Alert archive / Florida / Severe Thunderstorm Warnings in 1994

Severe Thunderstorm Warning 8, NWS Miami, FL

April 18, 1994Hendry County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Apr 18, 1994, 4:21 PM EDT for Hendry County, Florida. It was in force for 69 min.

The area

The counties it named.

The facts

Issued
Apr 18, 1994, 4:21 PM EDT (20:21 UTC)
Expired
Apr 18, 1994, 5:30 PM EDT
In force
69 min
Issued by
NWS Miami, FL
Area
Whole counties

County Hendry County, FL

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 8.4 hours before the alert went out and 177 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 12:00Z on 1994-04-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 43 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, Tampa Bay, FL at 12:00Z on 1994-04-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 28 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
43 J/kg
Mixed-layer CIN
-100 J/kg
Mixed-layer LCL
813 m above ground
0-6 km bulk shear
20 kt
0-1 km storm-relative helicity
28 m²/s²
0-3 km storm-relative helicity
61 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.9

Open this sounding in Storm Lab

The text

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

000 
TTAA00 KMIA 182022 RRA
SVRMIA
FLC051-182130-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
421 PM EDT MON APR 18 1994
 
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A
SEVERE THUNDERSTORM WARNING EFFECTIVE UNTIL  530 PM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION......
 
IN SOUTH FLORIDA
 
   ...HENDRY COUNTY
 
AT 4 PM EDT THE HENDRY COUNTY SHERIFF'S OFFICE REPORTED A POSSIBLE
TORNADO IN HENDRY COUNTY ABOUT 8 MILES SOUTH SOUTHWEST OF CLEWISTON.
 
NATIONAL WEATHER SERVICE DOPPLER WEATHER RADAR INDICATED SEVERAL
THUNDERSTORMS WITH VERY HEAVY RAINFALL ACROSS MUCH OF
THE SOUTH TWO THIRDS OF HENDRY COUNTY FROM SOUTH OF CLEWISTON TO JUST
EAST OF LEHIGH ACRES. LITTLE MOVEMENT WAS INDICATED.
 
ADDITIONAL THUNDERSTORM ACTIVITY MAY DEVELOP IN THIS SAME AREA DURING
THE NEXT SEVERAL HOURS, AND PERSONS IN THIS AREA SHOULD REMAIN ON THE
WATCH FOR THREATENING WEATHER.
 
 
 
IF THREATENING WEATHER IS SIGHTED...TPAKE SHELTER...THEN CALL THE
LOCAL NATIONAL WEATHER SERVICE OFFICE AT 305 666-0884 OR REPORT THE
SEVERE WEATHER TO YOUR NEAREST LAW ENFORCEMENT AGENCY.

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 18, 3:40 PM EDT, 41 minutes before
FLZ067-182040-

SPECIAL WEATHER STATEMENT AND RADAR SUMMARY
NATIONAL WEATHER SERVICE WEST PALM BEACH FL
340 PM EDT MON APR 18 1994

    ...STRONG THUNDERSTORMS OVER WESTERN PALM BEACH COUNTY...

AT 335 PM EDT NATIONAL WEATHER SERVICE RADAR INDICATED CLUSTERS OF
STRONG THUNDERSTORMS OVER SOUTHWESTERN AND WESTERN PALM BEACH COUNTY
FROM 5 MILES EAST OF CANAL POINT SOUTH TO 15 MILES SOUTH OF SOUTH BAY.

THESE THUNDERSTORMS SHOWED LITTLE MOVEMENT DURING THE LAST HOUR.

THESE THUNDERSTORMS MAY PRODUCE STRONG GUSTY WINDS...FREQUENT DANGEROUS
CLOUD TO GROUND LIGHTNING STRIKES...REDUCED VISIBILITIES IN HEAVY
DOWNPOURS ALONG WITH THE PONDING OF WATER ON ROADWAYS.

RESIDENTS OF WESTERN AND CENTRAL PALM BEACH COUNTY AS WELL AS BOATERS
OPERATING ON LAKE OKEECHOBEE SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER FOR THE NEXT ONE TO TWO HOURS. IF THREATENING WEATHER APPROACHES
YOUR LOCATION SEEK A SAFE SHELTER OR HARBOR IMMEDIATELY.

THESE THUNDERSTORMS WERE PART OF AN AREA OF SCATTERED SHOWERS AND
THUNDERSTORMS THAT WERE OVER THE SOUTHERN PENINSULA SOUTH AND EAST
OF A LINE FROM COCOA BEACH TO SARASOTA. OTHER SHOWERS AND THUNDERSTORMS
SOME WITH VERY HEAVY RAIN CONTINUED OVER THE ATLANTIC WATERS FROM THE
GRAND BAHAMA ISLAND NORTH TO WALKERS CAY.

LITTLE MOVEMENT WAS OBSERVED.

NNNN

The office that day

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

IssuedProductOfficeCountiesLasted
Apr 18, 5:32 PM EDTSevere Thunderstorm WarningMFLCollier58 min

Nearby

Severe Thunderstorm Warnings in Florida, 1994Every severe thunderstorm warning in 1994

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.