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Hurricane JOAQUIN Forecast Discussion Number 27
2015-10-04 10:43:45| National Hurricane Center (Atlantic)
Issued at 500 AM AST SUN OCT 04 2015 000 WTNT41 KNHC 040843 TCDAT1 HURRICANE JOAQUIN DISCUSSION NUMBER 27 NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015 500 AM AST SUN OCT 04 2015 The cloud pattern of Joaquin has continued to gradually deteriorate overnight with most of the deep convection now located over the eastern and southeastern portions of the circulation. The earlier reconnaissance aircraft mission reported peak 700-mb flight-level winds of 125 kt, and SFMR surface winds of 94 kt during its last pass through the southeastern portion of eyewall just before 0500 UTC. Dropsonde and SFMR data suggest that the flight-level winds are not mixing down as efficiently as before, and the initial intensity is lowered to 105 kt, which is a blend of the various reconnaissance wind data. Another Air Force Reserve Hurricane Hunter aircraft is currently en route to the storm and should provide a better assessment of Joaquin's intensity this morning. Recent center fixes indicate that the motion of Joaquin has started to bend toward the north-northeast, but the longer term motion is still northeastward or 040/17 kt. The hurricane should turn north-northeastward this morning, and pass near Bermuda this afternoon as it moves between a large mid- to upper-level low to its west and a mid-level ridge over the central Atlantic. After passing the Bermuda Joaquin is expected to turn northeastward, then east-northeastward after 48 hours when it reaches the mid-latitude westerlies. The updated NHC track is similar to the previous advisory and it remains near the center of the tightly cluster guidance models. Moderate to strong southwesterly shear is expected to cause some weakening during the next 12 to 24 hours, but Joaquin is forecast to remain a strong hurricane while it passes near or over Bermuda later today. Gradual weakening should continue after 24 hours, as the hurricane encounters cooler waters and remains within an environment of moderate shear. Joaquin is expected to become an extratropical cyclone over the North Atlantic in a little more than 72 hours. The official intensity forecast is close to the model consensus through 72 hours, and is based on guidance from the Ocean Prediction Center at 96 and 120 h when the cyclone will be post-tropical. FORECAST POSITIONS AND MAX WINDS INIT 04/0900Z 29.7N 67.7W 105 KT 120 MPH 12H 04/1800Z 31.6N 66.4W 90 KT 105 MPH 24H 05/0600Z 33.7N 65.5W 85 KT 100 MPH 36H 05/1800Z 35.5N 64.1W 80 KT 90 MPH 48H 06/0600Z 37.6N 61.0W 75 KT 85 MPH 72H 07/0600Z 41.8N 49.0W 65 KT 75 MPH 96H 08/0600Z 45.0N 33.0W 60 KT 70 MPH...POST-TROP/EXTRATROP 120H 09/0600Z 50.0N 21.0W 55 KT 65 MPH...POST-TROP/EXTRATROP $$ Forecaster Brown
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