WORLD METEOROLOGICAL ORGANIZATION
___________________________________________
RA IV HURRICANE COMMITTEE
THIRTY-EIGHTH SESSION
SAN JUAN, PUERTO RICO, USA
RA IV/HC-38/Doc.3.1
(14.III.2016)
________
ITEM: 3.1
Original: ENGLISH
23 TO 26 APRIL 2016
REVIEW OF THE PAST HURRICANE SEASON
SUMMARY OF THE PAST SEASON
2015 Atlantic and Eastern North Pacific Hurricane Season Summary
(Submitted by the RSMC Miami)
RA IV/HC-38/Doc. 3.1, p.2
2015 Atlantic and Eastern North Pacific Hurricane Season Summary
1
Atlantic
Tropical cyclone activity in the Atlantic basin during the 2015 season was
below average. Of the 11 tropical storms that formed, 4 became hurricanes, and
2 reached major hurricane strength (category 3 or higher on the Saffir-Simpson
Hurricane Wind Scale). In comparison, the 1981-2010 averages are 12 tropical
storms, 6 hurricanes and 3 major hurricanes. The Accumulated Cyclone Energy
(ACE) index, a measure that takes into account the strength, duration, and
frequency of the season’s tropical storms and hurricanes, was 68% of the long-term
median value. Most of the season’s tropical cyclones occurred well east of the United
States, although Tropical Storm Ana made landfall in South Carolina and Tropical
Storm Bill made landfall along the central Texas coast. In addition, Hurricane Joaquin
battered the southeastern and central Bahamas as a category 4 hurricane, and was
the strongest October hurricane known to have affected the Bahamas since 1866.
Figure 1 depicts the tracks of the tropical storms and hurricanes of the 2015 Atlantic
hurricane season.
Tropical Storm Ana
A non-tropical low pressure system formed early on May 6 just offshore of
the southeastern coast of Florida and moved slowly northward over the next two
days, gradually developing an associated area of gales. On May 8, the low acquired
sufficient thunderstorm activity for the system to be designated a subtropical storm
when it was located about 175 miles south-southeast of Myrtle Beach, South
Carolina. Ana moved slowly north-northwestward over the warm waters of the Gulf
Stream on May 8-9 and transitioned to a tropical storm early on May 9 about 130
miles southeast of Myrtle Beach. Ana’s intensity remained steady near 60 mph while
the cyclone was over the Gulf Stream. However, by late that day, the tropical storm
began to weaken as it moved off of the Gulf Stream and over the cooler coastal shelf
waters. Moderate to strong vertical wind shear enhanced the weakening process, and
Ana made landfall around 1000 UTC May 10 just southwest of North Myrtle Beach,
South Carolina, with an intensity of 45 mph. The May 10 landfall makes Ana the
earliest United States. landfalling tropical cyclone on record.
Shortly after making landfall, Ana slowed and turned northward and
weakened to a tropical depression. On May 11 the cyclone turned northeastward and
moved across eastern North Carolina, degenerating to a remnant low pressure area
before emerging off of the United States mid-Atlantic coast near the Delmarva
Peninsula by May 12. The low merged with a frontal system near Nova Scotia on
May 13.
Ana produced storm surge flooding up to 2.5 feet above normal tide levels
along portions of the coasts of South Carolina and North Carolina. Storm-total rainfall
of 3 to 6 inches occurred across portions of eastern North Carolina, producing some
inland freshwater flooding. Abnormally high tides in combination with Ana’s storm
surge resulted in minor beach erosion along the coasts of northeastern South
Carolina and southeastern North Carolina. Property damage in the United States was
minor.
RA IV/HC-38/Doc. 3.1, p.3
There was one direct death associated with rip currents off the coast of
North Carolina.
Tropical Storm Bill
Bill formed from the complex interaction of an upper-level trough over the
Gulf of Mexico, a broad area of low pressure near the Yucatan Peninsula, and
southerly winds associated with eastern North Pacific Hurricane Carlos. The
combination of these three features resulted in a broad disturbance forming over
northern Belize and the Yucatan Peninsula on June 13, which became a tropical
storm on June 16 while centered about 200 miles east-southeast of Corpus Christi,
Texas. Bill continued northwestward during most of June 16, but slowed down and
turned west-northwestward as it approached the Texas coast. Bill made landfall on
Matagorda Island at 1645 UTC June 16 with maximum winds of 60 mph. Later that
evening, Bill turned northward and accelerated inland over eastern Texas, weakening
to a tropical depression early on June 17 when centered about 35 miles east of
Austin, Texas. The depression continued northward for the next two days, and
became a remnant low on June 18 while located about 75 miles south-southeast of
Tulsa, Oklahoma. Bill’s remnant low moved east-northeastward for the next few
days, producing heavy rain, flooding, and tornadoes across southern Missouri,
northern Arkansas, and portions of the Ohio River Valley.
The low dissipated on June 21 over the mountainous terrain of West Virginia.
Bill produced a storm surge of 3.5 feet just east of its landfall point.
Combined with the normal tide, Bill’s surge produced inundation of 1 to 3 feet above
ground level for parts of the upper Texas and southwestern Louisiana coasts.
Heavy rains from Bill also fell from the central Texas coast northeastward
across eastern Texas, western Louisiana, and southern and eastern Oklahoma. Many
locations reported storm-total amounts in excess of 10 inches with the highest
rainfall report being 13.78 inches in Ganado, Texas. The heavy rainfall caused flash
floods and flooding of major rivers across portions of Texas and Oklahoma. The Red
River at Interstate 35 along the Texas/Oklahoma border reached a record crest of
42.05 feet, 17 feet above flood stage. Farther north, the Washita River near Dickson,
Oklahoma, reached a record crest of 48.70 feet, which was more than 21 feet above
flood stage. Flash flooding was reported in the Austin and San Antonio metro areas.
