Atlantic Hurricane Season In June

As we are in June and hurricane season is heating up. Where do most June tropical storms and hurricanes form and end up going?

Here is a GIS heat map I created. This is all June tropical storms and hurricanes from 1870 to 2015.

Most June tropical storms and hurricanes form in the Gulf of Mexico, Southwest Caribbean, and off the Carolinas. No surprise that Texas and Florida are most vulnerable to tropical storms and hurricanes in June.

2016 And 2017 Atlantic Hurricane Season Forecast

Christmas is sure looming, but the 2016 Atlantic Hurricane Season is not too far away, six months from now. I am going to also look at 2017 Hurricane Season, which would be second year following the strong El Nino of 2015-2016. That is eighteen months from now at the writing of this article.

Analog Years For 2016 (TS/H/MH ACE ACE/Storm)
1878 12/10/2 181 15.1
1889 9/6/0 104 11.6
1897 6/3/0 55 9.2
1942 11/4/1 63 5.7
1958 10/7/5 121 12.1
1998 14/10/3 182 13.0

Here is the overall Atlantic Hurricane Season Statistics

1870-2015 Atlantic Hurricane
10/5/2 (Round Up


Standard Deviation



Standard Deviation



Standard Deviation

I came up with the analog for 2016, since we are in El Nino and once El Nino fades, La Nina comes and it can get strong. It is based on past El Nino and warm Atlantic Multidecadal Oscillation (AMO). Here is the statistics for 2016 Analog Season.

11/7/2 (Round Up)

11/7/2 (Round Up)

Standard Deviation



Standard Deviation



Standard Deviation

Looking at it, it is above average ranging from number of storms and hurricanes. Major hurricanes is about the same. However, keep in mind, anything before satellite should taken with a grain of salt. Seasons prior to satellite would of likely had more storms than recorded, but they could be in the middle of the Atlantic or some short lived tropical storm. Seasons like 1889 and 1897 likely had major hurricanes.

So, what is my prediction for the 2016 Atlantic Hurricane Season
10 to 16 named storms, likely 14 named storms
6 to 10 hurricanes, likely 8 hurricanes
2 to 5 major hurricanes with 3 major hurricanes
ACE is 110 to 190 with ACE likely of 130 to 160

Looks to be an active 2016 Atlantic Hurricane Season.

Here is a GIS heat map I created for 2016 analog seasons. It is within 300 miles.


Looking at the heat map, there are areas most at risk. Off the Eastern Seaboard with North Carolina most at risk. Haiti and Dominican Republic, Caribbean and Cuba, Southwest Florida, and Gulf of Mexico. Anywhere is at risk, but those areas especially are the ones to keep an eye on. Let’s see what 2017 Atlantic Hurricane Season forecast.

Analog Years For 2017 (TS/H/MH ACE ACE/Storm)
1879 8/6/2 64 8.0
1890 4/2/1 33 8.3
1898 11/5/1 113 10.3
1943 10/5/2 94 9.4
1959 11/7/2 77 7.0
1999 12/8/5 177 14.8

I came up with the analog for 2017, based on the second year following El Nino. Warm AMO is taken into account. Here is the statistics for 2017 Analog Season.

10/6/2 (Round Up)

11/6/2 (Round Up)

Standard Deviation



Standard Deviation



Standard Deviation

Looking at it, 2017 is closer to average than 2016. Interestingly, there are more major hurricanes on average than compared to 2016 analog seasons. Still, looking at the actual analog seasons, it is generally less active. Again, keep in mind, anything before satellite should be taken with a grain of salt. There were likely more storms before satellite era that went undetected.

So, what is my prediction for the 2017 Atlantic Hurricane Season
9 to 14 named storms, likely 12 named storms
4 to 9 hurricanes, likely 7 hurricanes
2 to 4 major hurricanes with 3 major hurricanes
ACE is 100 to 180 with ACE likely of 120 to 150

Here is a GIS heat map I created for 2017 analog seasons. It is within 300 miles.


