Hurricane Formation

WEATHER UNDERGROUND HURRICANE FORMATION North Atlantic 111 111 Hurricane Must Haves Spin Moisture Instability Calm Seed Low pressure, African Easterly Waves BEGIN TO Weak FORM AT vertical wind shear NORTH MРН <22 Fuel WARM 80° Damage ~ Minimal a Moderate N Extensive 2 Extreme Catastrophic CATEGORY 1 CATEGORY 2 CATEGORY 3 CATEGORY 4 CATEGORY 5 Wind Factor J Largest hurricanes by diameter of gale-force winds GALE-FORCE WINDS 2 3 4 5 34 knots or Category Measuring a Hurricane's Power (Saffir-Simpson Scale) 39 mph - Sandy 2012: 945 miles 157+ 130-156 Igor 2012: 920 miles 111-129 96-110 - Olga 2001: 865 miles - Lili 1996: 805 miles 74-95 Karl 2004: 780 miles mph 95% 85% 1983 the year with fewest named storms in of all intense hurricane of all major hurricanes (category 3-4-5) originate from African easterly waves activity occurs from August to October modern records: 4 Likely Formations FACT: MILES 6,850 Most likely hurricane tracks (August, September, October) Longest distance traveled. Hurricane Faith 1966 August - September - October For more about hurricane formation go to www.wunderground.com Sources: Some data information provided by the National Hurricane Center & the National Oceanic and Atmospheric Administration WEATHER UNDERGROUND