Hurricane Philippe (2011)

Storm Active: September 24-October 8

A well-defined low pressure area formed west of the African nation of Guinea on September 23. The low deepened rapidly later that day, already having developed large rain bands spread out evenly around the circulation. Convection decreased that night, but became very concentrated near the center, and the system became closed early the next morning. It was then declared Tropical Depression Seventeen. Slow organization followed later in the day as Seventeen moved west-northwest, and the system soon intensified into Tropical Storm Philippe.

A weakness in the ridge to Philippe's north allowed it to turn northwestward and decelerate into the day of September 25, when it reached an intensity of 60 mph winds and a pressure of 997 mb. The tropical storm maintained this strength into September 26, by which time it began to encounter higher wind shear and cooler waters. A gradual weakening ensued, as the circulation became exposed on September 27. That afternoon, Philippe's forward motion slowed to 5 mph and its shallow circulation was steered back to the west-northwest with a restrengthening of the subtropical ridge to its north.

That night, despite the fact that Philippe was a minimal tropical storm with little convection near the center, the outflow remained fairly robust, and thunderstorm activity reappeared just north of the center on September 28. The cyclone even strengthened a little that day. On September 29, the center reformed to the north of its previous position, and once again was completely enveloped in the convection associated with Philippe. The exact center position of Philippe remained difficult to identify overnight, but the circulation became more well-defined on September 30, and the cyclone strengthened further.

As the storm moved farther to the northwest, it encountered very strong shear associated with the outflow of Ophelia, but the tropical storm once again demonstrated resilience to strong upper-level winds, and maintained its intensity, deep convection even increasing near the center of circulation overnight. An analysis of the windfield of Philippe revealed it to be stronger than expected, with winds of 65 mph. Late that night, more intensification occurred, bringing Philippe to the verge of hurricane strength early on October 2.

However, the unfavorable conditions near the cyclone finally began to take their toll that morning, exposing the center and weakening the system. As before, however, Philippe recovered its convection, as Ophelia moved north, and conditions became less hostile. The next day, winds were found to be stronger than previously estimated, and the cyclone was a strong tropical storm yet again. Meanwhile, the center reformed farther to the south than before, and Philippe moved west-southwestward during the day of October 3.

After navigating around the periphery of the ridge steering it, the tropical storm began to turn north on October 4. Recurvature occurred quickly during the following days, and shear gradually decreased. On October 5, the center remained displaced from the deepest convection, but, on October 6, strengthening finally began, bringing Philippe to hurricane strength after over 12 days as a tropical cyclone. An eye feature formed later that evening, particularly visible on infrared imagery, and the hurricane reached its peak intensity of 90 mph winds and a pressure of 976 mb that evening.

Upper-atmospheric conditions rapidly deteriorated on October 7, causing weakening as the cyclone accelerated to the east-northeast. The center quickly became exposed that afternoon, and Philippe's brief period as a hurricane was over. A front encouraged extratropical transition on October 8, and absorbtion completed in that afternoon. Philippe was the longest lived tropical cyclone in the Atlantic since Bertha of 2008, lasting over two weeks. Despite this, it affected no land.



Hurricane Philippe over the open Atlantic.



Track of Philippe.

Hurricane Ophelia (2011)

Storm Active: September 20-October 3

On September 17, a broad area of showers and thunderstorms formed in association with a large low pressure system in the eastern Atlantic. Three low pressure centers existed in close proximity near the area during the day of September 18, oriented west to east near the 10ºN parallel. Over time, the central low became stronger and dissipated the others, and convection increased. The circulation also increased in definition over the following days, but numerous reformations of the center kept the circulation open. However, late on September 20, thunderstorms became concentrated near a single circulation center, and the low was upgraded directly to Tropical Storm Ophelia.

As the tropical storm moved west over the central Atlantic, shear steadily increased, but despite unfavorable conditions, winds in Ophelia's rain bands increased significantly, and strengthening ensued. On September 21, convection was displaced to the east of the center, but notwithstanding any satellite data to the contrary, winds were reported that suggested a strong tropical storm intensity. By the morning of September 22, Ophelia had reached an intensity of 65 mph winds and a pressure of 994 mb.

