AmbergrisCaye.com Home
Posted By: Marty Unusually Quiet Atlantic Hurricane Season Ends - 11/29/13 06:10 PM

The Unusually Quiet Atlantic Hurricane Season of 2013 Ends

Jeff Masters

The end of the unusually quiet Atlantic hurricane season of 2013 is at hand. The final tally of thirteen named storms was above the average of eleven for a season, but the two hurricanes (Ingrid and Humberto) and zero major hurricanes were well below the average from 1950 - 2012 of six and three, respectively. The 2013 season ranked as the sixth-least-active Atlantic hurricane season since 1950, in terms of the collective strength and duration of named storms and hurricanes (ACE index), which was just 33% of the 1981 - 2012 average. The 2013 hurricane season was the first time since 1994 no major hurricanes formed, and was only the third below-normal season since the high-activity period for Atlantic hurricanes began in 1995. NOAA and the U.S. Air Force Reserve flew 45 hurricane hunter aircraft reconnaissance missions over the Atlantic basin this season, totaling 435 hours--the fewest number of flight hours since at least 1966, said NOAA in a press release summarizing the 2013 hurricane season.



Worst storm of the season: Ingrid
Mexico took a severe beating in 2013, with eight landfalling storms: one hurricane (Ingrid) and two tropical storms (Barry and Fernand) from the Atlantic side, and two hurricanes (Manuel and Barbara), and three tropical storms from the Pacific side. The deadliest and most expensive Atlantic storm of 2013 was Hurricane Ingrid, which weakened to a tropical storm with 65 mph winds before hitting Mexico about 200 miles south of the Texas border on September 16, 2013. Ingrid's heavy rains triggered flooding that killed 23 and did $1.5 billion in damage, making the storm the 7th costliest tropical cyclone in Mexican history. Barry and Fernand, which both hit the Mexican coast in the Gulf of Mexico between Tampico and Veracruz, dumped torrential rains and triggered floods that killed five and fourteen people, respectively. The first storm of the season, Tropical Storm Andrea, was the only named storm to make landfall in the United States this year. Andrea brought tornadoes, heavy rain, and minor flooding to portions of Florida, eastern Georgia and eastern South Carolina, causing one fatality and damage less than $25 million. No other deaths were recorded from Atlantic named storms in 2013. Tropical Storm Chantal did minor damage on Dominica and Martinique in the Lesser Antilles, and Tropical Storm Gabrielle did minor damage on Bermuda.


Figure 1. The strongest Atlantic hurricane of 2013, Category 1 Hurricane Ingrid, lays siege to Mexico on September 15, 2013. Ingrid killed 23 and did $1.5 billion in damage to Mexico. On the Pacific side, we see Tropical Storm Manuel, which killed 169 people and did $4.2 billion in damage to Mexico. Image credit: NASA Earth Observatory.

A preseason forecast bust
It was a bad year to be in the seasonal hurricane forecast business. All of the pre-season forecasts called for at least 7 hurricanes, 3 major hurricanes, and an ACE index at least 30% higher than average. With the actual numbers being 2 hurricanes, 0 major hurricanes, and an ACE index of just 33% of average , these forecasts were a major bust. The only pre-season forecast that one could deem successful was issued by a team at Penn State, led by Dr. Michael Mann, who only attempted to predict the number of named storms (they said 12 - 20, with a best estimate of 16.) The preseason forecasts largely failed because many of the factors that usually lead to active seasons that we can look at months beforehand all pointed towards an active season:

1) No El Ni�o was present. When El Ni�o conditions are not present in the Eastern Pacific, wind shear tends to be low over the tropical Atlantic, favoring hurricane formation.

2) Ocean temperatures were above average.

3) Sea level pressures were lower than average.

4) Wind shear was near average.

5) The African Monsoon was active, with many strong tropical waves emerging from the coast of Africa. These disturbances form the nucleus for about 85% of all major hurricanes.

However, these factors tell only roughly 50% of the story. The other 50% is not predictable more than a week or two in advance: the large-scale atmospheric circulation. This summer and fall, an unusually strong trough of low pressure over the Central Atlantic brought large amounts of dry, sinking air to the tropical Atlantic. Large amounts of dry air also invaded from the Sahara, and from Northeast Brazil, which had suffered the most expensive drought in Brazil's history ($8 billion) earlier in the year. The combined onslaught of dry air from these multiple sources was enough to overwhelm the otherwise favorable conditions for development, leading to one of the quietest Atlantic hurricane seasons on record. According to Phil Klotzbach of the Colorado State seasonal forecast team, the relative humidity at the 700 mb level (roughly 10,000 feet) in the Main Development Region of the tropical Atlantic (7.5- 22.5°N, 20-75°W) in August was the lowest observed in the past 35 years, and was the 8th lowest during September. The strength of the sinking motion of the air in this region during August and September was the second greatest of the past 35 years. It's tough to sustain a thunderstorm updraft when there is so much dry, sinking air at middle levels of the atmosphere.



