Tag Archives: Labrador

Hurricane Dorian Brings Powerful Winds to Nova Scotia

Hurricane Dorian brought powerful winds to Nova Scotia on Saturday.  At 8:00 p.m. EDT on Saturday the center of Hurricane Dorian was located at latitude 45.0°N and longitude 67.9°W which put it about 45 miles (75 km) northeast of Halifax, Nova Scotia.  Dorian was moving toward the northeast at 30 m.p.h. (48 km/h).  The maximum sustained wind speed was 100 m.p.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 960 mb.

Hurricane Warnings were in effect for Lower East Pubnico to Brule, Nova Scotia and from Indian Harbour to Hawke’s Bay, Newfoundland. Hurricane Watches were in effect for Prince Edward Island and for the Magdalen Islands. Tropical Storm Warnings were issued for Prince Edward Island and from Avonport to Lower East Pubnico, Nova Scotia. A Tropical Storm Warning was in effect for New Brunswick from Fundy National Park to Shediac. A Tropical Storm Warning was issued for the portion of the coast from Indian Harbour to Stone’s Cove, Newfoundland. Tropical Storm Warnings were issued for the portions of the coast from Hawke’s Bay to Fogo Island and from Mutton Bay to Mary’s Harbour.

Hurricane Dorian maintained its intensity and increased in size on Saturday while it sped across the northwestern Atlantic Ocean to the Canadian Maritime provinces.  Winds to hurricane force extended out about 115 miles (185 km) on the southern side of Hurricane Dorian.  Winds to tropical storm force extended out about 300 miles (480 km) from the center of circulation.  The Hurricane Intensity Index (HII) for Hurricane Dorian was 16.5.  The Hurricane Size Index (HSI) was 26.3 and the Hurricane Wind Intensity Size Index (HWISI) was 42.8.  Hurricane Dorian was capable of causing widespread serious damage.

There were reports of wind damage and widespread power outages around Nova Scotia even before the center of Hurricane reached that area.  The large circulation around Dorian brought tropical storm force winds to Nova Scotia a few hours before the center made landfall.  The center of Hurricane Dorian officially made landfall south of Halifax, Nova Scotia on Saturday evening.

Hurricane Dorian had almost completed a transition to a large powerful extratropical cyclone.  That transition contributed to the increase in size of the circulation.  The strongest part of Hurricane Dorian will move across Nova Scotia during the next few hours.  The winds are likely to cause additional damage on Saturday night.  Hurricane Dorian will race across Nova Scotia, Cape Breton Island and New Brunswick on Saturday night.  Dorian will move over Newfoundland and southeastern Labrador on Sunday.  Hurricane Dorian has the potential to cause serious damage in all of those locations.

Hurricane Gert Intensifies to Cat. 2 South of Nova Scotia

Hurricane Gert intensified to Category 2 on the Saffir-Simpson Scale as it sped over the Gulf Stream south of Nova Scotia on Wednesday afternoon.  At 5:00 p.m. EDT on Wednesday the center of Hurricane Gert was located at latitude 38.7°N and longitude 62.4°W which put it about 410 miles (665 km) south of Halifax, Nova Scotia.  Gert was moving toward the northeast at 31 m.p.h. (50 km/h).  The maximum sustained wind speed was 100 mp.h. (160 km/h) and there were wind gusts to 120 m.p.h. (195 km/h).  The minimum surface pressure was 970 mb.

Although Hurricane Gert is at a fairly high latitude, it has the classic structure of a Hurricane.  There is a fairly small eye at the center of circulation.  The eye is surround by a ring of strong thunderstorm and the strongest winds are occurring in this ring of thunderstorms.  There are additional bands of showers and thunderstorms revolving around the core of the hurricane.  The circulation is symmetrical and thunderstorms in the core are producing upper level divergence which is pumping away mass to the northeast of the hurricane.  Winds to hurricane force extend out about 40 miles (65 km) primarily to the east of the center of circulation.  Winds to tropical storm force extend out about 140 miles (225 km) from the center.

Hurricane Gert is moving over the Gulf Stream which means it is moving over water where the Sea Surface Temperature (SST) is near 28.5°C.  An upper level trough west of Gert is producing southwesterly winds which are blowing toward the top of the hurricane.  However, there is not much change of wind speed with height, which means that there is little vertical wind shear.  The combination of the warm water of the Gulf Stream and little vertical shear, allowed Hurricane Gert to strengthen on Wednesday.

Hurricane Gert could intensify during the next few hours, but it will soon move into a much less favorable environment.  Gert will soon move north of the Gulf Stream where the SSTs are much cooler.  The upper level trough is moving closer to Hurricane Gert and the winds are the upper level are forecast to get stronger.  When those winds increase, there will be much more vertical wind shear.  Colder water and more wind shear will cause Hurricane Gert to weaken on Thursday.  Gert could make a transition to an extratropical cyclone in colder environment of the North Atlantic.

Southwesterly winds in the upper level trough are steering Hurricane  Gert quickly toward the northeast and that general motion is expected to continue.  On its anticipated track, Hurricane Gert will move south of Labrador and Greenland.

Even as Hurricane Gert speeds away over the North Atlantic three new tropical waves over the tropical Atlantic have the potential to develop into tropical cyclones.  A tropical wave about 800 miles (1290 km) east of the Lesser Antilles designated as Invest 91L showed signs of organization on Wednesday.  A few more thunderstorms developed closed to the center of circulation.  A reconnaissance plane is scheduled to investigate this system on Thursday.  A little farther to the east another tropical wave designated Invest 92L was also showing evidence or more organization.  A third tropical wave just west of Africa also has the potential to develop during the next few days.

Tropical Storm Claudette Forms Southeast of New England

An area of low pressure off the East Coast of the U.S. rapidly acquired tropical characteristics on Monday and it was classified as Tropical Storm Claudette by the National Hurricane Center.  At 1:00 p.m. EDT on Monday the center of Tropical Storm Claudette was located at latitude 37.4°N and longitude 68.1°W which put it about 290 miles (465 km) south-southeast of Nantucket Island, Massachusetts and about 550 miles (885 km) south-southwest of Halifax, Nova Scotia.  Claudette was moving toward the northeast at 15 m.p.h. (24 km/h).  The maximum sustained wind speed as 50 m.p.h. (85 km/h) and there were gusts to 60 m.p.h. (95 km/h).  The minimum surface pressure was 1004 mb.

Claudette began as a small low pressure system along a nearly stationary frontal boundary off the East Coast of the U.S.  Moderate wind shear kept the system looking non-tropical for much of the weekend.  The wind shear decreased on Monday morning and as the low moved over the warmer water of the Gulf Stream, thunderstorms developed near the center of circulation.  The stationary frontal boundary dissipated and the system took on a more tropical appearance.  Latent energy released in thunderstorms near the center produced the development of a warm core and some banding developed in the eastern portion of the circulation.  As a result of those changes, the system was classified as Tropical Storm Claudette.

Claudette could strengthen in the short term.  It is still over the Gulf Stream and the upper level winds are not too strong.  However, once the tropical storm moves north of latitude 40°N, it will move over cooler Sea Surface Temperatures.  In addition, stronger upper level winds will increase the vertical wind shear in a day or two.  Claudette could make a transition to an extratropical cyclone within 48 hours.

A combination of a trough approaching the eastern U.S, and a ridge over the Atlantic are expected to steer Claudette toward the northeast.  On its anticipated track, Claudette could approach eastern Nova Scotia in about 24 hours and Labrador in 30 hours.