Wind shear began to finally take its toll on the system later that day, and the cyclone weakened. By the morning of September 23, Ophelia, had weakened to a minimal tropical storm, and all remaining convection was pushed northeast into a rain band that extended several hundred miles. Meanwhile, Ophelia took a turn to the west-northwest. Later on September 23, shear temporarily relaxed, and shower activity re-ignited near the center of the cyclone, causing it to unexpectedly strengthen that evening.

However, this increase in intensity did not persist, as strong upper-level winds resumed early on September 24. Ophelia weakened once again during that day, and, as a result, turned back to the west. As the system's circulation continued to become shallower, a due west motion was assumed, and by the morning of September 25, Ophelia was a minimal tropical storm. A large area of convection was over 150 miles east of the center during the day, with the center itself bare but for a few showers to the northeast. The Lesser Antilles, to Ophelia's southwest, experienced some gusty winds during the afternoon, as the center of the circulation became more elongated. Subsequently, the system was observed to lack tropical characteristics, and was downgraded to a remnant low.

The exposed center quickly dissipated, but a new swirl quickly became evident in the thunderstorm activity to the east. During the day of September 26, upper-level winds relaxed, and the circulation of the newly formed low became much better defined that evening. As the system continued to organize overnight, it drifted eastward and southward, stalling close to the Leeward Islands. On September 27, moderate rainfall occurred over these islands, as convection increased further during the afternoon, and the low became organized enough to be redesignated as Tropical Depression Ophelia.

Shear still abounded over the region overnight, and strengthening was gradual, bringing Ophelia to tropical storm strength during the morning of September 28. By this time, the cyclone had assumed a definite north-northwestward motion, and it moved away from the Caribbean. Outflow improved throughout the same day, allowing the cyclone to hold its own despite marginally favorable conditions. Further strengthening followed that night, and the system was a powerful tropical storm by September 29. An impressive banding feature formed to the east of the circulation later that afternoon, causing Ophelia to be upgraded to Category 1 hurricane status.

During the same evening, Ophelia's eyewall solidified, and the eye itself became more consistent in its appearance on satellite imagery. Following these structural changes, the cyclone rapidly strengthened. By the morning of September 30, Ophelia was a Category 2 hurricane! However, the strengthening was by no means over, as the hurricane assumed a more rounded appearance, the outflow improving and the eye broadening further. By that afternoon, Ophelia was a Category 3 hurricane. Meanwhile, the storm turned north and started to accelerate, as a large trough exited the U.S. east coast and pushed it farther poleward. Late that night, the system finally stabilized in intensity at 120 mph winds and a pressure of 956 mb.

Early on October 1, the pressure dropped slightly to 952 mb, and the outer bands of Ophelia began to impact Bermuda. During the day, gusty winds and scattered heavy squalls affected the island, but the hurricane passed well to the east, making its closest approach late that afternoon. Just after passing Bermuda, Ophelia unexpectedly underwent rapid intensification, bringing it to its peak intensity as a Category 4 hurricane with 140 mph winds and a pressure of 940 mb. During the morning of October 2, Opheila finally began to weaken as it turned to the north-northeast, reaching a forward speed of 30 mph north of 35ºN latitude. The circulation slowly lost definition as it raced towards Newfoundland ahead of a cold front to its west.

That night, Ophelia lost most of its remaining tropical characteristics, weakening to a tropical storm during the morning of October 3. Any central convection still associated with the system vanished as Ophelia made landfall in the Avalon Peninsula, and the system became extratropical. The cyclone continued northeastward until dissipating on October 5. Minimal damage was the only effect of Ophelia, with no fatalities occurring.



Hurricane Ophelia nearing peak intensity as a Category 4 hurricane.



Track of Ophelia, including time spent as an non-tropical system before reforming.

