Alert archive / Florida / Severe Thunderstorm Warnings in 2003

Severe Thunderstorm Warning 112, NWS Melbourne, FL

August 18, 2003Lake County, Florida

NWS Melbourne, FL issued this severe thunderstorm warning at Aug 18, 2003, 5:42 PM EDT for Lake County, Florida. It was in force for 63 min. No storm report in the archive falls inside the area while it was in force.

The area

The outline as issued.

The facts

Issued
Aug 18, 2003, 5:42 PM EDT (21:42 UTC)
Expired
Aug 18, 2003, 6:45 PM EDT
In force
63 min
Issued by
NWS Melbourne, FL
Area
Counties, with a storm outline in the text

County Lake County, FL

The radar

The Tampa radar (KTBW), 99 km from the middle of the area, began a volume at 21:46 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.

Did it verify

Not verified. The Iowa Environmental Mesonet's Cow found no qualifying storm report inside this severe thunderstorm warning while it was in force. That is not proof nothing happened: reports are thin where few people live.

Cow counts a report within 15 km of the polygon while the warning was in force: a tornado for a tornado warning; hail of 1 inch or more, a gust of 58 mph or more or wind damage for a severe thunderstorm warning; a flash flood report for a flash flood warning.

The nearest sounding before it

Tampa Bay, FL (KTBW), launched 12:00Z, 9.7 hours before the alert went out and 99 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 2003-08-18Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 1306 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 2003-08-18The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 30 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
1306 J/kg
Mixed-layer CIN
-19 J/kg
Mixed-layer LCL
807 m above ground
0-6 km bulk shear
3 kt
0-1 km storm-relative helicity
30 m²/s²
0-3 km storm-relative helicity
28 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 182142
SVRMLB
FLC069-182245-

BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE MELBOURNE FL
539 PM EDT MON AUG 18 2003

THE NATIONAL WEATHER SERVICE IN MELBOURNE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
  SOUTHERN LAKE COUNTY
  IN EAST CENTRAL FLORIDA

* UNTIL 645 PM EDT

* AT 540 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
  TWO SEVERE THUNDERSTORMS OVER SOUTHERN LAKE COUNTY. THE FIRST WAS
  14 MILES SOUTH OF CLERMONT...OR ABOUT 6 MILES WEST OF MGM STUDIOS
  ...ALONG THE ORANGE COUNTY LINE.

  THE SECOND WAS OVER EXTREME SOUTHWEST LAKE COUNTY ALONG THE POLK
  COUNTY LINE. BOTH STORMS WERE MOVING NORTH AT 5 MPH.

* THESE SEVERE THUNDERSTORMS WILL BE SPREAD NORTH TOWARD CLERMONT
  AND GROVELAND THROUGH 615 PM EDT. OTHER SEVERE STORMS WILL BE
  POSSIBLE.

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.

LAT...LON 2832 8171 2832 8178 2837 8183 2832 8188
          2838 8198 2853 8198 2868 8188 2868 8168

$$

CRISTALDI

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 Aug 18, 2:20 PM EDT, 3 hours 22 minutes earlier.

Area forecast discussion, Aug 18, 2:20 PM EDT, 3 hours 22 minutes before
EAST CENTRAL FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MELBOURNE FL
220 PM EDT MON AUG 18 2003

DEEP CONVECTION NOW UNDERWAY ALONG THE EAST COAST SEA BREEZE FROM
VOLUSIA TO MARTIN COUNTY. 15Z XMR SOUNDING INDICATING NEAR 2.2 INCH
PCP WATER AMOUNTS. SLOW INLAND PUSH TO SEA BREEZE AND WEAK SW TO NE
STEERING FLOW WILL KEEP COASTAL COUNTIES ACTIVE INTO THE EVENING
HOURS. FREQUENT LIGHTNING AND MINOR FLOODING WILL BE MAIN CONCERN.
PLAN ON GOING WITH HIGHER POPS ALONG COASTAL CTYS THIS EVE.
BREEZE/BNDRY COLLSION STILL LIKELY FROM CENTRAL VOLUSIA CTY TO NEAR
LK OKEECHOBEE.

TUE-THU...UPPER TROUGH ACROSS EASTERN STATES WILL SLIDE EAST WITH
RIDGE BUILDING IN. SEMI-PERMANENT ATLANTIC RIDGE WILL BE THE MAIN
PLAYER OVER THE NEXT FEW DAYS...WITH AXIS SHIFTING TO THE NORTH.
ATMOSPHERE SHOULD STAY QUITE MOIST (PW AT OR ABOVE 2 INCHES)...SO
SCATTERED POPS LOOK LIKE THE WAY TO GO. BIGGEST THREAT WILL BE HEAVY
RAIN AND POTENTIAL FLOODING WITH SLOW MOVING STORMS IN WEAK FLOW.
SMALL HAIL AND STRONG GUSTY WINDS ARE ALSO LIKELY IN THIS
ENVIRONMENT.

