Alert archive / Florida / Severe Thunderstorm Warnings in 2001

Severe Thunderstorm Warning 68, NWS Miami, FL

August 21, 2001Miami-Dade County, Florida

NWS Miami, FL issued this severe thunderstorm warning at Aug 21, 2001, 2:30 PM EDT for Miami-Dade County, Florida. It was in force for 60 min. 1 report came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Aug 21, 2001, 2:30 PM EDT (18:30 UTC)
Expired
Aug 21, 2001, 3:30 PM EDT
In force
60 min
Issued by
NWS Miami, FL
Area
Whole counties

County Miami-Dade County, FL

The radar

The Miami radar (KAMX), 9 km from the middle of the area, began a volume at 18:30 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.

What was reported inside it

TimeReportWhereRemark
Aug 21, 2:34 PM EDTHail 0.75Miami, FLDime-size hail was reported in Kendale Lakes.

NCEI Storm Data entries that began inside the alert's area while it was in force. Before 2003 the local storm report archive is thin, so this is the record of what happened rather than what was phoned in.

The nearest sounding before it

Miami, FL (KMFL), launched 12:00Z, 6.5 hours before the alert went out and 31 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, Miami, FL at 12:00Z on 2001-08-21Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1624 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Miami, FL at 12:00Z on 2001-08-21The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 26 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
1624 J/kg
Mixed-layer CIN
-47 J/kg
Mixed-layer LCL
1006 m above ground
0-6 km bulk shear
6 kt
0-1 km storm-relative helicity
26 m²/s²
0-3 km storm-relative helicity
36 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

The text of this product is not in the archive. The NWS text archive before 2002 is incomplete.

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.

NWS Miami, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Aug 21, 10:00 AM EDT, 4 hours 30 minutes earlier.

Area forecast discussion, Aug 21, 10:00 AM EDT, 4 hours 30 minutes before
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
1000 AM EDT TUE AUG 21 2001

AS OF THIS MOMENT...NO CHANGES IN THE PREVIOUS FORECAST PACKAGE.
HOWEVER..I DO BELIEVE WE COULD SEE ISOLATED HEAVY PRECIP IN SOME
AREAS THIS AFTERNOON AS 12Z SOUNDING CAME IN WITH A HIGHER PW (1.90)
AND STILL MEAN STEERING FLOW IS VERY LIGHT. THIS WILL ALLOW ANY
THUNDERSTORM THAT DEVELOP TO REMAIN NEARLY STATIONARY OR DRIFT VERY
SLOWLY.

.MIA...NONE.

GARCIA

In the hours before

Special weather statement, Aug 21, 9:30 AM EDT, 5 hours before
FLZ063-066>075-202000-

SOUTH FLORIDA HAZARDOUS WEATHER OUTLOOK...UPDATED
NATIONAL WEATHER SERVICE MIAMI FL
930 AM EDT TUE AUG 21 2001

...SCATTERED THUNDERSTORMS THIS AFTERNOON...
...SLIGHT CHANCE OF WATERSPOUTS ATLANTIC COASTAL WATERS...

SCATTERED THUNDERSTORMS WILL DEVELOP ALONG THE EAST AND WEST COAST
SEA BREEZES THIS AFTERNOON. DAYTIME HEATING AND ABUNDANT TROPICAL
MOISTURE WILL COMBINE TO PRODUCE SCATTERED THUNDERSTORMS OVER
INTERIOR SECTIONS OF SOUTH FLORIDA.

ON THE WEST COAST...THE THUNDERSTORM ACTIVITY WILL MOVE SLOWLY
TOWARD THE INTERIOR OF SOUTH FLORIDA. ON THE EAST COAST...THE
THUNDERSTORMS WILL MOVE TOWARD THE EAST COAST METROPOLITAN AREAS AND
ALONG THE SEA BREEZE.

THE PRIMARY HAZARDS FROM THESE THUNDERSTORMS WILL BE FREQUENT CLOUD
TO GROUND LIGHTNING STRIKES...LOCALLY HEAVY RAINFALL ALONG WITH
GUSTY WINDS. HOWEVER...SOME OF THE THUNDERSTORMS COULD APPROACH
SEVERE LIMITS WITH GUSTS UP TO 40 MPH. SPOTTER ACTIVATION IS
REQUESTED FOR THIS AFTERNOON.

A LIGHT EAST TO SOUTHEAST LOW TO MID LEVEL WIND FLOW WILL RESULT IN
A SLIGHT CHANCE OF WATERSPOUTS OVER THE ATLANTIC COASTAL WATERS
TODAY.

FOR ADDITIONAL INFORMATION VISIT THE NATIONAL WEATHER SERVICE IN
MIAMI WEBSITE AT HTTP://WWW.SRH.NOAA.GOV/MIA.

GARCIA

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 21, 1:20 PM EDTTornado WarningMFLMiami-Dade25 min
Aug 21, 1:44 PM EDTSevere Thunderstorm WarningMFLMiami-Dade46 min

Nearby

Severe Thunderstorm Warnings in Florida, 2001Every severe thunderstorm warning in 2001

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.