ZCZC MIATCDEP1 ALL
TTAA00 KNHC DDHHMM
Hurricane Norman Discussion Number 12
NWS National Hurricane Center Miami FL EP162018
800 PM PDT Thu Aug 30 2018
After the explosive intensification observed last night and
earlier today, Norman's intensity has leveled off. The eye of the
major hurricane remains quite circular and distinct with a
solid eyewall surrounding the center. The eastern portion of the
eyewall, however, has eroded a little during the past few hours.
Based on the steady state appearance, the initial intensity is held
at 130 kt, which lies at the upper end of the satellite intensity
estimates.
The environmental conditions surrounding Norman are expected to
only gradually become less favorable with SSTs and mid-level
humidity values slowly decreasing along Norman's track during the
next few days. There is a possibility of eyewall replacement cycles
in major hurricanes like Norman, which typically cause fluctuations
in strength and are challenging to forecast. The intensity models
all show a slow weakening trend, and the NHC forecast follows that
theme. This forecast is slightly below the previous one, trending
toward the latest consensus models.
Norman is moving west-southwestward at 8 kt steered by a
northeast-southwest oriented deep-layer ridge to the north of the
tropical cyclone. This general motion is expected to continue for
the next day or so. After that time, a change in the orientation
of the ridge should cause Norman to turn to the west and then
west-northwest with an increase in forward speed. The track models
remain in relatively good agreement, and the NHC track forecast lies
near the middle of the guidance envelope.
FORECAST POSITIONS AND MAX WINDS
INIT 31/0300Z 17.3N 119.6W 130 KT 150 MPH
12H 31/1200Z 17.0N 120.7W 125 KT 145 MPH
24H 01/0000Z 16.6N 122.3W 120 KT 140 MPH
36H 01/1200Z 16.2N 124.3W 110 KT 125 MPH
48H 02/0000Z 16.3N 126.3W 105 KT 120 MPH
72H 03/0000Z 17.8N 131.5W 95 KT 110 MPH
96H 04/0000Z 19.5N 137.0W 75 KT 85 MPH
120H 05/0000Z 20.5N 142.0W 60 KT 70 MPH
$$
Forecaster Cangialosi
NNNN