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HURRICANE JOAQUIN DISCUSSION NUMBER 30
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
1100 PM AST SUN OCT 04 2015
The coverage and intensity of deep convection associated with the
hurricane have diminished. Microwave imagery indicates that the
inner core has become less distinct, although the convective
banding features remain well defined. An Air Force Reserve
Unit Hurricane Hunter plane reported maximum 700 mb flight-level
winds of 87 kt over the southeastern quadrant of the circulation.
This corresponds to an intensity of about 75 kt. Only slight cooling
of waters along the path of the cyclone is indicated over the next
couple of days, since Joaquin will be moving along the Gulf Stream.
Dynamical guidance does not show the vertical shear becoming strong
until about 48 hours. Slow weakening is predicted for the next
couple of days, in general agreement with the SHIPS guidance. By 72
hours the sea surface temperatures should cool significantly, and
the global models depict the system as embedded within a baroclinic
zone. Therefore the forecast shows Joaquin becoming extratropical
by that time.
The initial motion continues to be north-northeastward, or 025/11
kt. A short wave ridge ahead of the hurricane appears to have
caused some temporary slowing of the forward motion. In a day or
two, the ridge flattens out, and the cyclone should begin to
accelerate within the mid-latitude westerlies. The official
forecast through 48 hours is close to the multi-model consensus.
The track, intensity, and wind radii for 72 hours and beyond are
based on the consensus as well as guidance from the Ocean Prediction
Tropical storm conditions are likely to continue on Bermuda for at
least the next several hours, with possible winds to hurricane
force in squalls especially at elevated locations.
FORECAST POSITIONS AND MAX WINDS
INIT 05/0300Z 33.1N 65.5W 75 KT 85 MPH
12H 05/1200Z 34.5N 64.7W 75 KT 85 MPH
24H 06/0000Z 36.2N 63.1W 70 KT 80 MPH
36H 06/1200Z 37.8N 59.8W 70 KT 80 MPH
48H 07/0000Z 39.5N 54.2W 65 KT 75 MPH
72H 08/0000Z 42.5N 38.5W 60 KT 70 MPH...POST-TROP/EXTRATROP
96H 09/0000Z 45.0N 23.5W 55 KT 65 MPH...POST-TROP/EXTRATROP
120H 10/0000Z 47.0N 16.0W 55 KT 65 MPH...POST-TROP/EXTRATROP