Intensification and Cuban landfalls Meteorological history of Hurricane Dennis

tropical storm dennis organizing on eastern caribbean sea on july 6

embedded within deep east-southeasterly flow , along periphery of subtropical ridge, depression moved rapidly along west-northwest course; made landfall on grenada @ 21:00 utc on july 4 maximum sustained winds of 35 mph (55 km/h). upon entering caribbean sea, deep convection flared on system. environmental conditions ahead of depression favored intensification hurricane, little no wind shear—analyzed 25 mph (35 km/h) below average—and high sea surface temperatures around 84 °f (29 °c) present along path. based on satellite intensity estimates obtained through dvorak technique, depression assessed have become tropical storm 12:00 utc on july 5. accordingly, nhc assigned name dennis @ time. marked earliest formation of season s fourth named storm on record; however, later surpassed tropical storm debby of 2012 named on june 23. further surpassed tropical storm danielle on june 19, 2016.

throughout july 6, convection steadily consolidated system acquired more northerly component track. hurricane hunters investigating dennis found steadily falling barometric pressures, indicative of intensification. around 22:00 utc, observation aircraft indicated dennis achieved hurricane-strength; central pressure of 985 mbar (hpa; 29.09 inhg) , flight-level winds of 91 mph (146 km/h) measured. central dense overcast blossomed on hurricane s center while microwave satellite imagery depicted closed, well-defined mid-level eye. @ point, factor inhibiting development interaction mountains of hispaniola , jamaica. dennis developed unusually prominent outflow, along western side, location , time of year due in part unseasonably weak trough on mid-atlantic.

hurricane dennis shortly before making landfall in matanzas province, cuba, on july 8 category 4.

rapid intensification ensued throughout july 7, dennis turned more northwest , tracked through jamaica channel. well-defined, 10 mi (16 km) eye formed within hurricane s central dense overcast evening. dennis achieved major hurricane status 18:00 utc , category 4 status 00:00 utc on july 8 approached southern cuba. abbreviated eyewall replacement cycle took place during period eye expanded 18 23 mi (29 37 km) in diameter. reconnaissance flying in storm reported flight-level winds of 154 mph (248 km/h), , based on dennis estimated have reached initial peak surface winds of 140 mph (225 km/h). around 02:45 utc, dennis briefly moved on granma province, cuba, center crossing coast near punta del inglés (close cabo cruz). violent , destructive winds battered province. weather station in cabo cruz reported sustained winds of 133 mph (214 km/h) , gust 148 mph (238 km/h) before being destroyed.

interaction land caused slight weakening; however, dennis emerged on gulf of guacanayabo , region s shallow, warm waters fueled abrupt reorganization. hurricane traveled along western spine of jardines de la reina archipelago, subjecting islands category 3 , 4 strength winds. paralleling coast of cuba, dennis attained peak winds of 150 mph (240 km/h) around 12:00 utc on july 8. hurricane hunters observed flight-level winds of 173 mph (278 km/h) , pressure of 938 mbar (hpa; 27.70 inhg) around time. former value indicated surface winds around category 5 strength while latter yielded lower winds, via pressure-wind relationship method. aforementioned peak strength chosen accordingly compromise between conflicting data. eyewall replacement cycle took place after peak , slight weakening ensued. around 18:45 utc, dennis made second landfall in cuba near punta mangles altos in matanzas province winds of 140 mph (225 km/h); gust of 149 mph (240 km/h) reported in cienfuegos. despite moving on land, weakening slow due hurricane s proximity water. 6 hours after moving ashore, unión de reyes subjected sustained winds of 110 mph (180 km/h) , gusts 123 mph (198 km/h).