Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 71, NWS Miami, FL

May 21, 1999Collier County, Monroe County, Florida

NWS Miami, FL issued this severe thunderstorm warning at May 21, 1999, 3:45 PM EDT for Collier County, Monroe County, Florida. It was in force for 30 min. 1 report came from inside the area while it was in force.

The area

The outline the Iowa Environmental Mesonet reconstructed for it; the warning itself named whole counties, with what was reported inside it.

The facts

Issued: May 21, 1999, 3:45 PM EDT (19:45 UTC)
Expired: May 21, 1999, 4:15 PM EDT
In force: 30 min
Issued by: NWS Miami, FL
Area: Whole counties; the outline is the Mesonet’s reconstruction

Counties Collier County, FL, Monroe County, FL

The radar

The Miami radar (KAMX), 72 km from the middle of the area, began a volume at 19:47 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

Time	Report	Where	Remark
May 21, 4:00 PM EDT	Hail 0.88	Monroe Station, FL

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, 7.8 hours before the alert went out and 85 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: 1466 J/kg
Mixed-layer CIN: -14 J/kg
Mixed-layer LCL: 969 m above ground
0-6 km bulk shear: 17 kt
0-1 km storm-relative helicity: -16 m²/s²
0-3 km storm-relative helicity: 27 m²/s²
Significant tornado parameter: 0.0
Supercell composite: 0.0

Open this sounding in Storm Lab

The text

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

999 
WUUS1 KMIA 211946 RRA
SVRMIA
FLC021-087-212015-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MIAMI FL
345 PM EDT FRI MAY 21 1999

THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  EXTREME SOUTHEASTERN COLLIER COUNTY IN FLORIDA
  NORTHWESTERN MONROE COUNTY IN FLORIDA

* UNTIL 415 PM EDT

* AT 344 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM 15 MILES SOUTHWEST OF PINECREST...MOVING       
  NORTHEAST AT 10 MPH. THIS STORM WILL MOVE ACROSS COUNTY ROAD 94 
  AND TOWARDS THE TAMIAMI TRAIL AT FIFTY MILE BEND. LARGE HAIL IS
  POSSIBLE WITH THIS STORM AS WELL AS HEAVY RAIN.    


REPORT SEVERE WEATHER TO THE NEAREST LAW ENFORCEMENT AGENCY. THEY
WILL RELAY YOUR REPORT TO THE NATIONAL WEATHER SERVICE FORECAST
OFFICE IN MIAMI.

LAT...LON 2561 8126 2551 8110 2574 8090 2587 8111

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

Local storm report, May 21, 10:14 AM EDT, 5 hours 31 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE MIAMI, FL
1014 AM EDT FRI MAY 21 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0232 PM    PALM BEACH GARDENS        FL   .75 INCH HAIL
05/20/99   PALM BEACH                     DIME SIZE HAIL REPORTED BY
                                          CHANNEL 25

Local storm report, May 21, 3:10 PM EDT, 35 minutes before

STORM REPORT
NATIONAL WEATHER SERVICE MIAMI, FL
310 PM EDT FRI MAY 21 1999

TIME(EDT)  .....CITY LOCATION..... STATE  ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0855 AM    NORTH PALM BEACH          FL
05/21/99   PALM BEACH                     NUMEROUS REPORTS OF FUNNEL
                                          CLOUDS FROM COMMUNITIES IN
                                          NORTHEAST PALM BEACH
                                          COUNTY REPORTED BY POLICE
                                          AND PUBLIC

0203 PM    BELLE GLADE               FL   .88 INCH HAIL
05/21/99   PALM BEACH                     NICKEL SIZE HAIL REPORTED
                                          IN BELLE GLADE BY POLICE
                                          DEPT

0244 PM    GOLDEN GATE               FL   .75 INCH HAIL
05/21/99   COLLIER                        DIME SIZE HAIL REPORTED AT
                                          THE ALLIGATOR ALLEY I-75
                                          TOLL BOOTH EAST OF NAPLES
                                          BY FLORIDA HIGHWAY PATROL

0300 PM    GOLDEN GATE               FL   1.25 INCH HAIL
05/21/99   COLLIER                        SILVER DOLLAR SIZE HAIL
                                          REPORTED IN GOLDEN GATE BY
                                          COLLIER COUNTY EMERGENCY
                                          MANAGEMENT

The office that day

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

Issued	Product	Office	Counties	Lasted
May 21, 1:23 PM EDT	Severe Thunderstorm Warning	MFL	Palm Beach	52 min
May 21, 1:59 PM EDT	Severe Thunderstorm Warning	MFL	Palm Beach	61 min
May 21, 2:29 PM EDT	Severe Thunderstorm Warning	MFL	Collier	61 min

Nearby

Severe Thunderstorm Warnings in Florida, 1999 Every severe thunderstorm warning 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; verification from NCEI's Storm Data; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.