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| #827987 (Received by flhurricane at: 3:38 PM 14.Jan.2016) TCDAT1 HURRICANE ALEX DISCUSSION NUMBER 5 NWS NATIONAL HURRICANE CENTER MIAMI FL AL012016 500 PM AST THU JAN 14 2016 Alex has been maintaining a fairly impressive appearance on satellite imagery, with a well-defined 15-20 n mi diameter eye embedded within cold cloud tops. Recent images do suggest some warming/erosion of the tops over the southwest quadrant. Dvorak T-numbers remain near 4.5 so the current intensity is held at 75 kt. Sea surface temperatures are now below 20 deg C and should continue to cool along the path of Alex. This, along with a little increase in southwesterly shear, should result in gradual weakening. However, Alex is expected to maintain hurricane strength while passing near or over the Azores. In 24 hours or so, the global models show a distinct warm front over the northeast portion of the circulation. This suggests extratropical transition, and the official forecast reflects this. Later in the forecast period, the global models show the system merging with another extratropical cyclone over the northern Atlantic. The initial motion is slightly east of due northward or 015/19. There is essentially no change to the track forecast reasoning. Alex continues to be steered by the flow of a shortwave mid-tropospheric trough that has been rotating around a broader trough to its northwest. This evolution should cause the cyclone to turn gradually to the left with increasing forward speed over the next couple of days. The dynamical track guidance models are in excellent agreement for the first 36 hours of the forecast, and the official forecast is near the consensus of these models. This is basically an update of the previous NHC track prediction. Alex's wind field is likely to expand as it nears and makes the extratropical transition. The wind radii forecasts are based primarily on guidance from the NOAA Ocean Prediction Center. FORECAST POSITIONS AND MAX WINDS INIT 14/2100Z 33.6N 27.8W 75 KT 85 MPH 12H 15/0600Z 36.4N 27.5W 75 KT 85 MPH 24H 15/1800Z 41.8N 27.9W 70 KT 80 MPH...POST-TROP/EXTRATROP 36H 16/0600Z 49.5N 29.7W 65 KT 75 MPH...POST-TROP/EXTRATROP 48H 16/1800Z 56.5N 34.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 72H 17/1800Z...MERGED WITH ANOTHER EXTRATROPICAL CYCLONE $$ Forecaster Pasch |
