Alert archive / Florida / Severe Thunderstorm Warnings in 1999

Severe Thunderstorm Warning 71, NWS Melbourne, FL

May 19, 1999Seminole County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at May 19, 1999, 5:53 PM EDT for Seminole County, Florida. It was in force for 47 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 19, 1999, 5:53 PM EDT (21:53 UTC)
Expired: May 19, 1999, 6:40 PM EDT
In force: 47 min
Issued by: NWS Melbourne, FL
Area: Whole counties

County Seminole County, FL

The radar

The Melbourne radar (KMLB), 88 km from the middle of the area, began a volume at 21:52 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.

What was reported inside it

Time	Report	Where	Remark
May 19, 6:00 PM EDT	Thunderstorm Wind 50	Geneva, FL	Thunderstorm winds blew down several trees on a house in Geneva.

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

Cape Canaveral, FL (KXMR), launched 12:00Z, 9.9 hours before the alert went out and 77 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: 372 J/kg
Mixed-layer CIN: -143 J/kg
Mixed-layer LCL: 1258 m above ground
0-6 km bulk shear: 14 kt
0-1 km storm-relative helicity: 18 m²/s²
0-3 km storm-relative helicity: 20 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.

000 
TTAA00 KMLB 192153 RRA
SVRMLB
FLC117-192240-

BULLETIN - IMMEDIATE BROADCAST REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
553 PM EDT WED MAY 19 1999

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
     EASTERN SEMINOLE COUNTY IN EAST CENTRAL FLORIDA

* UNTIL 640 PM EDT

* AT 553 PM...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
  SEVERE THUNDERSTORM GENIEVA TO JUST EAST OF OVIEDO.  MOVEMENT WAS
  SOUTHEAST AT 15 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
    LAKE HARNEY AND CROSS HWY 46



JP/RL

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 19, 2:18 PM EDT, 3 hours 35 minutes earlier.

Area forecast discussion, May 19, 2:18 PM EDT, 3 hours 35 minutes before

EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
218 PM EDT WED MAY 19 1999

TONIGHT...UPPER LEVEL SHORT WAVE/VORT MAX AND CONVERGENCE ZONE
AHEAD OF FRONT WILL MOVE SLOWLY SOUTHEAST AND KEEP THUNDERSTORMS
GOING THROUGH EARLY EVENING OVER FA. THE THUNDERSTORMS WILL
GENERALLY DEVELOP IN PROX TO SEA BREEZE COLLISION AND SHRT WV AXIS
IN THE N AND SHIFT SE TO COASTAL RGNS THIS EVE. THE HIGHEST POPS
TONIGHT WILL BE OVER THE S PTN OF FA DUE TO AFTERNOON INTERIOR
STORMS MOVING SOUTHEAST TOWARDS THE EAST COAST. THE COLD FRONT WILL
BECOME DIFFUSE OVERNIGHT AS RIDGE OF HIGH BUILD IN FROM THE NORTH.
PATCHY FOG SHOULD DEVELOP OVER FA EARLY THURSDAY MORNING DUE TO
LIGHT WINDS AND DECENT LOW LEVEL MOISTURE.

LONG TERM...SFC BNDRY WILL WASH OUT ACROSS NORTHERN PARTS OF FA AS
MID LVL SHRT WV/VRT AXIS MOVES SOUTH OF THE PENINSULA BY THU
MORNING. WATER VAPOR IMG SHOWS SIGNIFICANT DRYING IN THE MID LEVELS
BEHIND FEATURE BUT THE LOW LEVELS WL HAVE MINIMAL DRYING. MDL
GUIDANCE SHOWS PW VALUES FM A HIGH NEAR 1.4 THIS EVE TO JUST ABV 1.0
THU MORNING. MORE IMPORTANTLY HOWEVER...THERE SHUD BE SIGNIFICANT
SYNOPTIC DVM AS THE MDLS DIFFERENTIAL VORT ADV SHOWS BEHIND MID
LEVEL WV.

AS SFC RIDGE TENDS TO BRIDGE WHAT IS LEFT OF LOW LEVEL BNDRY AN
INVERTED TROF IS DEPICTED ESP IN ETA S OF THE HIGH. THIS IN PART MAY
BE THE REASON FOR HIER THAN EXPECTED POPS FOR TMRW. WILL BIAS POPS
HIGHEST IN THE S AS THEY SHUD HOLD ON TO THE MOISTURE THE LONGEST.

SFC RIDGE BUILDING ACROSS THE CAROLINAS WILL KEEP DEEP EASTERLY FLOW
ACROSS THE STATE INTO THE WEEKEND. GUIDANCE SHOWS LRG SCALE
SUBSIDENCE S OF RIDGE AXIS AND DRY AIR. REGARDLESS ESTRLIES WL PUSH
E COAST BREEZE RAPIDLY THRU FA DURING THE LT MORNING AND EARLY AFTN
LIMITING PCPN CHCS THRU THE WEEKEND. NOCTURNAL SHRA CHC WILL BE
LIMITED INITIALY FOR ABV MENTIONED SUBSIDENCE.

MARINE...SHRA/TS  ACTVTY WL MOVE OFF THE COAST THIS EVE AND INTO THE
OPEN WATERS. VRBL FLOW TO BECOME NE AND INC LATE THU AS RIDGE
SHIFTS S.

PRELIM...

DAB BU 064/083 065/083 068 0532-
MCO BU 065/086 066/087 067 0532-
MLB BB 067/084 068/084 069 05331

.MLB...NONE.

BORZILLERI/BLOTTMAN

The office that day

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

Issued	Product	Office	Counties	Lasted
May 19, 5:42 PM EDT	Severe Thunderstorm Warning	MLB	Volusia	48 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.