Property damage in the United States was minor.
Bill caused two direct deaths as a result of heavy rain and flooding in
Oklahoma during its tropical depression stage. In addition, Bill’s precursor
disturbance produced heavy rains, flooding, and landslides over portions of Central
America and the Yucatan Peninsula of Mexico. In Honduras, two people died in
floodwaters near Tegucigalpa, while two other people were reported missing. More
than 500 people were affected by floods and landslides in Honduras. Two people died
in landslides in Guatemala, with 516,000 people having been affected by flooding
and landslides in that country.
Tropical Storm Claudette
Claudette developed from a non-tropical surface low associated with a
mid-level trough that formed near Cape Hatteras on July 12. The low moved
eastward for the next 24 hours over the warm waters of the Gulf Stream and, early
on July 13, the low became a tropical depression. The system was sheared,
RA IV/HC-38/Doc. 3.1, p.4
thunderstorm activity displaced to the northeast of the circulation center. However,
the cyclone became a tropical storm by early July 13, and reached its peak intensity
of 50 mph later that day about halfway between Bermuda and Cape Cod. Claudette
then moved toward the northeast over the colder waters of the North Atlantic, where
strong vertical wind shear gradually separated the center from the intermittent
thunderstorm activity, and the cyclone degenerated to a remnant low, which was
quickly absorbed by a frontal system near Newfoundland.
Hurricane Danny
Danny developed from a vigorous tropical wave that moved off of the
coast of western Africa on August 14. A tropical depression formed on August 18 and
strengthened into a tropical storm later that day about 1600 miles east of the
Windward Islands. Danny moved generally westward across the eastern and central
tropical Atlantic over the next several days and steadily strengthened, becoming a
hurricane on August 20 when the cyclone was located about 1090 miles east of the
Windward Islands. A period of significant strengthening began immediately after
Danny achieved hurricane status, and the cyclone rapidly became a 125-mph major
hurricane by mid-day August 21. However, Danny’s rapid development was cut short
by intrusions of dry air and increasing vertical wind shear, which caused the cyclone
to weaken as quickly as it had strengthened. Danny became a tropical storm on
August 23 and a tropical depression on August 24 when the cyclone was moving
through the central and southern Leeward Islands. Danny degenerated into an open
wave when the system moved into the extreme northeastern Caribbean Sea. The
remnants of Danny moved westward across the northern Leeward Islands, the Virgin
Islands, Puerto Rico, and Hispaniola for the next day or so, bringing short-lived but
beneficial rains to those drought-stricken islands.
Tropical Storm Erika
Erika developed from a fast-moving wave, bypassing the tropical
depression stage, and became a 45-mph tropical storm on August 24 while centered
about 950 miles east of the Lesser Antilles. The cyclone continued westward at a
brisk pace, reaching the northern tip of Guadeloupe by early August 27. Erika moved
over the northeastern Caribbean Sea August 28, passing south of the United States.
Virgin Islands and Puerto Rico. Later that day, Hurricane Hunter aircraft observations
revealed that Erika no longer had a well-defined center of circulation, and the
tropical cyclone dissipated just south of the eastern tip of Hispaniola.
The largest rainfall amounts associated with Erika were observed on
Dominica, where maximum totals reached 12.62 inches. Practically all of this
precipitation occurred during a 12-hour period on August 27, and these torrential
rains produced catastrophic flooding and mudslides over the island. Erika was
responsible for 30 direct deaths, all in Dominica. Also, 574 persons on that island
were made homeless by the storm and 271 houses were reportedly damaged or
destroyed. There was also major damage to roads, bridges and other infrastructure
on the island, with the total damage estimated near US $ 500 million. Damage
estimated near $17.4 million also occurred in Puerto Rico, mainly due to losses of
plantains, bananas, and coffee.
RA IV/HC-38/Doc. 3.1, p.5
Hurricane Fred
Fred was the first hurricane to move through Cabo Verde since 1892. It
formed from a tropical wave that emerged from the west coast of Africa early on
August 29 and uncharacteristically began to develop just west of the coast of Guinea
later that day, with a tropical depression forming early on August 30 about 300 miles
west northwest of Conakry, Guinea. The depression moved quickly on an atypical
northwestward track toward Cabo Verde. The combination of above-average
sea surface temperatures and light vertical wind shear enabled rapid strengthening
to occur and the cyclone reached tropical storm strength 6 hours after genesis, and
became a hurricane by August 31 about 165 miles south-southeast of Sal, Cabo
Verde. Fred moved through the islands later that day, reaching a peak intensity of 85
mph. After that, a combination of decreasing sea-surface temperatures and
increasing southwesterly shear caused weakening, and Fred weakened to a tropical
storm early on September 1 as it moved away from Cabo Verde. Fred moved westnorthwestward to westward over the next few days, while gradually weakening. Fred
turned northward on September 6 and degenerated into a trough about 1200 miles
southwest of the Azores.
Storm surge and high surf affected several islands of Cabo Verde. It is
estimated that 6 to 8 inches of rain occurred on several of the Cabo Verde islands.
These rains caused some flooding, but also filled reservoirs that were low due to
drought. Fred caused 9 direct deaths. The Greek-registered fishing boat Dimitrios
sank off the coast of Guinea-Bissau due to the high waves generated by Fred, and
7 members of its crew of 19 were not found. In addition, two fishermen from Cabo
Verde were reported missing and presumed dead when their fishing boat failed to
return to the island of Boa Vista. Fred caused about US $1 million damage on several
islands of Cabo Verde, with Boa Vista being the hardest hit. Additional damage from
rough surf and above-normal tides occurred along the coast of Africa, with damage
to crops reported in Guinea-Bissau due to salt water inundation.
