Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 21, NWS Miami, FL

April 28, 1999Broward County, Collier County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Apr 28, 1999, 12:12 PM EDT for Broward County, Collier County, Florida. It was in force for 43 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: Apr 28, 1999, 12:12 PM EDT (16:12 UTC)
Expired: Apr 28, 1999, 12:55 PM EDT
In force: 43 min
Issued by: NWS Miami, FL
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Broward County, FL, Collier County, FL

The radar

The Miami radar (KAMX), 76 km from the middle of the area, began a volume at 16:16 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 4.2 hours before the alert went out and 69 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: 384 J/kg
Mixed-layer CIN: -46 J/kg
Mixed-layer LCL: 1060 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 93 m²/s²
0-3 km storm-relative helicity: 109 m²/s²
Significant tornado parameter: 0.1
Supercell composite: 3.4

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMFL 281612 RRA
SVRMIA
FLC011-021-281700-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
1212 PM EDT WED APR 28 1999

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  WESTERN BROWARD COUNTY IN FLORIDA
  EAST CENTRAL COLLIER COUNTY IN FLORIDA

* UNTIL 1255 PM EDT

* AT 1209 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM OVER EXTREME EAST CENTRAL COLLIER COUNTY...OR
  ABOUT 16 MILES NORTH OF FIFTYMILE BEND...MOVING NORTHEAST AT 20
  MPH.

* THIS STORM WILL MOVE ACROSS I-75 AT THE COLLIER/BROWARD BORDER AROUND
  1220 PM.

VERY LARGE HAIL IS POSSIBLE WITH THIS SEVERE THUNDERSTORM. IF YOU ARE
IN THE PATH OF THE STORM...PUT YOUR CAR IN A GARAGE AND MOVE TO A
SUBSTANTIAL SHELTER.

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH YOU SHOULD PREPARE
FOR DAMAGING WINDS IN EXCESS OF 55 MPH...LARGE HAIL...AND DEADLY
LIGHTNING. PEOPLE OUTSIDE SHOULD MOVE TO A SHELTER...PREFERABLY
INSIDE A STRONG BUILDING BUT AWAY FROM WINDOWS.

REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN MIAMI.

LAT...LON 2609 8105 2597 8091 2621 8060 2637 8078

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 28, 10:40 AM EDT	Severe Thunderstorm Warning	MFL	Hendry, Palm Beach	50 min
Apr 28, 2:51 PM EDT	Severe Thunderstorm Warning	MFL	Broward, Collier	39 min
Apr 28, 3:10 PM EDT	Severe Thunderstorm Warning	MFL	Broward	35 min
Apr 28, 3:38 PM EDT	Severe Thunderstorm Warning	MFL	Miami-Dade	52 min
Apr 28, 3:45 PM EDT	Severe Thunderstorm Warning	MFL	Broward	15 min

Nearby

Severe Thunderstorm Warnings in Florida, 1999 Every severe thunderstorm warning 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; radar from the NEXRAD Level II archive.