Special Characteristics of the 2013 Hurricane Season
The 2013 hurricane season had the following special characteristics, as summarized by Phil Klotzbach of the Colorado State seasonal forecast team:

� Thirteen named storms occurred during 2013. This is the most named storms to occur in a year with two or fewer hurricanes in the historical record. The 1931 hurricane season had thirteen named storms but only three hurricanes.

� 35.75 named storm days (NSD) occurred during 2013. This is the fewest NSD since 2009 (30 NSD).

� Two hurricanes formed in 2013. This is the fewest hurricanes since 1982, when two hurricanes also formed.

� No major hurricanes formed in 2013. The last year with no major hurricane formations was 1994.

� ACE in 2013 was only 30 units. This is the lowest ACE for an Atlantic hurricane season since 1983 (17 ACE units.)

� No major hurricanes made U.S. landfall in 2013. The last major hurricane to make U.S. landfall was Wilma (2005), so the U.S. has now gone eight years without a major hurricane landfall. Since 1878 when relatively reliable landfall data became available, the U.S. has never had an eight-year period without a major hurricane landfall.

� The maximum intensity reached by any hurricane this year was 85 mph (Humberto and Ingrid). This is the weakest maximum intensity achieved by the most intense hurricane of a season since 1968 (Gladys, 85 mph.)

� Humberto reached hurricane strength early on September 11. It became the second latest forming first hurricane of the year, developing into a hurricane just hours before the previous record latest forming first hurricane of the year (Gustav, 2002.)

� Two tropical cyclones (TCs) formed in the Main Development Region (south of 23.5°N, east of 75°W) prior to 1 August. The last year with two TCs forming in this region prior to 1 August was all-time busiest hurricane season on record, 2005. The median ACE of the 10 years with two TCs in the MDR prior to 1 August was 174 ACE units. The 2013 season clearly defied many of the typical pre-season climate signals.


Video 1. Wunderground member CycloneOz put together this animation of all the named storms of the 2013 Atlantic hurricane season.


Meteorologists rank 2013 Hurricane Season "below average"

Even though hurricanes were not a threat in 2013, stationary rains across the country led to flooding and much infrastructural damage.

The 2013 hurricane season is coming to an end, and according to the National Meteorological Service of Belize this year's season was just below average. Hurricane season will officially culminate on Saturday, November 30th, and while Belize was spared from any disastrous hurricane/ tropical cyclones, stationary thunderstorm systems did cause severe flooding in various areas of the country.

Out of the 20 predicted storms, a total of 13 systems formed in the Atlantic Basin. Two went on to form in to hurricanes (Humberto and Ingrid), and 11 became Tropical Storms (Andrea, Barry, Chantal, Dorian, Erin, Fernand, Gabrielle, Jerry, Karen, Lorenzo and Manuel). Hurricane Humberto became the first hurricane of the season on Sunday, September 1st, but quickly lost strength. Humberto brought continuous heavy rain to the Cape Verde Islands causing flooding, but overall the damage was considered minimal. Hurricane Ingrid formed in the Gulf of Mexico and became the second hurricane of the season on Saturday, September 14th. Ingrid weakened into a tropical storm before making landfall on Monday, September 16th at La Pesca, Mexico. However, the tropical storm brought severe flooding and mudslides when it was joined by Tropical Storm Manuel, which made land fall in the area at the same time. The disastrous event resulted in over 30 deaths in various Mexican states, most notably in the Acapulco coastline. The local San Pedro Lions Club joined the rest of Belize's clubs in sending financial donations to the Lion's Club International Foundation for the Mexican flood victims.

According to Chief Meteorologist of the National Meteorological Service of Belize, Dennis Gonguez, the low activity in the Atlantic Basin was a result of strong wind shears, a lot of dry air and unexpected, cooler sea temperatures. The strong wind speed above the earth's surface along with the lack of humidity and low water temperatures made it nearly impossible for storms to gain strength and develop completely.

"Although the season was just below average, the Meteorology Department warns residents not to become complacent, as next year may bring that big storm we fear," said Gonguez. "The best way to be prepared during the hurricane season is to stay in tune to local weather forecasts, adhere to National Emergency Management Organization (NEMO) alerts and store nonperishable and basic living necessities from early in the season."

Hurricane season predictions are not always a hundred percent reliable and residents should always be prepared for a large storm. Residents are encouraged to be prepared at all time. To learn more on hurricane preparedness visit your local NEMO agency.

