Alert archive / Florida / Tornado Warnings in 1999

Tornado Warning 8, NWS Miami, FL

September 21, 1999Miami-Dade County, Florida

NWS Miami, FL issued this tornado warning at Sep 21, 1999, 5:59 AM EDT for Miami-Dade County, Florida. It was in force for 31 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties.

The facts

Issued
Sep 21, 1999, 5:59 AM EDT (09:59 UTC)
Expired
Sep 21, 1999, 6:30 AM EDT
In force
31 min
Issued by
NWS Miami, FL
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Miami-Dade County, FL

The nearest sounding before it

Miami, FL (KMFL), launched 00:00Z, 10.0 hours before the alert went out and 3 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, Miami, FL at 00:00Z on 1999-09-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 841 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Miami, FL at 00:00Z on 1999-09-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 82 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
841 J/kg
Mixed-layer CIN
-5 J/kg
Mixed-layer LCL
899 m above ground
0-6 km bulk shear
26 kt
0-1 km storm-relative helicity
82 m²/s²
0-3 km storm-relative helicity
104 m²/s²
Significant tornado parameter
0.2
Supercell composite
2.5

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMFL 211004 RRA
TORMIA
FLC025-211030-

BULLETIN - EAS ACTIVATION REQUESTED
TORNADO WARNING
NATIONAL WEATHER SERVICE MIAMI FL
559 AM EDT TUE SEP 21 1999

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* TORNADO WARNING FOR...

  NORTHEASTERN MIAMI-DADE COUNTY IN FLORIDA

* UNTIL 630 AM EDT

* AT 559 AM EDT NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A   
  TORNADO JUST WEST OF MIAMI INTERNATIONAL AIRPORT...MOVING          
  NORTHEAST AT 25 MPH. THIS WILL MOVE TO VIRGINIA GARDENS AND WEST
  OF MIAMI SHORES.

SEEK A STURDY SHELTER IMMEDIATELY!

LAT...LON 2575 8044 2574 8025 2595 8013 2595 8031

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 21, 5:45 AM EDT, 14 minutes before
FLZ071>074-212200-

SOUTH FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MIAMI FL
545 AM EDT TUE SEP 21 1999

...TROPICAL STORM WARNING FOR COASTAL COUNTIES...
...WIND ADVISORY FOR GLADES...HENDRY AND THE FLORIDA KEYS...
...LOCAL FLOODING POSSIBLE...
...RIP CURRENTS WILL BE LIKELY ALONG COLLIER COUNTY BEACHES...
...POSSIBLE ISOLATED TORNADOS...

TROPICAL STORM HARVEY WILL MOVE ACROSS SOUTH FLORIDA TODAY WITH
ABUNDANT TROPICAL MOISTURE. THIS WILL LEAD TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS SOUTH FLORIDA TODAY WITH VERY WINDY CONDITIONS.
LOCALLY HEAVY RAINFALL IS POSSIBLE WITH RAINFALL AMOUNTS OF 5 TO 8
INCHES IN SOME AREAS THIS WILL RESULT IN MODERATE FLOODING OF LOW
LYING AREAS AND PONDING OF WATER ON ROADWAYS. MOTORISTS NEED TO
EXERCISE CAUTION AND REDUCE SPEED IN THE HEAVY RAIN AS VISIBILITY
WILL LOWER AND STANDING WATER MAY RESULT IN HAZARDOUS DRIVING
CONDITIONS.

WINDY CONDIITONS OF 30 TO 40 MPH WITH HIGHER GUSTS ARE EXPECTED TODAY
WITH THE PASSAGE OF TROPICAL STORM HARVEY. LOOSE OBJECTS MAY BE BLOWN
ABOUT AND HIGH PROFILE VEHICLES MAY BE DIFFICULT TO CONTROL AT TIMES.

