Alert archive / Florida / Severe Thunderstorm Warnings in 1999
Severe Thunderstorm Warning 59, NWS Melbourne, FL
NWS Melbourne, FL issued this severe thunderstorm warning at May 12, 1999, 2:53 PM EDT for Saint Lucie County, Florida. It was in force for 47 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 12, 1999, 2:53 PM EDT (18:53 UTC)
- Expired
- May 12, 1999, 3:40 PM EDT
- In force
- 47 min
- Issued by
- NWS Melbourne, FL
- Area
- Whole counties
County Saint Lucie County, FL
The radar
The Melbourne radar (KMLB), 84 km from the middle of the area, began a volume at 18:52 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
Miami, FL (KMFL), launched 12:00Z, 6.9 hours before the alert went out and 174 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
- 1036 J/kg
- Mixed-layer CIN
- -16 J/kg
- Mixed-layer LCL
- 811 m above ground
- 0-6 km bulk shear
- 20 kt
- 0-1 km storm-relative helicity
- -8 m²/s²
- 0-3 km storm-relative helicity
- 31 m²/s²
- Significant tornado parameter
- 0.0
- Supercell composite
- -0.1
The text
As transmitted, in the capitals the NWS used until 2016.
999
WUUS01 KMLB 121854
SVRMLB
FLC111-121940-
BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
253 PM EDT WED MAY 12 1999
THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A
* SEVERE THUNDERSTORM WARNING FOR...
ST. LUCIE COUNTY IN EAST CENTRAL FLORIDA
* UNTIL 340 PM EDT
* AT 350 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
SEVERE THUNDERSTORM NEAR INDRIO. MOVEMENT WAS NEARLY STATIONARY.
* OTHER STORMS MAY DEVELOP AND BECOME SEVERE ALONG THE EAST
COAST. LARGE HAIL WILL BE THE MAIN THREAT.
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.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 May 12, 2:35 PM EDT, 18 minutes earlier.
Area forecast discussion, May 12, 2:35 PM EDT, 18 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION NATIONAL WEATHER SERVICE MELBOURNE FL 235 PM EDT WED MAY 12 1999 CURRENTLY...INCREASING MOISTURE IS ALLOWING BOTH SEA BREEZES TO BECOME QUITE ACTIVE AND PRODUCE HIGHER COVERAGE OF THUNDERSTORMS THAN PREVIOUS DAYS. BOUNDARY COLLISIONS AND INTERACTIONS ALONG WITH INCREASING SOLAR HEATING WILL SUPPORT THUNDERSTORM DEVELOPMENT THE REMAINDER OF THE AFTERNOON AND INTO THIS EVENING. WESTERLY STEERING FLOW IS PUSHING STORMS ON THE WEST COAST BREEZE EASTWARD AT A GOOD CLIP TOWARDS OUR FA. TONIGHT...GOOD CHANCE POPS REQUIRED FOR EVENING AS RESIDUAL BOUNDARY INTERACTIONS TAKE PLACE AND STEERING FLOW PUSHES ACTIVITY SLOWLY TOWARDS THE EAST COAST. ACTIVITY WILL DIMINISH WELL AFTER SUNSET. LEFTOVER MID/HIGH CLOUD DEBRIS FROM CONVECTION SHOULD DOMINATE MUCH OF THE NIGHT. RIDGE AXIS OVER THE SOUTHERN PENINSULA WILL PRODUCE SOUTHWEST FLOW OVERNIGHT. AS A RESULT...EVEN WITH FAIRLY GOOD COVERAGE OF RAIN EXPECTED ACROSS FA...FOG SHOULD NOT BE A PROBLEM EXCEPT FOR SOME AVIATION FOG IN THE TYPICALLY FAVORED LOCATIONS IN THE NORTH AND INTERIOR. SOME STRATUS ALSO POSSIBLE. SEASONABLE TEMPS