Alert archive / Florida / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 18, NWS Melbourne, FL
NWS Melbourne, FL issued this severe thunderstorm warning at Apr 28, 1999, 4:45 PM EDT for Lake 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
- Apr 28, 1999, 4:45 PM EDT (20:45 UTC)
- Expired
- Apr 28, 1999, 5:45 PM EDT
- In force
- 60 min
- Issued by
- NWS Melbourne, FL
- Area
- Whole counties
County Lake County, FL
The radar
The Melbourne radar (KMLB), 126 km from the middle of the area, began a volume at 20:49 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 |
|---|---|---|---|
| Apr 28, 4:55 PM EDT | Thunderstorm Wind 50 | Altoona, FL | The US Forest Service reported numerous trees down from severe thunderstorm winds in Altoona. |
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
Tampa Bay, FL (KTBW), launched 12:00Z, 8.8 hours before the alert went out and 136 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
- 1203 J/kg
- Mixed-layer CIN
- -41 J/kg
- Mixed-layer LCL
- 869 m above ground
- 0-6 km bulk shear
- 10 kt
- 0-1 km storm-relative helicity
- 0 m²/s²
- 0-3 km storm-relative helicity
- 12 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- 0.0
The text
As transmitted, in the capitals the NWS used until 2016.
000 TTAA00 KMLB 282043 RRA SVRMLB FLC069-282145- BULLETIN - IMMEDIATE BROADCAST REQUESTED SEVERE THUNDERSTORM WARNING NATIONAL WEATHER SERVICE MELBOURNE FL 445 PM EDT WED APR 28 1999 THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED
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 Melbourne, FL wrote its last area forecast discussion before this severe thunderstorm warning went out at Apr 28, 4:08 PM EDT, 37 minutes earlier.
Area forecast discussion, Apr 28, 4:08 PM EDT, 37 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION...CORRECTED NATIONAL WEATHER SERVICE MELBOURNE FL 330 PM EDT WED APR 28 1999 CURRENTLY...H50 VORT MAX OVER FL PEN SPARKING WIDESPREAD CONVECTION ACROSS CWA. OUTFLOW BOUNDARY FROM SRN CONVECTION INTERACTING WITH WCSB TO SEND DEVELOPING TSTMS OVER NRN CWA THROUGH THE ROOF. TEMPS MUCH COOLER THAN EXPECTED DUE TO DENSE CLOUD SHIELD. TONIGHT/THU...H85-H25 OMEGA BLOCK WILL DEVELOP OVER CENTRAL U.S. THROUGH 12Z THU. H25 JET MAX OVER LOWER MS VALLEY WILL DRIFT SE UNDER THE RESULTING WIND FLOW...CAUSING THE LOW CENTER NEAR THE APPALACHAIN TO FILL AND ALLOWING A WK LOW OVER THE SW ATLC TO DEVELOP. UNDER THIS MOTION...THE BACKDOOR FRONT OVER SC/GA WILL COUPLE WITH THE LATE SEASON COLD FRONT IN THE NORTH GULF REGION AND THEN DRIFT INTO THE NRN FL PEN. SFC WINDS TO TURN W TO NW THORUGH 00Z FRI AS THE FRONT DRIFTS TOWARD THE AREA. H70 OMEGA...H50 VORT...AND H25 JET DYNAMICS ARE MARGINAL THROUGH 00Z FRI...BUT RH VALUES WILL REMAIN HIGH ENOUGH FOR MESO SCALE FEATURES TO TRIGGER PRECIP. SCT TO GOOD CHANCE POPS LOOK BEST...WITH HIGHER NUMBERS ALONG THE COAST. PATCHY LATE NIGHT/EARLY MORNING FOG WILL ALSO BE MENTIONED TONIGHT AS WINDS BECOMING LIGHT OVERNIGHT. AREAS WHICH RECEIVED SOME BENEFICIAL RAINS TODAY ARE MOST LIKELY TO SEE FOG/STRATUS. FRI...INTERESTING DAY WITH TEMPS ALOFT COOLING ANOTHER COUPLE DEG AS UPPER LOW DRIFTS ESE. EXPECT 500 TEMPS -14 TO -15C WITH RESIDUAL MOISTURE AHEAD OF SOUTHWARD SAGGING FRONTAL BOUNDARY. WILL KEEP POPS IN SCT CATEGORY. SAT-MON...DRY THROUGH THE PERIOD WITH TEMPS AT OR SLIGHTLY BELOW CLIMO...WARMING BY MON. MARINE...UNEVENTFUL OUTSIDE OF TSTMS/OUTFLOWS. LATE 3RD PD COULD SEE WINDS/SEAS PICK UP...ESP FLG-COF LEG DEPENDING ON INTENSITY OF OFFSHORE LOW. .MLB...NONE. CCF NUMBERS... DAB TB 066/087 064/079 057 60352 MCO BB 066/089 064/084 060 60242 MLB TB 067/088 066/082 060 60353 BRAGAW/CRISTALDI