Tropical Storm Grace
Grace formed from a well-organized tropical wave that left the coast of
western Africa on September 3. It developed into a tropical depression on September
5 about 170 miles south of Cabo Verde, and 12 hours later became a tropical storm.
Grace gradually strengthened over the next couple of days, reaching an estimated
intensity of 60 mph by mid-day September 6. The cyclone then moved into
unfavorable environmental conditions and weakened. Grace decayed to a tropical
depression on September 8 and degenerated to a trough on September 9 about
750 miles east of the Lesser Antilles. The remnants of Grace brought gusty winds
and heavy rains to the northeastern Leeward Islands and Puerto Rico a couple of
days later.
Tropical Storm Henri
Henri’s origin was non-tropical, resulting from a dissipating frontal boundary
interacting with an upper-level trough over the western Atlantic. A surface low
developed along the weakening front early on September 8 and became a tropical
depression by late that day about 220 miles east-southeast of Bermuda. The
depression intensified into a tropical storm on September 9 and reached a peak
intensity of 50 mph late that day when it turned northward ahead of an upper-level
trough. By early September 11, Henri’s circulation became distorted, and the cyclone
RA IV/HC-38/Doc. 3.1, p.6
degenerated into a trough later that day more than 500 miles south-southwest of
Cape Race, Newfoundland.
Tropical Storm Ida
The genesis of Ida was associated with a tropical wave that spawned a
tropical depression on September 18 more than 700 miles west of the southernmost
Cape Verde Islands. The depression moved west-northwestward and strengthened
into a tropical storm by early September 19. Westerly vertical wind shear inhibited
development, and Ida reached its maximum intensity of 50 mph early on September
21, when the cyclone was located about 1000 miles east of the northern Leeward
Islands. The shear steadily increased on September 21, causing Ida to slowly
weaken. Over the next few days, Ida meandered in weak steering currents, and it
eventually dissipated on September 28 about 860 miles east-northeast of the
northern Leeward Islands.
Hurricane Joaquin
Joaquin did not have tropical origins, which is rare for a major hurricane.
The incipient disturbance developed beneath a weak mid- to upper-level low over the
subtropical central Atlantic on September 26 about 400 miles east-northeast of San
Salvador Island in the central Bahamas, and a tropical depression formed two days
later. Moderate north-northwesterly shear prevented the depression from
strengthening initially, but the cyclone became a tropical storm early on September
29 while centered about 340 miles northeast of San Salvador.
A blocking ridge of high pressure located over the western Atlantic forced
Joaquin to move slowly southwestward over very warm waters near the Bahamas.
A 60-hour period of rapid intensification began on September 29, and Joaquin
became a hurricane on September 30 about 200 miles east-northeast of San
Salvador, and then a major hurricane on October 1 about 100 miles east of San
Salvador. Sea-surface temperatures in the area where Joaquin formed and rapidly
intensified were more than 1°C higher than normal, and were the warmest on record
for the period September 18-27.
A mid- to upper-level trough over the eastern United States deepened on
October 1-2, causing the hurricane to slow down as it approached the southeastern
and central Bahamas. Joaquin continued to strengthen, reaching a relative peak in
intensity as a 140-mph category 4 hurricane early on October 2. The powerful
cyclone made landfall as a major hurricane on several islands of the Bahamas
on October 1-2, first on Samana Cay in the morning of October 1, then on Rum Cay
and San Salvador during the afternoon of 2 October. In addition, Joaquin’s eyewall
moved over Crooked Island, Long Cay, and Long Island. Even though it weakened
slightly on October 2, Joaquin was a major hurricane the entire time that it moved
through the southeastern and central Bahamas, and it was the strongest October
hurricane known to have affected the Bahamas since 1866.
By early October 3, Joaquin accelerated northeastward away from the
Bahamas and re-intensified, reaching a peak intensity of 155 mph. The hurricane
moved north-northeastward over the western Atlantic and weakened, but it was still
a hurricane when the cyclone made its closest approach to Bermuda, about 70 miles
west-northwest of the island early on October 5. Joaquin turned northeastward and
east-northeastward on October 6-7 as it became embedded in the mid-latitude
RA IV/HC-38/Doc. 3.1, p.7
westerlies, where it weakened to a tropical storm early on October 7 while centered
about 480 miles southeast of Cape Race, Newfoundland.
Strong west-southwesterly shear caused the cyclone to become posttropical by October 8 about 440 miles west-northwest of the northwestern Azores. As
an extratropical low, Joaquin moved eastward and southeastward over the
northeastern Atlantic on October 9-12, with its center moving inland just north of
Lisbon, Portugal, early on October 12. The low then turned southward, weakened
below gale force, and moved back over the Atlantic waters off the coast of Portugal
on October 13. The low ultimately dissipated by October 15 between Portugal and
Morocco over the Gulf of Cádiz.
Joaquin produced storm surges of 12 to 15 feet on Rum Cay, Crooked
Island, and Acklins. Some coastal flooding due to Joaquin also occurred in the Turks
and Caicos Islands, Haiti, and Cuba, but no water level observations are available
from those areas. Joaquin also contributed to indirect surge impacts along the United
States east coast. Higher-than-normal tides, onshore gale-force winds behind a
frontal boundary, and swells propagating away from Joaquin all contributed to storm
surge flooding, with the worst flooding occurring in South Carolina, North Carolina,
and Virginia. The highest storm surges reported were about 4 feet above normal tide
levels in South Carolina and Virginia.
