Severe Weather Outbreak in South Florida: February 2, 1998

BRIEF METEOROLOGICAL SYNOPSIS
A low pressure center formed in the Gulf of Mexico on February 1, 1998 and eventually deepened to a minimum central pressure of 989 mb as it tracked across the northeast Gulf-- a not unusual occurrence during a strong El Niño episode. In response to the deepening low, winds increased to gale force during mid-morning of February 2 over south Florida. A warm front moved northward from the Straits of Florida ushering in tropical air to the Keys and the southern peninsula by midday. An area of severe thunderstorms formed in the warm sector over the southeast Gulf of Mexico and moved into the lower Keys beginning around mid-afternoon Monday, February 2, 1998, and spreading to the southeast Florida coast by evening.

TORNADOS AND SEVERE THUNDERSTORMS
The area of severe thunderstorms produced four confirmed tornado paths in south Florida. The tornado path in Dade-Broward county was likely caused by four individual tornados occurring simultaneously along a portion of its path making a total of seven tornado touchdowns. A dozen or more other severe thunderstorms (wind gusts above 57 mph) occurred across the Keys, most of Dade and Broward counties and portions of Palm Beach and Glades counties. The highest wind measured during the event was 119 mph, a delayed report from the C-MAN instrument at Long Key in the middle Keys. The ASOS at the Miami International Airport measured a peak wind gust of 104 mph. Rainfall along the southeast Florida coast was locally heavy with widespread amounts of 3 to 6 inches.

CHRONOLOGY AND STATISTICS OF DADE-BROWARD TORNADO
The tornado first touched down at 8:22 pm on the north edge of Miami International Airport near N.W. 36th Street and Curtis Parkway withF1-F2 intensity, damaging about a dozen planes. The NWS ASOS observation at Miami International Airport, located about 3/4 mile west of the touchdown point reported a wind gust of 104 mph (probably associated with the "rear flank downdraft". The F2 tornado crossed through Virginia Gardens and south portion of Miami Springs in a 100-200 yard-wide path damaging many buildings and hurling a 2x4 inch board through an apartment door. The tornado showed F1 intensity across the remainder of Miami Springs, damaging roof tops and uprooting large trees. At 8:27 pm the tornado intensified to its maximum F2 intensity (125-150 mph), as it moved into southern Hialeah, severly damaging structures. The tornado weakened to F1 intensity near the Hialeah Racetrack. Just north of Hialeah Racetrack, the damage path widened to one to three miles, with indications of three or four individual tornados of F1 intensity moving in tandem toward the north. At 8:31 pm, the main tornado reintensified to F2 status as it approached Opa Locka Airport severely damaging the roof of the UPS facility then damaging or destroying 140 aircraft and a hanger at the airport blowing some debris nearly half a mile. The ASOS at Opa Locka Airport measured a gust of 67 mph. The tornados weakened slightly to F1 intensity as they moved through Carol City damaging houses and utility lines. At 8:34 pm they crossed the Dade-Broward county line and damaged a strip shopping center in Miramar. The multiple tornados moved across North Perry Airport at 8:36 pm where 40 aircraft were destroyed and another 40 were damaged. The tornados weakened to F0-F1 intensity as they continued toward the north northeast damaging a shopping center in Davie near Orange Road and Hiatus Road. The tornados were F0 intensity as they moved north damaging trees, signs and some roofs before lifting at 8:44 pm near Broward Boulevard just west of the Florida Turnpike in Plantation. The thunderstorm that produced the tornados continued to the northeast producing sporadic minor damage through northeast Broward county before exiting the coast into the Atlantic.

CASUALTIES AND DAMAGE
In Dade and Broward counties the severe thunderstorms and tornados caused no fatalities but at least six injuries. A total of 235 aircraft were damaged or destroyed at Miami International, Opa Locka, and North Perry airports. Damage to structures in Dade county included 32 homes destroyed, 205 with major damage and 380 with minor damage. Hialeah Hospital, a flea market and a carnival suffered extensive damage. At least four vehicles were overturned. Dozens of utility poles along with hundreds of trees were snapped. In Dade and Broward counties around 600,000 people suffered power outages at some time, and 200 people were left homeless. Losses from the severe weather in south Florida are estimated between 120 and 148 million dollars, the greatest weather-related monetary loss ever, outside of a significant tropical cyclone or major freeze. The loss total was calculated as follows:

In the Keys, damage to houses occurred particularly near Grassy Key, Islamorada and Conch Key and utility lines were down over many areas of the Keys. Losses to marine equipment, especially lobster traps, was heavy.

In Glades county a tornado damaged several mobile homes in Buckhead Ridge and severe thunderstorm winds caused damage in Moore Haven and Lakeport. Damage totals are estimated at $75-100 thousand.

Damage in Palm Beach, Collier and Hendry counties is considered minimal.

MARINE CONDITIONS
Due to the deepening low pressure in the Gulf of Mexico, winds approaching gale force preceded the onset of the severe thunderstorms/tornados. One person was killed in the lower Keys when crushed between two boats during these strong winds. Several rescues of boaters were made in the lower Keys. At least three large boats ran aground off the southeast Florida coast. There was minor beach erosion and tidal flooding along portions of the Atlantic and Gulf of Mexico coasts of south Florida and in the Keys.

HISTORICAL PERSPECTIVE
The tornados in Dade county on February 2, 1998 were the most intense since December 20, 1973 (during another major El Niño episode) when an F2 tornado tore a 6-mile long path through Homestead, injuring 9 and causing about $3 million (adjusted to 1998 values) in damage. The February 2, 1998 tornados caused losses estimated between 65 and 80 million dollars, the highest amount ever recorded in Dade county from a tornadic event, exceeding the approximately $15 million sustained in the tornado of June 17, 1959 (damage adjusted to 1998).

Two F3 intensity tornados have been recorded in Dade county-- in 1959 and 1925. The 1959 tornado injured 77 people while the 1925 tornado on April 5 was the only killer tornado in Dade county history, killing five and injuring more than 35 (during a major La Niña episode).