****** Hurricane Felix Preliminary Report ****** ***** Excerpts courtesy of the National_Hurricane_Center_(NHC) --Written by Max Mayfield and Jack Beven ***** * Synoptic_History * Meteorological_Statistics * Casualty_and_Damage_Statistics **** Synoptic History **** A tropical wave moved off the African coast on 6 August. Satellite imagery indicated that it quickly displayed evidence of a circulation as it moved toward the west. The post-analysis "best track" shows that the disturbance became Tropical Depression Seven about 400 nmi west-southwest of the Cape Verde Islands at 0000 UTC 8 August when loosely organized deep convection increased. The depression strengthened into Tropical Storm Felix later on the 8th and followed a west-northwestward track at 15-20 knots for the next three days. Based on satellite intensity estimates, Felix reached hurricane strength at 0000 UTC 11 August while centered about 500 nmi east-northeast of the Leeward Islands. Reports from reconnaissance aircraft indicated rapid strengthening from the time of the first eye penetration near 1200 UTC on the 11th through the 12th. Maximum sustained surface winds of 120 knots are estimated to have occurred near 1800 UTC 12 August. A well-defined eye was visible in satellite imagery at this time. Felix moved northwestward on 12 August, and then turned more toward the north and started to weaken on 13 August. Two factors likely contributed to the weakening: 1) Felix went through a concentric eyewall cycle, and 2) wind shear increased over the system when Felix's upper-level anticyclone didn't remain centered over the lower-level cyclonic circulation. Aircraft data on the 13th when Felix was centered 300 to 400 nmi south-southeast of Bermuda indicated a large wind field with several wind maxima and no tight center. These characteristics would persist for much of the remainder of the storm's life. Felix's northward turn was due to a large deep-layer trough over the western Atlantic. The trough split as Felix approached, with one part moving northeastward and filling and the other moving southward to the southwest of the hurricane. The resulting steering pattern allowed Felix to resume a general northwestward motion by 15 August, with this motion persisting into the next day. This track took the storm within 65 nmi of Bermuda and toward the North Carolina coast. The split in the trough resulted in increased ridging over the western Atlantic that appeared to be strong enough to drive Felix into the eastern United States. However, a small weakness remained between and 70 and 75 degrees west as indicated by Air Force and NOAA reconnaissance data on the 16th. Felix turned northward into the weakness and almost stalled late on the 16th. It then moved slowly northeastward on 17 August. A second westerly trough failed to pick up the storm on 18-19 August, and Felix performed an anticyclonic loop offshore as the trough bypassed the tropical cyclone. The hurricane accelerated northward on 20 August and northeastward on 21 August in response to a third trough. During 17-19 August, Felix had a 50-70 nmi wide eye on aircraft radar and rather weak convection in satellite imagery. Despite this, the storm maintained 65-70 knot sustained winds and a central pressure near 970 mb. It is possible that this structure was due to cooler, drier air entering the circulation at low and mid-levels. Felix dropped below hurricane strength on 20 August as it moved over colder water and shear again increased. Felix became extratropical about 300 nmi east-northeast of Newfoundland on 22 August. The extratropical cyclone was tracked across the North Atlantic between Scotland and Iceland and then toward Norway. On a historical note, the threat of Hurricane Felix postponed Bermuda's scheduled vote for independence. Ironically, the first inhabitants at Bermuda were survivors of a hurricane-caused shipwreck on the island in 1609. Their stories helped inspire Shakespeare's writing of the Tempest. **** Meteorological Statistics **** U. S. Air Force Reserve aircraft provided a total of 70 operational center fixes on Felix. The 24 missions and approximately 280 flying hours of reconnaissance on this hurricane are both records for an Atlantic tropical cyclone. The maximum winds of 143 knots from a flight-level of 700 mb were measured at 1254 UTC 12 August. The minimum central pressure was 930 mb at 2328 UTC 12 August, and it is likely that the pressure was somewhat lower during the previous 10 hours when there were no aircraft measurements. In addition to the Air Force Reserve reconnaissance, two NOAA aircraft flew a research mission on 16 August. During most of the 15th and 16th, the minimum central pressure hovered between 965 and 970 mb, which would normally be consistent with 85-100 knot surface winds. However, maximum flight-level winds reported by reconnaissance aircraft were only 65-75 knots at 850 and 700 mb. This would suggest a minimal hurricane at most. The rawinsonde at Bermuda indicated 55 knot surface winds with 80 knots at 400 feet. Because a large component of these winds were probably brought to the surface in strong convective bands, the maximum sustained surface winds are estimated at 70-75 knots during this time. Numerous ship reports were received in the vicinity of Felix and were helpful in defining the extent of tropical storm force winds. Bermuda reported a minimum pressure of 988.1 mb and maximum sustained winds of 55 knots with gusts to 70 knots at 0000 UTC 15 August as the center of Felix passed about 65 nmi to the south-southwest. No sustained tropical storm force winds were reported by U. S. land stations. Wind gusts to 37 knots were reported from the NWS office at Buxton, North Carolina at 2058 UTC 16 August and at 0102 UTC 17 August while the hurricane was centered about 125 nmi to the east. The eye of Felix passed over NOAA buoy 41001 located at 34.7N 72.6W about 150 nmi east of Cape Hatteras, near 1600 UTC 16 August. The buoy reported a 970.4 mb pressure at this time with light winds. A 10-minute average wind of 53 knots and gusts to 66 knots were reported earlier by the buoy near 1200 UTC. Rain bands associated with Hurricane Felix remained offshore of the U. S. coast. Although the strong winds and heavy rains did not directly affect the United State, large swells generated by Felix produced dangerous surf conditions including some coastal flooding and rip currents from northeastern Florida to New England. Isolated areas of severe beach erosion occurred along the New Jersey coast, but the most significant beach erosion occurred on the Outer Banks of North Carolina. Highway 12 on the Outer Banks was flooded with sand and ocean overwash at times of high tides. Beach nourishment occurred in some coastal areas of North Carolina to the southwest of the Outer Banks. **** Casualty and Damage Statistics **** A total of 8 deaths were confirmed in association with Felix, 3 off the North Carolina coast and 5 off the New Jersey coast. All of these fatalities were a result of drowning. Although there was considerable beach erosion, little significant property damage occurred. =============================================================================== *** Acknowledgments: *** Some information in this report was provided by NWS offices in the watch and warning areas. Position estimates during the extratropical stage were provided by the Hydrological Prediction Center.