Joaquin produced 5 to 10 inches of rainfall in portions of the central and
southeastern Bahamas. In addition, moisture transported away from Joaquin
contributed to an historic rainfall and flooding event in South Carolina and parts of
southern North Carolina. Rainfall amounts exceeding 15 inches occurred in a swath
extending from the South Carolina Lowcountry northwestward through the Midlands,
as well as along the coast near the North Carolina/South Carolina border. In the
Lowcountry, rainfall amounts greater than 20 inches occurred in Charleston and
Berkeley Counties, with a maximum rainfall amount of 26.88 inches measured near
Mt. Pleasant. One-, two-, three-, and four-day rainfall records were set at the
Charleston International Airport. The airport measured a one-day rainfall amount of
11.50 inches on October 3 and a four-day total of 17.29 inches during October 1-4.
In the Midlands, rainfall amounts greater than 20 inches occurred in Richland,
Sumter, and Orangeburg Counties. One-, two-, and three-day rainfall records were
also set at the Columbia Metropolitan Airport, with 6.71 inches measured on October
4 and 11.44 inches for the entire event. In North Carolina, a maximum rainfall
amount of 18.79 inches was reported near Sunset Beach in Brunswick County.
Joaquin is directly responsible for 34 deaths in the waters off the Bahamas
and Haiti. Almost all of the deaths occurred when the U.S.-flagged cargo ship
El Faro was lost at sea near the Bahamas while Joaquin was moving through the
area. The Caribbean Disaster Emergency Management Agency (CDEMA) reported
that a fisherman in his 30s drowned when his and another fisherman’s boat capsized
in rough seas off the coast of Haiti between Petit-Trou-de-Nippes and Grand Boucan.
The prime minister of the Bahamas and the Bahamas Department of
Meteorology estimated the damage caused by Joaquin was well over US $ 60 million.
Seventy percent of Crooked Island was flooded with at least 5 feet of water. The
entire island lost power, and there was significant damage to buildings and homes.
On Acklins, significant flooding was reported, with an estimated 20 homes destroyed.
Power lines were downed, private fresh water wells were flooded, and structural
damage occurred to homes on Long Island. Over two-thirds of the island remained
RA IV/HC-38/Doc. 3.1, p.8
inundated with 4-6 feet of water by October 7. On Rum Cay, severe flooding,
downed trees, impassable roads, and downed power lines and poles were reported
across the island. On San Salvador, flooding, downed power lines and poles, and
significant damage to homes were reported throughout the island. Many roads were
impassable, and the airport building was completely destroyed. Extreme flooding and
downed power lines were reported on Exuma, but only minor damage to homes was
reported on Mayaguana. Less extensive damage was reported in the Turks and
Caicos Islands, northwestern Haiti, Bermuda, and in the Cuban province of Granma.
Hurricane Kate
The development of Kate was associated with a tropical wave that
spawned a tropical depression on November 8 just to the north of the Turks and
Caicos Islands. Although such development so late in the season is rare, it is not
unprecedented. The depression became a tropical storm the next day near the
central Bahamas while it moved toward the northwest and north, with its center
passing just to the east of the northwestern Bahamas late that day. The small
cyclone moved northward around the periphery of the Bermuda-Azores subtropical
high and steadily intensified. After recurving into the mid-latitudes, Kate reached
hurricane status by November 11, with its peak intensity of 85 mph occurring later
that day. After that time, the hurricane encountered strong westerly shear and cold
waters, and transformed into an extratropical cyclone by November 12. The powerful
low continued to move eastward until late November 13, when it was absorbed by a
larger extratropical cyclone over the north Atlantic.
RA IV/HC-38/Doc. 3.1, p.9
Table 1.
2015 Atlantic hurricane season statistics.
Storm
Name
Classa
Datesb
Max.
Winds
(kt)
Min.
Pressure
(mb)
Deaths
U.S.
Damage
($million)
Ana
TS
8 – 11 May
50
998
1
minor
Bill
TS
16 – 18 June
50
997
2
minor
Claudette
TS
13 – 14 July
45
1003
Danny
MH
18 – 24 August
110
960
Erika
TS
24 – 28 August
45
1001
30
17.4
Fred
H
30 August – 6 September
75
986
9
Grace
TS
5 – 9 September
50
1000
Henri
TS
8 – 11 September
45
1003
Nine
TD
16 – 19 September
30
1006
Ida
TS
18 – 27 September
45
1001
Joaquin
MH
28 September – 7 October
135
931
Kate
H
8 – 11 November
75
980
34
Tropical depression (TD), maximum sustained winds 33 kt or less; tropical storm
(TS), winds 34-63 kt; hurricane (H), winds 64-95 kt; major hurricane (MH), winds
96 kt or higher.
a)
Dates begin at 0000 UTC and include all tropical and subtropical cyclone stages;
non-tropical stages are excluded.
b)
RA IV/HC-38/Doc. 3.1, p.10
Figure 1. Tracks of the Atlantic tropical storms and hurricanes of 2015.
RA IV/HC-38/Doc. 3.1, p.11
2
Eastern North Pacific
The 2015 eastern North Pacific hurricane season was very active. Of the
18 cyclones that reached tropical storm strength, 13 became hurricanes and 9
reached major hurricane status (category 3 or higher on the Saffir-Simpson
Hurricane Wind Scale). The number of major observed in 2015 was the highest
since reliable records began in 1971. For comparison, the 1981-2010 seasonal
averages are 15 tropical storms, 8 hurricanes and 4 major hurricanes. The
Accumulated Cyclone Energy (ACE), which measures the combined strength and
duration of tropical storms and hurricanes was about 63 percent higher than the
1981-2010 median value. This ACE value is the highest observed in the basin since
1993. There were three unnamed tropical depressions, and another one that formed
in the basin and became a tropical storm (Ela) in the central North Pacific.