LIGHTNING AGAIN WILL BE A HAZARD SO PERSONS CONDUCTING OUTDOOR
ACTIVITIES SHOULD EXERCISE CAUTION AND SEEK SHELTER IF A
THUNDERSTORM APPROACHES.

AT THE BEACHES OF COLLIER COUNTY, WESTERLY WINDS OF 30 TO 40 MPH
ALONG WITH MODERATE SWELLS BEING GENERATED IN THE VICINITY OF
TROPICAL STORM HARVEY WILL MEAN RIP CURRENTS ARE LIKELY MAINLY
DURING THE AFTERNOON. IN ADDITION...HEAVY SURF WILL COMBINE TO
MAKE SWIMMING HAZARDOUS.

SPOTTER ACTIVATION MAY BE REQUIRED LATER TODAY...
Special weather statement, Sep 21, 5:45 AM EDT, 14 minutes before
FLZ071>074-212200-

SOUTH FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MIAMI FL
545 AM EDT TUE SEP 21 1999

...TROPICAL STORM WARNING FOR COASTAL COUNTIES...
...WIND ADVISORY FOR GLADES...HENDRY AND THE FLORIDA KEYS...
...LOCAL FLOODING POSSIBLE...
...RIP CURRENTS WILL BE LIKELY ALONG COLLIER COUNTY BEACHES...
...POSSIBLE ISOLATED TORNADOS...

TROPICAL STORM HARVEY WILL MOVE ACROSS SOUTH FLORIDA TODAY WITH
ABUNDANT TROPICAL MOISTURE. THIS WILL LEAD TO NUMEROUS SHOWERS AND
THUNDERSTORMS ACROSS SOUTH FLORIDA TODAY WITH VERY WINDY CONDITIONS.
LOCALLY HEAVY RAINFALL IS POSSIBLE WITH RAINFALL AMOUNTS OF 5 TO 8
INCHES IN SOME AREAS THIS WILL RESULT IN MODERATE FLOODING OF LOW
LYING AREAS AND PONDING OF WATER ON ROADWAYS. MOTORISTS NEED TO
EXERCISE CAUTION AND REDUCE SPEED IN THE HEAVY RAIN AS VISIBILITY
WILL LOWER AND STANDING WATER MAY RESULT IN HAZARDOUS DRIVING
CONDITIONS.

WINDY CONDIITONS OF 30 TO 40 MPH WITH HIGHER GUSTS ARE EXPECTED TODAY
WITH THE PASSAGE OF TROPICAL STORM HARVEY. LOOSE OBJECTS MAY BE BLOWN
ABOUT AND HIGH PROFILE VEHICLES MAY BE DIFFICULT TO CONTROL AT TIMES.

LIGHTNING AGAIN WILL BE A HAZARD SO PERSONS CONDUCTING OUTDOOR
ACTIVITIES SHOULD EXERCISE CAUTION AND SEEK SHELTER IF A
THUNDERSTORM APPROACHES.

AT THE BEACHES OF COLLIER COUNTY, WESTERLY WINDS OF 30 TO 40 MPH
ALONG WITH MODERATE SWELLS BEING GENERATED IN THE VICINITY OF
TROPICAL STORM HARVEY WILL MEAN RIP CURRENTS ARE LIKELY MAINLY
DURING THE AFTERNOON. IN ADDITION...HEAVY SURF WILL COMBINE TO
MAKE SWIMMING HAZARDOUS.

SPOTTER ACTIVATION MAY BE REQUIRED LATER TODAY...

The office that day

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

IssuedProductOfficeCountiesLasted
Sep 20, 10:00 PM EDTFlash Flood WarningMFLCollier5 hr
Sep 21, 3:00 AM EDTFlash Flood WarningMFLCollier9 hr
Sep 21, 4:50 AM EDTTornado WarningMFLBroward, Miami-Dade40 min
Sep 21, 5:27 AM EDTTornado WarningMFLBroward43 min

Nearby

Tornado Warnings in Florida, 1999Every tornado warning in 1999Tornadoes in 1999

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.