Alert archive / Florida / Severe Thunderstorm Warnings in 1997

Severe Thunderstorm Warning 1, NWS Miami, FL

April 12, 1997Collier County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Apr 12, 1997, 5:09 AM EDT for Collier County, Florida. It was in force for 66 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: Apr 12, 1997, 5:09 AM EDT (09:09 UTC)
Expired: Apr 12, 1997, 6:15 AM EDT
In force: 66 min
Issued by: NWS Miami, FL
Area: Whole counties

County Collier County, FL

The radar

The Miami radar (KAMX), 111 km from the middle of the area, began a volume at 09:14 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, 9.2 hours before the alert went out and 113 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-p

Temperature in red, dew point in green, the mixed-layer parcel dashed.

Hodograph

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: 218 J/kg
Mixed-layer CIN: -3 J/kg
Mixed-layer LCL: 956 m above ground
0-6 km bulk shear: 27 kt
0-1 km storm-relative helicity: 52 m²/s²
0-3 km storm-relative helicity: 109 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 KMIA 120911 RRA
SVRMIA
FLC021-121015-
 
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
NATIONAL WEATHER SERVICE MIAMI FL
509 AM EDT SAT APR 12 1997
 
THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A
SEVERE THUNDERSTORM AND SPECIAL MARINE WARNING
EFFECTIVE UNTIL  615 AM EDT
FOR PEOPLE IN THE FOLLOWING LOCATION......
 
IN SOUTHWEST FLORIDA
 
   ...WESTERN COLLIER COUNTY
 
AND THE ADJACENT COASTAL WATERS
 
NATIONAL WEATHER SERVICE RADAR HAS IDENTIFIED A SEVERE THUNDERSTORM
APPROXIMATELY 25 MILES WEST SOUTHWEST OF NAPLES AT 500 AM. THIS
PARTICULAR THUNDERSTORM DISPLAYS POTENTIAL FOR HIGH DAMAGING
WINDS...VERY HEAVY RAINS...AND POSSIBLE WATERSPOUTS AS IT COMES
ASHORE DURING THE NEXT HOUR. THE PUBLIC IS ADVISED THAT THE GREATEST
THREAT IS ALONG THE COAST BETWEEN MARCO ISLAND AND NAPLES AS WELL
AS FOR SEVERAL MILES INLAND.
 
DAMAGING WIND IN EXCESS OF 55 MPH...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.
 
THUNDERSTORMS THREATEN BOATER SAFETY WITH GUSTY WINDS IN EXCESS OF
35 KNOTS...ROUGH SEAS AND DEADLY LIGHTNING.  YOUR BEST COURSE OF
ACTION IS TO SEEK SAFE HARBOR...BUT IF YOU ARE CAUGHT ON THE OPEN
WATER...STAY BELOW DECK OR KEEP A LOW PROFILE AND KEEP AWAY FROM
UNGROUNDED METAL OBJECTS. WEAR FLOTATION DEVICES.

The office that day

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

Issued	Product	Office	Counties	Lasted
Apr 12, 6:14 AM EDT	Tornado Warning	MFL	Collier, Monroe	61 min
Apr 12, 7:53 AM EDT	Severe Thunderstorm Warning	MFL	Miami-Dade	67 min
Apr 12, 8:20 AM EDT	Flash Flood Warning	MFL	Collier	115 min
Apr 12, 10:40 AM EDT	Flash Flood Warning	MFL	Collier	110 min

Nearby

Severe Thunderstorm Warnings in Florida, 1997 Every severe thunderstorm warning in 1997

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.