The genesis of most of the tropical cyclones was associated with tropical
waves that moved westward from the Atlantic to the eastern North Pacific basin.
While strong westerly shear in the eastern part of the basin prevented most of these
waves from developing there, the western part of the basin had much lower shear
than average and the ocean was anomalously warm. A large area of an upper-level
diffluence and rising motion persisted during most of the active portion of the 2015
season (Fig.1). These very favorable conditions for genesis and intensification are
usually present in the basin during strong El Nino events, although the activity was
shifted even farther west than expected during those events.
Most of the cyclones intensified and moved away from Mexico. Despite the
above average season, record-breaking Patricia was the only hurricane to make
landfall in Mexico during 2015. Hurricane Patricia, which was the strongest hurricane
on record in the eastern North Pacific basin, weakened to category 4 strength on the
Saffir-Simpson Hurricane Wind Scale before it made landfall near Playa Cuixmala,
about 50 miles west-northwest of Manzanillo. Moisture from several tropical
cyclones spread northward causing locally heavy rainfall over portions of northern
Mexico and the southwestern United States during the season. Table 1 lists the
tropical cyclones of the 2015 season, and the tracks of the season’s tropical storms
and hurricanes are shown in Figures 2a and 2b.
Hurricane Andres
A tropical depression formed early on May 28 about 825 miles south of the
southern tip of the Baja California peninsula, and became a tropical storm later that
day. Andres moved west-northwestward and then northwestward, reaching
hurricane strength about 775 miles south-southwest of the southern tip of the Baja
California peninsula on May 29. A period of rapid intensification then began, and the
hurricane reached its peak intensity of 145 mph early on June 1. Weakening
occurred quickly as the cyclone moved west-northwestward over cooler waters.
RA IV/HC-38/Doc. 3.1, p.12
Hurricane Blanca
Blanca formed on May 31 about 390 miles south-southwest of Acapulco.
The cyclone initially moved west-northwestward to northwestward and was affected
by strong northwesterly wind shear associated with the outflow of Hurricane Andres
to its west. The shear relaxed and the system was able to strengthen while it drifted
erratically within poorly defined steering currents. Blanca became a major hurricane
with a pinhole eye on June 3, and reached its peak intensity of 145 mph later that
day about 470 miles south of Manzanillo. Due to the upwelling of cooler waters, the
cyclone weakened, but as Blanca moved away from its cold wake it temporarily reintensified. The maximum winds had diminished to near 45 mph by the time Blanca
made landfall on the west coast of Baja California Sur early on June 8. Later that
day, the center of the cyclone moved briefly over water to the west of Baja California
Sur and then made its final landfall on the west coast of that state. Moisture
associated with Blanca’s remnants produced mostly light rains over portions of the
southwestern United States. Rainfall totals were mostly less than an inch, with
higher amounts at some of the more elevated areas.
Hurricane Carlos
Carlos began as a tropical depression on June 10 about 290 miles
south-southwest of Puerto Escondido. Despite moderate shear, the system reached
tropical storm intensity on the 11th about 230 miles south of Acapulco, and became a
hurricane two days later while moving parallel to the southern coast of Mexico. Data
from an Air Force Reconnaissance plane indicated that Carlos attained its peak
intensity of 90 mph around midday June 16, about 105 miles south of Manzanillo.
Only 6 h after the cyclone attained its peak intensity, the surface center separated
from the deep convection and Carlos rapidly decayed. The cyclone made landfall in
Mexico near Tenacatita with 50-mph winds and then dissipated in the vicinity of the
Islas Marias.
Carlos caused locally heavy rains over portions of southern and western
Mexico from 11-19 June. The heaviest amounts occurred in the state of Oaxaca with
Union Hildago reporting 11.97 inches and Chicapa 10.83 inches. La Jornada, a
Mexico City newspaper, reported that high surf generated by Carlos damaged a few
dozen boats and sank several boats in Acapulco, while strong winds knocked down
trees and billboards. According to the news site MiMorelia.com, large waves and
heavy rain caused at least US $326,000 in damage to coastal structures near Lazaro
Cardenas.
Hurricane Dolores
A surface low pressure system developed about 345 miles southsouthwest of Salina Cruz on July 10, and although southerly shear was affecting the
disturbance, a tropical depression formed early July 11 about 345 miles southsoutheast of Acapulco. The depression intensified while it moved parallel, but far
enough off of the southwestern coast of Mexico to keep winds of tropical storm force
offshore. Dolores moved away from the coast and became a hurricane late on July
13 about 165 miles south-southwest of Manzanillo, and reached its peak intensity of
130 mph on the June 15. A slow weakening occurred while the hurricane was
passing not too far from Socorro Island late that day, where sustained 80-mph winds
with gusts to 115 mph were observed. The cyclone weakened over cool waters and
dissipated early on June 22 a few hundred miles west-southwest of San Diego,
RA IV/HC-38/Doc. 3.1, p.13
California. Moisture associated with the remnants of the cyclone produced very rare
July heavy rains over portions of southern California.
Tropical Storm Enrique
The tropical depression that became Enrique formed from a broad area of
low pressure on July 12 about 1200 miles west-southwest of the southern tip of the
Baja California peninsula. The cyclone moved slowly north-northwestward, reaching
its peak intensity of 50 mph on the 14th. Early the next day, increasing southsouthwesterly vertical wind shear caused the circulation to become tilted and the
tropical cyclone weakened. Enrique degenerated to a remnant low about 1600 miles
west of the southern tip of the Baja California peninsula on July 18, and dissipated
on July 22.
