIGHTNING STRIKES AND POSSIBILY STRONG GUSTY WIND WITH SMALL HAIL.

THE THUNDERSTORMS ARE MOVING EASTERLY AT 15 MPH.

REMEMBER...WHEN A THUNDERSTORM THREATENS ALL LIGHTNING EXPERTS AGREE
THAT THE MOST IMPORTANT SINGLE THING YOU CAN DO IS TO GET INSIDE A
HOME OR LARGE BUILDING. IF YOU DO NOT HAVE TIME TO REACH A SAFE BUILDING
OR CAR...AVOID AN OPEN FIELD SUCH AS GOLF COURSES...BASEBALL FIELDS...
BEACHES OR FISHING FROM A SMALL BOAT OR PIERS.

MARINE INTERESTS OPERATING IN THE COASTAL WATERS OFF FERNANDINA BEACH
AND MAYPORT SHOULD REMAIN ALERT FOR ..STRONG GUSTY WINDS...BUILDING SEAS
...AND POOR VISIBILITY AS THESE THUNDERSTORMS MOVE OFF THE COAST
WITHIN THE HOUR. SEEK SAFE HARBOR IF THREATENING CONDITIONS ARE
SIGHTED.

The office that day

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

IssuedProductOfficeCountiesLasted
Jun 17, 2:30 PM EDTSevere Thunderstorm WarningJAXDuval, Saint Johns30 min

Nearby

Tornado Warnings in Florida, 1987Every tornado warning in 1987Tornadoes 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.