Alert archive / Florida / Severe Thunderstorm Warnings in 1991

Severe Thunderstorm Warning 9, NWS Melbourne, FL

April 17, 1991Palm Beach County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Apr 17, 1991, 7:25 PM EDT for Palm Beach County, Florida. It was in force for 65 min.

The area

The counties it named.

The facts

Issued
Apr 17, 1991, 7:25 PM EDT (23:25 UTC)
Expired
Apr 17, 1991, 8:30 PM EDT
In force
65 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Palm Beach County, FL

The nearest sounding before it

Cape Canaveral, FL (KXMR), launched 12:00Z, 11.4 hours before the alert went out and 203 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 1991-04-17Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 516 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 1991-04-17The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 10 square meters per square second.193958Sfc1 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
516 J/kg
Mixed-layer CIN
-26 J/kg
Mixed-layer LCL
875 m above ground
0-6 km bulk shear
23 kt
0-1 km storm-relative helicity
10 m²/s²
0-3 km storm-relative helicity
-12 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.2

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KPBI 172325
SVRPBI
FLC099-180030-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE WEST PALM BEACH FL
725 PM EDT WED APR 17 1991
 
THE NATIONAL WEATHER SERVICE IN WEST PALM BEACH HAS ISSUED A
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
EFFECTIVE UNTIL  830 PM EDT
FOR THE FOLLOWING LOCATIONS...
 
IN SOUTHEAST FLORIDA
 
   ...PALM BEACH COUNTY
 
  AND FOR BOATERS ON THE WATERS...
 
   ...PALM BEACH INLET  TO  JUPITER INLET
 
AT 7:25 PM NATIONAL WEATHER SERVICE RADAR INDICATED VERY STRONG
THUNDERSTORMS WITH VERY HEAVY RAINFALL OVER CENTRAL AND SOUTHWEST PALM
BEACH COUNTY. MOVEMENT OF THESE THUNDERSTORMS WERE EAST AT 10 MPH.
 
RESIDENTS AND MARINERS IN PALM BEACH COUNTY AND ADJACENT COASTAL
WATERS MAY ENCOUNTER BRIEF HEAVY DOWNPOURS...STRONG GUSTY
WINDS...HAIL...AND FREQUENT DANGEROUS LIGHTNING. MARINERS SHOULD BE
AWARE OF THESE STORMS AND HEAD FOR SAFE HARBOR.
 
 
WHEN THUNDERSTORMS ARE OCCURRING...PEOPLE SHOULD MOVE INSIDE A
STRONG BUILDING.  DO NOT STAND BY WINDOWS.  DON'T USE TELEPHONES
OR ELECTRICAL APPLIANCES UNLESS IN AN EMERGENCY UNTIL THE STORM
HAS PASSED.  MOTORISTS SHOULD NOT DRIVE INTO LOW WATER CROSSINGS.
 
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55
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 SdO
DON'T DRIVE INTO AREAS WHERE WATER COVERS THE ROAD.
 
 
NNNN

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, Apr 17, 1:46 PM EDT, 5 hours 39 minutes before
FLZ017-011-016-012-009-171845-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
145 PM EDT WED APR 17 1991

AT 135 PM SHOWERS AND THUNDERSTORMS WERE SCATTERED OVER MUCH OF EAST
CENTRAL FLORIDA. THE STRONGEST STORMS WERE OVER CAPE CANAVERAL
EXTENDING JUST OFFSHORE OF COCOA BEACH...NEAR DISNEY WORLD...OVER LAKE
COUNTY FROM LEESBURG TO ASTOR PARK NORTH TO LAKE GEORGE...AND ON THE
WESTERN FRINGES OF FLAGLER AND VOLUSIA COUNTIES. OTHER STRONG
STORMS WERE OVER SOUTHERN OSCEOLA AND SOUTHERN BREVARD COUNTIES.
THE STORMS WERE MOVING NORTHEAST AT 15 MPH.

SOME OF THESE STORMS CAN PRODUCE VERY HEAVY DOWNPOURS...STRONG GUSTY
WINDS...FREQUENT DANGEROUS LIGHTNING...AND POSSIBLE SMALL HAIL.
IF THREATENING WEATHER APPROACHES GO TO A PLACE OF SAFETY. BOATERS AND
OTHER MARINE INTERESTS SHOULD BE ON THE LOOKOUT FOR THESE STORMS AS
THEY MOVE OFFSHORE FROM FLAGLER BEACH TO SEBASTIAN INLET AND SEEK SAFE
HARBOR.