In the hours before
Special weather statement, Apr 28, 11:25 AM EDT, 5 hours 20 minutes before
AMZ550-555-FLZ041-044>047-053-054-058-059-064-281725- EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MELBOURNE FL 1125 AM EDT WED APR 28 1999 ...A FEW SEVERE THUNDERSTORMS POSSIBLE THIS AFTERNOON AND EVENING... SUFFICIENT MOISTURE WILL COMBINE WITH A MODERATELY UNSTABLE ATMOSPHERE AND SEA BREEZES TO PRODUCE SOME MUCH NEEDED RAIN THIS AFTERNOON AND EVENING. RAINFALL COVERAGE IS EXPECTED TO BE A LITTLE HIGHER THAN ON TUESDAY...WITH THE GREATEST CHANCES OVER THE COASTAL COUNTIES DURING THE AFTERNOON. A CLUSTER OF LIGHTNING STORMS BETWEEN LAKE OKEECHOBEE AND THE MELBOURNE ORLANDO AREA WILL CONTINUE TO DRIFT TO THE EAST. A WELL DEVELOPED SEA BREEZE FROM THE FLORIDA WEST COAST WILL MOVE EAST INTO CENTRAL FLORIDA. ADDITIONAL LIGHTNING STORM DEVELOPMENT IS EXPECTED OVER MUCH OF CENTRAL FLORIDA AS THIS SEA BREEZE COLLIDES WITH THE OUTFLOW BOUNDARY MOVING NORTH FROM THE SOUTHERN STORMS. THE GREATEST THREAT FOR LIGHTNING STORMS AND POSSIBLY LARGE HAIL AND DAMAGING WINDS WILL EXTEND FROM THE GREATER ORLANDO AREA TO THE COAST AND AS FAR NORTH AS DAYTONA BEACH. MOST LIGHTNING FATALITIES AND INJURIES OCCUR IN OPEN FIELDS OR UNDER TREES. IF OUTDOORS...SEEK SHELTER IN A STURDY BUILDING OR CAR. DO NOT TAKE SHELTER IN SMALL SHEDS...UNDER ISOLATED TREES...OR IN CONVERTIBLE AUTOMOBILES. MARINE OUTLOOK...SCATTERED STORMS WILL PRODUCE CLOUD TO GROUND LIGHTNING NEAR OR EAST OF THE INTRACOASTAL WATERWAYS AS THE INLAND LIGHTNING STORMS MOVE EAST THIS AFTERNOON. THESE STORMS WILL LAST INTO THE EARLY EVENING. DECKER
Local storm report, Apr 28, 4:07 PM EDT, 38 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
407 PM EDT WED APR 28 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0150 PM ORLANDO INTL ARPT FL 1.75 INCH HAIL
04/28/99 ORANGE GOLF BALL SIZE HAIL WAS
REPORTED JUST SOUTHEAST OF
ORLANDO INTERNATIONAL
AIRPORT.
0205 PM DAYTONA BEACH FL TSTM WIND
04/28/99 VOLUSIA THE PUBLIC REPORTED TWO
TREES BLOWN DOWN IN
DAYTONA BEACH.
0320 PM ORLANDO FL 1 INCH HAIL
04/28/99 ORANGE QUARTER SIZE HAIL WAS
REPORTED BY ORANGE COUNTY
SKYWARN.Local storm report, Apr 28, 4:07 PM EDT, 38 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE FL
407 PM EDT WED APR 28 1999
TIME(EDT) .....CITY LOCATION..... STATE ...EVENT/REMARKS...
....COUNTY LOCATION....
0150 PM ORLANDO INTL ARPT FL 1.75 INCH HAIL
04/28/99 ORANGE GOLF BALL SIZE HAIL WAS
REPORTED JUST SOUTHEAST OF
ORLANDO INTERNATIONAL
AIRPORT.
0205 PM DAYTONA BEACH FL TSTM WIND
04/28/99 VOLUSIA THE PUBLIC REPORTED TWO
TREES BLOWN DOWN IN
DAYTONA BEACH.
0320 PM ORLANDO FL 1 INCH HAIL
04/28/99 ORANGE QUARTER SIZE HAIL WAS
REPORTED BY ORANGE COUNTY
SKYWARN.The office that day
Everything else NWS Melbourne, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| Apr 28, 1:48 PM EDT | Severe Thunderstorm Warning | MLB | Orange | 42 min |
| Apr 28, 2:44 PM EDT | Severe Thunderstorm Warning | MLB | Orange | 46 min |
| Apr 28, 4:39 PM EDT | Severe Thunderstorm Warning | MLB | Volusia | 61 min |
| Apr 28, 7:02 PM EDT | Tornado Warning | MLB | Osceola | 33 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.