San Pedro Sun

2013 Atlantic Hurricane Season In Review
Rob Lightbown of Crown Weather Services

Sunday, December 8, 2013 12:04 pm

The very unusual and quiet 2013 Atlantic Hurricane season is now done. In total, there were 13 named storms, 2 hurricanes and no major hurricanes. Even though 2013 had a total of 13 named storms, most of these storms were short-lived and relatively weak in intensity. The accumulated cyclone energy (ACE) measures the total energy output of all tropical systems during the hurricane season. In 2013 the ACE was just 33% of the 1981 to 2012 average and 2013 is the sixth least active Atlantic season, measured by the ACE index since 1950. In addition, 2013 has the fewest number of hurricanes since 1982 and is the first time since 1994 there were no major hurricanes.

The 2013 Hurricane season actually started out quite active. Four named storms formed before August 1st. The Cape Verde Season was halted by an extensive amount of dry air associated with the Saharan Air Layer. Additionally, upper level winds were also quite hostile for much of the season. The first hurricane of 2013 did not form until September 11th.

Tropical Storm Andrea was the only tropical cyclone of the season to make landfall in the United States. It formed in the eastern Gulf of Mexico on June 5th and made landfall as a 65 mph tropical storm in coastal Dixie County Florida on June 6th. Andrea produced heavy amounts of rainfall across much of Florida with the jackpot of 14.27 inches recorded at North Miami Beach.

Barry was the first of four tropical cyclones to make landfall in eastern Mexico. Barry formed in the Bay of Campeche and made landfall near Veracruz on June 20th. Up to 10 inches of rainfall fell in Belize as Barry tracked across the Yucatan Peninsula. A few weeks later Chantal formed on July 8th in the east central Atlantic with the tropical storm dissipating over the mountainous terrain of Hispaniola around July 10th. Chantal ended up bringing heavy rain to the Lesser Antilles.


In late August Tropical Storm Dorian developed near the Cape Verde Islands on July 24th. As with most of the tropical cyclones during the 2013 season, it struggled and succumbed to dry air and strong upper level winds. Now, Dorian did regenerate east of Florida on August 3rd and only survived 12 to 24 hours, staying out to sea. Erin was another Cape Verde tropical storm that ended up dissipating over the open Atlantic on August 18th.


In late August, Fernand spun up quite rapidly in the Bay of Campeche making landfall near Veracruz, Mexico on August 26th. Tropical Storm Gabrielle developed in the eastern Caribbean on September 4th. It tracked northward between Puerto Rico and the Dominican Republic and lost its tropical characteristics in the western Atlantic. Gabrielle ended up regaining tropical storm strength for a second time on September 12th before it dissipated out in the open Atlantic on September 13th. The third tropical cyclone in the Atlantic to affect east Mexico was Tropical Depression 8. It made landfall on September 8th near Tampico Mexico and brought flash flooding and mudslides to Veracruz.


The first hurricane of 2013, Humberto, developed on September 13th near Africa. It brought squalls to the Cape Verde Islands. Humberto was overcome by dry air and quickly fell apart by September 14th. A few days Humberto regained tropical storm strength well out in the open Atlantic.

Ingrid was the second hurricane of the 2013 season. Mexico received a double whammy with extensive flooding on the east coast from Ingrid and on the west coast from Manuel in the eastern Pacific. Ingrid made landfall in eastern Mexico on September 16th as a Category 1 hurricane.

Tropical Storm Jerry developed in the Central Atlantic at the end of September. Much like many of the other storms this season, Jerry dissipated on October 3rd due to strong wind shear and dry air.

Karen formed in the southern Gulf of Mexico on October 3rd and tracked northward towards the northern Gulf coast. Strong wind shear ended up ripping Karen apart before it came ashore along the northern Gulf coast on October 6th. Karen did produce heavy rainfall across much of the deep South and the energy from Karen produced a nor-easter along the Mid-Atlantic coast.

Tropical Storm Lorenzo developed over the open Atlantic on October 21st and only survived a couple of days due to unfavorable atmospheric conditions. Tropical Storm Melissa developed along an old frontal boundary in the central Atlantic on November 18th and dissipated just north of the Azores Islands on November 21st.


As we all know, all of the seasonal Hurricane forecasts ended up far under what ended up occurring; this includes our own forecast here at Crown Weather Services. Most notably was the landfall forecast I issued in which I thought the seasonal wind pattern would steer the storms towards the central and eastern Gulf coast. Fortunately, this did not happen, however, the early predictions of a higher than average landfall risk along the central and eastern Gulf coast likely caused unneeded worry and panic.

