Alert archive / Florida / Tornado Warnings in 1987

Tornado Warning 9, NWS Jacksonville, FL

September 11, 1987Saint Johns County, Florida

NWS Jacksonville, FL issued this tornado warning at Sep 11, 1987, 4:44 PM EDT for Saint Johns County, Florida. It was in force for 31 min.

The area

The counties it named.

The facts

Issued
Sep 11, 1987, 4:44 PM EDT (20:44 UTC)
Expired
Sep 11, 1987, 5:15 PM EDT
In force
31 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, 8.7 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 1987-09-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1074 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 1987-09-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 32 square meters per square second.193958Sfc1 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
1074 J/kg
Mixed-layer CIN
-39 J/kg
Mixed-layer LCL
911 m above ground
0-6 km bulk shear
19 kt
0-1 km storm-relative helicity
32 m²/s²
0-3 km storm-relative helicity
54 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 112048
TORJAX
FLC109-112115-

BULLETIN - IMMEDIATE BROADCAST REQUESTED/EBS ACTIVATION REQUESTED
TORNADO AND SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE JACKSONVILLE FL
444 PM EDT FRI SEP 11 1987

THE NATIONAL WEATHER SERVICE HAS ISSUED A TORNADO AND SPECIAL
MARINE WARNING EFFECTIVE UNTIL 515 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

A TORNADO WAS SIGHTED BY THE PUBLIC NEAR HASTINGS MOVING
NORTHEAST AT 10 TO 20 MPH. THIS WAS CONFIRMED BY CIVIL DEFENSE.

IF YOU ARE IN THE PATH OF THIS TORNADO..THE SAFEST PLACE IS A
BASEMENT. GET UNDER A PIECE OF STURDY FURNITURE. IF NO BASEMENT IS
AVAILABLE..SEEK SHELTER IN AN INTERIOR ROOM ON THE LOWEST FLOOR.
USE BLANKETS OR PILLOWS TO COVER YOUR BODY. AVOID WINDOWS.

THIS IS A DANGEROUS STORM SITUATION. ACT QUICKLY. IF YOU ARE IN
THE PATH OF THIS TORNADO MOVE TO A SHELTER BELODW GROUND IF
AVAILABLE OTHERWISE..GO TO A SMALL INTERIOR ROOM ON THE LOWEST
FLOOR POSSIBLE AVOID WINDOWS. ABANDON CARS AND MOBILE HOMES FOR A
REINFORCED BUILDING OR GET INTO A DITCH OR CULVERT.

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, Sep 11, 3:35 PM EDT, 1 hour 9 minutes before
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE JACKSONVILLE FL
335 PM EDT FRI SEP 11 1987

...STRONG THUNDERSTORMS IN THE JACKSONVILLE METROPOLITAN AREA...

DURING THE PAST HOUR STRONG THUNDERSTORMS HAVE DEVELOPED IN THE
JACKSONVILLE METROPOLITAN AREA. SOME STRONG THUNDERSTORMS AND SHOWERS
WERE ALSO NEAR THE COAST FROM DAYTONA BEACH NORTH TO FERNANDINA BEACH.

IN THE PAST HOUR NEARLY AN INCH OF RAIN HAS FALLEN IN THE GLENLEA
SECTION OF JACKSONVILLE AND IT IS STILL RAINING HARD. SOME STREET
FLOODING WAS OCCURRING IN THE GLENLEA SECTION OF JACKSONVILLE.

PERIODS OF LOCALLY HEAVY RAIN...GUSTY WINDS...DANGEROUS LIGHTNING
STRIKES...AND POSSIBLY SOME SMALL HAIL WILL ACCOMPANY THESE STRONGER
THUNDERSTORMS.
REMEMBER...MORE PEOPLE ARE KILLED BY LIGHTNING IN FLORIDA THAN ANY
OTHER STATE IN THE COUNTRY. WHEN A THUNDERSTORM THREATENS TRY TO GET
INSIDE A HOME OR LARGE BUILDING. IF YOU DO NOT HAVE TIME TO REACH A
SAFE BUILDING OR CAR...AVOID OPEN FIELDS SUCH AS GOLF COURSES...
BASEBALL FIELDS...BEACHES...OR FISHING FROM A SMALL BOAT OR PIERS.