Looking at the hot spots, West Indies, Lesser Antilles, Caribbean and Cuba, Off the Eastern Seaboard, Bahamas, and Western Gulf of Mexico with Texas and Louisiana at most risk. Again, anywhere is at risk, but those areas especially are the ones to keep an eye on.

The 2016 and 2017 Atlantic Hurricane Forecast is all preliminary at this time. It is subject to change. I should have a better idea about the 2016 Atlantic Hurricane Season in April 2016 and for 2017, April 2017. That would be sixteen months from now of course. This is just a thought because of the strong El Nino we have and what impact a strong El Nino has on the Atlantic. By Summer 2016, it could be still El Nino. It could also be Neutral or La Nina by than. Until than, please check back in April 2016 for the 2016 Atlantic Hurricane Season forecast.

The Tropical Atlantic Is Heating Up For 9/13/2015

We are in mid September and the tropics are heating up. There are three areas of interest in the tropics; Invest 93L, 94L, and 95L.


Invest 94L is the closest to Texas. 94L has a low chance of development. It is close to land and has to contend with wind shear. Here is the 5 day forecast of where 94L will go.


Most have it going to Mexico. One has it going into Texas, which is an outlier. Another has it going south into the Yucatan Peninsula. I do not think 94L will become tropical. Even the intensity forecast models do not support it.


Most forecast models have 94L below tropical depression. A couple of models have it as a tropical storm in the next two days. Two models have 94L as a tropical storm in five days. Forecasting intensity has a long way to go.

Verdict: Invest 94L will not develop into something tropical.

Now, let’s go to Invest 93L. I think this one could develop in the next couple of days if conditions are right. It has to deal with wind shear and dry Saharan air, which has been persistent due to El Nino. The forecast models are hinting it could become a named storm within 24 hours. It would be Ida.


I am not too sure if 93L will develop. If so, it will probably develop into a tropical storm at most.


Most forecast models keep 93L out to sea. When a storm intensifies into in the middle of the Atlantic, they tend to be more influenced by upper air patterns. This holds true with hurricanes.

Verdict: Invest 93L could develop, but will not hold my breath for it.

Finally, let’s look at Invest 95L. It just came off of West Africa. 95L has a better chance of developing in the next five days. One thing about Invest 93L, it has to also deal with dry air. That could favor 95L as it can intensify. I think 95L could become Ida or Joaquin, which ever develops first.


Some of the forecast models have 95L as a hurricane in the next two to three days. It peaks as a Category 2 hurricane. If Ida was to develop, I would not be surprised if 95L became a Category 3 hurricane. Now, where does it go?


Invest 95L has a more west northwest direction. Even five days later, it is still in the middle of the Atlantic. Could it pose a threat to land? Depending how fast it develops. The slower it develops, the better chance that it could pose a threat to land.

Verdict: Invest 95L is the one to watch this week.

We are in the peak month of hurricane season. So, the tropics are heating up.

April 2013 Hurricane Season Forecast

2013 Hurricane Season is fast approaching. Tropical Storm Risk, ImpactWeather, CrownWeather, and Joe Bastardi have issued their April 2013 forecast. Keep in mind this is very preliminary at this time as things change.

Tropical Storm/Hurricane/Major Hurricane ACE=Accumulated Cyclone Energy ACE/Storm

Colorado State University
18/9/4 ACE: 165

Tropical Storm Risk
15/8/3 ACE: 134

16 to 20 Storms/7 to 9 Hurricanes/Did Not Release Major Hurricane Numbers ACE: None

Joe Bastardi
16/12/5 ACE: 165

North Carolina State University
13 to 17 Storms/7 to 10 Hurricanes/3 to 6 Major Hurricanes ACE: None

Right now, the Pacific Decadal Oscillation (PDO) is in a cool phase, while Atlantic Multidecadal Oscillation (AMO) is in a warm phase. We are right now in a Neutral phase of El Nino Southern Oscillation (ENSO) as this past winter was. Most forecast models have ENSO in a Neutral phase to Fall (Northern Hemisphere) or Spring (Southern Hemisphere) 2013. Forecasting El Nino is very tricky and often comes out incorrect as it happened last year and in 2006.

