Alert archive / Florida / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 35, NWS Miami, FL

March 20, 1998Monroe County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Mar 20, 1998, 6:07 PM EST for Monroe County, Florida. It was in force for 78 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
Mar 20, 1998, 6:07 PM EST (23:07 UTC)
Expired
Mar 20, 1998, 7:25 PM EST
In force
78 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 23:07 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, 11.1 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 12:00Z on 1998-03-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 254 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 1998-03-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 57 square meters per square second.19395878Sfc1 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
254 J/kg
Mixed-layer CIN
-60 J/kg
Mixed-layer LCL
655 m above ground
0-6 km bulk shear
44 kt
0-1 km storm-relative helicity
57 m²/s²
0-3 km storm-relative helicity
115 m²/s²
Significant tornado parameter
0.1
Supercell composite
0.7

Open this sounding in Storm Lab

The text

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

716 
WUUS1 KMIA 202308 RRA
SVRMIA
AMZ654-674-675-FLC087-210025-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
607 PM EST FRI MAR 20 1998

THE NATIONAL WEATHER SERVICE IN MIAMI FL HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL 725 PM EST
FOR PEOPLE IN THE FOLLOWING LOCATIONS...

IN SOUTHERN FLORIDA

   ...MONROE LOWER KEYS INCLUDING ADJACENT COASTAL WATERS

AT 605 PM EST... DOPPLER RADAR INDICATED AN AREA OF SEVERE
THUNDERSTORMS LOCATED NEAR THE MARQUESAS KEYS. THE STORMS
ARE MOVING EAST AT 25 MPH AND WILL AFFECT THE LOWER KEYS
INCLUDING KEY WEST DURING THE NEXT HOUR.

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

DPB

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, Mar 20, 1:40 PM EST, 4 hours 27 minutes before
FLZ063-066>068-202345-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
140 PM EST FRI MAR 20 1998

A FLOOD WATCH CONTINUE IN EFFECT THIS AFTERNOON FOR GLADES.. HENDRY...
AND PALM BEACH COUNTIES. AS OF 120 PM DOPPLER RADAR INDICATED ONLY
LIGHT SHOWERS OVER PARTS OF GLADES COUNTY. HOWEVER... A AREA OF SHOWERS
AND THUNDERSTORMS HAS FORMED IN THE EASTERN GULF OF MEXICO WEST OF
COLLIER COUNTY AND WAS MOVING EAST NORTHEAST TOWARD THE COAST.

SHOWERS AND THUNDERSTORMS ARE EXPECTED TO SPREAD SOUTH AND EAST ACROSS
THE WATCH AREA THE REMAINDER OF THE AFTERNOON. ONE TO THREE INCHES OF
RAINFALL ARE POSSIBLE AND THIS COULD PRODUCE SOME FLOODING OF MAINLY
LOW-LYING EASILY FLOODED AREAS. RESIDENTS SHOULD KEEP IN TOUCH WITH
LATER STATEMENTS AND/OR POSSIBLE WARNINGS.
Special weather statement, Mar 20, 3:32 PM EST, 2 hours 35 minutes before
AMZ610-650-656-670-676-FLZ063-066>070-202330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
332 PM EST FRI MAR 20 1998

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 7 PM EST...

A SEVERE THUNDERSTORM WATCH CONTINUES IN EFFECT UNTIL 7 PM FOR
GLADES.. HENDRY.. COLLIER.. AND PALM BEACH COUNTIES. NO SEVERE
WEATHER WAS OCCURRING AS OF 320 PM. HOWEVER STRONG THUNDERSTORMS
HAD DEVELOPED ACROSS THE AREA JUST NORTH OF LAKE OKEECHOBEE AND
ALSO OVER THE SOUTHEAST GULF OF MEXICO FROM JUST OFF THE COAST
OF COLLIER COUNTY TO WEST OF THE DRY TORTUGAS.

THESE THUNDERSTORMS ARE EXPECTED TO AFFECT THE AREA FROM ABOUT
4 PM ONWARD THROUGH SUNSET. STRONG DAMAGING WIND GUSTS AS WELL AS
SOME HAIL IS STILL POSSIBLE IN THIS AREA AS THESE THUNDERSTORMS
MOVE THROUGH. IN ADDITION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
WERE DEVELOPING OVER MOST OF SOUTH FLORIDA AND OFFSHORE THE DADE
COUNTY AND UPPER KEYS COAST.

PERSONS IN THE WATCH AREA AND ALSO THE REMAINDER OF SOUTH FLORIDA
SHOULD KEEP A CLOSE EYE ON THE WEATHER DURING THE REMAINDER OF THE
AFTERNOON AND EARLY EVENING HOURS.
Special weather statement, Mar 20, 3:32 PM EST, 2 hours 35 minutes before
AMZ610-650-656-670-676-FLZ063-066>070-202330-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
332 PM EST FRI MAR 20 1998

...SEVERE THUNDERSTORM WATCH IN EFFECT UNTIL 7 PM EST...

A SEVERE THUNDERSTORM WATCH CONTINUES IN EFFECT UNTIL 7 PM FOR
GLADES.. HENDRY.. COLLIER.. AND PALM BEACH COUNTIES. NO SEVERE
WEATHER WAS OCCURRING AS OF 320 PM. HOWEVER STRONG THUNDERSTORMS
HAD DEVELOPED ACROSS THE AREA JUST NORTH OF LAKE OKEECHOBEE AND
ALSO OVER THE SOUTHEAST GULF OF MEXICO FROM JUST OFF THE COAST
OF COLLIER COUNTY TO WEST OF THE DRY TORTUGAS.

THESE THUNDERSTORMS ARE EXPECTED TO AFFECT THE AREA FROM ABOUT
4 PM ONWARD THROUGH SUNSET. STRONG DAMAGING WIND GUSTS AS WELL AS
SOME HAIL IS STILL POSSIBLE IN THIS AREA AS THESE THUNDERSTORMS
MOVE THROUGH. IN ADDITION... WIDELY SCATTERED SHOWERS AND THUNDERSTORMS
WERE DEVELOPING OVER MOST OF SOUTH FLORIDA AND OFFSHORE THE DADE
COUNTY AND UPPER KEYS COAST.

PERSONS IN THE WATCH AREA AND ALSO THE REMAINDER OF SOUTH FLORIDA
SHOULD KEEP A CLOSE EYE ON THE WEATHER DURING THE REMAINDER OF THE
AFTERNOON AND EARLY EVENING HOURS.

The office that day

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

IssuedProductOfficeCountiesLasted
Mar 19, 10:39 PM ESTSevere Thunderstorm WarningMFLCollier61 min
Mar 19, 11:53 PM ESTSevere Thunderstorm WarningMFLBroward62 min
Mar 20, 12:25 AM ESTSevere Thunderstorm WarningMFLMiami-Dade60 min
Mar 20, 12:49 AM ESTSevere Thunderstorm WarningMFLMiami-Dade61 min

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.