WORLD METEOROLOGICAL ORGANIZATION
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RA IV HURRICANE COMMITTEE
RA IV/HC-XXXII/Doc. 4.2 (4)
(08.II.2011)
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THIRTY - THIRD SESSION
ITEM 4.2
GRAND CAYMAN, CAYMAN ISLANDS
8 TO 12 MARCH 2011
Original: ENGLISH
REVIEW OF THE PAST HURRICANE SEASON
REPORTS OF HURRICANES, TROPICAL STORMS, TROPICAL
DISTURBANCES AND RELATED FLOODING DURING 2010
(Submitted by the United States of America)
2010 was the most active season on record in the Atlantic that did not feature a landfalling
hurricane in the United States. This is attributed to a persistent trough of low pressure near the U. S.
east coast that diverted most storms approaching from the east and southeast away from the coast.
In addition, cyclones south of the United States were mostly steered into Central America and Mexico
by a persistent ridge of high pressure over the southwestern United States.
1.
Hurricane Alex
Hurricane Alex made landfall around 0200 UTC July 1 near Soto la Marina, Mexico with
sustained winds of 110 mph – Category 2 on the Saffir-Simpson Hurricane Wind Scale. Port Isabel,
Texas, reported sustained winds of 51 mph and a peak gust of 62 mph. The main U.S. impact of Alex
was heavy rainfall, with widespread estimates of 5 to 10 inches in eastern Texas. Severe flooding
also occurred along the Rio Grande River. In addition, the hurricane produced nine tornadoes in
Texas.
2.
Tropical Storm Bonnie
Bonnie made landfall around 1430 UTC July 23 near Elliot Key, Florida with maximum
sustained winds of 40 mph, and then it weakened to a tropical depression while moving westward over
southern Florida. It continued to weaken over the eastern Gulf of Mexico.
There were several reports of tropical-storm-force wind gusts along the coastal areas of
Broward and Miami-Dade County in southeastern Florida. Sustained tropical-storm-force winds were
reported at Virginia Key and Fowey Rocks, Florida. The strongest wind speeds reported during
Bonnie’s trek across South Florida was a sustained wind of 47mph with a gust to 56 mph from the
Fowey Rocks C-MAN station, at a height of 144 ft/44 m ASL. Bonnie caused minor impacts southern
Florida.
3.
Hurricane Earl
Earl formed in the eastern Atlantic and became a hurricane by 1200 UTC 29 August, when
centered about 250 east of the northern Leeward Islands. Tropical-storm force winds were reported in
RA IV/HC-XXXII/Doc. 4.2(3), p. 2
the U.S. Virgin Islands and Puerto Rico and the storm also produced locally heavy rains over these
Caribbean islands. After moving well north of the U.S. Virgin Islands and Puerto Rico, Earl continued
west-northwestward and reached its peak intensity of 125 kt about 380 n mi southeast of Wilmington,
North Carolina at 1800 UTC 1 September. Earl moved northeastward parallel to, but offshore of, the
east coast of the United States and NOAA buoy 41046 reported sustained winds of 82 mph with a
peak gust of 100 mph as the eye of Earl passed over it on September 3. The highest storm surge
value reported was 4.27 ft at Hatteras Village, North Carolina. Earl produced a surge of up to 3 ft
across a large portion of the U.S. coast from North Carolina to Maine. The hurricane produced high
waves over a large portion of the western Atlantic basin for several days. In North Carolina the
combination of high surf and a storm surge flooded numerous homes along the coast.
Four casualties were caused by Hurricane Earl in the United States. Two of these occurred
offshore of New Jersey, where two men, aged 20 and 23, drowned in rough surf. A 7-year-old girl was
swept out to sea in large waves at Acadia National Park in Maine, and a 14-year-old girl died due to
the high surf in northeastern Florida. Hyde and Dare counties in North Carolina were among the
hardest hit with monetary damage estimates over 2 million and one half million dollars, respectively. In
eastern Massachusetts, there were reports of downed trees and power lines. The total damage
estimate associated with Earl in the U.S. was about $18 million.
4.
Tropical Storm Hermine
Hermine made landfall on the coast of northeastern Mexico about 25 n mi south of Brownsville,
Texas at its peak intensity of 70 mph and a minimum pressure of 989 mb at 0200 UTC 7 September.
Hermine was strengthening when it crossed the coast, and remained a tropical storm for about 16
hours after landfall while moving northward over Texas. The cyclone produced tropical-storm-force
winds over a large area to the east of the center. In fact, these tropical-storm-force winds extended
eastward to the coast. The cyclone weakened to a tropical depression over central Texas by 0000
UTC 8 September, and then continued northward and northeastward over Oklahoma. It became a
remnant low and dissipated at 0000 UTC 10 September over southeastern Kansas.
Harlingen, Texas, reported sustained winds of 59 mph and a peak gust of 72 mph. The storm
produced locally heavy rains over portions of Texas and Oklahoma, with a storm total of 16.27 inches
reported at Georgetown Lake, Texas. In addition, the storm caused two known tornadoes in central
and northern Texas. Six people died due to Hermine, including one drowning in a coastal rip current
and five drownings in freshwater flooding. Hermine was the costliest U. S. tropical cyclone of 2010,
with property damage estimated at $240 million.
5.
Hurricane Otto
A surface circulation formed under the upper-level trough on October 6 about 265 miles northnorthwest of San Juan, Puerto Rico, resulting in the formation of a subtropical depression which
strengthened to a subtropical storm shortly thereafter. Otto evolved from a subtropical to a tropical
storm on October 7 and became a hurricane on October 8. Heavy rainfall associated with Otto and its
precursor disturbance occurred from 4-8 October over the eastern Caribbean. The heavy rains caused
significant damage to portions of the northeastern Caribbean islands, including Puerto Rico and the
U.S. Virgin Islands. Mudslides overturned cars, toppled power lines, flooded homes, and washed out
roads.
RA IV/HC-XXXII/Doc. 4.2(3), p. 3
Table 1. Tropical storms and hurricanes that affected the United States in 2010.
Class*
Dates**
Max.
Winds
(mph)
Min.
Pressure
(mb)
Deaths
U. S.
Damage
($million)
Alex
H
June 25 - July 2
110
946
12
<25
Bonnie
TS
July 22 - 24
45
1005
Earl
MH
August 25 – September 4
145
927
5
18
Hermine
TS
September 6 - 8
70
989
6
240
Storm
Name
Otto
H
October 6 - 10
85
976
TS - tropical storm, winds 39-73 mph; H - hurricane, winds 74-110 mph; MH - major hurricane, winds
111 mph or higher.
** Dates based on UTC time and include tropical depression stage
Fig. 1. Tracks of the Atlantic tropical storms and hurricanes that impacted the U.S during 2010
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