This timeline documents all the storm formations, strengthening, weakening, landfalls, extratropical transitions, as well as dissipation during the 2011-12 Alaska hurricane season. The season officially began on November 1, 2011, and will end on March 31, 2012. The timeline also includes information which was not operationally released, meaning that information from post-storm reviews by the Alaska Hurricane Center, such as information on a storm that was not operationally warned on, have been included.
Timeline of events
November
- November 1
- 0900 UTC (12:00am AST) - The 2011-12 Alaska hurricane season officially begins.
Tropical Storm Abby's track.
- November 3
- 0600 UTC (9:00pm AST November 2) - Tropical Depression One-K forms 100 miles south of Unalaska Island.
- November 5
- 1800 UTC (9:00am AST) - Tropical Depression One-K strengthens into Tropical Storm Abby.
- November 7
- 1500 UTC (6:00am AST) - Tropical Depression Two-K forms in the central Gulf of Alaska.
- November 9
- 0600 UTC (9:00pm AST November 8) - Tropical Depression Two-K dissipates.
- 2100 UTC (12:00pm AST) - Tropical Storm Abby becomes post-tropical.
- November 12
- 0900 UTC (12:00am AST) - Tropical Depression Three-K forms south-west of Umnak Island.
- 2100 UTC (12:00pm AST) - Tropical Depression Three-K strengthens into Tropical Storm Bertha.
- November 13
- 0900 UTC (12:00am AST) - Tropical Storm Bertha strengthens into a Category 1 hurricane.
- November 14
- 0300 UTC (6:00pm AST November 13) - Hurricane Bertha strengthens rapidly into a Category 2 hurricane.
- 1500 UTC (6:00am AST) - Tropical Depression Four-K forms off the coast of Russia.
- 2100 UTC (12:00pm AST) - Hurricane Bertha strengthens into a Category 3 major hurricane.
- 2100 UTC (12:00pm AST) - Tropical Depression Four-K strengthens into Tropical Storm Claudette.
- November 15
- 0900 UTC (12:00am AST) - Hurricane Bertha strengthens into a Category 4 hurricane.
- 1500 UTC (6:00am AST) - Tropical Storm Claudette strengthens into a Category 1 hurricane.
- 1800 UTC (9:00am AST) - Hurricane Claudette makes landfall on the Alaska Peninsula
- 1930 UTC (10:30am AST) - Hurricane Claudette weakens back to a tropical storm.
- 2100 UTC (12:00pm AST) - Hurricane Bertha weakens back into a Category 3 hurricane.
- November 16
- 0300 UTC (6:00pm AST November 15) - Tropical Storm Claudette strengthens back into a Category 1 hurricane.
- 0900 UTC (12:00am AST) - Hurricane Bertha weakens back to a Category 2 hurricane.