Published: November 30,2015
The 2015 hurricane season has officially come to a close in both the Atlantic and eastern/central Pacific basins. November 30 is the final day of the season each year, though occasionally a named storm may occur beyond that date.
Here are 11 things we'll remember from the 2015 hurricane season.
1.) Another Hyperactive Pacific Season; Atlantic Slightly Below Average
Tracks of all the Atlantic tropical cyclones in 2015.
Tracks of all the central and eastern Pacific tropical cyclones in 2015.For the second year in a row, the Pacific was much more active than the Atlantic.
The eastern Pacific had 18 named storms plus four additional tropical depressions for a total of 22 tropical cyclones. In the Atlantic, we saw 11 named storms and one additional tropical depression, bringing the number of tropical cyclones in that basin this season to 12.
Though several of them were short-lived, the 11 named storms in the Atlantic was just short of the 30-year average (1981-2010) of 12 named storms per season. Four of those named storms became hurricanes, which is below the average of six hurricanes during the same 30-year period.
Meanwhile, the eastern Pacific's 18 named storms was above the 30-year average of 15 per season. Of those 18 named storms, 13 went on to become hurricanes, which is well above the average of 8 per season.
The central Pacific was also unusually active in 2015 with a record eight tropical cyclones forming in the basin. An additional seven originated in the eastern Pacific, later crossing into the central Pacific for a total of 15 tropical cyclones in the central Pacific basin this season.
The previous record for the number of cyclones passing through the central Pacific basin in one year was 11 tropical cyclones in 1992 and 1994. The previous record number of cyclones originating in the central Pacific was just four in 1982 – which like 2015 was the beginning of a strong El Niño.
2.) El Niño Likely Played a Role in the 2015 Hurricane Season
This track line shows how Hurricane Danny reached Category 3 strength in the Atlantic, but then degenerated into an elongated area of low pressure as it approached the Caribbean. This weakening was due to a "wall of wind shear" near the Caribbean. Wind shear is common in this area during El Nino events.
El Niño likely helped to shape the outcome of the 2015 hurricane season.
As mentioned before, a record number of named storms developed during the central Pacific hurricane season. This is a basin where we typically see an uptick in tropical activity during El Niño.
We also saw strong wind shear near the Caribbean Sea and other parts of the Atlantic Basin, contributing to the demise of Hurricane Danny, Tropical Storm Erika, Hurricane Fred, Tropical Storm Grace and Tropical Storm Ida from mid-August through September.
Stronger wind shear tends to appear in parts of the Atlantic Basin in a season in which El Nino has developed. When winds strongly change with height, either in speed and/or direction, convection (rain and thunderstorm activity) can get blown away from the center of a storm. This wind shear can keep tropical cyclones from forming and can rip apart any existing storms.
Hurricane Danny was a perfect example of how wind shear can take a toll on a powerful hurricane. After reaching Category 3 status in the western Atlantic on Aug. 21, Danny dissipated into an elongated area of low pressure as it entered the eastern Caribbean on Aug. 24.
3.) A Category 5 Landfall With No Fatalities
A look at the track history of Hurricane Patricia (2015) in the eastern Pacific.
Hurricane Patricia became the strongest hurricane on record on Oct. 23, 2015. At one point, sustained winds reached 200 mph and the storm's central pressure fell to 879 millibars. Among all tropical cyclones known to modern science, only a few typhoons in the Western Pacific have ever been stronger.
Even with weakening prior to reaching Mexico's Pacific coast, Patricia made landfall as a Category 5 hurricane near Cuixmala, Mexico. Maximum sustained winds were estimated at 165 mph.
A combination of a relatively small core wind field with Patricia, sparse population near the point of landfall and preparedness led to no reported fatalities. Patricia is likely the only Category 5 landfall on record to not cause any deaths.
(MORE: How Did Mexico Escape Patricia with No Deaths?)
