Alert archive / Florida / Severe Thunderstorm Warnings in 1990

Severe Thunderstorm Warning 45, NWS Melbourne, FL

August 11, 1990Osceola County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Aug 11, 1990, 3:15 PM EDT for Osceola County, Florida. It was in force for 45 min.

The area

The counties it named.

The facts

Issued
Aug 11, 1990, 3:15 PM EDT (19:15 UTC)
Expired
Aug 11, 1990, 4:00 PM EDT
In force
45 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Osceola 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

Cape Canaveral, FL (KXMR), launched 12:00Z, 7.3 hours before the alert went out and 78 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, Cape Canaveral, FL at 12:00Z on 1990-08-11Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1272 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, Cape Canaveral, FL at 12:00Z on 1990-08-11The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 45 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
1272 J/kg
Mixed-layer CIN
-29 J/kg
Mixed-layer LCL
1058 m above ground
0-6 km bulk shear
15 kt
0-1 km storm-relative helicity
45 m²/s²
0-3 km storm-relative helicity
16 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.

000 
TTAA00 KMLB 111916
SVRMLB
FLC097-112000-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
315 PM EDT SAT AUG 11 1990
 
THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  400 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATIONS...
 
IN CENTRAL FLORIDA
 
   ...NORTHERN OSCEOLA COUNTY
 
AT 312 PM NATIONAL WEATHER SERVICE RADAR INDICATED POSSIBLE SEVERE
THUNDERSTORM JUST WEST OF KISSIMMEE MOVING TO THE SOUTHEAST AT 30 MPH.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 58
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN.
FOR YOUR PROTECTION MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR
OF YOUR HOME OR BUSINESS.  HEAVY RAINS FLOOD ROADS QUICKLY SO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.

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, 12:52 PM EDT, 2 hours 23 minutes before
FLZ006>017-020-111840

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DAYTONA BEACH FL
1250 PM EDT SAT AUG 11 1990

...THIS STATEMENT IS FOR PERSONS IN THE EAST HALF OF MARION AND THE WESTERN
SECTIONS OF FLAGLER AND VOLUSIA COUNTIES...

AT 1228 PM A LINE OF THUNDERSTORMS CAPABLE OF PRODUCING STRONG GUSTY WINDS...
FREQUENT DANGEROUS LIGHTNING STRIKES...POSSIBLY SMALL HAIL...AND VERY HEAVY
RAINS CONTINUED TO DEVELOP OVER THE INTERIOR OF THE STATE. THE LINE EXTENDED
FROM 10 MILES NORTHWEST OF PALATKA TO AROUND TAMPA.

SOME OF THE HEAVIEST SHOWERS WERE OCCURRING OVER THE EAST HALF OF MARION COUNTY
AROUND THE OKLAWAHA RIVER.

THE LINE OF THUNDERSTORMS WAS MOVING SLOWLY EAST AND WILL LIKELY AFFECT THE
WESTERN SECTIONS...AROUND THE ST JOHNS RIVER...OF FLAGLER AND VOLUSIA COUNTIES
WITHIN AN HOUR. SHOULD THESE THUNDERSTORMS CONTINUE PROGRESSING EASTWARD...
FURTHER STATEMENTS WILL BE ISSUED FOR THE COASTAL AREAS.

RESIDENTS ARE ADVISED TO BE PREPARED FOR THE APPROACH OF THESE THUNDERSTORMS
AND TO SEEK SAFE SHELTER IMMEDIATELY WHEN THEY ARE SIGHTED.
Special weather statement, Aug 11, 1:18 PM EDT, 1 hour 57 minutes before
FLZ011-111830-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
115 PM EDT SAT AUG 11 1990

...STRONG THUNDERSTORMS MOVING INTO LAKE COUNTY...

AT 110 PM EDT A LINE OF STRONG THUNDERSTORMS WAS MOVING INTO NORTHERN AND
CENTRAL LAKE COUNTY. EARLIER THIS AFTERNOON THIS LINE OF STORMS PRODUCED
STRONG GUSTY WINDS AND HEAVY RAIN OVER MARION COUNTY.