Hurricane Nate (2011)

Storm Active: September 7-11

After Tropical Storm Lee became extratropical over the southeast U.S., an extension of its associated frontal boundary dipped into the southern Gulf of Mexico. On September 6, the interaction of this front with a trough of low pressure caused a low pressure system to form in the Bay of Campeche. Over the next day, the low hardly moved, and organized rapidly. On September 7, the low-level circulation of the low became more well-defined and the system was upgraded into Tropical Storm Nate.

Nate formed with a very slow motion to the southeast, and did not move significantly overnight. Despite a low shear environment, there was one inhibiting factor to strengthening: a large area of dry air to the system's northwest, occupying the entire northern Gulf. During the day of September 8, the center drifted further southeast, becoming closer to the convection, which had been displaced to the southwest of the center by moderate wind shear. Nate was sheltered somewhat, and strengthening commenced. By the evening of that day, Nate was completely stationary, and at its peak intensity of 75 mph and a pressure of 994 mb*.

Dry air entered the system during the early morning of September 9, however, and weakening took place. Later that day, Nate began to move slowly northwest, away from the Yucatan Peninsula, as further weakening occurred. By the morning of September 10, rainbands had recovered somewhat on the periphery of the cyclone, but the center remained devoid of convection, giving Nate a hollow appearance. The tropical storm finally adopted a definite motion later that day, moving due west. As it did so, conditions improved slightly and re-strengthening occurred afternoon. Nate reached its secondary peak intensity of 65 mph winds before convection decreased once again early on September 11.

The position of the center became very uncertain as Nate approached the Mexican coast, and the definition of the circulation decreased, lowering Nate's intensity to only 45 mph as it made landfall in Veracruz. The cyclone quickly weakened to a remnant low that night. Not much convection was associated with Nate over its lifetime, but its slow movement still allowed prolonged periods of gusty winds and rain along many parts of the coast of the Bay of Campeche. 7 fatalities were the result of Nate.

*Nate was upgraded to a hurricane during the 2011 postseason analysis, its maximum winds having previously been recorded as only 70 mph.



Tropical Storm Nate at peak intensity on September 8. At this time, Nate was nearly stationary.



Track of Nate.

Hurricane Maria (2011)

Storm Active: September 6-16

On September 4, a tropical wave off of the African coast began to generate shower activity south of the Cape Verde Islands. This activity became more widespread and more organized with the westward moving wave on September 5, as surface pressures began to drop over the region. A low pressure center developed in association with the wave that day, and the circulation became closed on September 6, announcing the formation of Tropical Depression Fourteen. The depression slowly organized over the next day, as it moved quickly west-northwest. A rapid intensification occurred during the morning of September 7, as an area of deep convection appeared northeast of the center, and the cyclone was upgraded to Tropical Storm Maria, with 50 mph winds.

High wind shear affected the system from its formation, however, and a powerful ridge to Maria's north imparted it with an extremely rapid westward motion of 23 mph during the night and into the morning of September 8. The storm struggled to maintain a circulation during the afternoon, and began to weaken as a result. All but minimal central convection disappeared during the early evening, and Maria became a minimal tropical storm. Overnight, however, a huge area of convection appeared. Despite this new thunderstorm activity, Maria did not intensify significantly on September 9, as the low level center was ill-defined and difficult to locate on satellite imagery.

On September 10, all convection was displaced to the northeast of the center by wind shear. So although being in close proximity to the northeast Caribbean Islands, the storm caused nearly no rain there as Maria moved northwest. The cyclone began to recover organization once again during the morning of September 11, and became a strong tropical storm as it moved west-northwest past the U.S. Virgin Islands that afternoon. A powerful trough coming off of the United States east coast started to affect Maria that evening, and it took a turn to the north on September 12, though slowing to nearly stationary. On September 13, the system began to accelerate, and finally moved away from the upper-level low that had been affecting it for so long with wind shear.