FRI-MON...WELL-DEFINED FRONTAL BOUNDARY PUSHES EAST ACROSS MIDWEST
AND NORTHEAST STATES BUT WEAKENS AS IT RUNS INTO RIDGE OFFSHORE.
FRONT MAY MAKE IT INTO SOUTHEAST STATES BUT WILL LIKELY DISSIPATE
BEFORE REACHING THE PENINSULA. RIDGE AXIS WILL RESPOND BY SINKING
SLOWLY BACK TO THE SOUTH. NOT MUCH VARIABILITY IN THE MREF MEMBERS
SO WILL BASE FORECAST LARGELY ON INFLUENCE OF SYNOPTIC WIND REGIME.

MARINE...WITH RIDGE AXIS CLOSE BY...WINDS WILL REMAIN LIGHT. SWELLS
NOT A FACTOR SO WIND WAVES ARE PRIMARY CONTRIBUTOR TO SEAS. WAVE
WATCH HAS A GOOD HANDLE ON THINGS...WITH SEAS PEAKING AT 2 FT
THROUGH THE PERIOD.

...PRELIMINARY POINT TEMPS/POPS...
DAB BE 073/088 073/089 073 343
MCO TT 074/090 073/090 074 353
MLB EE 074/089 073/088 074 343
VRB BE 074/089 074/088 074 343

.MLB WATCHES/WARNINGS/ADVISORIES...NONE.

SHORT TERM...BLOTTMAN
LONG TERM...HIRSCH
Hazardous weather outlook, Aug 18, 6:00 AM EDT, 11 hours 42 minutes before
AMZ550-555-570-575-FLZ041-044>047-053-054-058-059-064-141-144-147-
181900-

EAST CENTRAL FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE MELBOURNE FL
600 AM EDT MON AUG 18 2003

.DAY ONE...TODAY

...SCATTERED THUNDERSTORMS THIS AFTERNOON AND EVENING...

INCREASED MOISTURE IS EXPECTED TO LEAD TO THE DEVELOPMENT OF MORE
AFTERNOON STORMS THAN YESTERDAY.  THE INITIAL FOCUS FOR STORMS WILL
BE THE SEA BREEZE DURING THE EARLY AFTERNOON...PARTICULARLY IN
SOUTHERN SECTIONS WHERE IT INTERACTS WITH THE LAKE OKEECHOBEE
BOUNDARY.  COVERAGE AND INTENSITY OF STORMS WILL THEN INCREASE
THROUGH THE AFTERNOON AS NUMEROUS BOUNDARY INTERACTIONS OCCUR.

THE STRONGEST STORMS ARE EXPECTED DURING THE LATE AFTERNOON WHEN A
MORE SUBSTANTIAL BOUNDARY COLLISION OCCURS ASSOCIATED WITH THE EAST
AND WEST COAST SEA BREEZES.  THIS IS EXPECTED TO BE ORIENTED FROM
VOLUSIA COUNTY TO OSCEOLA COUNTY.  STORM MOTION WILL BE TO THE
NORTHEAST AROUND 10 MPH AND A FEW STORMS SHOULD PUSH BACK TOWARDS THE
COAST THROUGH EARLY EVENING.

THE MAIN THREAT FROM STORMS WILL BE FREQUENT LIGHTNING STRIKES.  IF
YOU HEAR THUNDER...YOU ARE WITHIN RANGE OF A THUNDERSTORM AND SHOULD
SEEK SHELTER IMMEDIATELY.  A FEW OF THE STRONGER STORMS COULD PRODUCE
QUICK 2 INCH DOWNPOURS...WHICH WOULD AGGRAVATE STANDING WATER
PROBLEMS IN SOME AREAS.

.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY:
BY MID WEEK...THE MAIN FOCUS FOR AFTERNOON STORMS SHOULD SHIFT TO THE
INTERIOR AND WESTERN PORTIONS OF THE PENINSULA.

.SPOTTER INFORMATION STATEMENT...

SKYWARN SPOTTER ACTIVATION IS NOT EXPECTED TODAY.

FOR A GRAPHICAL VERSION OF THIS HAZARDOUS WEATHER OUTLOOK...GO TO
WWW.WEATHER.GOV AND CLICK ON EAST CENTRAL FLORIDA.

RL

In the hours before

Special weather statement, Aug 18, 2:12 PM EDT, 3 hours 30 minutes before
FLZ059-181845-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
212 PM EDT MON AUG 18 2003

...STRONG STORMS WITH FREQUENT TO EXCESSIVE LIGHTNING OVER EASTERN
ST. LUCIE COUNTY...

AT 209 PM EDT...NATIONAL WEATHER SERVICE LIGHTNING DETECTION
EQUIPMENT INDICATED A STORM WITH FREQUENT TO EXCESSIVE LIGHTNING
OVER FORT PIERCE SOUTH.  THE STORM WAS DRIFTING SOUTH AT 5 MPH.

LOCATIONS IN THE PATH OF THE LIGHTNING STORM INCLUDE INDIAN RIVER
ESTATES...FORT PIERCE NORTH...PORT SAINT LUCIE RIVER PARK AND SAINT
LUCIE AIRPORT.

