As I have mentioned in other posts usually in July we see tropical storm or hurricane development in the Gulf, Caribbean, and Gulf Stream. We usually do not see development in the far Atlantic until late summer and early fall. However, two major hurricanes formed in the far Atlantic in the month of July. Both storms were named Bertha. Bertha 2008 and Bertha from 1996. I have also included Bertha from 1990 for comparison.

So what caused Bertha of 2008 and Bertha of 1996 to develop a month ahead of schedule. First, the Monsoon in the Sub-Saharan part of Africa arrived a month earlier than it normally does in 1996 and 2008. Therefore, you had tropical waves with decent convection coming off of the coast of Africa. Typically for June and July the waves come off but they have little thunderstorm activity as the monsoon usually has not arrived. Also the tropical waves have to deal with dry air. Second, the environment was favorable with warm water temperatures and no shearing winds. This could have been enhanced by La Nina's as 1996 and 2008 had active La Ninas during the Hurricane Season. Moreover, lets learn more about the Berthas.

Bertha 2008

Bertha 2008 developed into a tropical storm as soon as it came off the coast of Africa. This was rare as this usually does not happen until August-early October in the Far Atlantic. Due to above average water temperatures Bertha steadily intensified into a hurricane. It eventually reached a peak of 125 mph making Bertha a major hurricane and a category 3 one at that. Due to warm waters Bertha was able to last a long time. After peaking as a major hurricane Bertha fluctuated between a category 1 and category 2 hurricane for several days before eventually moving over colder waters in the Northern part of the Atlantic Basin. Although the storm never impacted any land. Berta of 2008 did cause three drowning deaths due to rip currents in the Antilles.

Bertha 1996

A vigorous tropical wave moved off the coast of Africa in early July 1996. This wave got the attention of the National Hurricane Center. Satellite data indicated a tropical storm had formed in the Far Atlantic again a rare event for July. The tropical storm was given the next name which was Bertha. As Bertha moved west it steadily intensified into a hurricanes while above the Antilles. When Bertha went over the Gulf Stream it intensified into a major category 3 hurricane with winds of 115 mph. The next day dry air from the Eastern Coast caused Bertha to weaken to a category 1 hurricane. Once Bertha moved away from the dry air it started to re-strengthen some. Bertha strengthened into a 100-105 mph category 2 hurricane before striking the outer banks of North Carolina.

After Making landfall in North Carolina Bertha weakened into a tropical Storm. Then the storm traveled up the East Coast bringing heavy rain and wind. Overall Bertha caused 12 deaths and $335 million in damages.

Even though this Bertha did not form in the far Atlantic I think it is worth mentioning it.

Hurricane Bertha of 1990.

Bertha of 1990 was a typical July system. As it developed over the Gulf Stream. Typically that is where a tropical storm would be expected to develop for the month of July along with the Gulf or Caribbean.

Bertha of 1990 originated from a Low Pressure system moving off the east coast of the USA. As the low moved over the warm waters it started to take on tropical characteristics. It was eventually given the name Bertha. This Bertha intensified into a category 1 hurricane with winds up to 80 mph. After making a few loops the hurricane weakened to a tropical storm before striking Canada. Bertha caused 9 drowning deaths in the USA and Canada from rip currents. In Canada the storm produced $3.91 million dollars worth of damage.

In conclusion, Bertha of 2008 and 1996 were historic because they formed in a region of the Atlantic that is normally hostile for tropical systems in July. Berth of 1990 was a typical July tropical storm or hurricane.