The center of Maria reformed within an area of deep convection late that night, and banding features increased in organization. During the morning of September 14, intensification began, and shear decreased. The decrease was gradual, however, and no further change occurred during the afternoon. By this time, Maria had turned to the north-northeast and already was accelerating extremely rapidly. Conditions in Bermuda deteriorated late that night and into the morning of September 15, as Maria passed to its west at near hurricane strength. Deep convection appeared near the eye that afternoon, and an eye structure began to form. Maria was therefore upgraded to hurricane status.

That night, Maria reached its peak intensity of 80 mph winds and a pressure of 979 mb. During the morning of September 16, the cyclone's forward speed exceeded 50 mph. Its closed circulation vanishing, Maria made landfall in Newfoundland as a minimal hurricane on the cusp of extratropical transition that afternoon, followed by absorbtion by a front a few hours later.



Hurricane Maria moving rapidly northward. The cyclone is already exhibiting some extratropical traits.



Track of Maria.

Tropical Storm Lee (2011)

Storm Active: September 1-4

During the day of August 30, shower activity increased with a tropical wave moving west-northwestward through the western Caribbean Sea. Meanwhile, a stationary low pressure trough was situated over the Gulf of Mexico. During the next few days, the tropical moisture of these two systems combined, forming a very large area of strong thunderstorms over the eastern Gulf, stretching from the Yucatan Peninsula to Florida. Shear from the west affected the system, but began to slowly abate during the day of September 1. During that afternoon a circulation appeared on the western edge of the clouds, becoming closed by the evening. Tropical Depression Thirteen had formed.

During the night, the depression's center reformed farther south and lost nearly all of its initial motion to the northwest, Due to weak steering currents, the system remained nearly stationary through the morning of September 2. Also, an area of deep convection developed near the center, despite the center itself remaining rather elongated. Due to the system's large size, rain and gusty winds already were moving into southeastern Louisiana. The circulation of the system became more well-defined that afternoon, and Thirteen became Tropical Storm Lee.

Lee had an unusually large windfield even at the time of its formation, and it continued to expand later that day. The cyclone itself also slowly strengthened, moving erratically, but generally northward. Lee still exhibited some characteristics of a non-tropical cyclone even into September 3, with the southwest quadrant still devoid of convection. During that morning, heavy rain continued across Louisiana and Mississippi, and tornadoes were reported within the heaviest bands, located in southern Louisiana.

Lee strengthened further as it slowly moved toward the Gulf coast, reaching its peak winds of 60 mph during the day. However, a second low-level center developed within the system early that afternoon, the original over land, and the second still off the coast. The new formed center took over the circulation while the other dissipated, and Lee therefore stalled off of the coast of Louisiana, with tropical storm conditions still extending far inland all across the central Gulf states. During the night, convection decreased, with the only rain band near the center extending to the southwest. Gradual weakening occurred, but Lee still did not assume any definite motion, and was still hovering over the coast, continuing the already severe flooding of the surrounding areas. Despite the winds having fallen, Lee's central pressure decreased to 987 mb early on September 4. The system finally made landfall in Louisiana later that morning.

The circulation actually became better defined for a brief period over land that afternoon, but the cyclone quickly degenerated, weakening further that evening, and began extratropical transition late that night. The system was fully extratropical by the next day, but the rain was by no means over. During the day of September 5, the remnants of Lee combined with a powerful cold front. With the addition of tropical moisture, a region of heavy rain formed from the tail end of Lee, in Louisiana, through the end of the front, in Canada! Lee's remnants lost their well-defined center on September 8, but rainfall continued for two more days, finally ending on September 10. The several days that Lee spent moving up the coast saw unprecedented flooding in the the mid-Atlantic states, New England, and even in some areas as far north as Canada. Rainfall totals from the combined storm system exceeding 6 inches in widespread areas, with local amounts significantly greater. 21 fatalities resulted from Lee, along with over $250 million in damages.



Lee strengthening over the northern Gulf of Mexico.



Track of Lee.

Note: In post-season analysis, Lee was confirmed to have been subtropical from September 3 up to the points of extratropical transition. This means that the cyclone transitioned from tropical to subtropical, a very rare event.

