Alert archive / Florida / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 15, NWS Miami, FL

August 11, 1990Glades County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Aug 11, 1990, 8:06 PM EDT for Glades County, Florida. It was in force for 54 min.

The area

The counties it named.

The facts

Issued
Aug 11, 1990, 8:06 PM EDT (00:06 UTC)
Expired
Aug 11, 1990, 9:00 PM EDT
In force
54 min
Issued by
NWS Miami, FL
Area
Whole counties

County Glades County, FL

The radar

The WSR-88D network and its archive begin in 1991, so there is no radar volume for this alert.

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 00:00Z, 0.1 hours before the alert went out and 146 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, Tampa Bay, FL at 00:00Z on 1990-08-12Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 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, Tampa Bay, FL at 00:00Z on 1990-08-12The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity -6 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
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
NaN m above ground
0-6 km bulk shear
21 kt
0-1 km storm-relative helicity
-6 m²/s²
0-3 km storm-relative helicity
32 m²/s²
Significant tornado parameter
0.0
Supercell composite
-0.1

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMIA 120007
SVRMIA
FLC043-120100-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
806 PM EDT SAT AUG 11 1990
 
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  900 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN SOUTH FLORIDA
 
   ...CENTRAL GLADES COUNTY
 
AT 800 PM RADAR INDICATED A SEVERE THUNDERSTORM IN BETWEEN CALUSA AND
PALMDALE IN GLADES COUNTY. THE STORM WAS MOVING SLOWLY SOUTH.
 
DAMAGING WIND...LARGE HAIL...VERY HEAVY RAIN...AND DEADLY LIGHTNING
ARE ALL POSSIBLE IN A SEVERE THUNDERSTORM. SEEK SHELTER IN A STRONG
BUILDING. STAY AWAY FROM WINDOWS. DO NOT USE TELEPHONES OR
ELECTRICAL APPLIANCES. A MOBILE HOME IS NOT A SAFE REFUGE FROM A
SEVERE THUNDERSTORM...MOVE TO A MORE SUBSTANTIAL BUILDING.
 
IF THREATENING WEATHER IS SIGHTED...TAKE SHELTER...THEN ASK A LAW
ENFORCEMENT AGENCY TO RELAY YOUR SEVERE WEATHER REPORT TO THE LOCAL
NATIONAL WEATHER SERVICE OFFICE.

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, Aug 11, 3:51 PM EDT, 4 hours 15 minutes before
FLZ020-020-020-112200-

SPECIAL WEATHER AND MARINE STATEMENT
NATIONAL WEATHER SERVICE WEST PALM BEACH FL
353 PM EDT SAT AUG 11 1990

RADAR SHOWED CLUSTERS OF THUNDESTORMS OVER EASTERN PALM BEACH...MARTIN
AND ST LUCIE COUNTIES.

THESE THUNDERSTORMS HAD PERSISTED FOR THE PAST COUPLE OF HOURS AND NOW
HAD INTENSIFIED OVER THE LAKE WORTH AREA AND WEST OF PALM BEACH
GARDENS. MOVEMENT HAD BEEN SLOW AND GENERALLY TOWARD THE COAST.

THESE THUNDERSTORMS WOULD PRODUCE VERY HEAVY RAINS IN A VERY SHORT
TIME CAUSING FLOODING IN LOW PLACES AND ON SOME ROADWAYS.
FREQUENT LIGHTNING STRIKES WERE LIKELY. THUNDERSTORMS MAY DEVELOP OVER
AREAS OF PALM BEACH...MARTIN AND ST LUCIE COUNTIES THAT HAVE NOT HAD
RAIN YET THIS AFTERNOON.

RESIDENTS AND BOATERS SHOULD BE ALERT FOR THESE STRONG THUNDERSTORMS.

NNNN
Special weather statement, Aug 11, 3:57 PM EDT, 4 hours 9 minutes before
FLZ020-020-020-112200-

SPECIAL WEATHER AND MARINE STATEMENT
NATIONAL WEATHER SERVICE WEST PALM BEACH FL
353 PM EDT SAT AUG 11 1990

RADAR SHOWED CLUSTERS OF THUNDESTORMS OVER EASTERN PALM BEACH...MARTIN
AND ST LUCIE COUNTIES.

THESE THUNDERSTORMS HAD PERSISTED FOR THE PAST COUPLE OF HOURS AND NOW
HAD INTENSIFIED OVER THE LAKE WORTH AREA AND WEST OF PALM BEACH
GARDENS. MOVEMENT HAD BEEN SLOW AND GENERALLY TOWARD THE COAST.

THESE THUNDERSTORMS WOULD PRODUCE VERY HEAVY RAINS IN A VERY SHORT
TIME CAUSING FLOODING IN LOW PLACES AND ON SOME ROADWAYS.
FREQUENT LIGHTNING STRIKES WERE LIKELY. THUNDERSTORMS MAY DEVELOP OVER
AREAS OF PALM BEACH...MARTIN AND ST LUCIE COUNTIES THAT HAVE NOT HAD
RAIN YET THIS AFTERNOON.

RESIDENTS AND BOATERS SHOULD BE ALERT FOR THESE STRONG THUNDERSTORMS.

NNNN
Special weather statement, Aug 11, 4:03 PM EDT, 4 hours 3 minutes before
FLZ022-112100-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
358 PM EDT SAT AUG 11 1990

...THUNDERSTORMS INTENSIFYING IN BROWARD AND DADE COUNTIES...

