Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 34, NWS Miami, FL

May 9, 1999Collier County, Florida

NWS Miami, FL issued this severe thunderstorm warning at May 9, 1999, 2:56 PM EDT for Collier County, Florida. It was in force for 34 min. No storm report in the archive falls inside the area while it was in force.

The area

The counties it named.

The facts

Issued
May 9, 1999, 2:56 PM EDT (18:56 UTC)
Expired
May 9, 1999, 3:30 PM EDT
In force
34 min
Issued by
NWS Miami, FL
Area
Whole counties; the outline is the Mesonet’s reconstruction

County Collier County, FL

The watch it was issued in

The SPC watch in force over the same counties when this warning went out.

IssuedProductOfficeLasted
May 9, 2:00 PM EDTSevere Thunderstorm WatchSPC6 hr

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 6.9 hours before the alert went out and 113 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 12:00Z on 1999-05-09Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1797 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, Miami, FL at 12:00Z on 1999-05-09The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -33 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
1797 J/kg
Mixed-layer CIN
-27 J/kg
Mixed-layer LCL
812 m above ground
0-6 km bulk shear
18 kt
0-1 km storm-relative helicity
-33 m²/s²
0-3 km storm-relative helicity
-18 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

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 severe thunderstorm 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, May 9, 2:35 PM EDT, 21 minutes before
FLZ063-066>078-100100-

SOUTH FLORIDA HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
235 PM EDT SUN MAY 9 1999

...SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...

VERY UNSTABLE AIR ACROSS SOUTH FLORIDA ALONG WITH A WEAK DISTURBANCE
ALOFT WILL TRIGGER SEVERE THUNDERSTORMS ACROSS SOUTH FLORIDA THIS
AFTERNOON AND EVENING. THESE THUNDERSTORM ARE CAPABLE OF PRODUCING
DAMAGING WIND AND LARGE HAIL...UP TO 2 INCHES IN DIAMETER...ACROSS
MUCH OF MAINLAND SOUTH FLORIDA.

THE ACTIVITY HAS ALREADY BEGUN ALONG THE SOUTHWEST FLORIDA COAST AND
IN PALM BEACH COUNTY AND WILL SPREAD SLOWLY TOWARD THE EAST. IT WILL
LIKELY BEGIN AFFECTING THE BROWARD AND DADE METRO AREAS SOMETIME
AFTER 4 PM AND MAY LAST INTO THE EVENING HOURS.

PERSONS OUTDOORS SHOULD MOVE QUICKLY INDOORS IF THUNDERSTORMS
APPROACH.

SPOTTER ACTIVATION IS REQUESTED.
Special weather statement, May 9, 2:35 PM EDT, 21 minutes before
FLZ063-066>078-100100-

SOUTH FLORIDA HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
235 PM EDT SUN MAY 9 1999

...SEVERE THUNDERSTORMS EXPECTED THIS AFTERNOON AND EVENING...

VERY UNSTABLE AIR ACROSS SOUTH FLORIDA ALONG WITH A WEAK DISTURBANCE
ALOFT WILL TRIGGER SEVERE THUNDERSTORMS ACROSS SOUTH FLORIDA THIS
AFTERNOON AND EVENING. THESE THUNDERSTORM ARE CAPABLE OF PRODUCING
DAMAGING WIND AND LARGE HAIL...UP TO 2 INCHES IN DIAMETER...ACROSS
MUCH OF MAINLAND SOUTH FLORIDA.

THE ACTIVITY HAS ALREADY BEGUN ALONG THE SOUTHWEST FLORIDA COAST AND
IN PALM BEACH COUNTY AND WILL SPREAD SLOWLY TOWARD THE EAST. IT WILL
LIKELY BEGIN AFFECTING THE BROWARD AND DADE METRO AREAS SOMETIME
AFTER 4 PM AND MAY LAST INTO THE EVENING HOURS.

PERSONS OUTDOORS SHOULD MOVE QUICKLY INDOORS IF THUNDERSTORMS
APPROACH.

SPOTTER ACTIVATION IS REQUESTED.

The office that day

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

IssuedProductOfficeCountiesLasted
May 9, 1:42 PM EDTSevere Thunderstorm WarningMFLGlades, Hendry63 min
May 9, 1:54 PM EDTSevere Thunderstorm WarningMFLCollier61 min
May 9, 2:24 PM EDTSevere Thunderstorm WarningMFLPalm Beach51 min
May 9, 3:13 PM EDTSevere Thunderstorm WarningMFLPalm Beach32 min

Nearby

Severe Thunderstorm Warnings in Florida, 1999Every 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.