Tropical Storm Felicia
Short-lived Felicia formed on July 23, about 430 miles southwest of the
southern tip of the Baja California peninsula and became a 40-mph tropical storm 6
h later. As the cyclone moved northwestward, strong shear caused the storm to
weaken, and the cyclone degenerated into a remnant low on the 24th about 545
miles west of the southern tip of the Baja California peninsula.
Hurricane Guillermo
An area of low pressure formed near 6˚N south of the Baja California
peninsula the morning of July 27. Over the next two days, cyclonically curved
rainbands developed, marking the formation of a tropical depression on July 29
about 1300 miles southwest of the southern tip of the Baja California peninsula. The
depression moved west-northwestward into a very favorable environment and
became a tropical storm on July 30 and a hurricane the next day. The strengthening
process continued, and Guillermo, with a distinct eye, reached its peak intensity of
110 mph. After that time, weakening occurred, but the hurricane maintained winds
of 105 mph while moving west-northwestward into the Central Pacific Hurricane
Center’s area of responsibility. Guillermo passed just to the north of the Hawaiian
Islands as a weakening cyclone and produced unusually large surf of up to 15 feet on
east-facing shores, sending water and debris over roads on August 6.
Hurricane Hilda
Hurricane Hilda developed from a small but well-defined area of low
pressure late on August 5 about 1500 miles west-southwest of Cabo San Lucas and
rapidly became a tropical storm. With a very small inner core, the cyclone
strengthened, and satellite intensity estimates indicated that Hilda reached its peak
intensity of 140 mph on 8 August just before moving into the central Pacific basin
well south of the Hawaiian Islands, where it gradually weakened.
Hurricane Ignacio
A low pressure area led to the formation of a tropical depression on August 25
about 1500 miles west-southwest of the southern tip of the Baja California peninsula.
Moving westward and west-southwestward on the south side of the subtropical ridge,
the depression became a tropical storm on August 25 and a hurricane the next day.
Ignacio turned west-northwestward and moved into the Central Pacific basin on
RA IV/HC-38/Doc. 3.1, p.14
August 27 with maximum winds of 90 mph. Once over the central Pacific, the
hurricane reached its peak intensity of 145 mph early on August 30 about 500 miles
east-southeast of Hilo, before it merged with a cold front and dissipated south of the
Aleutian Islands.
Very large and powerful surf of up to 20 feet, heights rarely seen on the
east sides of the Hawaiian Islands, washed up sand and debris on windward coastal
highways throughout the state on September 1. Deep tropical moisture associated
with the outer circulation of Ignacio caused major flash flooding in downtown
Honolulu on September 3 causing considerable damage to businesses and
automobiles.
Hurricane Jimena
Jimena, which rapidly deepened to its peak intensity of 155 mph – just
below category 5 status on the Saffir-Simpson Hurricane Wind Scale early on August
29, formed from a broad low pressure area that became a tropical depression a few
days earlier about 740 miles southwest of Manzanillo. Jimena experienced a period
of explosive strengthening, when the hurricane was located about 1200 miles
southwest of the southern tip of Baja California. Shortly after reaching its peak
intensity, however, an eyewall replacement cycle occurred and a weakening trend
began. Jimena continued west-northwestward as it moved into the Central Pacific
hurricane basin early on September 1, and dissipated about 200 miles north of the
Hawaiian Islands on September 10. Immediately on the heels of Ignacio, Jimena
sent a second very large and persistent east swell with waves up to 20 feet to the
east shores of the islands from September 4 through September 6.
Tropical Storm Kevin
An elongated area of low pressure centered at relatively low latitude
became a tropical depression about 750 miles south of the southern tip of the Baja
California peninsula on August 30. During the next couple of days, the cyclone
moved northwestward and reached tropical storm strength on September 1 about
725 miles south-southwest of the southern tip of Baja California. A microwave pass
over the cyclone showed a mid-level eye late on September 3, suggesting the
potential for strengthening, but Kevin’s mid-level circulation separated from the lowlevel center, and on the 5th, Kevin became a remnant low.
Hurricane Linda
On September 2, despite a prevailing moderate northeasterly shear, a
broad area of low pressure led to the formation of a tropical depression on
September 5, about 490 miles southwest of Manzanillo. The cyclone became a
tropical storm early the next day and reached hurricane status several hours later.
The center of the intensifying cyclone passed midway between Socorro and Clarion
Islands with a distinct eye, and on September 8, Linda reached its peak intensity of
125 mph before moving over cooler waters and degenerating into a post-tropical
cyclone.
Moisture partially originating from Linda spread northward, causing locally
heavy rainfall over portions of the southwestern United States. On 15 September, a
strong mid- to upper-level trough and the remnants of Linda moved eastward into
southern California producing 2.39 inches of rain in Los Angeles on that day. This
RA IV/HC-38/Doc. 3.1, p.15
was the second-wettest September day since records began in that city in 1877.
A rainfall total of 1.15 inches was observed in San Diego that same day, which was
also that city’s second-wettest September day on record.
Linda and its remnants caused no casualties or damage in either Mexico or
the United States. Media reports, however, indicate that 7 hikers died in a narrow
canyon in Utah’s Zion National Park when it filled with rushing water during the flash
flood. That same day, 12 other people, including nine children, died in Hildale, Utah,
when two vehicles were swept away in flash flooding. A 6-year old child in one of
the vehicles remains missing and is presumed to have perished. The 20 fatalities
that occurred in Utah that day makes it the deadliest flood event in the state’s
history. These are not considered direct deaths caused by the tropical cyclone.