AT 350 PM EDT SATELLITE AND RADAR SHOWED THAT THUNDERSTORMS WERE
BEGINNING TO DEVELOP RAPIDLY IN DADE AND BROWARD COUNTIES. THE
STORMS EXTENDED FROM NEAR HOMESTEAD NORTHWARD TO NEAR MIAMI LAKES AND
ACROSS BROWARD COUNTY TO NEAR TAMARAC. THESE THUNDERSTORMS ARE MOVING
SLOWLY NORTHEASTWARD TOWARD THE COAST.

THE STORMS WILL CONTINUE TO PRODUCE FREQUENT LIGHTNING...STRONG GUSTY
WINDS AND POSSIBLY SOME SMALL HAIL UNTIL ABOUT 500 PM.  PERSONS
ENGAGED IN ANY OUTSIDE ACTIVITY SHOULD SEEK PROTECTION INSIDE UNTIL
THE THREAT FROM THESE STORMS HAS ENDED.
Special weather statement, Aug 11, 5:11 PM EDT, 2 hours 55 minutes before
FLZ022-112315-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MIAMI FL
509 PM EDT SAT AUG 11 1990

...THUNDERSTORMS CONTINUE IN BROWARD COUNTY...

AT 503 PM RADAR INDICATED THE STRONGEST THUNDERSTORM IN BROWARD COUNTY
WAS WEST OF CORAL SPRINGS. MOST OF THE REST OF EASTERN BROWARD
COUNTY WAS RECEIVING RAIN FROM EARLIER THUNDERSTORMS. AS OF 500 PM
THE THUNDERSTORM WARNING FOR WESTERN BROWARD COUNTY HAD EXPIRED. FOR
THE NEXT COUPLE OF HOURS THE THUNDERSTORMS IN BROWARD COUNTY
SHOULD BE DECREASING.

HOWEVER PEOPLE SHOULD STILL CONTINUE TO AVOID OUTSIDE ACTIVITIES
UNTIL THE THREAT FROM THESE THUNDERSTORMS HAS ENDED.
Special weather statement, Aug 11, 5:45 PM EDT, 2 hours 21 minutes before
FLZ015>023-112235-
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MIAMI FL
545 PM EDT SAT AUG 11 1990

AT 534 PM RADAR INDICATED CLUSTERS OF STRONG THUNDERSTORMS WITH VERY HEAVY
RAIN BLANKETING THE SOUTHERN PENINSULA SOUTH OF A VERO BEACH/FORT MYERS LINE.
ABOUT THE ONLY AREA THAT THE THUNDERSTORMS WERE NOT AFFECTING WAS THE LOWER
SOUTHEAST COAST OF DADE COUNTY WHERE ONLY LIGHT RAIN WAS OCCURRING.

RESIDENTS AND OTHER CONCERNED INTERESTS IN THE AFFECTED AREAS SHOULD BE ALERT
FOR THESE THUNDERSTORMS AS THEY WILL BE ACCOMPANIED BY FREQUENT DANGEROUS
LIGHTNING STRIKES...STRONG GUSTY WINDS...AND SHARPLY REDUCE VISIBILITIES IN
PERIODS OF VERY HEAVY RAIN AND CAUSE POOLING OF WATER ON LOY LYING POOR DRAINAGEROADWAYS DURING THE NEXT HOUR OR SO.

ELSEWHERE SHOWERS AND THUNDERSTORMS WERE SCATTERED OVER THE LOWER FLORIDA KEYS
...AND OVER THE ATLANTIC THROUGHOUT THE NORTHERN AND WESTERN BAHAMA ISLANDS.

THUNDERSTORM MOVEMENT W?AS NORTHEAST 5 MILES AN HOUR.
<
THE MAXIMUM PRECIPITATION TOP WAS 51 THOUSAND FEET OVER THE EVERGLADES OF
WESTERN DADE COUNTY.
Special weather statement, Aug 11, 7:42 PM EDT, 24 minutes before
FLZ015>023-120035-
SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE MIAMI FL
740 PM EDT SAT AUG 11 1990

AT 732 PM RADAR INDICATED STRONG THUNDERSTORMS WITH VERY HEAVY RAIN OVER THE
SOUTH CENTRAL SECTIONS OF THE PENINSULA...MAINLY GLADES AND HENDRY COUNTIES.

RESIDENTS OF GLADES AND HENDRY COUNTIES SHOULD BE ALERT FOR THESE THUNDERSTORMS
AS THEY WILL BE ACCOMPANIED BY FREQUENT DANGEROUS LIGHTNING STRIKES...STRONG
GUSTY WINDS...AND REDUCED VISIBILITIES IN PERIODS OF VERY HEAVY RAIN.

ELSEWHERE OVER THE PENINSULA...PATCHES OF RAIN...SCATTERED SHOWERS AND ISOLATED
THUNDERSTORMS WITH VERY HEAVY RAIN CONTINUED SOUTH OF A VERO BEACH/CAPE ROMANO
LINE...SOUTH TO THE KEYS AND EAST TO THE NORTHERN AND WESTERN BAHAMAS.

MOVEMENT WAS EAST 10 MILES AN HOUR.

THE MAXIMUM PRECIPITATION TOP WAS 48 THOUSAND FEET ALONG THE GLADES/HENDRY
COUNTY LINE NEAR LABELLE

Nearby

Severe Thunderstorm Warnings in Florida, 1990Every severe thunderstorm warning in 1990

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.