Alert archive / Florida / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 69, NWS Miami, FL
NWS Miami, FL issued this severe thunderstorm warning at May 21, 1999, 1:59 PM EDT for Palm Beach County, Florida. It was in force for 61 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
- May 21, 1999, 1:59 PM EDT (17:59 UTC)
- Expired
- May 21, 1999, 3:00 PM EDT
- In force
- 61 min
- Issued by
- NWS Miami, FL
- Area
- Whole counties
County Palm Beach County, FL
The radar
The Miami radar (KAMX), 115 km from the middle of the area, began a volume at 18:02 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, 2:03 PM EDT | Hail 0.88 | Belle Glade, 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, 6.0 hours before the alert went out and 93 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.
- 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
The text
As transmitted, in the capitals the NWS used until 2016.
999 WUUS1 KMIA 211800 RRA SVRMIA FLC099-211900- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MIAMI FL 159 PM EDT FRI MAY 21 1999 THE NATIONAL WEATHER SERVICE IN MIAMI HAS ISSUED A * SEVERE THUNDERSTORM WARNING FOR... WEST CENTRAL PALM BEACH COUNTY IN SOUTHEASTERN FLORIDA * UNTIL 300 PM EDT * AT 157 PM EDT...MIAMI NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A SEVERE THUNDERSTORM JUST NORTH OF BELLE GLADE DRIFTING SOUTHWEST AROUND 10 MPH. LARGE HAIL IS LIKELY WITH THIS SEVERE THUNDERSTORM. * SOME LOCATIONS AFFECTED... BELLE GLADE...SOUTH BAY...RUNYON SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 55 MPH... LARGE HAIL...DEADLY LIGHTNING...AND VERY HEAVY RAIN. SEEK SHELTER IN A STRONG BUILDING. STAY AWAY FROM WINDOWS. DO NOT USE TELEPHONES OR ELECTRICAL APPLIANCES.
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, 3 hours 45 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 25The 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, 2:29 PM EDT | Severe Thunderstorm Warning | MFL | Collier | 61 min |
| May 21, 3:45 PM EDT | Severe Thunderstorm Warning | MFL | Collier, Monroe | 30 min |
Nearby
Severe Thunderstorm Warnings in Florida, 1999Every 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.