Alert archive / Florida / Severe Thunderstorm Warnings in 2000

Severe Thunderstorm Warning 51, NWS Melbourne, FL

July 20, 2000Osceola County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Jul 20, 2000, 7:34 PM EDT for Osceola County, Florida. It was in force for 56 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
Jul 20, 2000, 7:34 PM EDT (23:34 UTC)
Expired
Jul 20, 2000, 8:30 PM EDT
In force
56 min
Issued by
NWS Melbourne, FL
Area
Whole counties

County Osceola County, FL

The radar

The Melbourne radar (KMLB), 49 km from the middle of the area, began a volume at 23:35 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, 11.6 hours before the alert went out and 129 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-pSkew-T log-p diagram, Tampa Bay, FL at 12:00Z on 2000-07-20Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 3636 joules per kilogram.LCLLFCEL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Tampa Bay, FL at 12:00Z on 2000-07-20The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 3 square meters per square second.1939Sfc1 km3 km6 km9 kmRMLM
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
3636 J/kg
Mixed-layer CIN
-4 J/kg
Mixed-layer LCL
608 m above ground
0-6 km bulk shear
2 kt
0-1 km storm-relative helicity
3 m²/s²
0-3 km storm-relative helicity
54 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 
WUUS52 KMLB 202336
SVRMLB
FLC097-210030-
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
734 PM EDT THU JUL 20 2000

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  OSCEOLA COUNTY
  ...IN EAST CENTRAL FLORIDA

* UNTIL 830 PM EDT

* AT 732 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A 
  SEVERE THUNDERSTORM NEAR LAKE TOHO...MOVING NORTHEAST AT 20 MPH.

* THE SEVERE THUNDERSTORM WILL BE NEAR...
  NEAR SAINT CLOUD AT 745 PM EDT
  NEAR NARCOOSSEE AT 810 PM EDT

SEVERE THUNDERSTORMS PRODUCE DAMAGING WINDS IN EXCESS OF 58 MILES AN
HOUR...DESTRUCTIVE HAIL...DEADLY LIGHTNING AND VERY HEAVY RAIN. IF
THE STORM APPROACHES YOU...MOVE TO AN INTERIOR ROOM ON THE LOWEST
FLOOR.

LARGE HAIL...EXCESSIVE LIGHTNING AND DAMAGING WINDS ARE LIKELY. TAKE
COVER IN A STURDY BUILDING UNTIL THE STORM PASSES.

REPORT LARGE HAIL...DIME SIZE OR LARGER...OR SIGNIFICANT WIND DAMAGE
TO LOCAL LAW ENFORCEMENT FOR IMMEDIATE RELAY TO THE NATIONAL WEATHER
SERVICE.

$$

LAT...LON 2833 8162 2778 8114 2792 8088 2835 8089

28

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 Jul 20, 2:10 PM EDT, 5 hours 24 minutes earlier.

Area forecast discussion, Jul 20, 2:10 PM EDT, 5 hours 24 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
210 PM EDT THU JUL 20 2000

CURRENTLY/TONIGHT...CLOUDS LOOK LESS DEVELOPED THAN 24 HOURS
AGO...LIKELY FEELING THE EFFECTS OF THE WEAK SUBSIDENCE/DRYING THAT
WAS STILL EVIDENT ON THE WATER VAPOR IMAGERY.  EXPECT THAT STORMS
FIRING WEST OF LAKE OKEECHOBEE AND THE ATTENDANT OUTFLOWS WILL
PROPAGATE ACTIVITY TO THE NORTHEAST THROUGH THE AFTERNOON AND
EVENING. NO SEA BREEZE HAS DEVELOPED AND IT LOOKS DOUBTFUL THAT ONE
WILL FORM SO WILL JUST GO WITH SLIGHT CHANCE POPS FOR NOW...AND
ADJUST AS NEEDED BEFORE ZONE ISSUANCE.

FRIDAY/SATURDAY...WEAKENING FRONTAL TROUGH WILL BE STALLING NORTH OF
THE AREA AS SHORTWAVE LIFTS OUT AND NEXT ONE DROPS INTO BASE OF EAST
COAST TROUGH. SURFACE RIDGE STAYS SUPPRESSED TO THE SOUTH WITH A
CONTINUATION OF THE SOUTHWEST FLOW. H25 RIDGE AXIS IS PROGGED TO
WEAKEN AND SHIFT SLIGHTLY SOUTH.  THIS SHOULD ALLOW SUBSIDENCE TO
DIMINISH.  DEEP MOISTURE IS PROGGED BY ALL THE MODELS TO BE AT OR A
LITTLE ABOVE NORMAL (1.7 INCHES) WITH LITTLE CHANGE IN MID LEVEL
LAPSE RATES. GRADIENT FLOW MAY BE ENOUGH TO HOLD OFF A SEA BREEZE
ONCE AGAIN...EVEN THOUGH FWCS INSIST ONE WILL DEVELOP.  IT WILL
CONTINUE HOT WITH MID 90S IN MOST PLACES.  WILL NOT GO ABOVE THE 40
PERCENT FWC/FAN POPS DUE TO SEA BREEZE UNCERTAINTY.

SUNDAY THROUGH TUESDAY...SUCCESSION OF WEAK SHORTWAVES DROPPING
THROUGH MEAN EAST COAST TROUGH WILL KEEP A SURFACE FRONTAL TROUGH
QUASI STATIONARY JUST NORTH OF THE AREA AND SURFACE RIDGE AXIS
SUPPRESSED NEAR OR SOUTH OF LAKE OKEECHOBEE. RESULTANT SOUTHWEST
FLOW PATTERN FAVORS WARM TEMPS WITH SCATTERED AFTERNOON STORMS.  MRF
IS SHOWING THAT THE H25 RIDGE WILL WEAKEN/SHIFT SOUTH AS FLOW
PATTERN AMPLIFIES OVER THE EASTERN PART OF THE COUNTRY. THIS MAY
LEAD TO A LITTLE BIT OF AN INCREASE IN ACTIVITY.

MARINE...GRADIENT CONTINUES SLIGHTLY GREATER OVER NORTHERN SECTIONS
DUE TO WEAK SURFACE LOW VICINITY OF SOUTH CAROLINA. MODEL BOUNDARY
LAYER WIND PROGS SHOW QUITE A LOT OF 15 KNOT BARBS. WILL CONTINUE TO
SHOW SOME NORTH/SOUTH CONTRAST BUT OVERALL NO PROBLEMS NEAR SHORE
DUE TO THE WARM SOUTHWEST FLOW AND MAYBE 4 FEET OVER THE OUTER LEGS.

PRELIMINARY NUMBERS...
DAB BB 076/096 076/095 075 2324
MCO BB 077/096 076/095 075 2424
MLB BB 077/095 076/094 075 2424

.MLB...NONE.

PUBLIC/MARINE...LASCODY
AVIATION/FIRE WX...PENDERGRAST

The office that day

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

IssuedProductOfficeCountiesLasted
Jul 20, 5:41 PM EDTSevere Thunderstorm WarningMLBLake49 min
Jul 20, 6:28 PM EDTSevere Thunderstorm WarningMLBLake32 min
Jul 20, 6:39 PM EDTSevere Thunderstorm WarningMLBVolusia51 min
Jul 20, 7:08 PM EDTSevere Thunderstorm WarningMLBLake67 min
Jul 20, 7:30 PM EDTTornado WarningMLBLake30 min

Nearby

Severe Thunderstorm Warnings in Florida, 2000Every severe thunderstorm warning in 2000

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.