Post-Tropical Cyclone Teddy - September 22-24, 2020
A strong tropical wave moved offshore the African coast on September 10th, which
an accompanying large area of thunderstorms.
A broad low pressure area formed on the 11th southwest of Cabo Verde. A well-defined
center formed, which led to the formation of
a tropical depresion early on the 12th. Development was slow, with Teddy becoming a
tropical storm late on the 13th as it moved
quickly to the west-northwest. Late on the 15th, Teddy became a hurricane well east-
northeast of Barbados. The cyclone turned
northwest, and Teddy became a major hurricane during the morning of the 17th well east-
northeast of Guadeloupe. Teddy peaked in
strength that evening, with later weakening caused by an eyewall replacement cycle and an
increase of vertical wind shear. It was
no longer a major hurricane late on the 19th. On the 20th, Teddy was a few hundred miles
southeast of Bermuda when an upper level
trough approached from the northwest, turning the storm north-northwest. Teddy missed
Bermuda a couple hundred miles to the east
and the system grew in size due to the favorable baroclinic interaction. The cyclone
also accelerated around the upper level system
as it acquired non-tropical character. Extratropical transition had begun with Teddy
becoming assymetric and fronts forming around
its periphery. Central convection became less central and weaker. Underlying cool
water temperatures hastened the process.
Teddy was fully extratropical/a post-tropical cyclone late on the 22nd as it approached
Nova Scotia from the south. The system
moved north and north-northeast, making landfall near Ecum Secum early on the 23rd at
storm force. Weakening continued as it
moved through Atlantic Canada and the Gulf of St. Lawrence, with the system absorbed
by another extratropical low early on
the morning of the 24th.
The graphics below show the storm total rainfall for Teddy, which used
rain gage information from Environment Canada and CoCoRAHS.