Alert archive / Florida / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 91, NWS Miami, FL

August 18, 1998Monroe County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Aug 18, 1998, 11:39 PM EDT for Monroe County, Florida. It was in force for 81 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
Aug 18, 1998, 11:39 PM EDT (03:39 UTC)
Expired
Aug 19, 1998, 1:00 AM EDT
In force
81 min
Issued by
NWS Miami, FL
Area
Whole counties

County Monroe County, FL

The radar

The Miami radar (KAMX), 51 km from the middle of the area, began a volume at 03:22 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 00:00Z, 3.7 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-pSkew-T log-p diagram, Miami, FL at 00:00Z on 1998-08-19Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1886 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 00:00Z on 1998-08-19The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 19 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
1886 J/kg
Mixed-layer CIN
-10 J/kg
Mixed-layer LCL
1050 m above ground
0-6 km bulk shear
13 kt
0-1 km storm-relative helicity
19 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

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

119 
WUUS1 KMIA 190340 RRA
SVRMIA
FLC087-190510-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
1139 PM EDT TUE AUG 18 1998

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  MONROE MIDDLE KEYS IN SOUTHERN FLORIDA
  MONROE LOWER KEYS IN SOUTHERN FLORIDA

* UNTIL 100 AM EDT

* AT 1134 PM EDT... DOPPLER RADAR INDICATED A LINE OF
THUNDERSTORMS MOVING ACROSS THE FLORIDA STRAITS TOWARD
THE MIDDLE AND LOWER KEYS...ACCOMPANIED BY A LEADING
GUST OF WIND ESTIMATED AT 55 MPH OR GREATER.

* STORMS WILL PROGRESS TO THE MIDDLE AND LOWER KEYS AND
 CONTINUE INTO FLORIDA BAY. SPECIAL MARINE WARNINGS ALSO
 REMAIN IN EFFECT FOR ALL WATERS SURROUNDING THE KEYS
 THROUGH 1 AM.


SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH...
...DEADLY LIGHTNING...AND VERY HEAVY RAIN. SEEK SHELTER
IN A STRONG BUILDING. STAY AWAY FROM WINDOWS. DO NOT USE TELEPHONES
OR ELECTRICAL APPLIANCES.

Nearby

Severe Thunderstorm Warnings in Florida, 1998Every severe thunderstorm warning in 1998

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.