Hurricane Bertha (1990)

Infobox Hurricane
Name=Hurricane Bertha
Type=hurricane
Year=1990
Basin=Atl
Image location=Hurricane Bertha (1990).jpg


Formed=July 24, 1990
Dissipated=August 2, 1990
1-min winds=70
Pressure=973
Da

Inflated=
Fatalities=9 direct
Areas=Florida, Atlantic Canada
Hurricane season=1990 Atlantic hurricane season

Hurricane Bertha was a Category 1 tropical cyclone that formed in late July and lasted though early August of the 1990 Atlantic hurricane season. The second named storm and first hurricane of the 1990 season, Bertha formed as a subtropical cyclone on July 24 and moved southward where it gained tropical characteristics and became a tropical storm. Bertha flucuated between hurricane and tropical storm status as it turned northeastward before brushing past Nova Scotia as an extratropical storm on August 2.

Bertha caused moderate structural damage and six injuries in Nova Scotia, the storm also caused minor beach erosion on the East Coast of the United States. Offshore, the storm caused high waves that capsized a freighter, drowning nine crewmen. Bertha also caused two indirect fatalities due to drowning incidents off the Florida coast.

Meteorological history

A cold front moved eastward through the United States in the middle part of July, and reached the east coast by July 23. On July 24, an area of low pressure developed just southeast of Cape Hatteras, North Carolina ahead of the frontal zone, and quickly formed into a subtropical depression. In association with a nearby upper-level low, the depression tracked quickly southeastward before turning to the southwest. The subtropical depression gradually organized, and satellite classifications began subsequent to merging with a tropical wave on July 25. Convection developed closer to the center of circulation as it gradually decelerated while continuing southwestward, and on July 27 the system organized into Tropical Depression Three while located about 335 miles (539.1 km) east of Daytona Beach, Florida.cite web|author=National Hurricane Center|year=1990|title=Hurricane Bertha Preliminary Report Page 1|accessdate=2007-03-08|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/prelim01.gif]

Upon transitioning into a tropical cyclone, the depression executed an elongated counter-clockwise loop to the northeast. Conditions favored further intensification, and it is estimated the depression strengthened into Tropical Storm Bertha early on July 28, based on a nearby ship report. Bertha quickly strengthened to attain hurricane status early on July 29 about halfway between Cape Canaveral, Florida and Bermuda. The strengthening trend was short lived, however, as increased vertical wind shear weakened it back to a tropical storm late on July 29, with the center exposed from the deep convection. Bertha continued slowly northeastward to ridging from the Bermuda high extending westward to the United States.

Operationally, forecasters at the National Hurricane Center speculated whether Bertha was transitioning into a subtropical cyclone, due to its deep convection being located, at times, over 200 miles (321.8 km) from the center. However, the convection progressively returned to the center, and by late on July 30 Bertha re-intensified into a hurricane as the convection covered the center, about 415 miles (667.8 km) east of where it first formed. Early on July 31 the hurricane briefly attained peak winds of 80 mph (130 km/h) before weakening, and accelerated northeastward as the ridge of high pressure was slowly eroded. Bertha maintained hurricane status as it approached Atlantic Canada, and briefly reached winds of 80 mph (129 km/h) before weakening and making landfall near Sydney, Nova Scotia on August 1 as a 70 mph (113 km/h) tropical storm. The storm was transitioning into an extratropical cyclone while approaching Atlantic Canada, and lost all tropical characteristics shortly after moving ashore. The weakening extratropical remnants of Bertha turned northward into the Gulf of Saint Lawrence and lost its identity shortly thereafter.cite web|author=National Hurricane Center|year=1990|title=Hurricane Bertha Preliminary Report Page 2|accessdate=2007-03-08|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/prelim02.gif]

