On the evening of July 20th, 2000, severe thunderstorms moved across Lake County  three times. The first storms moved out of Sumter County across the Mascotte area to near Mount Dora producing minor wind damage. The second group of storms developed over sparsely populated areas of northern Lake County between Cassia and Paisley and moved into western Volusia County causing wind damage in the Deland area. The third, and most intense round of severe thunderstorms, developed rapidly north of Leesburg, moved south and produced wind damage in the Leesburg area.  The thunderstorms were unusually strong for July due to a combination of abundant low-level moisture, unseasonable cold, dry, air above 10,000 feet, and record-breaking temperatures. This resulted in a very unstable atmosphere conducive to severe thunderstorms which was noted in Hazardous Weather Outlooks issued by the National Weather Service in Melbourne at 6 AM and 1137 AM.

By late afternoon on July 20th severe thunderstorms were developing rapidly over Lake County.  The National Weather Service uses a combination of radar data and spotter reports to predict and track severe weather. The Lake County Amateur Radio Emergency Service (ARES) SKYWARN Spotters were very effective in passing real-time information to the National Weather Service.

For a chronology of the products issued by the NWS in Melbourne, click here.

The National Weather Service conducted a ground survey of the damage east of Leesburg and determined the damage was caused by a classic, but relatively large "Macroburst"  which is defined as a downdraft from a thunderstorm greater than 2 1/2 miles wide.  The Leesburg "macroburst" was unusally broad and extended for nearly 5 miles along Highway 441 east of Leesburg and produced mostly minor wind damage and general  wind speeds were estimated at 50 to 60 mph. This macroburst marked the downrush of rain-cooled winds associated the intense severe thunderstorm.  Embedded within the larger macroburst were a number of small, but intense "microbursts", with wind speeds approaching 100 mph that caused the most significant damage at and near the Leesburg Airport and at several trailer parks east of the airport. A report of a 125 mph wind was reported from the Lake County Emergency Management Office at 745 pm.

There are additional references to this phenomena at the National Severe Storms Laboratory.

Index to summary sections:

Radar Imagery
Conceptual Macroburst Diagram
Damage Area Map
Damage Photos
Products Issued
Local Storm Report
 

If you have any questions regarding this event, please contact our Warning Coordination Meteorologist.
 

METEOROLOGICAL OBSERVATIONS

WSR-88D Doppler Radar

Conceptual diagram of macroburst over damage area, based on survey and interpretation of radar imagery.

Damage Photos, taken by the NWS Survey Team:
Numbers correspond to those on the survey map, above.
Click the small picture to view a larger image.

Chronology of NWS product issuances for Lake County:

Here is an excerpted Local Storm Report issued by WFO MLB on the evening of 7/20/00
 

 ZCZC MIALSRMLB
TTAA00 KMIA 210156

LSRMLB
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MELBOURNE, FL
954 PM EDT THU JUL 20 2000

TIME(EDT)  .....CITY LOCATION.....STATE   ...EVENT/REMARKS...
           ....COUNTY LOCATION....

0728 PM    LEESBURG                 FL   WIND DAMAGE
07/20/00    LAKE                           LAW ENFORCEMENT REPORTED
                                                       POSSIBLE TORNADO SIGHTED AT
                                                       LAKE SQUARE MALL.

0740 PM   TAVARES                    FL   WIND DAMAGE
07/20/00   LAKE                            TRAINED SPOTTER REPORTED
                                                        DAMAGE TO CRUISE BOAT.

0742 PM    LEESBURG                  FL   WIND DAMAGE
07/20/00    LAKE                           TRAINED SPOTTER REPORTED
                                                        DAMAGE TO STORE.

0740 PM   LEESBURG                  FL   WIND DAMAGE
07/20/00   LAKE                           TRAINED SPOTTER REPORTED
                                                       TREES DOWN US 441 AT LAKE
                                                       GRIFFIN HARBOR.

0725 PM    LEESBURG                  FL   WIND DAMAGE
07/20/00    LAKE                           TREE DOWN ON MOBILE HOME.

0730 PM    LEESBURG                  FL   .75 INCH HAIL
07/20/00    LAKE

0725 PM    THE VILLAGES           FL   WIND DAMAGE
07/20/00   LAKE                             TRAINED SPOTTER REPORTED
                                                         TREES DOWN

06/30/03    JP/DJ

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