Hurricane Katia (2011)

Storm Active: August 29-September 10

A low formed just off of the African coastline on August 27, associated with a tropical wave, and was already showing signs of organization. The broad area of showers and thunderstorms quickly became concentrated over the next day, as the system passed well south of the Cape Verde Islands. Rapid development continued, and the system became Tropical Depression Twelve early on August 29. The depression also formed at 9.4º N, fairly far south for a tropical cyclone. Some shear out of the east affected the system from the beginning, and, as a result, the center remained on the eastern tip of the cloud cover through the day, A ore circular area of convection developed early on August 30, and although shear continued, the system was organized enough to be named Tropical Storm Katia.

Katia adopted a west-northwest motion that morning, and also accelerated somewhat in forward speed. Through the day, shear lessened significantly, and Katia began to rapidly intensify. Deep convection had enveloped the center by that afternoon, and Katia quickly became a strong tropical storm that evening. The intrusion of dry air on the circulation delayed intensification overnight, but Katia resumed a slow strengthening trend by August 31. Meanwhile, the cyclone moved even faster to the west-northwest, under the influence of a ridge to its northeast, its forward speed exceeding 20 mph. Katia continued to slowly organize, and the development of a well-defined eyewall merited the upgrade of the system to a hurricane late that night.

However, some dry air entered the circulation from the south, temporarily weakening the eyewall early on September 1, and causing the cyclone to stabilize in intensity. Katia also returned to a westerly motion that morning. However, shear increased during the day from an upper-level low to Katia's north, due to the close proximity of the low, and Katia again became disorganized weakening back to a tropical storm. A deeper burst of convection appeared with the system early on September 2, but the center remained on the periphery of this cloud cover during the early morning hours. Katia decelerated significantly, and turned once again to the west-northwest. Despite somewhat hostile conditions, Katia regained hurricane status later that morning, as a gradual turn to the northwest began.

Katia continued to struggle against wind shear throughout the day, and even developed an eye for a time that evening! However, the eye remained too close to the edge of convection to survive, and clouded over early on September 3. The cyclone's central pressure dropped, and Katia maintained minimal hurricane intensity. Thunderstorm activity decreased in the eastern half of the circulation that afternoon, and the cyclone became slightly lopsided. As a result, Katia again weakened to a tropical storm. Later in the evening, the fluctuations in intensity continued, as convection once again increased, and another eye formed. Due to this, Katia was once again upgraded to a hurricane during the morning of September 4. Through the night, Katia had still maintained a general northwest motion.

Later that morning, a well-defined eye developed, and Katia underwent rapid strengthening, becoming a Category 2 hurricane. That afternoon, Katia reached an intensity of 105 mph winds and a pressure of 965 mb. However, dry air invaded the system once again, this time from the northeast quadrant, and Katia weakened slightly during the early morning of September 5. Rather than disrupting the circulation in the long term, however, the dry air was incorporated into a large eye that appeared later in the morning. Katia once again strengthened rapidly, as outflow also improved that afternoon. Following these structural changes, the cyclone was subsequently upgraded to a major hurricane. Further intensification ensued late that evening, and Katia quickly reached its peak intensity as a Category 4 hurricane, with 135 mph winds and a pressure of 946 mb.

However, as the storm continued northwest, it began to encounter less favorable conditions, including lower ocean temperatures, and increased wind shear. A general weakening trend began, and Katia soon lost Category 4 status. The hurricane force wind field remained quite broad, though, and even became larger during the morning of September 6. These winds extended up to 55 miles from the center that afternoon. Rip currents and high surf were already beginning to affect Bermuda, and the threat increased on September 7. In the face of dry air and wind shear from the west, the circulation became more lopsided, with any remaining symmetry in the eyewall disappearing by that morning.