Preparations and Impact

The formation of Bertha in close proximity of the East Coast of the United States prompted residents to stock up on emergency supplies and monitor the storm. [cite web|author=Pat Butler|year=1990|title=BERTHA JANGLES NERVES COASTAL RESIDENTS STOCK UP, STAY ON GUARD JUST IN CASE|publisher=The State|accessdate=2007-03-13|url=http://nl.newsbank.com/nl-search/we/Archives?p_product=CS&s_site=thestate&p_multi=CS&p_theme=realcities&p_action=search&p_maxdocs=200&p_topdoc=1&p_text_direct-0=0EB580A4F4C4CC0E&p_field_direct-0=document_id&p_perpage=10&p_sort=YMD_date:D&s_trackval=GooglePM] The Canadian Hurricane Centre (then called the Maritimes Weather Center) and National Hurricane Center began to issue warnings for Nova Scotia and most of Atlantic Canada on July 31 and August 1.cite web|author=National Hurricane Center|year=1990|title=Hurricane Bertha Premilary Report Page 10|accessdate=2007-03-13|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/prelim10.gif] On August 2, all warnings and advisories for Atlantic Canada were dropped as Bertha dissipated.

Bertha's broad circulation produced high waves which were reported along the southeastern coast of the United States, in North Carolina, the storm produced waves of 25-50 feet (7.6-15.2 meters). The waves caused minor beach erosion along the North Carolina coastline including the Outer Banks.In Florida, rip currents from Bertha caused two drowning fatalities. 200 other swimmers were rescued from the rough seas.cite web|author=National Hurricane Center|year=1990|title=Hurricane Bertha Preliminary Report Page 3|accessdate=2007-03-12|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/prelim03.gif] Offshore, several ships came in contact with Bertha, many reported sustained winds of 35-58 mph (56-93 km/h) and a Canadian ship reported a barometric pressure of 985 millibars.The only reported shipwreck caused by Bertha was when the Corazon, a Greek freighter capsized and sank during the storm. The ship which was off the coast of Cape Cod at the time of its sinking, was experiencing strong winds up to 78 mph (126 km/h) and 30 feet (9.1 m) waves. The rough seas caused the ships keel to break, causing the crewmen to send a distress signal and evacuate the sinking vessel. During the evacuation, one crewman drowned when trying to board a lifeboat, his body was later found by a Soviet merchant ship. Another merchant ship, the Vyapel spotted twelve of the 27 sailors in their liferaft and the crew of the Vyapel tried to rescue the sailors but to no avail as the rough seas caused the liferaft to drift near the ships propeller and rudder area. The turbulence caused by the ships propeller knocked seven sailors into the water, five of them drowned and a search for their bodies continued until the following day.cite web|author=Associated Press|title=Ship's lifeboats were unusable|publisher=Syracuse Herald Journal|accessdate=2007-03-12|url=http://www.thehurricanearchive.com/Viewer.aspx?
] The remaining 21 sailors were later rescued by crews of other freighters and merchant ships.An investigation by the United States Coast Guard revealed that the Corazans own lifeboats was in poor condition to use in case of an emergency.

In Atlantic Canada, brought strong tropical storm force winds and heavy rainfall. Two weather stations in Braddeck, Nova Scotia and Hunters Mountain recorded 7 inches of rainfall. In Prince Edward Island, the storm produced a wind gust of 71 mph (115 km/h) and 4.72 inches (101.6 mm) of rain. A weather station in Port-aux-Basques reported a wind gust of 63 mph (102 km/h) and 2.51 inches (50 mm) of rain. [cite web|author=National Hurricane Center|year=1990|title=Hurricane Bertha Premilnary Report Page 9|accessdate=2007-03-13|url=http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/prelim09.gif] The high winds brought by Bertha caused moderate damage to tobacco and corn crops in Prince Edward Island and damaged a suspension bridge in Nova Scotia. Heavy rainfall from Bertha caused minimal flooding at a golf course. In Peggys Cove, Nova Scotia, six people were injured when waves from Bertha washed them into the sea. A damage estimate from Berthas impact on Atlantic Canada is unknown.

Due to the minor damage, the name "Bertha" was not retired; it was re-used in 1996, 2002, and was used again for the 2008 season.

ee also

* List of Atlantic hurricanes

External links

* [http://www.nhc.noaa.gov/archive/storm_wallets/atlantic/atl1990-prelim/bertha/ National Hurricane Center Preliminary Report for Hurricane Bertha]

References