F1 tornado, Thonotosassa, Florida, July 8, 2003

1. F040 to 72 mph

   Light damage. Surface peeled off some roofs, gutters and siding damaged, branches broken, shallow-rooted trees pushed over.

2. F173 to 112 mphthis tornado

   Moderate damage. Roofs badly stripped, mobile homes overturned or badly damaged, exterior doors lost, windows broken.

3. F2113 to 157 mph

   Considerable damage. Roofs torn off well-built houses, frame homes shifted on their foundations, mobile homes destroyed, large trees snapped or uprooted, cars lifted off the ground.

4. F3158 to 206 mph

   Severe damage. Whole stories of well-built houses destroyed, large buildings badly damaged, trains overturned, trees debarked, heavy cars lifted and thrown.

5. F4207 to 260 mph

   Devastating damage. Well-built houses leveled, structures with weak foundations moved some distance, cars thrown and large missiles generated.

6. F5261 to 318 mph

   Incredible damage. Strong frame houses swept off their foundations, car-sized missiles thrown more than 100 meters, steel-reinforced concrete badly damaged, high-rise buildings deformed.

7. Unrated

   The survey recorded a tornado but could not put a number on it, most often because it crossed open country and damaged nothing a rating can be read from.

Rating

F1

Date

July 8, 2003

Touchdown

6:35 PM EDT (22:35 UTC)

Path length

2.2 miles (3.5 km)

Path width

200 yards (183 m)

Deaths

0

Injuries

0

Property damage

$20,000

County

Hillsborough County

Touchdown point

28.020, -82.270

Lift-off point

28.070, -82.270

Record number

486

The tornado occurred on the north end of a large thunderstorm causing mostly tree damage in rural Hillsborough County. The tornado started at the end of Collins Ranch Road and traveled north across Thonotosassa road at the County Park and Boat Ramp. It then continued north into the southeast corner of Lake Thonotosassa where it because stationary and "sucked up boat loads of water" according to one observer. Finally the tornado came back onshore and headed north just west of Hendry Ranch Road before dissipating a short time later. Most of the damage from the tornado occurred at the end of Collins Ranch Road where several light structures were destroyed and trees were snapped off at the base. One was thrown onto a nearby vehicle. Boaters on Lake Thonotosassa were stuck in the middle of the lake as they watched the tornado plow through the boat ramp area. Observers witnessed trees with limbs reaching toward the sky before the entire tree was lifted into the air.

From NOAA NCEI's Storm Events Database, the narrative the local forecast office wrote for Storm Data.

6 minutes of warning. NWS TBW issued a tornado warning for this county at 22:29 UTC, 6 minutes before the tornado touched down, in force until 23:00 UTC.

Every warning and watch covering the touchdown point that day, from the Iowa Environmental Mesonet's archive of National Weather Service products. Lead time is measured from the issue of the warning in force to the touchdown time in the database, both of which were recorded to the minute by different people.

The Storm Prediction Center had this point in a General Thunderstorms Risk. The outlook in force was issued at 20:03 UTC.

SPC's Day 1 convective outlook as it stood when the tornado began, read at the touchdown point. The same archive is on the radar archive.

NWS Tampa Bay, FL wrote its last area forecast discussion before the tornado touched down at Jul 8, 1:00 PM EDT, 5 hours 35 minutes earlier.

WEST CENTRAL AND SOUTHWEST FLORIDA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
100 PM EDT TUE JUL 8 2003

JULY HEAT/HUMIDITY WILL DOMINATE THE REMAINDER OF THE WORK WEEK WITH
LOWER THAN NORMAL PCPN CHANCES AND COVERAGE.  BY LATE
WEEKEND/EARLY NEXT WEEK...UPPER TROUGH TRIES TO REESTABLISH ACROSS
THE NE U.S...WHICH MAY ALLOW REMNANT MOISTURE FROM TROPICAL WAVE NOW
MOVING INTO THE W CARIBBEAN TO ARRIVE...PERHAPS INCREASING CLOUD
COVER/PCPN CHANCES AND LOWERING DAYTIME TEMPS A HAIR.

MODELS IN GOOD AGREEMENT GIVEN NON-DESCRIPT FLOW UNDERNEATH FLAT 500
MB RIDGE.

SHORT TERM (TONIGHT - THURS):
WHAT YOU SEE IS WHAT YOULL GET.  HOT/HUMID DAYS AND MUGGY NIGHTS
WITH LOW PCPN CHANCES FOR EARLY JULY.  WIND FIELDS ARE VARIABLE...
SO ANY TSTMS THAT DEVELOP WILL BE DRIVEN BY SEA/BAY BREEZES.  HEAT
INDEX VALUES A BIT UNCOMFORTABLE...BUT STILL UNDER ADVISORY CRITERIA.

