Most Hurricanes are Category 1-3 on the Saffir-Simpson scale. Few are 4 & 5. 1900-2007 climatology.

Most Hurricanes are Category 1-3 on the Saffir-Simpson scale. Few are 4 & 5. 1900-2007 climatology.

September is Hurricane Month.

Global sea surface temperatures

T > 81 oF=27 °C for hurricane formation

North African dust storms can weaken a hurricane season.

Warm enough ocean temperatures & large enough Coriolis force (Latitudes greater than 10 degrees)

Vertical Wind Shear

Vertical Wind Shear

High Vertical Wind Shear:Destroys hurricane formation

Low Vertical Wind ShearEnhances hurricane formation

Stages in development

20-34 knots

>64 knots

35-63 knots

Complexes of thunderstorms

Names are given to Tropical storms and Hurricanes

Eye

Eye WallRain Bands

Katrina August 28, 2005 TRMM (Tropical Rainfall Measuring Mission)

Surface Pressure lowest in eye and wind speeds highest in eye-wall

Hurricanes are in the water near North America, Typhoons Near Eastern Asia, Cyclones everywhere else.

Climatology

El Nino and Hurricanes

Red- tropical storms and hurricanesYellow- hurricanes onlyGreen- cat 3 or larger.