EXPECTED AND FWC/FAN GUIDANCE LOOKS GOOD. THU/FRI...LOW LEVEL RIDGE AXIS BECOMES WELL DEFINED ACROSS FLORIDA KEYS THROUGH FRI. SW TO W LOW LEVEL FLOW WILL TIGHTEN UP AS PRESSURES RISE A BIT TO THE S AND BEGIN TO FALL ACROSS THE TN VALLEY AND CAROLINAS AS A NEW SHORT WAVE TROUGH APPROACHES FROM THE NW. 500MB TEMPS WARM TO ABOUT -11C INITIALLY AS HEIGHTS RISE...BUT LOOK POISED TO FALL AGAIN BY H48 WITH THE APPROACHING UPPER TROUGH...ESP NORTH. AIR MASS MAY DRY OUT SOME BY FRI...BUT WILL STILL BE MOIST ENOUGH TO PRODUCE SCATTERED POPS EACH DAY...REGIME DOMINATED MORE BY WEST COAST BREEZE MOVING EAST INTO MLB CWA LATE. SAT/SUN/MON...00Z NOGAPS DISCARDED DUE TO INADEQUATE DEPICTION OF UPPER TROUGH BY 12Z FRI. UKMET/ECMWF/MRF ALL SIMILAR AT 500MB WITH AN UPPER LOW CUTTING OFF EAST OF GA/SC. MRF SHOWS A CONSOLIDATED SFC LOW WHILE THE EURO MODELS DEVELOP AN INVERTED TROUGH SOUTH INTO THE COASTAL WATERS. UKMET AND MRF ACTUALLY RETROGRADE THE SURFACE AND UPPER SYSTEMS WSW-WARD ACROSS THE PENINSULA AND H144 ECMWF HINTS AT DOING THE SAME. THIS COULD BODE FOR A VERY WET AND UNSETTLED WX PATTERN EARLY NEXT WEEK. MARINE...WINDS/SEAS GRADUALLY VEER AND INCREASE (MAINLY OFFSHORE) THROUGH PERIOD WITH MODERATELY STRONG SW-W FLOW DEVELOPING. NO HILITES NEEDED AT THIS TIMFE. THANX FOR COORD MIA. CCF NUMBERS... DAB BB 065/090 065/090 065 60544 MCO BB 066/088 067/091 066 60543 MLB BB 066/089 067/089 066 60544 .MLB...NONE. KELLY/CRISRALDI
In the hours before
Special weather statement, May 12, 11:45 AM EDT, 3 hours 8 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-122200- EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MELBOURNE FL 1145 AM EDT WED MAY 12 1999 ...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS...SOME STRONG... A WEAK SURFACE LOW PRESSURE CENTER ALONG THE GEORGIA COAST WILL LIFT NORTH TODAY AND ALLOW A RIDGE OF HIGH PRESSURE TO BUILD FROM THE ATLANTIC ACROSS SOUTHERN SECTIONS OF THE FLORIDA PENINSULA. THIS WILL RESULT IN A DEVELOPING WESTERLY COMPONENT TO THE LOW LEVEL WIND FLOW. THEREFORE...STORMS THAT FORM ALONG THE SEA BREEZE BOUNDARY THIS AFTERNOON WILL MOVE EAST...BACK TOWARDS THE COAST... WITH AN INCREASE IN COVERAGE EXPECTED COMPARED TO THE LAST FEW DAYS. THE EAST COAST SEA BREEZE WILL DEVELOP AND PUSH INLAND TO AROUND INTERSTATE 95 BY MID AFTERNOON WHERE WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO FORM. ADDITIONAL STORMS MAY DEVELOP OVER INTERIOR SECTIONS THROUGH EARLY EVENING. IT APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS TO DEVELOP IS NORTH OF A LINE FROM CAPE CANAVERAL TO LEESBURG. IN ADDITION...STRONG SOLAR HEATING AND DEEPER ATMOSPHERIC MOISTURE EXISTS OVER MARTIN AND ST LUCIE COUNTIES MAKING THAT AN AREA FAVORABLE FOR DEVELOPMENT AS WELL. HOWEVER...MID LEVEL CLOUDS ARE MOVING INTO THAT AREA WHICH MAY INHIBIT THUNDERSTORM DEVELOPMENT. CONTINUED COLD TEMPERATURES ALOFT WILL AGAIN ALLOW HAIL TO OCCUR IN THE STRONGER STORMS. INCREASED COVERAGE OF STORMS AND MORE OF A WESTERLY WIND COMPONENT IN THE ATMOSPHERE SHOULD RESULT IN A GREATER DANGER FROM LIGHTNING...SINCE STRIKES CAN OCCUR WELL AWAY FROM THE HEAVY RAIN ASSOCIATED WITH A THUNDERSTORM. MARINE...STORMS THAT FORM OVER LAND DURING THE DAY MAY AFFECT THE INTRACOASTAL AND NEARSHORE ATLANTIC WATERS BY THE EARLY EVENING. HAIL...GUSTY WINDS TO 35 MPH AND FREQUENT CLOUD TO WATER LIGHTNING CAN BE EXPECTED IN THE STRONGER STORMS. KELLY