AT 115 PM THIS LINE WAS MOVING EAST AT 10 MPH AND IT WILL MOVE ACROSS
NORTHERN LAKE COUNTY BETWEEN 115 AND 230 PM. THE COMMUNITIES OF MT DORA...
LEESBURG AND CLERMONT SHOULD BE ADVISED THAT THESE STORMS MAY PRODUCE STRONG
GUSTY WINDS... POSSIBLE SMALL HAIL AND HEAVY RAIN. NUMEROUS CLOUD TO
GROUND LIGHTNING STROKES WIL#L ALSO OCCUR IN THIS SITUATION.
MOVEMENT WAS EAST 15 MPH.
Special weather statement, Aug 11, 1:45 PM EDT, 1 hour 30 minutes before
FLZ006>017-020-111840

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DAYTONA BEACH FL
140 PM EDT SAT AUG 11 1990

...A SEVERE THUNDERSTORM WARNING REMAINS IN EFFECT UNTIL 200 PM FOR EASTERN
MARION COUNTY AND NORTHWEST VOLUSIA COUNTY...

AT 131 PM A NEARLY SOLID BAND OF THUNDERSTORMS WITH VERY HEAVY RAINS...ABOUT 30
MILES WIDE...EXTENDED FROM JUST WEST OF ST AUGUSTINE ACROSS LAKE GEORGE AND
CONTINUED SOUTH TO NEAR LAKELAND.

THE THUNDERSTORMS WERE MOVING EAST AT AROUND 15 MPH.

THE THUNDERSTORMS OVER NORTHWEST VOLUSIA AND EASTERN MARION COUNTY REMAIN
DANGEROUS...CAPABLE OF PRODUCING WIND GUSTS IN EXCESS OF 50 MPH AND LARGE HAIL.
THESE THUNDERSTORMS WILL ALSO PRODUCE F:REQUENT DANGEROUS LIGHTNING STRIKES AND
VERY HEAVY RAINFALL AMOUNTS.

RESIDENTS ARE ADVISED TO BE PREPARED FOR THE APPROACH OF THESE THUNDERSTORMS
AND TO SEEK SAFE SHELTER IMMEDIATELY WHEN THEY ARE SIGHTED.
Special weather statement, Aug 11, 1:45 PM EDT, 1 hour 30 minutes before
FLZ011-016-017-111945-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
145 PM EDT SAT AUG 11 1990

...STRONG THUNDERSTORMS MOVING TOWARDS METRO ORLANDO...

AT 140 PM A BROKEN LINE OF SHOWERS AND THUNDERSTORMS EXTENDED FROM PALATKA
TO ASTOR PARK... TO JUST NORTH OF LEESBURG AND THEN TO NEAR MASCOTTE.
SOME OF THE THUNDERSTORMS CONTAIN GUSTY WINDS AND HEAVY RAIN. AT THIS
TIME THE STRONGEST STORMS WERE NEAR ASTOR PARK9 AND MASCOTTE.

BETWEEN 145 AM AND 345 PM SHOWERS AND THUNDERSTORMS WILL MOVE ACROSS
LAKE COUNTY AND INTO SEMINOLE AND ORANGE COUNTIES. THESE STORMS WILL
MOVE INTO WESTERN ORANGE COUNTY BY 230 PM AND REACH METRO ORLANDO BY
300 PM.
Special weather statement, Aug 11, 2:10 PM EDT, 1 hour 5 minutes before
FLZ012-111940

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE DAYTONA BEACH FL
210 PM EDT SAT AUG 11 1990

...THIS IS A SPECIAL WEATHER STATEMENT FOR FLAGLER AND NORTHERN VOLUSIA
COUNTIES AND THEIR ADJACENT COASTAL WATERS...

AT 205 PM STRONG THUNDERSTORMS CAPABLE OF PRODUCING STRONG GUSTY WINDS...
FREQUENT DANGEROUS LIGHTNING STRIKES...POSSIBLY SMALL HAIL...AND VERY HEAVY
RAIN EXTENDED FROM THE NORTHWEST CORNER OF FLAGLER COUNTY INTO NORTHWEST
VOLUSIA NEAR DELAND.

THE THUNDERSTORMS WERE MOVING EAST AT AROUND 10 MPH AND WILL LIKELY REMAIN
DANGEROUS AS THEY MOVE TO THE ADJACENT COASTAL WATERS.

RESIDENTS AND ARE ADVISED TO BE PREPARED FOR THE APPROACH OF THESE
THUNDERSTORMS AND TO SEETK SAFE SHELTER IMMEDIATELY WHEN THEY ARE SIGHTED.
BOATERS TOO...SHOULD BE PREPARED TO SEEK SAFE HARBOR.

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 11, 4:30 PM EDTSevere Thunderstorm WarningMLBBrevard60 min

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.