OVER THE NEXT TWO HOURS THUNDERSTORMS WILL CONTINUE OVER A GOOD
PORTION OF EAST CENTRAL FLORIDA AND THE COASTAL WATERS FROM FLAGLER
BEACH TO SEBASTIAN INLET.

R.SMITH
Special weather statement, Apr 17, 1:49 PM EDT, 5 hours 36 minutes before
FLZ006>017-020-171900-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE DAYTONA BEACH FL
145 PM EDT WED APR 17 1991

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

NUMEROUS STRONG THUNDERSTORMS CAPABLE OF PRODUCING STRONG GUSTY WINDS...
...FREQUENT DANGEROUS LIGHTNING STRIKES...POSSIBLY SMALL HAIL...AND
VERY HEAVY RAINFALL CONTINUE MOVING SLOWLY EAST ACROSS NORTHEAST FLORIDA.

THE THUNDERSTORMS HAD MADE THEIR WAY INTO THE WESTERN AREAS OF FLAGLER AND
VOLUSIA COUNTIES AND CAN BE EXPECTED TO REMAIN STRONG AS THEY MAKE THEIR WAY TO
THE COASTAL AREAS. WINDS GUSTS IN EXCESS OF 30 MILES AND HOUR ARE LIKELY TO
ACCOMPANY THESE THUNDERTORMS AS WELL AS NUMEROUS LIGHTNING STRIKES.

RESIDENTS AND MARINERS ARE ADVISED TO BE PREPARED FOR THE APPROACH OF THESE
THUNDERSTORMS AND BE PREPARED TO SEEK SAFE SHELTER IMMEDIATELY...KEEPING
IN MIND LIGHTNING SAFETY TIPS.

RADAR INDICATED NUMEROUS THUNDERSTORMS WITH VERY HEAVY RAIN EXTENDING FROM
SOUTHEAST GEORGIA DOWN THE ST JOHNS RIVER TO AROUND DELAND. THE THUNDERSTORMS
THEN BECAME WIDELY SCATTERD FROM AROUND ORLANDO SOUTHWARD TO THE PEACE RIVER.
A SOLID AREA OF THUNDERSTORMS WAS ALSO ALONG THE EAST CENTRAL FLORIDA COAST
FROM TITUSVILLE TO VERO BEACH.

THUNDERSTORM MOVEMENT WAS EAST AT 10 TO 15 MPH.
Special weather statement, Apr 17, 2:12 PM EDT, 5 hours 13 minutes before
FLZ017-011-016-012-009-171915-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
211 PM EDT WED APR 17 1991

AT 210 PM A STRONG THUNDERSTORM WAS OVER ORANGE COUNTY JUST SOUTHWEST
OF ORLANDO INTERNATIONAL AIRPORT. ONE HALF INCH HAIL HAS BEEN REPORTED
SOUTH OF THE METROPOLITAN ORLANDO AREA WITH THIS STORM. THE STORM WAS
MOVING NORTHEAST AT 15 MPH AND WILL MOVE THROUGH THE ORLANDO AREA
WITHIN THE NEXT HOUR.

ST2RONG WIND GUSTS...LARGE HAIL...AND FREQUENT DANGEROUS LIGHTNING
CAN BE EXPECTED WITH THIS STORM. PERSONS IN ORANGE COUNTY FROM JUST
EAST OF DISNEY THROUGH THE ORLANDO AREA SHOULD TAKE SAFE SHELTER
AS THIS STORM MOVES THROUGH.

R.SMITH
Special weather statement, Apr 17, 2:52 PM EDT, 4 hours 33 minutes before
FLZ017-011-016-012-009-172000-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
251 PM EDT WED APR 17 1991

AT 240 PM SHOWERS AND THUNDERSTORMS CONTINUED OVER PARTS OF EAST
CENTRAL FLORIDA. THE STRONGEST STORMS WERE OVER ORANGE COUNTY FROM NEA
TO WINTER GARDEN EAST TO METROPOLITAN ORLANDO...OVER INDIAN RIVER
COUNTY WEST OF FELLSMERE...AND OFFSHORE OUT 10 MILES FROM COCOA BEACH.
WATER SPOUTS HAVE BEEN REPORTRD WITH THE STORM OFFSHORE OF COCOA...AND
ONE HALF INCH HAIL WAS REPORTED SOUTH OF ORLANDO. WINDS ALSO GUSTED
TO 53 MPH AT 222 PM AT THE ORLANDO INTERNATIONAL AIRPORT. OTHER STORMS
WERE EXTENDED FROM BITHLO TO TITUSVILLE AND ANOTHER WAS NEAR
MASCOTTE. STORMS WERE ALSO OVER WESTERN VOLUSIA AND MUCH OF FLAGLER
COUNTY. THE STORMS WERE MOVING NORTHEAST AT 15 MPH.

