Alert archive / Florida / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 75, NWS Melbourne, FL
NWS Melbourne, FL issued this severe thunderstorm warning at May 21, 1999, 1:57 PM EDT for Okeechobee County, Florida. It was in force for 48 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
- May 21, 1999, 1:57 PM EDT (17:57 UTC)
- Expired
- May 21, 1999, 2:45 PM EDT
- In force
- 48 min
- Issued by
- NWS Melbourne, FL
- Area
- Whole counties
County Okeechobee County, FL
The radar
The Melbourne radar (KMLB), 84 km from the middle of the area, began a volume at 18:00 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
Tampa Bay, FL (KTBW), launched 12:00Z, 6.0 hours before the alert went out and 153 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
- 1033 J/kg
- Mixed-layer CIN
- -65 J/kg
- Mixed-layer LCL
- 947 m above ground
- 0-6 km bulk shear
- 15 kt
- 0-1 km storm-relative helicity
- 36 m²/s²
- 0-3 km storm-relative helicity
- 76 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
999
WUUS01 KMLB 211758 RRA
SVRMLB
FLC093-211845-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
157 PM EDT FRI MAY 21 1999
THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
SOUTHERN OKEECHOBEE COUNTY IN EAST CENTRAL FLORIDA
* UNTIL 245 PM EDT
* AT 155 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM ALONG THE NORTH SHORE OF LAKE OKEECHOBEE JUST
SOUTH OF THE TOWN OF OKEECHOBEE. THE STORM WAS DRIFTING NORTHWEST.
* THE SEVERE THUNDERSTORM WILL AFFECT AREAS FROM
THE NORTH SHORE OF THE LAKE TO THE TOWN OF OKEECHOBEE.
SEVERE THUNDERSTORMS PRODUCE DAMAGING WIND IN EXCESS OF 58
MPH...DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN.
MOVE TO AN INTERIOR ROOM ON THE LOWEST FLOOR OF A STRONG BUILDING.
GLITTOWhat 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 Melbourne, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at May 21, 12:34 PM EDT, 1 hour 23 minutes earlier.
Area forecast discussion, May 21, 12:34 PM EDT, 1 hour 23 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 1010 AM EDT FRI MAY 21 1999 LOST THE GAMBLE...FEW SHOWERS BEGINNING TO POP OVER NRN CWA. WILL UPDATE ZONES SHORTLY. .MLB.h..NONE BRAGAW
In the hours before
Special weather statement, May 21, 12:15 PM EDT, 1 hour 42 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-212200- EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MELBOURNE FL 1215 PM EDT FRI MAY 21 1999 ...INCREASED CHANCE OF AFTERNOON THUNDERSTORMS... ...RIP CURRENT THREAT... THE ATMOSPHERE REMAINS MODERATELY UNSTABLE SOUTH OF ORLANDO AND CAPE CANAVERAL. COLD AIR ALOFT AND SUFFICIENT LOW LEVEL MOISTURE WILL COMBINE WITH THE EAST COAST SEA BREEZE THIS AFTERNOON TO PRODUCE THUNDERSTORMS. AN UPPER LEVEL DISTURBANCE OVER THE CENTRAL FLORIDA PENINSULA COULD ENHANCE SOME OF THE STORMS TO NEAR SEVERE LEVELS. WEAK FLOW ALOFT WILL ALLOW THE STORMS TO REMAIN NEARLY STATIONARY. AS A RESULT...THE STORMS COULD PRODUCE HEAVY RAIN IN A SHORT PERIOD OF TIME. IN ADDITION...SMALL HAIL...GUSTY WINDS AND FREQUENT CLOUD TO GROUND LIGHTNING WILL OCCUR IN THE STRONGER STORMS. TAKE SHELTER AT THE FIRST SIGN OF THREATENING SKIES. THE BEST CHANCE FOR THUNDERSTORMS WILL BE OVER INDIAN RIVER... MARTIN...OKEECHOBEE AND ST LUCIE COUNTIES...MAINLY WEST OF INTERSTATE 95. THE STORMS COULD DEVELOP AS FAR NORTH AS SOUTHERN BREVARD AND OSCEOLA COUNTIES. ELSEWHERE...A LONG PERIOD SWELL WILL RESULT IN A GREATER THAN NORMAL THREAT FOR RIP CURRENTS ALONG THE BEACHES OF VOLUSIA...BREVARD... INDIAN RIVER...ST LUCIE AND MARTIN COUNTIES. THE THREAT WILL BE GREATEST BETWEEN 2 AND 8 PM DURING THE OUTGOING TIDE. SWIM ON GUARDED BEACHES. NEVER ATTEMPT TO SWIM DIRECTLY AGAINST A CURRENT... BUT MOVE AT AN ANGLE TO IT...THEN BACK TO SHORE. BRAGAW
Special weather statement, May 21, 12:15 PM EDT, 1 hour 42 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-212200- EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MELBOURNE FL 1215 PM EDT FRI MAY 21 1999 ...INCREASED CHANCE OF AFTERNOON THUNDERSTORMS... ...RIP CURRENT THREAT... THE ATMOSPHERE REMAINS MODERATELY UNSTABLE SOUTH OF ORLANDO AND CAPE CANAVERAL. COLD AIR ALOFT AND SUFFICIENT LOW LEVEL MOISTURE WILL COMBINE WITH THE EAST COAST SEA BREEZE THIS AFTERNOON TO PRODUCE THUNDERSTORMS. AN UPPER LEVEL DISTURBANCE OVER THE CENTRAL FLORIDA PENINSULA COULD ENHANCE SOME OF THE STORMS TO NEAR SEVERE LEVELS. WEAK FLOW ALOFT WILL ALLOW THE STORMS TO REMAIN NEARLY STATIONARY. AS A RESULT...THE STORMS COULD PRODUCE HEAVY RAIN IN A SHORT PERIOD OF TIME. IN ADDITION...SMALL HAIL...GUSTY WINDS AND FREQUENT CLOUD TO GROUND LIGHTNING WILL OCCUR IN THE STRONGER STORMS. TAKE SHELTER AT THE FIRST SIGN OF THREATENING SKIES. THE BEST CHANCE FOR THUNDERSTORMS WILL BE OVER INDIAN RIVER... MARTIN...OKEECHOBEE AND ST LUCIE COUNTIES...MAINLY WEST OF INTERSTATE 95. THE STORMS COULD DEVELOP AS FAR NORTH AS SOUTHERN BREVARD AND OSCEOLA COUNTIES. ELSEWHERE...A LONG PERIOD SWELL WILL RESULT IN A GREATER THAN NORMAL THREAT FOR RIP CURRENTS ALONG THE BEACHES OF VOLUSIA...BREVARD... INDIAN RIVER...ST LUCIE AND MARTIN COUNTIES. THE THREAT WILL BE GREATEST BETWEEN 2 AND 8 PM DURING THE OUTGOING TIDE. SWIM ON GUARDED BEACHES. NEVER ATTEMPT TO SWIM DIRECTLY AGAINST A CURRENT... BUT MOVE AT AN ANGLE TO IT...THEN BACK TO SHORE. BRAGAW
The office that day
Everything else NWS Melbourne, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 20, 11:23 PM EDT | Severe Thunderstorm Warning | MLB | Brevard | 47 min |
| May 21, 12:12 AM EDT | Severe Thunderstorm Warning | MLB | Brevard | 63 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; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.