EXTENDED (THURS NIGHT - TUE):
SURFACE RIDGE AXIS WILL SETUP ACROSS SOUTH CENTRAL FLORIDA...AROUND
LAKE OKEECHOBEE...LATE IN THE WEEK INTO THE WEEKEND AS UPPER LEVEL
TROUGH DEEPENS OVER EASTERN U.S.  RIDGE AXIS WILL THEN DRIFT NORTH
AGAIN EARLY NEXT WEEK AS TROUGH MOVES OFF EAST COAST OF U.S. AND
UPPER LEVEL RIDGE BUILDS IN FROM THE WEST.  ONLY QUESTION THAT
REMAINS IS HOW MUCH MOISTURE IF ANY SNEAKS UP FROM THE TROPICAL WAVE
MOVING ACROSS THE CARIBBEAN AND ACROSS YUCATAN PENINSULA LATE IN THE
WEEK INTO THE WEEKEND.  LATEST GFS KEEPS DEEPEST MOISTURE SOUTH OF
THE FORECAST AREA AND WILL CONTINUE TO GO WITH SCATTERED MAINLY
AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS EACH DAY WITH
TEMPERATURES REMAINING NEAR NORMAL.

MARINE...LIGHT GENERALLY ESE WINDS EXCEPT FOR AFTN SEA BREEZE
NEAR SHORE EACH AFTN THROUGH FRI.  PERHAPS A SUBTLE SHIFT TO
S/SE OVER THE WEEKEND...WILL DEPEND ON HOW STRONG NE U.S. UPPER
TROUGH IS.

FIRE WX...NO CONCERNS WITH LIGHT WINDS IN THE MIXED LAYER AND RH
ABOVE 50 PERCENT.

PRELIM NUMBERS:
TPA 077/093 077/093 2323
FMY 075/093 075/093 2323
GIF 075/094 075/094 2323
SRQ 075/092 075/092 2323
BKV 073/094 073/094 2323

.TBW...NONE

BSG/PRC

FLZ039-042-043-048>052-055>057-060>062-065-081400-

WEST CENTRAL AND SOUTHWEST FLORIDA HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE TAMPA BAY AREA - RUSKIN FL
600 AM EDT TUE JUL 8 2003

THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY:

ATMOSPHERIC MOISTURE IS HIGHER THAN THE PAST FEW DAYS AND
SOUTHEAST FLOW WILL KEEP AFTERNOON TEMPERATURES WARM. SCATTERED
THUNDERSTORMS WILL DEVELOP OVER THE INTERIOR AREA THIS AFTERNOON AND
MOVE NORTHWEST TOWARDS THE COAST. A WEAK SEA BREEZE WILL DEVELOP
AROUND 4 PM AND WILL ENHANCE THE CONVECTION. SOME STORMS
MAY BECOME STRONG NEAR INTERSECTING SEA BREEZE AND OUTFLOW
BOUNDARIES. THE PRIMARY THREAT FROM THUNDERSTORMS TODAY WILL BE
DANGEROUS CLOUD TO GROUND LIGHTNING AND LOCALLY HEAVY RAINFALL. A FEW
STORMS MAY HAVE WIND GUSTS TO NEAR 50 MPH LATE THIS AFTERNOON AND
EVENING.

.DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY:

A RIDGE OF HIGH PRESSURE WILL DRIFT SOUTH ACROSS THE FORECAST AREA
THROUGH THE WEEKEND RESULTING IN SCATTERED THUNDERSTORMS DEVELOPING
A BIT EARLIER EACH DAY.

.SPOTTER CALL TO ACTION STATEMENT...

SPOTTER ACTIVATION MAY BE REQUIRED TODAY.

FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT
HTTP://WWW.SRH.NOAA.GOV/TBW

The radiosonde launches on either side of the tornado, from the nearest station that was launching then, drawn and analyzed the way Storm Lab does: the same diagram, the same parcel and shear definitions SPC's mesoanalysis uses.

The Tampa radar (KTBW), 40 km away, was scanning. The volume nearest the touchdown began at 22:33 UTC.

Open the radar archive at this moment, over the track

Reflectivity and velocity, decoded from the Level II archive in the browser. Volumes take a few seconds to open the first time.

The live radar over the trackEvery 2003 tornado in FloridaEvery tornado in Florida since 1950Warnings in force in Florida nowThe forecast where you are

5 more were confirmed in the United States that day.

Ratings are the survey's, read off the damage rather than measured; the rating scale is above. Tornado counts rise through the record as reporting improved, so a year in the 1950s is not comparable with one today except for the strongest tornadoes, which were always noticed.

NOAA Storm Prediction Center tornado database, 1950-2025, the official record kept by NOAA's Storm Prediction Center.