I am now questioning the value and need of seasonal hurricane forecasts and am strongly considering discontinuing the seasonal forecasts that we issue. This, I feel, will allow me to concentrate much more on the current tropical weather situation and what may happen in the next week or two rather than a six month forecast, which more than likely, will not verify. I want to repeat, I am NOT discontinuing the daily tropical weather discussions, I am just considering not writing the seasonal forecasts anymore.

Some of the reasons why I am strongly considering discontinuing our seasonal forecasts:

- The seasonal forecasts can be misleading and can oftentimes lead to unneeded worry and panic. Our focus should be on the near term predictors of tropical storms and hurricanes and instead look at what atmospheric conditions may lead to tropical development within the next couple of weeks or so.

- It is much more useful to write a daily synopsis and a one to two week forecast of tropical cyclone chances than a general 6 month seasonal forecast. I think for some reason this past season that the various seasonal models missed the very minute details that led to strong wind shear and dry air which plagued many of the storms this year. This is why the many seasonal forecasts for 2013 fell short of what was predicted.

- What really counts in a seasonal forecast is not the number of storms, but where will they go and we do not have the capability to predict upper level winds for 3 to 6 months in advance. It is fine to put out a prediction of 18 named storms, which would be a busy hurricane season; the impact would be minimal, however, if all of the storms remain out in the open Atlantic. On the opposite end of the scale, a seasonal forecast of 6 named storms would lead one to believe that it will be a quiet hurricane season. Now, what if 4 of those storms made landfall with significant impacts on life and property; not so much of a quiet season.

So, I am going to leave this final decision up to you. Please let me know by e-mail at [email protected] if you want me to continue writing up seasonal forecasts every spring or if you would rather me not issue a seasonal hurricane forecast and instead write and concentrate on the daily tropical weather discussions that I issue.

2013 HURRICANE SEASON "SIXTH LEAST ACTIVE SEASON SINCE 1950, WITH THE FEWEST HURRICANES SINCE 1982"

[Linked Image]
Total Rainfall and it's normal per station for August, September, October 2013


Whereas the 2013 Atlantic Hurricane Season saw a below-average year-due to dry conditions at the mid-level of the atmosphere-Belize experienced above-average rainfall for the last four months of the season, in some cases, double the usual rainfall, according to information supplied to us by forecaster Derek Rudon of the National Meteorological Service.

"This unexpectedly low [cyclone] activity is linked to an unpredictable atmospheric pattern that prevented the growth of storms by producing exceptionally dry, sinking air and strong vertical wind shear in much of the main hurricane formation region, which spans the tropical Atlantic Ocean and Caribbean Sea," said Gerry Bell, Ph.D., lead seasonal hurricane forecaster at NOAA's Climate Prediction Center, a division of the National Weather Service. "Also detrimental to some tropical cyclones this year were several strong outbreaks of dry and stable air that originated over Africa," Bell noted.

Rudon told Amandala that all the experts who made seasonal hurricane predictions called for an above-average season, but the season turned out to be below average.

"It turned out to be the sixth least active season since 1950, with the fewest hurricanes since 1982," Rudon said.

The National Hurricane Center (NHC) in Miami reported, in its season summary, that, "Thirteen named storms formed in the Atlantic basin this year. Two, Ingrid and Humberto, became hurricanes, but neither became major hurricanes."

Rudon told us that the average number of hurricanes per season is 6 - this one had 2. On average 3 major hurricanes are formed, but this season saw none, he added.

The NHC noted that, "Tropical storm Andrea, the first of the season, was the only named storm to make landfall in the United States this year. Andrea brought tornadoes, heavy rain, and minor flooding to portions of Florida, eastern Georgia and eastern South Carolina, causing one fatality."

Rudon said that Belize was affected by one tropical depression - TD#2 - which formed on June 17 near the Bay Islands or 60 miles east of Monkey River around 6:00 a.m. and made landfall with maximum winds of 30 knots in the evening around 4:00 near Big Creek. That depression emerged on June 19 in the Bay of Campeche as Tropical Storm Barry.

June to November is also the rainy season. Official data indicate that some parts of the country experienced twice the amount of rainfall. For November, Central Farm recorded more than 14 inches of rainfall, just over double the average recorded since 1981. Meanwhile, November brought 11 inches of rain to Libertad, well above the 8-inches recorded since 1981.

There was also plenty of rain from August to October. Middlesex reported the highest increase in rainfall, registering at nearly 60 inches over the three months, contrasting with the average 40 inches recorded since 1981. Punta Gorda was the wettest location with nearly 63 inches of rainfall recorded during that period.

This week's continuous rains are being caused by a cold front which has stalled over the Bay of Campeche and a surface trough moving in from Caribbean. The rains, said Rudon, should persist over the next couple of days, but ease on Friday.

Amandala
© Ambergris Caye Belize Message Board