By PDC’s Senior Weather
Specialist Glenn James
CURRENT TROPICAL CYCLONES:
Tropical Cyclone 07L (Fiona)…is located about 910 miles south-southwest of Halifax, Nova Scotia
Tropical Cyclone 08L (Gaston)…is located about 205 miles northwest of Faial Island in the Azores
Tropical Cyclone 07L (Fiona)
TROPICAL STORM CONDITIONS BEGINNING ON BERMUDA WITH HURRICANE CONDITIONS EXPECTED OVERNIGHT… …HURRICANE WARNINGS ISSUED FOR PORTIONS OF ATLANTIC CANADA
Fiona is moving toward the north-northeast near 21 mph (33 km/h). A north-northeast or northeastward motion with an increase in forward speed is expected through Friday. Some reduction in forward speed with a turn toward the north is forecast Friday night through Sunday.
On the forecast track, the center of Fiona will pass just to the west of Bermuda overnight. Fiona’s center will then approach Nova Scotia on Friday, move across Nova Scotia and into the Gulf of St. Lawrence on Saturday, and then across Labrador over the Labrador Sea on Sunday.
Data from an Air Force Reserve Hurricane Hunter aircraft indicate that Maximum sustained winds remain near 130 mph (215 km/h) with higher gusts. Fiona is a category 4 hurricane on the Saffir-Simpson Hurricane Wind Scale.
Some slight weakening is forecast to begin tonight or on Friday, however Fiona is forecast to be a large and powerful post-tropical cyclone with hurricane-force winds when it approaches and moves over Nova Scotia Friday night and Saturday.
Hurricane-force winds extend outward up to 115 miles (185 km) from the center and tropical-storm-force winds extend outward up to 275 miles (445 km).
HAZARDS AFFECTING LAND
WIND: Hurricane conditions are expected on Bermuda beginning tonight and continuing through Friday morning./span>
RAINFALL: Fiona is forecast to produce the following rainfall:
Bermuda: 2 to 4 inches.
Nova Scotia, Prince Edward Island, and western Newfoundland: 3 to 6
inches, with local maximum up to 10 inches. This rainfall could
result in areas of flooding, some of which may be significant in
Eastern Quebec: 2 to 5 inches.
Eastern New Brunswick: 1 to 3 inches.
STORM SURGE: A storm surge will cause elevated water levels along the coast of Bermuda in areas of onshore winds beginning tonight. Near the coast, the surge will be accompanied by large and destructive waves.
SURF: Swells generated by Fiona are affecting the Turks and Caicos Islands, the Bahamas, the southeastern United States coast, and Bermuda.
These swells will continue to spread northwestward across the western Atlantic toward the mid-Atlantic and northeast coasts of the United States over the next day or so. The swells will also reach Atlantic Canada on Friday. These swells are likely to cause life-threatening surf and rip current conditions.
Tropical Cyclone 08L (Gaston)
TROPICAL STORM CONDITIONS AFFECTING PORTIONS OF THE AZORES
Gaston is moving toward the east near 12 mph (19 km/h). A slower southeastward motion is forecast later today followed by a southward, and then southwestward, motion tonight and early Saturday.
On the forecast track, the center of Gaston will move near or over portions of the Azores tonight through early Saturday. Maximum sustained winds are near 65 mph (100 km/h) with higher gusts.
Gradual weakening is expected over the next few days. Tropical-storm-force winds extend outward up to 115 miles (185 km) from the center.
HAZARDS AFFECTING LAND
WIND: Tropical-storm-force winds are expected in portions of the western Azores beginning tonight.
SURF: Swells generated by Gaston are expected to affect the Azores beginning later today. These swells are likely to cause life-threatening surf and rip current conditions.
Southeastern Caribbean Sea
Showers and thunderstorms remain disorganized in association with a low pressure system located over the southeastern Caribbean Sea about 150 miles east-northeast of Curacao.
The upper-level wind environment over the low is expected to become more conducive for development, and a tropical depression is expected to form during the next day or two while moving west-northwestward at 10 to 15 mph across the central Caribbean Sea.
Locally heavy rainfall and gusty winds are likely to affect northwestern Venezuela, the ABC island chain, and northeastern Colombia through Friday. Interests in Jamaica and the Cayman Islands should closely monitor the progress of this system.
* Formation chance through 48 hours…high…90 percent
* Formation chance through 5 days…high…90 percent
Eastern Tropical Atlantic:
A broad area of low pressure, associated with a tropical wave and located about 100 miles west of Dakar, Senegal, is producing a disorganized area of showers and thunderstorms off the coasts of Senegal and Mauritania.
Although the system is pulling in nearby dry air, environmental conditions are forecast to otherwise be conducive for some development, and a tropical depression could form by this weekend while the system moves northward at about 10 mph, parallel to the coast of west Africa.
* Formation chance through 48 hours…medium 60 percent
* Formation chance through 5 days…medium…60 percent
Central Tropical Atlantic:
Shower and thunderstorm activity has decreased since earlier today in association with a broad area of low pressure located several hundred miles west-southwest of the Cabo Verde Islands.
Despite marginal environmental conditions, some slow development of this system is possible over the next several days while it drifts northwestward or northward over the central tropical Atlantic.
* Formation chance through 48 hours…low…20 percent
* Formation chance through 5 days…low…30 percent