SLOW MOVING THUNDERSTORMS PRODUCING LOCALLY HEAVY RAINS WILL CAUSE
TEMPORARY FLOODING OF SMALL CREEKS...LOW LYING AREAS...DRAINAGE
DITCHES...AND UNDERPASSES FOR THE NEXT 1 TO 3 HOURS.

MARINE INTERESTS OPERATING IN THE COASTAL WATERS OFF MAYPORT...
ST. AUGUSTINE...AMELIA ISLAND BE ALERT FOR GUSTY WINDS...BUILDING
SEAS...AND POOR VISIBILITY AS THESE THUNDERSTORMS MOVE OFF THE COAST
WITHIN THE HOUR. BE PREPARED TO SEEK SAFE HARBOR IF THREATENING
CONDITIONS ARE SIGHTED.
Special weather statement, Sep 11, 4:03 PM EDT, 41 minutes before
SPECIAL WEATHER STATEMENT...CORRECTED...
NATIONAL WEATHER SERVICE JACKSONVILLE FL
335 PM EDT FRI SEP 11 1987

...STRONG THUNDERSTORMS IN THE JACKSONVILLE METROPOLITAN AREA...

DURING THE PAST HOUR STRONG THUNDERSTORMS HAVE DEVELOPED IN THE
JACKSONVILLE METROPOLITAN AREA. SOME STRONG THUNDERSTORMS AND SHOWERS
WERE ALSO NEAR THE COAST FROM DAYTONA BEACH NORTH TO FERNANDINA BEACH.

IN THE PAST HOUR NEARLY AN INCH OF RAIN HAS FALLEN IN THE GLENLEA
SECTION OF JACKSONVILLE AND IT IS STILL RAINING HARD. SOME STREET
FLOODING WAS OCCURRING IN THE GLENLEA SECTION OF JACKSONVILLE.

PERIODS OF LOCALLY HEAVY RAIN...GUSTY WINDS...DANGEROUS LIGHTNING
STRIKES...AND POSSIBLY SOME SMALL HAIL WILL ACCOMPANY THESE STRONGER
THUNDERSTORMS.

REMEMBER...MORE PEOPLE ARE KILLED BY LIGHTNING IN FLORIDA THAN ANY
OTHER STATE IN THE COUNTRY. WHEN A THUNDERSTORM THREATENS TRY TO GET
INSIDE A HOME OR LARGE BUILDING. IF YOU DO NOT HAVE TIME TO REACH A
SAFE BUILDING OR CAR...AVOID OPEN FIELDS SUCH AS GOLF COURSES...
BASEBALL FIELDS...BEACHES...OR FISHING FROM A SMALL BOAT OR PIERS.

SLOW MOVING THUNDERSTORMS PRODUCING LOCALLY HEAVY RAINS WILL CAUSE
TEMPORARY FLOODING OF SMALL CREEKS...LOW LYING AREAS...DRAINAGE
DITCHES...AND UNDERPASSES FOR THE NEXT 1 TO 3 HOURS.

MARINE INTERESTS OPERATING IN THE COASTAL WATERS OFF MAYPORT...
ST. AUGUSTINE...AMELIA ISLAND BE ALERT FOR GUSTY WINDS...BUILDING
SEAS...AND POOR VISIBILITY AS THESE THUNDERST3ORMS MOVE OFF THE COAST
WITHIN THE HOUR. BE PREPARED TO SEEK SAFE HARBOR IF THREATENING
CONDITIONS ARE SIGHTED.

MOVEMENT OF THESE THUNDERSTORMS WAS NORTHEAST AT 10 MPH.

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 11, 4:39 PM EDTTornado WarningJAXColumbia66 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.