THIS STORM WILL PRODUCE VERY HEAVY RAINFALL OF 1 TO 2 INCHES...
FREQUENT TO EXCESSIVE CLOUD TO GROUND LIGHTNING STRIKES AND GUSTY
WINDS TO 45 MPH.

IF YOU ARE OUTDOORS...TAKE SHELTER IN A BUILDING OR ENCLOSED
AUTOMOBILE. TREES AND OPEN SHELTERS FOUND ON A GOLF COURSE OFFER NO
PROTECTION.

15
Special weather statement, Aug 18, 2:56 PM EDT, 2 hours 46 minutes before
FLZ059-064-181945-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
256 PM EDT MON AUG 18 2003

...STRONG STORM CAPABLE OF PRODUCING WIND GUSTS UP TO 50 MPH OVER
SOUTHEASTERN ST. LUCIE COUNTY AND EASTERN MARTIN COUNTY...

AT 254 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STORM CAPABLE OF PRODUCING STRONG WIND GUSTS TO 45 TO 50 OVER PORT
SAINT LUCIE...MOVING SOUTHEAST AT 10 MPH.

THIS STORM WILL MOVE INTO NORTHEAST SECTIONS OF MARTIN COUNTY.
LOCATIONS IN THE PATH OF THE STORM WHICH MAY EXPERIENCE STRONG WINDS
INCLUDE NORTH RIVER SHORES AND PALM CITY.

THE STORM WILL ALSO CONTAIN VERY HEAVY RAINFALL OF 1 TO 2 INCHES AND
FREQUENT CLOUD TO GROUND LIGHTNING.

IF THE STORM STRENGTHENS FURTHER...A WARNING WILL BE ISSUED.

15
Special weather statement, Aug 18, 3:19 PM EDT, 2 hours 23 minutes before
FLZ047-182000-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
319 PM EDT MON AUG 18 2003

...STRONG STORM CAPABLE OF PRODUCING WINDS UP TO 50 MPH AND SMALL
HAIL JUST WEST OF PALM BAY...

AT 314 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STORM CAPABLE OF PRODUCING STRONG WINDS AND SMALL HAIL OVER PALM
BAY...MOVING WEST AT 5 MPH. THIS STORM WILL ALSO PRODUCE HEAVY
RAINFALL AMOUNTS NEAR 2 INCHES AND FREQUENT LIGHTNING.

IF THE STORM STRENGTHENS FURTHER...A WARNING WILL BE ISSUED.

15
Special weather statement, Aug 18, 3:36 PM EDT, 2 hours 6 minutes before
FLZ064-182015-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
336 PM EDT MON AUG 18 2003

...STRONG STORM CAPABLE OF PRODUCING WIND GUSTS UP TO 50 MPH OVER
CENTRAL MARTIN COUNTY...

AT 334 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A
STORM CAPABLE OF PRODUCING STRONG WIND GUSTS UP TO 50 MPH 7 MILES
WEST OF PALM CITY...MOVING SOUTH AT 10 MPH.

THIS STORM WILL ALSO PRODUCE VERY HEAVY RAINFALL NEAR 2 INCHES AND
FREQUENT TO EXCESSIVE LIGHTNING STRIKES. IF THIS STORM APPROACHES
YOUR AREA SEEK SHELTER INDOORS AWAY FROM WINDOWS.

ANOTHER STRONG THUNDERSTORM WAS DEVELOPING BETWEEN PORT MAYACA AND
INDIANTOWN AS WAS DRIFTING WEST.

IF THESE STORMS STRENGTHEN FURTHER...WARNINGS WILL BE ISSUED.

15
Special weather statement, Aug 18, 4:36 PM EDT, 1 hour 6 minutes before
FLZ053-182115-

SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE MELBOURNE FL
436 PM EDT MON AUG 18 2003

...STRONG STORMS CAPABLE OF PRODUCING WIND GUSTS UP TO 50 MPH AND
INTENSE RAIN OVER SOUTHERN OSCEOLA COUNTY...

AT 436 PM EDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STORMS CAPABLE OF PRODUCING STRONG WIND GUSTS...FREQUENT TO
EXCESSIVE LIGHTING AND INTENSE RAINFALL OVER SOUTH CENTRAL OSCEOLA
COUNTY...MOVING NORTH AT 10 MPH.

THE STORMS WILL AFFECT LAKE KISSIMMEE TO KENANSVILLE AND EVENTUALLY
HOLOPAW THROUGH 515 PM EDT.

JP

The office that day

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

IssuedProductOfficeCountiesLasted
Aug 18, 2:05 PM EDTSpecial Marine WarningMLB85 min
Aug 18, 5:35 PM EDTTornado WarningMLBOrange, Osceola40 min
Aug 18, 6:12 PM EDTSevere Thunderstorm WarningMLBOrange63 min

Nearby

Severe Thunderstorm Warnings in Florida, 2003Every severe thunderstorm warning in 2003

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.