Yachting World — November 2017

November 2017 49

Hurricanes are typically 150-200 miles across

Hurricane Irma was more than 400 miles wide.

Outflow cirrus

Well defined eye

Hurricane Irma

6 September 2017 0135am AST

Tropospheric gravity waves

Irma top wINd speed:

185mph

oNly HurrIcaNe alleN

IN 1980 recorded

stroNger wINds at

190 mph

sustaINed 185mpH for

37 hours

lowest atmospHerIc

pressure:

(^) 914 millibars
greatest dIameter:
420 miles
tropIcal storm force
wINds spaNNed
70,000
sq miles
NOOA
NOAA