VERY HEAVY DOWNPOURS...STRONG GUSTY WINDS...HAIL...AND FREQUENT
DANGEROUS LIGHTNING CAN BE EXPECTED WITH THESE STORMS. PERSONS
SHOULD BE READY TO TAKE SAFE SHELTER IF THREATENING WEATHER
APPROACHES.

OVER THE NEXT TWO HOURS THUNDERSTORMS WILL CONTINUE OVER PARTS OF
EAST CENTRAL FLORIDA...WITH THE STRONGEST ACTIVITY MOVING THROUGH
ORANGE COUNTY... SOUTHERN BREVARD COUNTY...OFFSHpORE OF COCOA BEACH AND
NEAR FLAGLER BEACH..

R.SMITH
Special weather statement, Apr 17, 3:46 PM EDT, 3 hours 39 minutes before
FLZ017-011-016-012-009-172045-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
345 PM EDT WED APR 17 1991

...SEVERE THUNDERSTORM WARNING FOR NORTHERN BREVARD COUNTY UNTIL 415
AND A SPECIAL MARINE WARNING FROM CAPE CANAVERAL TO VERO BEACH UNTIL
500 PM...

AT 240 PM SEVERE THUNDERSTORMS WERE MOVING OVER NORTHERN BREVARD
COUNTY TOWARD CAPE CANAVERAL AND COCOA. OTHER STRONG THUNDERSTORMS
WERE OVER WESTERN INDIAN RIVER COUNTY...AND ANOTHER AREA EXTENDED
FROM NEAR APOPKA TO DISNEY TO LAKELAND. A STRONG THUNDERSTORM
WAS ALSO 10 MILES OFFSHORE COCOA BEACH AND ANOTHER OFFSHORE FROM
SEBASTIAN.

PERSONS SHOULD BE PREPARED TO SEEK SAFE SHELTER SHOULD THREATENING
WEATHER APPROACH. ANY OF THESE STORMS CAN PRODUCE VERY HEAVY
DOWNPOURS...STRONG GUSTY WINDS...HAIL...AND FREQUENT DANGEROUS
LIGHTNING. BOATERS SHOULD BE AWARE OF THESE STORMS AND HEAD FOR
SAFE HARBOR IF POSSIBLE.

R.SMITH
Special weather statement, Apr 17, 4:45 PM EDT, 2 hours 40 minutes before
FLZ017-011-016-012-009-172145-

SPECIAL EAST CENTRAL FLORIDA WEATHER UPDATE
NATIONAL WEATHER SERVICE MELBOURNE FL
444 PM EDT WED APR 17 1991

...SPECIAL MARINE WARNING FROM CAPE CANAVERAL TO VERO BEACH UNTIL
5PM...

AT 430 PM STRONG THUNDERSTORMS WERE SCATTERED OVER EAST CENTRAL
FLORIDA FROM COCOA TO CAPE CANAVERAL EXTENDING OFFSHORE 30 TO 50 MILES
FROM THE CAPE TO ST AUGUSTINE. OTHER STORMS WERE FROM SANFORD TO
ORLANDO AND KISSIMMEE SOUTHWEST TO LAKELAND. ANOTHER STORM WAS NEAR
FELLSMERE IN INDIAN RIVER COUNTY. THE STORMS WERE MOVING NORTHEAST
AT 15 MPH.

SOME OF THESE STORMS CAN PRODUCE VERY HEAVY DOWNPOURS...STRONG
WINDS...SMALL HAIL AND DANGEROUS LIGHTNING.

DURING THE NEXT TWO HOURS THE STORMS WILL CONTINUE TO MOVE NORTHEAST
AND BE FROM ST CLOUD TO BITHLO TO CAPE CANAVERAL. ANOTHER STORM WILL
MOVE ACROSS INDIAN RIVER COUNTY TOWARD SEBASTIAN. STORMS WILL ALSO
CONTINUE OFFSHORE FROM THE CAPE NORTH TO ST AUGUSTINE OUT 30 TO 50
MILES. BOATERS SHOULD SEEK SAFE HARBOR AS THESE STORMS MOVE OVER THE
COASTAL WATERS FROM NORTH OF COCOA BEACH TO WELL OFFSHORE
ST AUGUSTINE.

R.SMITH

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 17, 3:17 PM EDTSevere Thunderstorm WarningMLBBrevard58 min
Apr 17, 5:26 PM EDTSevere Thunderstorm WarningMLBMartin, Saint Lucie2 hr

Nearby

Severe Thunderstorm Warnings in Florida, 1991Every severe thunderstorm warning in 1991

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.