Mid April 2013 IRI/CPC Plume-Based ENSO Forecast

Mid April 2013 IRI/CPC Plume-Based ENSO Forecast

Mid-April 2013 ENSO Predictions Plume

Mid April 2013 ENSO Predictions Plume

Based on phase of PDO, AMO, and previous winter ENSO, the analog seasons for 2013 are 1952, 1960, 1961, 1966, and 2004. Those years started with a Neutral, Weak El Nino, or Weak La Nina and went Neutral, Weak El Nino, or Weak La Nina by the peak of hurricane season to end of the year. 1966 started with Weak El Nino and went to Weak La Nina by end of that year. 2004 started as Neutral and went to Weak El Nino by end of that year. It shows that ENSO is difficult to predict and left leeway as a result. On the other hand, PDO and AMO does not change much. 1952, 1960, 1961, and 1966 were in cool phase of PDO and warm phase of AMO, while 2004 was in warm phase of PDO and AMO. So, how were the analog seasons like.

Analog Years (TS/H/MH ACE ACE/Storm)
1952 7/6/3 87 12.4
1960 7/4/2 88 12.6
1961 11/8/7 205 18.6
1966 11/7/3 145 13.2
2004 15/9/6 224 14.9

2013 Atlantic Hurricane Season analogs.

2013 Atlantic Hurricane Season analogs.

All were devastating seasons. 1952 had Hurricane Fox make landfall on Cuba as a Category 4 hurricane, making it one of the strongest to make landfall on the island nation. 1960 had a Unnamed Tropical Storm that dumped heavy rain that led to flooding in Texas after a dry spell. Later that season, Hurricane Donna ravaged the the Caribbeans and Florida. 1961 started late, but went into over drive with Carla ravaging the Texas Coast and Hattie ravaging Belize. 1966 had Alma hitting Cuba and Florida, while Inez was a long lived storm that devastated Caribbean, Cuba, Florida, and Mexico. 2004 had Charley, Frances, Ivan, and Jeanne ravaged Florida and Alabama within six weeks.

Let’s look at the statistics of the analog seasons.

10.2/6.8/4.2 149.8 14.4
10/7/4 149.8 14.4

11/7/3 145 13.2

Standard Deviation
3.3/1.9/2.2 63.9 2.6

Let’s look the overall Atlantic Hurricane Season statistics from 1870 to 2012.

Hurricane Season Average (1870-2012)
9.5/5.5/2.1 92.1 9.7
10/6/2/ 92.1 9.7

9/5/2 84.0 9.1

Standard Deviation
4.1/2.6/1.7 54.0 4.2

The analog years about average number of storms as it is within standard deviation. However, major hurricane, ACE, and ACE/Storm are above average. The analog years 1961 and 2004 have some of the highest ACE on record for the Atlantic basin. This shows it is not number of storms that makes it active, it is how many long lived, hurricanes, and major hurricanes are in a season.

This season may not see as many named storms from 2010 to 2012, but they could be powerful and long lived. Since some of the analog seasons started late like 1961 and 2004, while 1952 had an early start in February. The 2013 season could start late, but I think it will start in June.

However, since 2010, there have been 19 named storms due to the use of satellites. My thinking is the 2013 Atlantic Hurricane Season could have more named storms than in the analog years.

What is my prediction for this season?
14 to 20 named storms, likely 16 named storms
7 to 10 hurricanes, likely 9 hurricanes
3 to 6 major hurricanes with 5 major hurricanes
ACE is 170 to 230 with ACE likely of 180 to 220.

I think the 2013 Atlantic Hurricane Season is going to have 16 named storms, 9 hurricanes, and 5 major hurricanes with ACE of 200. This could be a very active season ahead. The number is subject to change at a later date. I do not expect any El Nino or La Nina to develop at this time. I think this season will most likely be a Neutral ENSO season because of cool PDO, which inhibits any potential El Nino development. This is on top of a warm AMO phase we are in, which started in 1995. Most forecast models show Neutral ENSO, neither La Nina or El Nino.