Bermuda also received gusty winds and scattered showers, being on the periphery of Katia's powerful east side. By that afternoon, the cyclone's winds had decreased to 85 mph, a Category 1 intensity. A turn to the north followed during the early evening hours, and Katia's forward motion increased. Despite moving into cooler waters, the upper atmospheric conditions near Katia improved that night and it strengthened slightly as it recovered the western half of the eyewall somewhat. The system made its closest approach to Bermuda the following morning, passing well to the west. Once again, Katia's convection actually increased over cool waters during the day of September 8. A turn to the northeast commenced that evening, and Katia's motion rapidly increased. By September 9, the cyclone was speeding away from the New England coast. Extratropical transition began later that day, and Katia finally became extratropical during the morning of September 10, after reaching a forward speed of over 50 mph.

At the time of the last advisory, Katia still packed winds of 80 mph, and became a powerful extratropical cyclone, impacting north portions of the British Isles on September 11 with high winds and rain as it passed to the north. Katia indirectly affected the Lesser Antilles, Bermuda, the east coast of the United States, and the United Kingdom. 2 fatalities, one direct and one indirect, were the result of Katia.



Katia near peak intensity as a Category 4 hurricane.

Tropical Storm Jose (2011)

Storm Active: August 28-29

On August 19, a tropical wave moved off of Africa, and was immediately monitored for development upon leaving the coast. A broad low pressure system quickly formed in conjunction with the wave, and convection increased, but despite favorable conditions, no closed circulation formed as the system passed near the Cape Verde Island on August 20. The low's circulation became elongated during the day of August 21, and it moved northwest, into cooler waters. THe system did not dissipate, however, and still produced some shower activity over the next few days. The low elongated further on August 25, and degenerated into a trough of low pressure. This trough interacted with another to its west, and a weak low formed from this union on August 27, now located south-southeast of Bermuda. The low deepened and moved generally northwest, but very high shear from the outflow of Hurricane Irene ripped convection from the low faster than it could form. Despite these extremely hostile conditions to tropical development, the circulation, although being nearly devoid of convection, became closed, and gale force winds in the low's southeast quadrant caused it to be named Tropical Storm Jose during the morning of August 28.

Due to its proximity to Bermuda, a tropical storm warning was issued there. Against all odds, Jose's southern side developed some deep convection that afternoon and the system strengthened slightly as it moved north, past Bermuda, and reached its peak intensity of 45 mph winds and a central pressure of 1007 mb. Overnight, Jose accelerated northward and was weakening by the morning of August 29, as it encountered cooler waters. By later that day, the circulation no longer existed, and Jose dissipated, downgraded to a trough of low pressure. In the wake of Jose, to its south, large areas of thunderstorms appeared near Bermuda for the remainder of the day, partly having their origin in tropical moisture from the cyclone, which was displaced to the south by shear. Therefore, Jose indirectly caused some minimal damage to Bermuda.



Track of Jose.

Tropical Depression Ten (2011)

Storm Active: August 25-26

During the afternoon of August 22, a low pressure system moved into the Atlantic off of the African coast. The circulation of the low was not yet well-defined, but it slowly moved west-southwest over the next few days, gaining convection and organization as it went. As the low passed to the south of the Cape Verde Islands, scattered showers occurred there. By August 24, the system was moving west away from the islands, and was quickly organizing. Early on August 25, a well-defined circulation developed, and the existence of a rain band circumnavigating the center, confirmed the formation of Tropical Depression Ten.

Initially, the depression seemed on the verge of tropical storm strength, but as it tracked west-northwest, the convection decreased, and was minimal by later in the morning on August 25. Despite a return of convection during the day, the circulation became elongated, and badly defined. This trend continued into August 26, keeping the cyclone at tropical depression intensity. Winds near gale force still appeared periodically, but the circulation became so stretched that the depression no longer met the standards of a tropical cyclone by later that night. Tropical Depression Ten officially degenerated into a trough near midnight, losing its definition entirely by August 27. The cyclone affected no land masses, with the exception of a few storms in the Cape Verde Islands.



Tropical Depression Ten over the east Atlantic.



Track of Tropical Depression Ten.

