Hurricane Fran formed from a tropical wave that emerged from the west coast of Africa on 22 August. Deep convection associated wih the wave was organized in a banding-type pattern and animation of satellite images suggested a cyclonic circulation. Ship reports soon confirmed that the circulation was on the surface. The system became a tropical depression just southeast of the Cape Verde Islands at 1200 UTC 23 August.
The tropical depression moved westward near 15 knots for the next few days without significant developement. This lack of development may be attributed, in part, to disrupted low-level inflow due to the large and powerful Hurricane Edouard which was centered about 750 n mi to the west-northwest. Satellite intensity estimates suggest that the depression became Tropical Storm Fran at 1200 UTC 27 August while located about 900 n mi east of the lesser Antilles.
Fran began to track toward the west-northwest in the wake of Hurricane Edouard. Deep convection became more concentrated and Fran is estimated to have reached hurricane status at 0000 UTC 29 August while centered about 400 n mi east of the Leeward Islands. The center of Fran was about 150 n mi to the northeast of the Leeward Islands near 1200 UTC 30 August.
The tropical cyclone weakened to just below hurricane strength later on the 30th, possibly due to the low-level inflow being disrupted again by Edouard. About this time, changing steering currents caused Fran to turn toward the northwest and slow to about 5 knots.
By 1200 UTC 31 August, as Edouard moved farther away, Fran had regained hurricane strength. As Hurricane Edouard moved northward off the U.S. mid-Atlantic coast, the subtropical ridge became better established to the north of Fran, causing Fran to resume a west-northwestward motion with an increased forward speed of about 10 knots. Fran moved on a track roughly parallel to the Bahama Islands with the eye remaining a little more than 100 n mi to the northeast of the islands.
Fran strengthened to a category three hurricane by the time it was northeast of the central Bahamas on 4 September. The powerful tropical cyclone began to be influenced by a cyclonic circulation centered over Tennessee that was most pronounced in mid to upper levels of the atmosphere. Fran was steered by the resulting flow around the low over Tennessee and the western extension of the subtropical ridge over the northwest Atlantic. the hurricane gradually turned toward the northwest to north-northwest and inceased in forward speed.
The minimum central pressure dropped to 946 mb and maximum sustained surface winds reached 105 knots, Fran's peak intensity, near 0000 UTC 5 September when the hurricane was centered about 250 n mi east of the Florida east coast.
Fran was moving northward near 15 knots when it made landfall on the North Carolina coast. The center moved over the Cape Fear area around 0030 UTC 6 September, but the circulation and radius of maximum winds were large and hurricane force winds likely extended over much of the North Carolina coastal areas of Brunswick, New Hanover, Pender, Onslow, and Carteret counties. At landfall, the minimum central pressure is estimated at 954 mb and the maximum sustained surface winds are estimated at 100 knots. The strongest winds likely occured in streaks within the deep convective areas north and northeast of the center.
Fran weakened to a tropical storm while centered over central North Carolina and subsequently to a tropical depression while moving through Virginia. The tropical cyclone gradually lost its warm core as it moved over the eastern Great Lakes and became extratropical near 0000 UTC 9 September while centered over southern Ontario. The remnants of Fran were absorbed into a frontal system near 0600 UTC 10 September.
All operational aircraft reconnaissance flights into Fran were provided by the U.S. Air Force Reserves. These "Hurricane Hunters" made 71 center fixes during 17 flights. The minimum central pressure reported by aircraft was 946 mb at 2306 UTC 4 September. A circular eye with a diameter of 25 n mi was observed on aircraft radar at this time. The 946 mb minimum pressure was measured by dropsonde and was the lowest pressure reported during Fran's existence. The maximum winds of 114 knots from a flight level of 700 mb (near 10,000 feet) were measured about 6 hours prior to the 946 mb report. Flight-level winds in excess of 100 knots were reported several times during the two days prior to landfall. 113-knot winds were reported from aircraft 52 n mi east of the hurricane center at 2314 UTC 5 September, and 107-knot winds were reported 41 n mi northeast of the center at the time of landfall. However, the core of the hurricane weakened somewhat on radar presentations, and a closed eyewall was not reported by aircraft during the two hours prior to the center moving onshore.
Objective intensity estimates from digital infrared satellite imagery peaked near the time that the minimum central pressure was reported by reconnaissance aircraft.