Let’s see how my May 2012 hurricane forecast compare to the actual 2012 season.

9 to 12 named storms, likely 11 named storms
3 to 6 hurricanes, likely 5 hurricanes
1 to 3 major hurricanes with 2 major hurricanes
ACE is 75 to 100 with ACE likely of 75 to 90.

2012 Actual Number
19 Named Storms
10 Hurricanes
2 Major Hurricanes
133 ACE

I was off with the number of storms, hurricanes, and ACE. One can call it a bust. However, I was right with the number of major hurricanes as there were two (Michael and Sandy). The reason I made the lower than normal 2012 hurricane season forecast is that I was expecting El Nino to develop, in which many forecast models forecasted. El Nino never developed in 2012 due to a unusually cool PDO in the Fall of 2012. The 2012 Atlantic Hurricane Season was largely Neutral phase of ENSO, which allowed a more active season.

Regardless of how many storms form and how late it starts, I think no one is going to be safe and there could be multiple major hurricanes making landfall. This could end the drought of major hurricanes making landfall on America, which started after Wilma in 2005. Again, it only takes one to be a devastating season, like in 1983 with Alicia, 1992 with Andrew, or 2012 with Sandy.

2011 Hurricane Season Is Over

2011 Hurricane Season is over. This season was active in the term of number of storms. However, the number of them becoming hurricane was rather low due to the lack of instability in the upper atmosphere. However, the number of major hurricane was within the norm. Two storms made landfall on America, Don and Irene. Irene was the first hurricane to hit America since Ike in 2008. It was forecasted to be the “Big One” for the East Coast from Carolinas to New York. As it turned out, the storm surge was not bad for New York. However, Irene was a huge flood event for New England, so it was the “Big One” in terms of flooding.

So, how does 2011 stack up? All mean, medians, and standard deviation is from 1870 to 2010. Statistical value has changed because there have been changes made for the past seasons.

19 Storms
Mean = 9.34 (9)
Median = 9
Standard Deviation = 3.98 (4)

It is an above average season with 19 storms. A season with 13 or more storms is above average. In fact, 2011 ties with 1995 and 2010 Hurricane Season. How often do we have season with back to back with 19 storms? 19 storms is an outlier, which is a rarity. Only 2005 (28) and 1933 (21) had more.

7 Hurricanes
Mean = 5.43 (5)
Median = 5
Standard Deviation = 2.61 (3)

The number of hurricanes is within average. A season with 8 or more hurricanes is above average. 2005 had the most hurricanes in one season at 15.

3 Major Hurricanes
Mean = 2.07 (2)
Median = 2
Standard Deviation = 1.75 (2)

The number of major hurricanes is within average. A season with 4 or more major hurricane is above average. This time, 1950 had the most major hurricanes on record with 8. However, re-analysis show that 1950 may not have had 8 major hurricanes, but instead 6 major hurricanes. So, 2005 would be the winner with 7 major hurricanes.

119 Accumulated Cyclone Energy (ACE)
Mean = 91.62 (92)
Standard Deviation = 54.30 (54)
Median = 83

The ACE is within average. A season with an ACE of +54 above standard deviation or 146 or above is considered active. The season with the most ACE is 2005 at 248.

6.3 ACE/Storm
Mean = 9.74 (9.7)
Median = 9.1
Standard Deviation = 4.18 (4.2)

The ACE/Storm is within average. Anything above the standard deviation of 4.2 for the mean or 13.9 is considered above average. The season with the highest ACE/Storm is 1915 at 21.2, but that is before satellites. The season with the highest ACE/Storm in the satellite era is 1961 at 18.6 ACE/Storm. 1961 was the year Hurricane Carla made landfall on Texas. For kicks, the ACE/Storm for 2005 was within average of 8.9.