Hurricane Irene (2011)

Storm Active: August 20-29

On August 15, a tropical wave moved off of Africa, but dry air near the system did not allow significant development. However, on August 17, a small area of convection formed in associated with the wave, followed by a low pressure center on August 19, when a definite circulation appeared in the clouds. Pressure in the area began to fall overnight, but no surface circulation had yet formed. During the evening of August 20, however, rapid intensification occurred, and a very organized surface circulation appeared. Hurricane hunter aircraft found winds high enough for the system to skip the tropical depression stage, and the low became Tropical Storm Irene, packing 50 mph winds even at its formation!

Early on August 21, Irene moved over the Lesser Antilles, and, being a fairly large cyclone, caused gale force winds and tropical storm conditions over a wide area as it entered the Caribbean. The cyclone was still moving westward at a fast clip, with its forward speed exceeding 20 mph. Irene maintained its intensity throughout the day, and made landfall in Puerto Rico that evening, causing heavy rain and very strong winds over the entire island. Despite some interaction with land, Irene rapidly strengthened, its circulation and outflow improving greatly that night. A huge burst of convection engulfed the system early on August 22, and the cyclone became Hurricane Irene, the first hurricane of the 2011 season.

Irene decelerated during the morning, and continued to move west-northwest, leaving Puerto Rico, where over 10 inches of rain fell in localized areas. The eyewall developed further during the evening of August 22, and the Irene rapidly intensified into a Category 2 hurricane with 100 mph winds as it passed just to the north of the Dominican Republic, with tropical storm conditions covering much of the country, and gusts of hurricane force on the northern coasts. Irene slowed down even more during the morning of August 23, with a forward speed of 10 mph to the west-northwest as it approached the Bahamas.

Later in the morning, a ragged eye appeared, and the central pressure of Irene dropped slightly. However, it was not a well-formed structure, and it clouded over in the afternoon, causing a weakening not uncharacteristic of eye replacement, putting the system back to a Category 1 intensity. Land interaction decreased considerably as Irene moved away from Hispaniola during the evening, convection returned in earnest, the central pressure dropped further, and another, more organized eye appeared. The cyclone soon regained its lost strength, and then intensified further, as it encountered the Turks and Caicos Islands during the morning of August 24. The system's winds surpassed 110 mph that same morning, and Irene became the first major hurricane of the season, with 115 mph winds and a pressure of 957 mb.

By later in the day, Irene had entered the Central Bahamas, the eye was tightening, and a new eyewall was forming. As a result of this, the eye began to cloud over, causing fluctuations in intensity. However, the system remained a Category 3, and the central pressure continued to steadily drop. Irene maintained its northwest motion into August 25, as surf began to increase along the U.S. coast. Later in the day, Irene finally left the Bahamas, and made a turn northward, toward the Outer Banks of North Carolina, early on August 26. The pressure of the cyclone dropped to 942 mb, the lowest yet for the cyclone, but another eye replacement weakened the system, decreasing its wind speeds to that of a Category 2 hurricane.

Rain bands from Irene were already beginning to sweep across the U.S. east coast from Florida up through the Carolinas. The internal structure of Irene remained slightly disorganized, and gradual weakening occurred as conditions became less favorable for intensification. Powerful outer bands packing tropical storm force winds penetrated into North Carolina through the day. Late on August 26, the convection became rather lopsided, with the southwest quadrant weak, and Irene subsequently weakened to a Category 1 hurricane early on August 27. Around 8:00 am EDT that morning, Hurricane Irene made landfall with 85 mph winds in eastern North Carolina, just west of the Outer Banks.

The cyclone began to assume a more asymmetrical appearance that afternoon, with most of the rain extending northward, reaching even Pennsylvania and New Jersey by early afternoon. The circulation, however, actually increased in definition as the day wore on. The forward speed of Irene finally began to increase that evening, but the cyclone moved steadily north-northeast, and emerged over water once again later that night, paralleling the Virginia coastline. Dry air entered Irene's southern side, and weakened it slowly through the morning of August 28, as the center of the hurricane made landfall in New Jersey before sunrise. At the time, the cyclone had weakened to a strong tropical storm, with 70 mph winds.