4.) Tropical Storm Erika Causes Deadly Flooding in Dominica
Flooding is seen at Douglas-Charles Airport in northeastern Dominica on Thursday, Aug. 27, 2015. (Twitter/Alison Kentish/Emerline Anselm)
Tropical Storm Erika provided an example of why you don't need a powerful hurricane like Patricia to cause deadly and devastating impacts.
Erika was just a 45 mph tropical storm as it passed through the Lesser Antilles on Aug. 27, but it was accompanied by torrential rainfall. The small island of Dominica saw more than a foot of rain in 12 hours from Erika, resulting in damaged homes, roads washed out, and a flooded airport. At least 20 people were killed by Erika's flooding in Dominica.
During a televised address, Dominica Prime Minister Roosevelt Skerrit said Erika set the nation's developmental progress back 20 years, as hundreds of homes and multiple other structures were destroyed.
Erika will also be remembered for its uncertain forecast, with some projections showing that it could impact Florida as a strong tropical storm or a hurricane. This prompted a State of Emergency to be declared in Florida. However, Erika never made it to the U.S. intact, instead it dissipated near eastern Cuba thanks to a combination of wind shear, dry air and land interaction.
5.) Hurricane Joaquin Batters the Bahamas; South Carolina Moisture Injection
Infrared satellite from the morning of Oct. 3. It shows an intense area of rainfall represented by the dark red and black shadings (colder and therefore higher cloud tops) extending from South Carolina to off the Southeast coast. Also shown is Hurricane Joaquin, which peaked as a Category 4 hurricane with maximum sustained winds of 155 mph at that time.
Despite an early start to the 2015 Atlantic hurricane season, things remained fairly tame through the climatological peak of the season in September.
That suddenly changed when Joaquin rapidly intensified near the Bahamas to become a Category 4 hurricane on the first day of October. By doing so, it was the latest Category 4 (or stronger) hurricane on record to impact the Bahamas.
Not only was Joaquin an intense hurricane, but it also persistently lashed the Bahamas for two days, resulting in severe impacts there. A total blackout was reported on the three hardest-hit islands of the central Bahamas. About 85 percent of the homes in one settlement on Crooked Island were reportedly destroyed.
Joaquin also contributed to the sinking of a cargo ship known as the El Faro, resulting in the deaths of the 33 crew members that were aboard.
Although Joaquin remained well off the U.S. coast, it helped provide an extra injection of moisture to the catastrophic flooding that South Carolina saw from a separate weather system in early October.
(MORE: Hurricane Joaquin Recap)
6.) 65 Atlantic Hurricanes in a Row Have Not Hit Florida
A record 65 straight hurricanes in the Atlantic have missed Florida.
Florida is often at the center of attention when it comes to hurricanes in the Atlantic Basin, which includes the Gulf of Mexico. Despite that fact, another season has gone by without an Atlantic hurricane hitting the state.
(MORE: 10 Years Later, Still No Hurricanes Have Hit Florida)
With hurricanes Danny, Fred, Joaquin and Kate all missing the U.S. in 2015, there have now been 65 hurricanes in a row across the Atlantic Basin that have not hit Florida, a record according to Dr. Phil Klotzbach, a Colorado State University research scientist specializing in tropical cyclones.
The last hurricane to strike the state was Wilma on Oct. 24, 2005, so the Florida hurricane drought has extended past the 10-year mark.
(MORE: Hurricane Wilma: A Look Back, in Photos)
7.) Bill Spends 83 Percent of Its Life Over Land
A look back at the track of Tropical Storm Bill, including the two days before the storm was named, while the system was not yet an official tropical cyclone (just an "invest" tropical wave, being monitored for further organization).
Tropical cyclones may thrive over water, but that does not mean that they cannot move inland. That said, it is unusual for such a storm to remain tropical for any extended period of time over land.
