Alert archive / Florida / Severe Thunderstorm Warnings in 1998

Severe Thunderstorm Warning 74, NWS Miami, FL

July 22, 1998Palm Beach County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Jul 22, 1998, 4:15 AM EDT for Palm Beach County, Florida. It was in force for 35 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
Jul 22, 1998, 4:15 AM EDT (08:15 UTC)
Expired
Jul 22, 1998, 4:50 AM EDT
In force
35 min
Issued by
NWS Miami, FL
Area
Whole counties

County Palm Beach County, FL

The radar

The Miami radar (KAMX), 115 km from the middle of the area, began a volume at 08:18 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, 8.3 hours before the alert went out and 93 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 1998-07-22Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 903 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 1998-07-22The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 104 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
903 J/kg
Mixed-layer CIN
-67 J/kg
Mixed-layer LCL
1063 m above ground
0-6 km bulk shear
27 kt
0-1 km storm-relative helicity
104 m²/s²
0-3 km storm-relative helicity
135 m²/s²
Significant tornado parameter
0.3
Supercell composite
1.1

Open this sounding in Storm Lab

The text

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

734 
WUUS1 KMIA 220816 RRA
SVRMIA
FLC099-220850-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
415 AM EDT WED JUL 22 1998

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  PALM BEACH COUNTY IN SOUTHEASTERN FLORIDA

* UNTIL 450 AM EDT

* AT 415 AM...NATIONAL WEATHER SERVICE RADAR CONTINUE TO
  DETECT A LINE OF SEVERE THUNDERSTORMS MOVING NORTH THROUGH
  PALM BEACH COUNTY. THE LINE IS MOVING NORTH AT 25 MPH AND
  WILL AFFECT MUCH OF NORTHERN PALM BEACH COUNTY THROUGH
  450 AM.

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.

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 22, 3:28 AM EDTSevere Thunderstorm WarningMFLBroward, Palm Beach47 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.