Hurricane Isaias Event Summary, Canadian & Selected New England Data

11:57 AM ADT Wednesday 05 August 2020

Tropical cyclone information statement for:

New Brunswick

Québec - south:

Amqui - Matapédia Valley

Beauce

Charlevoix

Drummondville - Bois-Francs

Eastern Townships

Forillon National Park - Gaspé - Percé

Gaspésie National Park - Murdochville

Kamouraska - Rivière-du-Loup - Trois-Pistoles

Lanaudière

Matane

Mauricie

Metro Montréal - Laval

Montmagny - L'Islet

New Carlisle - Chandler

Québec

Restigouche - Bonaventure

Richelieu Valley - Saint-Hyacinthe

Rimouski - Mont-Joli

Sainte-Anne-des-Monts - Grande-Vallée

Témiscouata

Vaudreuil - Soulanges - Huntingdon

For Post-tropical Storm Isaias.

This is an updated meteorological summary for Post-tropical Storm Isaias. This will be the final information statement for this storm.

1. Full discussion of the event.

Isaias is currently a post-tropical system that impacted much of the Caribbean and the Atlantic Coast of the United States as a Category 1 Hurricane. The storm started developing off the coast of Africa, and reached Tropical Storm status on July 30 as it moved west towards the Caribbean. The next day, Isaias reached hurricane strength with a maximum intensity of 137 kilometres per hour with a central pressure of 997 millibars. The storm impacted North Andros in the Bahamas on August 1 and then weakened to a tropical storm as it moved up along the East Coast of the United States. As it moved towards the Carolinas, it re-intensified to a Category 1 system just before making landfall near Ocean Isle Beach in North Carolina, near midnight on August 3. Isaias then remained inland as it moved up along the coast towards New England as a strong tropical storm. Numerous warnings and watches were issued for the Caribbean, the Bahamas, and much of the East Coast of the United States, including hurricane warnings and watches, and storm surge warnings from the Carolinas south.

On August 4th, Isaias moved through New York into Vermont, then crossed the border into Quebec that evening. While weakening gradually it continued to move northeastward and cross the St. Lawrence River just east of Trois-Rivières. Impacts for Canada were high rainfall amounts, winds gusting to storm force Tuesday evening. There was some possible local flash flooding, with widespread rainfall ahead of the storm in the 30 to 60 millimetre range, and locally reaching over 100 millimetres near Trois-Rivières and west to north of the Montreal area. Wind gradually dropped off during the evening and overnight, except for parts of the St. Lawrence River, where winds of near storm force persisted into the overnight period. Areas around Quebec City saw some wind damage from fallen trees and several thousand were without power Tuesday night.

The storm is weakening as it continues north, where it will merge with a low pressure system and then pass east into Labrador.

2. Summary of rainfall amounts in millimetres in Quebec:

Charlevoix (Massif): 124.7

Trois-Rivières: 90.2

Nicolet: 85.7

Shawinigan: 82.6

Saint-Jean-sur-Richelieu: 69.6

L'Acadie: 65.7

Boloeil: 65.3

Saint-Hyacinthe: 63.9

Saint-Armand: 59.2

Deschambaults: 57.3

Saint-Germain-De-Grantham: 54.6

Lemieux: 53

Ste-Clotilde: 51.0

Quebec/Jean Lesage: 46.6

Sainte-Foy: 46.5

Dollard-Des Ormeaux: 45.2

Montreal (downtown): 45.0

Deux-Montagnes: 45.0

La Tuque: 45

Frelighsburg: 43.4

3. Summary of maximum wind gusts in kilometres per hour in Quebec:

Ile d'Orleans: 91

Beauport: 78

Quebec/Jean Lesage: 69

Ste - Foy University of Laval: 63

Sherbrooke: 63

Iles-aux-Grues: 57

4. Summary of maximum wind gusts in kilometres per hour in New England and Maine:

Quonset Airport: 98

Bradley International Airport: 91

Providence: 87

Boston Airport (Logan): 85

Windham Airport: 83

Portsmouth: 82

Mt. Washington Regional Airport: 78

5. Summary of maximum wind gusts in kilometres per hour in the Gulf of Maine south to Long Island, from buoys C-Man stations:

Station IOSN3: 74

Buoy 44007: 70

Buoy 44037: 67

Buoy 44030: 63

Buoy 44029: 57

Forecaster(s):McArthur/Mercer

Please continue to monitor alerts issued by the Canadian Hurricane Centre and forecasts issued by Environment Canada.