Special weather statement, May 12, 11:45 AM EDT, 3 hours 8 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-122200- EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE MELBOURNE FL 1145 AM EDT WED MAY 12 1999 ...SCATTERED AFTERNOON AND EVENING THUNDERSTORMS...SOME STRONG... A WEAK SURFACE LOW PRESSURE CENTER ALONG THE GEORGIA COAST WILL LIFT NORTH TODAY AND ALLOW A RIDGE OF HIGH PRESSURE TO BUILD FROM THE ATLANTIC ACROSS SOUTHERN SECTIONS OF THE FLORIDA PENINSULA. THIS WILL RESULT IN A DEVELOPING WESTERLY COMPONENT TO THE LOW LEVEL WIND FLOW. THEREFORE...STORMS THAT FORM ALONG THE SEA BREEZE BOUNDARY THIS AFTERNOON WILL MOVE EAST...BACK TOWARDS THE COAST... WITH AN INCREASE IN COVERAGE EXPECTED COMPARED TO THE LAST FEW DAYS. THE EAST COAST SEA BREEZE WILL DEVELOP AND PUSH INLAND TO AROUND INTERSTATE 95 BY MID AFTERNOON WHERE WIDELY SCATTERED THUNDERSTORMS ARE EXPECTED TO FORM. ADDITIONAL STORMS MAY DEVELOP OVER INTERIOR SECTIONS THROUGH EARLY EVENING. IT APPEARS THAT THE BEST CHANCE FOR THUNDERSTORMS TO DEVELOP IS NORTH OF A LINE FROM CAPE CANAVERAL TO LEESBURG. IN ADDITION...STRONG SOLAR HEATING AND DEEPER ATMOSPHERIC MOISTURE EXISTS OVER MARTIN AND ST LUCIE COUNTIES MAKING THAT AN AREA FAVORABLE FOR DEVELOPMENT AS WELL. HOWEVER...MID LEVEL CLOUDS ARE MOVING INTO THAT AREA WHICH MAY INHIBIT THUNDERSTORM DEVELOPMENT. CONTINUED COLD TEMPERATURES ALOFT WILL AGAIN ALLOW HAIL TO OCCUR IN THE STRONGER STORMS. INCREASED COVERAGE OF STORMS AND MORE OF A WESTERLY WIND COMPONENT IN THE ATMOSPHERE SHOULD RESULT IN A GREATER DANGER FROM LIGHTNING...SINCE STRIKES CAN OCCUR WELL AWAY FROM THE HEAVY RAIN ASSOCIATED WITH A THUNDERSTORM. MARINE...STORMS THAT FORM OVER LAND DURING THE DAY MAY AFFECT THE INTRACOASTAL AND NEARSHORE ATLANTIC WATERS BY THE EARLY EVENING. HAIL...GUSTY WINDS TO 35 MPH AND FREQUENT CLOUD TO WATER LIGHTNING CAN BE EXPECTED IN THE STRONGER STORMS. KELLY
The office that day
Everything else NWS Melbourne, FL issued on the same UTC day.
| Issued | Product | Office | Counties | Lasted |
|---|---|---|---|---|
| May 11, 8:40 PM EDT | Severe Thunderstorm Warning | MLB | Orange, Osceola | 45 min |
| May 12, 2:58 PM EDT | Severe Thunderstorm Warning | MLB | Indian River | 47 min |
| May 12, 3:47 PM EDT | Severe Thunderstorm Warning | MLB | Indian River | 63 min |
| May 12, 5:20 PM EDT | Severe Thunderstorm Warning | MLB | Okeechobee | 45 min |
| May 12, 5:57 PM EDT | Severe Thunderstorm Warning | MLB | Volusia | 48 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.