Alert archive / Florida / Tornado Watches in 1999

Tornado Watch 9

January 3, 199913 counties in Florida

The Storm Prediction Center issued this tornado watch at Jan 3, 1999, 12:45 AM EST for 13 counties in Florida. It was in force for 5 hr.

The area

The outline as issued.

The facts

Issued: Jan 3, 1999, 12:45 AM EST (05:45 UTC)
Expired: Jan 3, 1999, 6:00 AM EST
In force: 5 hr
Issued by: the Storm Prediction Center

Counties Broward County, FL, Charlotte County, FL, Collier County, FL, DeSoto County, FL, Glades County, FL, Hendry County, FL, Highlands County, FL, Martin County, FL, Miami-Dade County, FL, Monroe County, FL, Okeechobee County, FL, Palm Beach County, FL, Saint Lucie County, FL

The radar

The Miami radar (KAMX), 100 km from the middle of the area, began a volume at 05:51 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.

Warnings issued inside it

14 tornado, severe thunderstorm and flash flood warnings for its counties while it was in force.

Issued	Product	Office	Counties	Lasted
Jan 3, 1:01 AM EST	Severe Thunderstorm Warning	MFL	Collier	29 min
Jan 3, 1:07 AM EST	Severe Thunderstorm Warning	MFL	Glades	38 min
Jan 3, 1:14 AM EST	Tornado Warning	TBW	Highlands	46 min
Jan 3, 1:28 AM EST	Severe Thunderstorm Warning	MFL	Collier	47 min
Jan 3, 1:36 AM EST	Severe Thunderstorm Warning	MLB	Okeechobee	64 min
Jan 3, 1:42 AM EST	Severe Thunderstorm Warning	MFL	Glades	48 min
Jan 3, 2:14 AM EST	Severe Thunderstorm Warning	MFL	Collier, Hendry	46 min
Jan 3, 2:29 AM EST	Severe Thunderstorm Warning	MLB	Indian River, Saint Lucie	31 min
Jan 3, 2:37 AM EST	Severe Thunderstorm Warning	MFL	Monroe	53 min
Jan 3, 3:00 AM EST	Severe Thunderstorm Warning	MFL	Broward, Collier, Hendry, Palm Beach	45 min
Jan 3, 3:00 AM EST	Severe Thunderstorm Warning	MFL	Miami-Dade	45 min
Jan 3, 3:40 AM EST	Severe Thunderstorm Warning	MFL	Broward, Miami-Dade, Palm Beach	40 min
Jan 3, 4:20 AM EST	Severe Thunderstorm Warning	MFL	Broward, Miami-Dade	40 min
Jan 3, 4:20 AM EST	Severe Thunderstorm Warning	MFL	Palm Beach	40 min

The nearest sounding before it

Miami, FL (KMFL), launched 00:00Z, 5.8 hours before the alert went out and 81 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: 1088 J/kg
Mixed-layer CIN: -2 J/kg
Mixed-layer LCL: 710 m above ground
0-6 km bulk shear: 32 kt
0-1 km storm-relative helicity: 109 m²/s²
0-3 km storm-relative helicity: 176 m²/s²
Significant tornado parameter: 0.5
Supercell composite: 3.3

Open this sounding in Storm Lab

The text

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

999 
WWUS9 KMKC 030518
SEL9  
MKC WW 030518
FLZ000-031100-

URGENT - IMMEDIATE BROADCAST REQUESTED
TORNADO WATCH NUMBER 9
STORM PREDICTION CENTER NORMAN OK
118 AM EDT SUN JAN 3 1999

THE STORM PREDICTION CENTER HAS ISSUED A
TORNADO WATCH FOR PORTIONS OF

   SOUTHERN FLORIDA                            
   AND ADJACENT COASTAL WATERS

EFFECTIVE THIS SUNDAY MORNING FROM 145 AM UNTIL 700 AM EDT.

TORNADOES...HAIL TO 1 INCHES IN DIAMETER...THUNDERSTORM WIND GUSTS
TO 70 MPH...AND DANGEROUS LIGHTNING ARE POSSIBLE IN THESE AREAS.

THE TORNADO WATCH AREA IS ALONG AND 70 STATUTE MILES EAST AND WEST
OF A LINE FROM 75 MILES NORTHWEST OF WEST PALM BEACH FLORIDA TO 55
MILES SOUTH SOUTHWEST OF MIAMI FLORIDA.

REMEMBER...A TORNADO WATCH MEANS CONDITIONS ARE FAVORABLE FOR
TORNADOES AND SEVERE THUNDERSTORMS IN AND CLOSE TO THE WATCH AREA. 
PERSONS IN THESE AREAS SHOULD BE ON THE LOOKOUT FOR THREATENING
WEATHER CONDITIONS AND LISTEN FOR LATER STATEMENTS AND POSSIBLE
WARNINGS.

OTHER WATCH INFORMATION...  CONTINUE...WW 7...WW 8...

DISCUSSION...CONVECTIVE LINE BUILDING SOUTHWARD INTO SOUTHERN
FLORIDA AHEAD OF STRONG COLD FRONT. VEERING WIND PROFILE...MODERATE
INSTABILITY AND ABUNDANT LOW LEVEL MOISTURE INDICATE POTENTIAL FOR
A FEW TORNADIC SUPERCELLS.

AVIATION...TORNADOES AND A FEW SEVERE THUNDERSTORMS WITH HAIL
SURFACE AND ALOFT TO 1 INCHES.  EXTREME TURBULENCE AND SURFACE WIND
GUSTS TO 60 KNOTS.  A FEW CUMULONIMBI WITH MAXIMUM TOPS TO 450. 
MEAN STORM MOTION VECTOR 24035.


...ROGASH

272,0794 250,0793 250,0814 272,0820

SPC that day

Everything else SPC issued on the same UTC day.

Issued	Product	Office	Counties	Lasted
Jan 2, 9:00 PM EST	Tornado Watch	SPC	Alachua, Baker, Bradford, Brevard, Citrus, Clay and 26 more	6 hr

Nearby

Tornado Watches in Florida, 1999 Every tornado watch in 1999

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.