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#827924 (Received by flhurricane at: 9:37 AM 14.Jan.2016) TCDAT1 HURRICANE ALEX DISCUSSION NUMBER 4 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012016 1100 AM AST THU JAN 14 2016 Remarkably, Alex has undergone the transformation into a hurricane. A distinct eye is present, embedded within a fairly symmetric mass of deep convection. Water vapor imagery shows that the upper-level trough is now west of the cyclone, with divergent flow over the center - indicative of a tropical transition. It is very unusual to have a hurricane over waters that are near 20 deg C, but the upper-tropospheric temperatures are estimated to be around -60 deg C, which is significantly colder than the tropical mean. The resulting instability is likely the main factor contributing to the tropical transition and intensification of Alex. With these changes, the government of the Azores has issued warnings for most of the Azores islands. The initial intensity is set to 75 kt in accordance with the analyzed Dvorak T-number of 4.5. Only slight additional intensification seems possible since the system will be passing over even colder waters during the next day or two. In 36 hours, the global models suggest that the cyclone will become extratropical as it begins to merge with a large low pressure area at high latitude. The post-tropical cyclone is then likely to lose its identity after 48 hours. The initial motion is north-northeastward or 020/17 kt. Alex is being steered by a shortwave mid-level trough that is rotating around a larger trough to the northwest. This should cause the cyclone to turn northward and north-northwestward and accelerate over the next couple of days. The official track forecast is very similar to the previous one and also quite close to the consensus of the tightly-packed dynamical model forecast tracks. Alex is the first hurricane to form in the month of January since 1938, and the first hurricane to occur in this month since Alice of 1955. FORECAST POSITIONS AND MAX WINDS INIT 14/1500Z 31.5N 28.4W 75 KT 85 MPH 12H 15/0000Z 34.3N 27.7W 80 KT 90 MPH 24H 15/1200Z 38.9N 27.7W 75 KT 85 MPH 36H 16/0000Z 45.3N 28.6W 60 KT 70 MPH...POST-TROP/EXTRATROP 48H 16/1200Z 53.0N 31.5W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 17/1200Z...DISSIPATED $$ Forecaster Pasch |