After Leslie passes across Bermuda this weekend, the system will move quickly into Atlantic Canada waters early next week.
Residents, travelers and fishing interests from Nova Scotia to Prince Edward Island, the Gulf of St. Lawrence and Newfoundland should keep a close eye on Leslie and be prepared for tropical storm or hurricane conditions early next week. Conditions could rapidly deteriorate Monday evening.
Deep sea fishing interests in New England should also monitor Leslie and expect significant building seas in the vicinity of Georges Bank Sunday night and Monday.
Leslie will generate rough surf and increase the number and strength of rip currents along much of the eastern coast of the United States through the weekend.
Leslie has been moving very slowly, was located about 400 miles south-southeast of Bermuda Friday morning, but that will soon change.
According to Dan Kottlowski, head of the AccuWeather.com Hurricane Center, "We are confident Leslie will pick up forward speed moving between 20 and 30 mph at the latitude of New England to Newfoundland."
Leslie strengthened to a hurricane Wednesday afternoon, but continued to battle wind shear Thursday into Friday. Upwelling due to the stalled state of the storm has temporarily shut off the warm supply of moisture to the system, causing it to weaken to a tropical storm Friday midday.
While Leslie is forecast to pass east of Bermuda Sunday, it will do so as a hurricane, by moving over warmer water and may still not clear the coast of Atlantic Canada.
The exact path of Leslie is dependent on how a developing trough of low pressure over the eastern United States interacts with the system.
The majority of tropical cyclones are swept to the northeast after passing Bermuda's latitude. However, a small number of systems do not curve enough to avoid a collision with Nova Scotia and/or Newfoundland. In 2003, Juan rolled in from the south across Nova Scotia and caused significant damage.
"There is a possibility that the developing feature over the United States captures Leslie and flings the storm more to the north early next week," Kottlowski said, "People in Newfoundland especially should keep a close eye on Leslie."
Waters are warmer than usual south of Atlantic Canada. The combination of this and quickening steering winds may result in slower weakening of a hurricane either moving by at sea or plowing toward the coast.
Any non-destructive rain would be welcomed over much of Atlantic Canada, due to a warm, dry summer in the region. Unfortunately, in order for significant rain to occur, the system would have to push well inland with damaging wind and flooding rain, rather than brush the coast with a few gusts and brief showers.
The midwestern United States will be in the crosshairs of potent thunderstorms into Saturday night.
Much of the eastern United States will continue to swelter with above-average temperatures into the end of the month.
Tropical Storm Darby, located over the Central Pacific, is expected to bring locally heavy rain and high surf to the islands this weekend.
Those looking for a break from the heat across the central United States will be in luck as a slow cooldown is in store starting this weekend.
The more than 100,000 people expected to attend the annual Glorious Goodwood festival next week will want to keep a brolly handy.
While a vast amount of dry air has dominated and will continue to impact the Atlantic basin over the next few weeks, tropical activity could spark near the west coast of Africa.
Minneapolis, MN (1987)
10 inches of rain fell in 6.5 hours.
Montpelier, ID (1990)
75 mph winds gust; tree damage.
Seattle, WA (1991)
99 degrees, all-time record high for July.