36.8 Percent Of Storms Became Hurricanes
Mean= 58%
Median = 58%
Standard Deviation = 17%

The percentage of storms that became hurricane is below average. This is despite the fact that 19 storms formed in 2011. In fact, it is more than 17% (standard deviation) below the mean. This would show that the lack of vertical instability was a huge factor. The season with the highest percentage of storms becoming hurricane is 1884 at 100%, but this is before satellite were used. The season with the highest percentage of storms becoming hurricane is 1977 at 83%. Interesting fact about 1977, it was quiet in the Atlantic, East Pacific, and West Pacific. It comes to show that even active seasons do not have high percentage of storms becoming hurricane, like 2005, which was 54% of storms became hurricanes.

15.8 Percent Of Storms Became Major Hurricanes
Mean = 21%
Median = 20%
Standard Deviation = 15%

The percentage of storms becoming major hurricane is within average. This is rather strange for a season where a low percentage of storms becoming hurricanes. All in all, the 2011 Hurricane Season was active despite the low percentage of hurricanes and lack of vertical instability. The season with the highest percentage of storms becoming major hurricane is 1930 at 67%, but this is before satellite were used. The season with the highest percentage of storms becoming major hurricane is 1961 at 64%. In the active 2005 season, only 25% of storms became major hurricanes and that is within average.

What does the 2012 Hurricane Season be like? It will be hard to say at this time since it does not start until June 1, 2012. Usually, when there are two back to back season that are active, the next season is usually less active. Right now, we are in a La Nina and usually by the spring and summer, it is Neutral. Rarely, a year can go from La Nina to El Nino. The last time that happened was in 2009, in which the season was quiet. Here are the years that went from La Nina to El Nino.

If 2012 does not see an El Nino and stays Neutral, we can be in it for another active season. 2003 to 2005 had three active back to back seasons. 2005 was the most active on record with 28 storms. It was the year Hurricane Katrina ravaged the Gulf Coast. I would not rule out 2012 being active like 2010 and 2011. I should have a much better idea by Spring of 2012. So stay tuned.

2011 Hurricane Season So Far and Stats

We are now in October of the 2011 Atlantic Hurricane Season. So far we have 16 storms, 4 hurricanes, and 3 major hurricanes with an Accumulated Cyclone Energy (ACE) of 99. So, how is this season stacking up to be? Is it truly an active season? All statistical values are from 1870 to 2010.

16 Storms
Mean = 9
Std Dev = 4.02
Kurtosis = 2.88
S.E. Kurt = 0.41
Skewness = 1.14

We are way above average in number of storms. Anything above a standard deviation of 4 is extremely active.

4 Hurricanes
Mean = 5
Std Dev = 2.61
Kurtosis = 0.75
S.E. Kurt = 0.41
Skewness = 0.80

We are close to average in number of hurricanes. It is within average. Anything +/-3 is above or below average is unusually active or inactive.

3 Major Hurricanes
Mean = 2
Std Dev = 1.75
Kurtosis = 0.84
S.E. Kurt = 0.41
Skewness = 1.10

We have an average number of major hurricanes so far this season. Anything above standard deviation of 2 is active, which would be 4 or more major hurricanes.

ACE of 99
Mean = 91
Std Dev = 54.28
Kurtosis = 0.40
S.E. Kurt = 0.41
Skewness = 0.93

We are withing average of ACE for the 2011 season. Anything above standard deviation of 54 is hyperactive, which would be 145.

ACE/Storm of 6.2
Mean = 9.78
Std Dev = 4.22
Kurtosis = -0.18
S.E. Kurt = 0.41
Skewness = 0.58

The ACE/Storm is rather low, but within the average. Below average ACE/Storm would be below standard deviation of 4.22 or 5.56 or less ACE/Storm.

25% Became Hurricanes
Mean = 0.59 (59%)
Std Dev = 0.17
Kurtosis = 0.89
S.E. Kurt = 0.41
Skewness = -0.29

The percentage of storms that became hurricanes in the 2011 season is unusually low, at 25 percent. In a normal season, 59 percent of storms become hurricanes. Even if we subtract the standard deviation of 0.17 from the mean, it is 0.42 or 42 percent.