Hurricane Marty
Marty began as a tropical depression on September 26 about 340 miles
southwest of Acapulco, and strengthened into a tropical storm on September
27 while moving northward. Despite the prevailing shear, Marty became a hurricane
about 220 miles west of Acapulco, and data from an Air Force Reserve
reconnaissance flight indicate that the hurricane reached a peak intensity of 80 mph.
Under the influence of a trough to the northwest, the cyclone slowly turned
northeastward toward the coast, but strong shear caused weakening, and Marty
degenerated into a post-tropical low early on September 30 about 140 miles westsouthwest of Acapulco.
Tropical-storm-force winds remained offshore of the southwestern coast of
Mexico, but rains from Marty flooded three hundred homes west of Acapulco in the
vicinity of Río Coyuca.
Tropical Storm Nora
A tropical depression formed on October 9 about 1850 miles eastsoutheast of the Hawaiian Islands, and became a tropical storm later that day. Nora
moved west and west-northwest into the Central Pacific Hurricane Center’s area of
responsibility on October 11 with 70- mph winds. The cyclone encountered a hostile
environment in the central Pacific and dissipated on the 15 th well to southwest of the
Hawaiian Islands. Nora’s remnants, however, brought heavy rainfall to the windward
sections of the state from the Big Island to Oahu. Rainfall of 3 to 6 inches produced
significant runoff that closed a major highway north of Hilo on the Big Island.
Hurricane Olaf
Increasing convection associated with a low pressure area led to the
formation of a tropical depression on October 15 about 990 miles south-southwest of
Cabo San Lucas. The depression strengthened into a tropical storm about 48 h later,
and Olaf became a hurricane at 9°N, unusually low latitude. The hurricane moved
into the central Pacific basin, and reached its peak intensity of 150 mph early on
October 20. Steadily weakening occurred over the next few days, when a strong
upper-level trough approached from the northwest, causing increased vertical wind
shear and forcing the cyclone to recurve back into the eastern North Pacific. Olaf
degenerated into a trough on October 28.
RA IV/HC-38/Doc. 3.1, p.16
Hurricane Olaf produced unusually high east-shore surf as it passed well
to the east of the islands during October 21 through 26. Surf heights up to 20 feet
were reported on the Big Island, and the large waves caused coastal flooding of a
highway south of Hilo on October 22.
Hurricane Patricia
Patricia, the strongest hurricane on record in the eastern North Pacific, and
the strongest hurricane on record to affect Mexico, had a slow and complicated
genesis involving the interaction of multiple weather systems. It began as an
elongated area of low pressure that extended from the Yucatan Peninsula southward
for several hundred miles into the eastern Pacific on October 16. Deep convection
associated with this system increased, and a tropical depression formed on October
20 about 200 miles south-southeast of Salina Cruz.
The depression drifted west-southwestward while it gradually
strengthened. By the time a NOAA Hurricane Hunter aircraft reached the cyclone on
October 21, Patricia already had reached an intensity of 60-mph. Patricia
strengthened into a hurricane later that day about 230 miles south of Acapulco. By
October 22, a NOAA plane indicated that Patricia’s intensity had reached 130 mph
and a minimum pressure of 957 mb. The rapid intensification phase continued into
the night while Patricia turned northwestward and slowed down. By the time an Air
Force Hurricane Hunter aircraft reached the cyclone around midnight, Patricia had
intensified into an extremely powerful hurricane with maximum sustained winds of
205 mph and a minimum central pressure of around 879 mb. The cloud pattern
continued to increase in organization over the next several hours after the plane left,
and the hurricane reached a peak intensity of 215 mph in the morning of the 23 rd
about 150 miles southwest of Manzanillo. This intensity makes Patricia the strongest
hurricane on record in the eastern North Pacific; it should be noted, however, that
records for the most intense eastern North Pacific hurricanes are particularly
uncertain prior to 1988.
Patricia turned north-northwestward and then northward toward the coast
of Mexico while essentially maintaining its intensity. By the time the last
reconnaissance mission reached Patricia in the afternoon of October 23, the surface
winds were still near 205 mph, but a final pass by the plane a few hours later
indicated that a rapid filling of the cyclone had begun. In fact, the peak flight-level
winds had decreased nearly 50 kt in the same quadrant traversed earlier, while the
central pressure had risen 24 mb in the 3 h since the first fix.
Patricia made landfall in the state of Jalisco, near Playa Cuixmala, late on
October 23 with an intensity of 150 mph and a minimum pressure of around 932 mb,
the lowest central pressure for a landfalling Pacific hurricane in Mexico in the
historical database. A minimum pressure of 934.2 mb was observed late on the 23 rd
by an automated weather station at Playa Cuixmala while a storm chaser in Emiliano
Zapata, a couple of nautical miles inland from the landfall point, measured a
minimum pressure of 937.8 mb on the eastern edge of the eye. The hurricane
weakened rapidly during the next several hours while it moved over the high terrain
of the Sierra Madre where it dissipated.
Patricia is the strongest hurricane on record to affect Mexico in the
historical data base extending back to 1949. Because of the sparse nature of station
observations over Mexico, however, the reliable record for extreme landfalling
RA IV/HC-38/Doc. 3.1, p.17
Mexican hurricanes is also tied to the availability and interpretation of satellite
imagery of these systems, and is thought to be reliable only back to 1988.
A sparsely populated area of the southwestern coast of Mexico in Jalisco,
nearly midway between Manzanillo and Puerto Vallarta was battered by the
hurricane. A joint survey conducted by CONAGUA and the United States National
Weather Service after the storm indicated that Patricia produced a narrow swath of
severe damage along and just inland from the coast near where the hurricane made
landfall. The villages of Emiliano Zapata and Chamela sustained the worst damage,
according to press reports and eyewitness accounts. Large swells associated with
Patricia caused significant coastal flooding for several days that resulted in beach
erosion and damage to some structures in the Mexican states from Jalisco to
Guerrero. According to media reports, the preliminary damage from Patricia is
estimated to be $325 million (USD).
