ZCZC MIATCDAT3 ALL TTAA00 KNHC DDHHMM TROPICAL STORM COLIN DISCUSSION NUMBER 7 NWS NATIONAL HURRICANE CENTER MIAMI FL AL032016 1100 PM EDT MON JUN 06 2016 Surface observations and shortwave infrared imagery suggest that the center of Colin is just offshore of the coastline in the Big Bend region of Florida, and the system should make landfall very soon. Due to the displacement of the strong winds and heavy rainfall from the center of Colin, however, it is important to not focus on the time or location of landfall, or on the exact forecast track. Heavy rainfall, strong winds, and coastal flooding have been affecting much of Florida and these conditions should spread northward and northeastward over the southeast United States. The intensity estimate remains at 45 kt, under the assumption that wind speeds near this value are still being experienced at some locations along the coast. Global models indicate that Colin will deepen when it moves over the Atlantic, probably due to baroclinic energetics. Although Colin is expected to lose tropical characteristics within 24 hours, the models do not show it fully embedded within a frontal zone, i.e. extratropical, until about 48 hours. The official forecast goes with this scenario. The initial motion estimate is 050/19. Colin should accelerate northeastward ahead of a broad mid-level trough over the eastern United States for the next day or two. After that, the forward speed of the cyclone is likely to slow as it interacts with a couple of other extratropical lows over the north Atlantic. It should be noted that Colin will probably lose its status as a tropical cyclone while impacts are still occurring along the coast. In this case, NHC will continue to issue advisories and warnings on the post-tropical cyclone. FORECAST POSITIONS AND MAX WINDS INIT 07/0300Z 29.8N 83.8W 45 KT 50 MPH 12H 07/1200Z 32.9N 79.0W 50 KT 60 MPH 24H 08/0000Z 36.5N 71.2W 55 KT 65 MPH...POST-TROPICAL 36H 08/1200Z 41.0N 62.5W 55 KT 65 MPH...POST-TROPICAL 48H 09/0000Z 45.0N 55.0W 50 KT 60 MPH...POST-TROP/EXTRATROP 72H 10/0000Z 49.0N 42.0W 40 KT 45 MPH...POST-TROP/EXTRATROP 96H 11/0000Z 54.0N 31.5W 40 KT 45 MPH...POST-TROP/EXTRATROP 120H 12/0000Z 56.0N 27.5W 35 KT 40 MPH...POST-TROP/EXTRATROP $$ Forecaster Pasch NNNN