But after making landfall in Texas as a tropical storm, Bill moved north across the Plains and east into the Mississippi and Ohio valleys before finally becoming post-tropical in eastern Kentucky.
Bill spent three days over land, or 83 percent of its total life span as a tropical cyclone, while it was only over water as a named system for about 14 hours.
The most serious impact from Bill was the rainfall flooding it caused in the already saturated south-central states, particularly Texas and Oklahoma.
(MORE: Tropical Storm Bill Leaves Behind Flooding)
8.) Ana, Second Earliest U.S. Tropical Cyclone Landfall on Record
This May 8, 2015 satellite image shows Ana organizing off of the Southeast coast.
The Atlantic hurricane season does not officially begin until June, but that didn't stop an Atlantic tropical storm from making landfall in May.
Tropical Storm Ana began as a subtropical storm on May 7, but transitioned to a purely tropical storm before making landfall near Myrtle Beach, South Carolina, on May 10.
(MORE: Tropical Storm Ana Recap)
The only other tropical storm to make landfall earlier in a calendar year in the U.S. was an unnamed tropical storm in February 1952, which struck southern Florida.
9.) A Record Late Category 4 Hurricane
Hurricane Sandra as a Category 4 on Nov. 26, 2015. (RAMMB/CIRA)
From Ana's early landfall as a tropical storm in May, we switch gears to a record late Category 4 hurricane in the eastern Pacific.
On Nov. 26, Hurricane Sandra intensified into a Category 4 well off the Pacific coast of Mexico. This made Sandra the latest Category 4 on record in either the eastern Pacific or Atlantic basins. The previous latest Category 4+ tropical cyclone in either the eastern Pacific or Atlantic basins was Hurricane Kenneth on Nov. 22, 2011.
Sandra never made landfall in Mexico since wind shear weakened it quickly, causing it to degenerate into a remnant low south of Cabo San Lucas on Nov. 28.
10.) Three Central/Eastern Pacific Category 4 Hurricanes at the Same Time
On the morning of Aug. 30, 2015, three Category 4 hurricanes can be seen on this satellite image of the Pacific. Kilo (left), Ignacio (center) and Jimena (right).
In late August not one, not two, but three Category 4 hurricanes were active in the central or eastern Pacific Ocean at the same time: Kilo, Ignacio and Jimena. This was the first time on record that this has happened.
(MORE: Three Category 4 Hurricanes in the Pacific Ocean)
The instance of two simultaneous major hurricanes (Kilo and Ignacio) in the central Pacific by itself was also a first for the basin that has seen record tropical cyclone activity this year.
At the time, this was only the third occurrence on record of three major hurricanes or equivalent typhoons (Category 3 or stronger) in the entire north Pacific simultaneously. However, less than two months later, this happened again when Olaf and Patricia were ongoing as major hurricanes in the central and eastern Pacific, while Champi was a Category 3 equivalent typhoon in the western Pacific.
11.) Odd Storm Tracks in the Central and Eastern Pacific
Hurricanes Oho and Olaf took interesting tracks in the central and eastern Pacific in October 2015.
Tropical Storm Olaf became the first tropical cyclone on record to start in the eastern Pacific, move westward into the central Pacific and turn back east into the eastern Pacific in October 2015. By doing so, the Central Pacific Hurricane Center (CPHC) handed off responsibility for tracking the system to the National Hurricane Center (NHC).
Olaf wasn't the first oddly-tracking system of the season in the central Pacific. Oho developed south of Hawaii and moved northeast earlier in October, most likely joining only 1982's Ema for such a track.
(MORE: Hurricane Oho Recap)
An unnamed hurricane in 1975 also moved northeast in the central Pacific, but to the north of Hawaii. Although the 1975 storm and Ema both crossed the 140 degrees West back into the eastern Pacific before dissipating, Olaf was "almost certainly" the first system handed off between the basins from CPHC to NHC, according to NHC hurricane specialist Eric Blake.