18.8% Became Major Hurricanes
Mean = 0.21 (21%)
Std Dev = 0.15
Kurtosis = -0.02
S.E. Kurt = 0.41
Skewness = 0.56

The percentage of major hurricanes is within average. An Atlantic season with 6 percent or less would be an outlier. The last season with such a low percentage was 1994. No major hurricanes formed in 1994 as it was a quiet year due to El Nino.

The last time we had a season with many storms in a short time was 2005, which is the most active season record. 2005 had 28 storms, 15 hurricanes, and 7 major hurricanes with an ACE of 248. 2005 is an outlier, except some things and I will show you that.

28 Storms

15 Hurricanes

7 Major Hurricanes

ACE of 248

ACE/Storm of 8.9
The ACE/Storm in 2005 is within the mean. The reason is many of those storms in 2005 formed close to land. The ACE/Storm of 2004 was 14.9 because only 15 storms formed that year and many formed in the open Atlantic, intense, and were long lived.

53.6% Became Hurricanes
The percentage of storms that became hurricanes in 2005 is also within in the mean. 15 hurricanes is an outlier in that regard, but when it comes to percentage, not so. Keep in mind that 28 storms formed in 2005 and that right there is an outlier.

18.8% Became Major Hurricanes
The percentage of storms becoming major hurricanes is also within the mean. 1999 had 12 storms and 5 became major hurricanes, which is 41 percent, which makes it more than 0.15 (15 percent) standard deviation above the mean.

Source of data.
NOAA HRD-How many tropical cyclones have there been each year in the Atlantic basin? What years were the greatest and fewest seen?

The Average Tropical Cyclone Eye Size, ROCI, and Ambient Pressure

Let’s start with the Atlantic Basin. This is from 1988-2010 Best Track for Atlantic Hurricane
1988-2010 Best Track for Atlantic Hurricane

Eye Size
23.1 Nautical Miles (nm)

20 nm

Standard Deviation

5 nm (I do not know what is up with this, but the Best Track lists Wilma’s eye as 5 nm, even though the actual size was 2 miles or 1.7 nm)
Wilma 10/19/2005 1200 UTC (Z)

90 nm
Ophelia 9/13/2005 0000Z

Ambient Pressure
1011.1 Millibars (mb)

1011 mb

Standard Deviation

988 mb
Earl 9/5/2010 0000Z

Isidore 9/28/1996 0600Z

Radius of the Outer Closed Isobar (ROCI)
186.4 nm

180 nm

Standard Deviation

30 nm
Iris 9/20/1989 0000Z

555 nm
Gilbert 9/12/1988 1200Z

Here is the East Pacific, which is off the West Coast of Mexico.
For the East Pacific.

From 2001-2010 Best Track for East Pacific Hurricane
2001-2010 Best Track for East Pacific Hurricane

Eye Size
16.7 nm

15 nm

Standard Deviation

5 nm (There are probably East Pacific Hurricanes with smaller eyes.)
Juliette 9/24/2001 0600Z

75 nm
Douglas 7/24/2002 0000Z

Ambient Pressure
1009.2 mb

1009 mb

Standard Deviation

1000 mb
Blanca 6/23/2003 0000Z

1017 mb
Fausto 9/3/2002 0000Z

166 nm

160 nm

Standard Deviation

10 nm
Blanca 6/23/2003 0000Z

340 nm
Jimena 8/31/2009 0000Z

Here is a graph for mean and median.



Based on the statistics, Atlantic storms are larger than East Pacific. No surprise that the Atlantic Basin is much larger than the East Pacific Basin because there is cooler water to the west towards Hawaii. However, in El Nino years, the waters of East Pacific is more favorable, which means tropical cyclones last longer and can even travel into the Central Pacific and West Pacific as it happened with Hurricane John in 1994. The East Pacific is one of the most active basins in the world.