The WSR-88D (Weather Surveillance Radar - 1988 Doppler) at Wilmington, North Carolina, measured winds in excess of 120 knots aloft as the inner convective bands approached the Cape Fear area at 2130 UTC 5 September.
A ship with call sign LAVX4 reported 85 knot winds and a pressure of 984 mb at 1800 UTC 5 September while located about 60 n mi northeast of the hurricane center. Several other ship reports were helpful in defining the extent of tropical storm force winds, as were reports from a network of drifting buoys deployed offshore of the Carolinas in advance of Fran.
Several wind gusts to hurricane force were measured from coastal areas in North Carolina. As usual for landfalling hurricanes, however, reports of sustained hurricane force winds are difficult to find. THE NOAA C-MAN station at Frying Pan Shoals (about 50 n mi south-southeast of Wilmington, North Carolina) reported sustained winds of 79 knots and gusts to 108 knots from a tower about 80 feet above sea level.
Numerous pressure and wind reports from North Carolina were relayed to the NHC through amateur radio volunteers. The lowest measured pressure was 954 mb from Southport. The highest measured wind gust was 119 knots at an elevation of 30 feet (mounted on a house approximately 4 feet above the chimney) from a Davis wind instrument located on Hewletts Creek in Wilmington. A gust to 109 knots was measured in Wrightsville Beach. Although these measurements are very much desired to supplement the more official observations, they will not be listed until their accuracy is verified.
Several tornadoes were indicated by Doppler radar in North Carolina and Virginia. Confirmation, however, has been diffiult due to the extensive nature of straight line wind damage across the region.
At the time of this report, a post-storm high water mark survey was being conducted by U.S. Army Corps of Engineers and the U.S. Geological Survey. Many high water marks remain to be surveyed and "tied into" bench marks. The locations of the maximum values cannot be finalized until the survey is complete. However, initial survey results show an extensive storm surge along the North Carolina coast primarily southwest of Cape Lookout. Still water mark elevations on the inside of buildings, indicative of the storm surge, range from 8 to 12 feet. Outside water marks on buildings or debris lines are higher due to the effect of breaking waves.
Rainfall totals exceeding six inches were common near the path of Fran. WSR-88D radar precipitation estimates were as high as 12 inches over portions of Brunswick and Pender counties in North Carolina. Extensive flooding spread well inland from the Carolinas into Virginia, West Virginia and Pennsylvania. Some of this flooding was considered the most severe in years. Near Washington, D.C., for example, the Old Town district of historic Alexandria was partially evacuated as the Potomac River rose, flooding streets with more than three feet of water. The next update of this report will include an analysis of rainfall along the path of Fran to be provided by the NWS Eastern Region Headquarters.
According to Associated Press Reports, Hurricane Fran was responsible for 34 deaths. Most of the deaths were caused by flash flooding in the Carolinas, Virginia, West Virginia and Pennsylvania. Twenty-one died in North Carolina alone. However, the total death count will likely be revised downward in the next update of this report based on data from NWS personnel to be published in Storm Data, since the NWS attempts to list deaths directly attributable to the weather. For example, most vehicle accidents and heart attacks from over-exertion after a hurricane are not considered direct deaths.
Storm surge on the North Carolina coast destroyed or seriously damaged numerous beachfront houses. Widespread wind damage to trees and roofs, as well as downed power lines, occurred as Fran moved inland over North Carolina and Virginia. Extensive flooding was responsible for additional damage in the Carolinas, Virginia, West Virginia, Maryland, Ohio and Pennsylvania.
Nearly a half-million tourists and residents were ordered to evacuate the coast in North and South Carolina. Press reports from Reuters News Service stated that 4.5 million people in the Carolinas and Virginia were left without power.
The Property Claims Services Divsion of the American Insurances Services Group reports that Fran caused an estimated $1.6 billion dollars in insured property damage to the United States. This estimate includes $1.275 billion in North Carolina, $20 million in South Carolina, $175 million in Virginia, $50 million in Maryland, $20 million in West Virginia, $40 million in Pennsylvania and $20 million in Ohio. A conservative ratio between total damage and insured property damage, compared to past landfalling hurricanes, is two to one. Therefore, the total U.S. damage estimate is $3.2 billion.
Some of the information in this report was provided by NWS offices in the Eastern Region and is greatly appreciated.