The windfield of the storm, however, was larger than ever, as tropical storm force winds spanned portions of 8 states. During the morning, Irene began to rapidly accelerate to the north-northeast, while quickly transitioning to an extratropical cyclone. By this time, all precipitation associated with Irene was on its north side, with the exception of one rain band, which protruded to the southwest, and affected areas as far south as Maryland even into early afternoon. The cyclone weakened to a tropical storm before making landfall in New York City that same morning. Irene persisted in the same general motion throughout the day, still bringing gusty winds to much of the northeast, before finally becoming extratropical near the U.S. border with Canada late that night. Rainfall continued in Canada as the remnants of Irene continued speeding northeastward, and the low emerged into the north Atlantic on August 30, passing near Greenland by the next day.

Irene had a devastating impact on areas from the Lesser Antilles to Vermont, and caused between 10 and 20 inches of rainfall locally in all regions along its path. The Bahamas, in particular, suffered high wind damages, as Irene was at peak intensity over the islands. Damage is estimated at $10.1 billion, and 54 fatalities resulted from the cyclone. Irene was also the first storm to make landfall in the U.S. at hurricane intensity since Ike of 2008.



Irene as a major hurricane entering the Bahamas.



Track of Irene on its path through the Caribbean, the Bahamas, and along the east coast of the United States.

Tropical Storm Harvey (2011)

Storm Active: August 18-22

On August 10, a vigorous tropical wave emerged off of Africa, and immediately began to produce an area of concentrated thunderstorms southeast of the Cape Verde Islands. On August 11, the system became more organized as a low pressure centered formed. However, the dry air of the eastern Atlantic penetrated the system, and cloud cover rapidly decreased as the low degenerated back into a tropical wave. The wave continued its journey westward, and convection once again erupted over a large area surrounding the system as it entered the moist waters near the Lesser Antilles. A broad upper-level circulation developed on August 16, but the system lacked a surface low, which inhibited further development as it entered the Caribbean Sea. The system moved due west for another few days before developing a surface low late on August 18, and being classified Tropical Depression Eight.

Eight was already producing rain and wind near the Honduras-Nicaragua border at formation, and conditions worsened on the northern coast of Honduras as the cyclone paralleled this coast, just a few miles offshore. Despite its proximity to land, the system developed deep convection and rain bands about the center, and a jog northeast on August 19 made conditions more favorable for strengthening as the day went on. A well-defined eyewall appeared on the south and west sides of the center during the afternoon, and Eight was named Tropical Storm Harvey shortly after.

The cyclone continued on a westward track through the evening of August 19, and strengthened rapidly, reaching an intensity of 65 mph winds and a pressure of 994 mb before temporarily stabilizing in intensity early on August 20. Since the tropical storm force winds extended only about 20 miles south of the center, (they extended 35 miles north at the time) gale force winds missed Honduras for the most part, although heavy rain fell throughout the region. Harvey continued to maintain the above peak intensity through landfall in Belize, which occurred that afternoon.

After landfall, Harvey continued to move west to west-northwest, and maintained a tropical storm intensity for an impressive 12 hours before weakening into a tropical depression over northern Guatemala. Thunderstorm activity continued throughout the region even as Tropical Depression Harvey crossed from inland Guatemala into inland Mexico on August 21. Later that day, the center, which was still well-defined, jogged to the north, and the depression emerged over the Bay of Campeche. With this new found access to water, Harvey strengthened slightly, but did not regain tropical storm intensity before making a turn to the west-southwest and making landfall in the southern Gulf coast of Mexico early on August 22.

Harvey quickly weakened as it moved inland, and dissipated later that morning. Only minimal damage was sustained, but 3 fatalities occurred from flooding, as Harvey dumped many inches of precipitation over Central America. Since Harvey did not reach hurricane strength, the record of consecutive named storms to not became hurricanes to start the season was extended to eight.



Tropical Storm Harvey shortly after formation.



Track of Harvey.