- When
- September 9, 10:15 AM EST to September 10, 4:30 PM EST
- Where
- Monroe/Lower Keys forecast zone
- Category
- 4
- Deaths
- 2 direct, 2 indirect
- Injuries
- 20 direct, 0 indirect
- Reported by
- NWS Storm Survey
- Coordinates
- 25.557, -80.917 (the zone’s center; the record gives no point)
The eye of Hurricane Irma moved ashore in the Lower Florida Keys over Cudjoe Key at 9:10 am EDT Sunday, September 10, with a minimum central pressure of 929 mb and maximum sustained winds near 115 knots (130 mph). The highest sustained winds in the Lower Florida Keys were measured at 61 knots (70 mph) at a NOAA National Ocean Service station at Key West Harbor, with a peak measured gusts at 120 mph at the Key Deer National Wildlife Refuge and a private residence on Big Pine Key. Storm survey evidence of hurricane-force wind gusts include: From Ohio, Missouri, Bahia Honda through Little Torch Keys, the strongest estimated winds were evident, possibly attributable to a mesoscale eyewall vortex circulation within the northeast quadrant of the eyewall. A general path of of maximum wind damage occurred from the western end of Scout Key, just south of Big Pine Key Park, through Key Deer Boulevard north of South Street. Complete roof structure failure involving snapped wood trusses was observed on several homes along with complete exterior wall failure on one waterfront home. The path continued across Key Deer Boulevard where utility pole both of wood and hollow-spun concrete design were snapped with numerous spans lying in completely opposite directions. The southern spans opposite to the direction of the mean wind. Peak wind gusts were estimated 150 to 160 mph along the northern side of the apparent circulation. Elsewhere across Big Pine Key, significant roofing loss and collapse of exterior walls on older mobile homes, large sections of roof coverings of all types, soffet damage and large metal roof, wall and door failures on modern metal building systems indicated more widespread estimated peak wind gusts of 120 to 130 mph. From Ramrod Key through Sugarloaf Key, widespread business and residential roof covering damage of all types was observed, with isolated roof truss or gable end failures of older design. It was noted a diagonal metal cross brace on an electric power transmission line across Niles Channel became detached from one vertical concrete column, indicative of significant deformation or flexing of the transmission towers. Estimated peak wind gusts of 110 to 120 mph were attributed to this damage. From Lower Sugarloaf Key through Big Coppitt Key, widespread small residential and business roof coverings with isolated structural gale end or overhang damage was noted especially in areas of open north wind exposure. Isolated mobile home destruction including collapse of all walls was observed, although some modern mobile homes adjacent to properties with severe destruction exhibited few signs of cosmetic damage. Estimated peak wind gusts 100 to 110 mph were attributed. From Boca Chica Key through Key West, losses of roof coverings, soffet damage to residential homes and condominiums were noted, with two hotels exhibiting gable-end wood truss failures and sheathing of both mid-rise and two-story design. Peak estimated wind gusts 90 to 100 mph were attributed, although the hotel mid-rise roof structure failure was in an area of open north wind exposure directly off the Gulf of Mexico may have indicated wind gusts in the 100 to 110 mph range. Injuries estimated due to no operating hospitals nor rescue services available during the time of hurricane force wind impact.