Category 5 Hurricane (SSHS)
Hurricane Isac.jpg
Hurricane Isac at peak intensity
Formed June 27, 2011
Dissipated July 2, 2011
Highest winds 1-minute sustained:
175 mph (280 km/h)
Lowest pressure 918 mbar (hPa); 27.11 inHg
Fatalities 550 (30)
Damage $22.5 billion (2011 SCS)
Areas affected San Francisco
Part of the 2011 Biolixi Ocean hurricane season

Isac was the 9th named storm, 6th hurricane, and 5th major hurricane of the 2011 Biolixi Ocean hurricane season. Isac's duration was between June 27 and July 2. Isac was a category 5 hurricane with winds at 175 mph and pressure at 918 mbar. Isac was a deadly storm that affected San Francisco, mainly Coconut City and Irene. Isac made landfall as a category 5 with maximum winds of 170 mph. After landfall Isac crossed the San Francisco Peninsula and San Francisco Bay; Isac made a second landfall near Clark City as a category 1. Isac was the 5th most destructive hurricane to hit that area, even though Isac was a small hurricane in size.

Meteorological HistoryEdit

Hurricane Isac's Path

Isac's Path

On June 25 a vigorous low pressure system developed just west of the San Francisco Gulf; the low pressure system soon developed into Tropical Depression Nine on June 27. Nine only lasted 15 hours before becoming Tropical Storm Isac later that day. Isac soon sparked a potentialy dangerous situation for the San Francisco Peninsula, according to the National Hurricane Center. The National Hurricane Center forecasted that Isac could become a major hurricane before possible landfall somewhere along the San Francisco Peninsula. Due to this possible threat manditory evacuations were ordered on June 28, when Isac became a category 1 hurricane. Hurricane Isac was heading east towards the coast over very warm waters and little to no wind shear was present; later that same day on June 28 Isac strengthened into a category 2. On June 29 Isac strengthened rapidly; Isac became a major category 3 hurricane and was heading East-Southeast towards Coconut City. Since Isac had become a major hurricane, mass evacuations were ordered for the San Francisco Peninsula, especially Coconut City. Early on June 30 Isac strengthened into a category 4 hurricane and was still continuing its dangerous path towards the San Francisco Peninsula; later that day right before its devestating landfall Isac became a category 5. Isac made landfall at Coconut City as a category 5; which brought imensely strong winds and very heavy rainfall. After making landfall Isac remained a hurriane onshore and then entered San Francisco Bay; Isac then made its second landfall on the eastern half of San Francisco as a category 1. On July 1 Isac weakened into a tropical storm over land; the next day on July 2 Isac weakened further into a tropical depression and then dissipated later that day.

Preparations and ImpactEdit

San FranciscoEdit

Since San Francisco has had many devestating systems in the past, they prepared very quickly for Isac. They prepared with everything necessary, they even created a new hurricane evacuation route which stretched from Coconut City to Clark City. When Isac made landfall as a category 5, the cities of Coconut City, Irene, and Tree Beach were affected tremendously. The storm surge was measured at 35ft (25ft higher than the elevation of Coconut City), this flooded the entire city. Isac in all killed 550 sims and caused 22.5 billion simoleons in damage.


Hurricane Sydney

Hurricane Sydney of 2010.

Hurricane Sydney of 2010 is considered to be the exact same scenario from Hurricane Isac. Although Isac made landfall as a category 4 hurricane instead of category 5 hurricane like Sydney. Sydney also caused a lot more damage due to poor preparation and evacuation orders.


Due to the devastation caused by Hurricane Isac, the name "Isac" was retired by the National Hurricane Center and was replaced by "Ivette" for the 2017 Biolixi Ocean hurricane season.

See alsoEdit

Tropical cyclones in the 2011 Biolixi Ocean hurricane season
Saffir–Simpson Hurricane Scale
TD TS C1 C2 C3 C4 C5