Rainfall accumulations of about 8 to 13 inches occurred over mountainous
terrain, with Nevado Colima in Jalisco reporting a storm total rainfall of 12.50 inches.
Press reports indicate that there were two direct deaths attributed to Patricia. Two
women, one from Argentina and the other from Coahuila, Mexico, were crushed
when a tree fell on them at a campsite in the Tapalpa forest in Jalisco. There were
four indirect deaths associated with the storm, when four passengers were killed in
an automobile accident on the Colima-Guadalajara highway during heavy rains and
strong winds associated with the storm.
Tropical Storm Rick
A tropical depression formed on November 18 about 715 miles
south-southeast of the southern tip of the Baja California Peninsula, and as the shear
decreased, the cyclone strengthened to a tropical storm with an estimated peak
intensity of 40 mph the next day. The cyclone moved general west-northwestward,
but encountered dry air that prevented any additional strengthening. Rick remained
a tropical storm until November 22 when the associated convection dissipated and
the cyclone became a remnant low.
Hurricane Sandra
Sandra, the latest-forming major hurricane in the eastern North Pacific
basin during the satellite era, originated from a broad low pressure area south of
Mexico, and became a tropical depression on November 23 about 575 miles southsouthwest of Acapulco. The depression moved west-northwestward and
strengthened, becoming a tropical storm about 575 miles south of Manzanillo. An
eye feature with a diameter of 25-30 miles developed on November 24, initiating a
period of rapid intensification. During the next 36 h, the cyclone strengthened
significantly, reaching its peak intensity of 150 mph early on November 26.
Increasing southwesterly vertical wind shear became established and the cyclone
degenerated into a trough of low pressure about 60 miles southwest of Culiacán.
Culiacán.
RA IV/HC-38/Doc. 3.1, p.18
3
Forecast Verification.
For all operationally designated tropical or subtropical cyclones in the Atlantic and
eastern North Pacific basins, the National Hurricane Center (NHC) issues an “official”
forecast of the cyclone’s center location and maximum 1-min surface wind speed.
Forecasts are issued every 6 h, and contain projections valid 12, 24, 36, 48, 72, 96,
and 120 h after the forecast’s nominal initial time (0000, 0600, 1200, or 1800 UTC)
At the conclusion of the season, forecasts are evaluated by comparing the projected
positions and intensities to the corresponding post-storm derived “best track”
positions and intensities for each cyclone. A forecast is included in the verification
only if the system is classified in the final best track as a tropical (or subtropical
cyclone at both the forecast’s initial time and at the projection’s valid time. All other
stages of development (e.g., tropical wave, [remnant] low, extratropical) are
excluded. For verification purposes, forecasts associated with special advisories do
not supersede the original forecast issued for that synoptic time; rather, the original
forecast is retained. All verifications in this report include the depression stage. The
2015 official forecast errors for the Atlantic and Eastern North Pacific are included in
Figures 5 and 6, respectively.
Acknowledgements:
The cyclone summaries are based on Tropical Cyclone Reports prepared by the RSMC
Hurricane Specialist Unit.
These reports are available on the Internet at
http://www.nhc.noaa.gov/data/tcr/index.php?season=2015&basin=atl
www.nhc.noaa.gov/2015epac.shtml
RA IV/HC-38/Doc. 3.1, p.19
Table 2.
2015 eastern North Pacific hurricane season statistics.
Dates
Max.
Winds
(kt)
Min.
Pressur
e (mb)
MH
May 28 –June 4
125
937
Blanca
MH
May 31- June 9
125
936
Carlos
H
June 10-17
80
978
Ela
TS
July 8-10
40 c
1002 c
Dolores
MH
July 11-18
115
946
Enrique
TS
July 12-18
45
1000
Felicia
TS
July 23-24
35
1004
Guillermo
H
July 29- Aug 7
110
967
Hilda
MH
August 6-13
120
946
Ignacio
MH
August 25- September 5
125
942 c
Jimena
MH
August 26–September 9
135
932
Kevin
TS
August 31- September 5
50
998
Linda
MH
September 5-10
110
950
Marty
H
September 26-30
70
987
Nora
TS
October 9-15
60
993 c
Olaf
MH
October 15-27
130
938
Patricia
MH
October 20-24
185
872
Rick
TS
November 18-22
35
1002
Sandra
MH
November 23-28
130
934
Storm
Name
Class
Andres
a
b
c
c
Death
s
U.S.
Damage
($million
)
0.3
2
325
Tropical depression (TD), maximum sustained winds 33 kt or less; tropical storm
(TS), winds 34-63 kt; hurricane (H), winds 64-95 kt; major hurricane (MH), winds
96 kt or higher.
a
Dates begin at 0000 UTC and include all tropical and subtropical cyclone stages;
non-tropical stages are excluded.
b
Peak intensity and minimum pressure was reached outside the eastern North Pacific
hurricane basin.
RA IV/HC-38/Doc. 3.1, p.20
Figure 2a. Tracks of the eastern north Pacific tropical storms and hurricanes of
2015.
RA IV/HC-38/Doc. 3.1, p.21
Figure 3b. Tracks of the eastern north Pacific tropical storms and hurricanes of
2015.
RA IV/HC-38/Doc. 3.1, p.22
Figure 5. 2015 RSMC Miami Official forecast verification for the Atlantic.
Figure 6. 2015 RSMC Miami Official forecast verification for the eastern North
Pacific.