je.st
news
Hurricane Fernanda Forecast Discussion Number 8
2017-07-13 22:38:39| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Thu Jul 13 2017 000 WTPZ41 KNHC 132038 TCDEP1 Hurricane Fernanda Discussion Number 8 NWS National Hurricane Center Miami FL EP062017 200 PM PDT Thu Jul 13 2017 Fernanda is rapidly intensifying. Satellite imagery indicates that the central convection has become more symmetric, and there have been hints of an eye in visible imagery. In addition, earlier microwave imagery showed at lease a partial ring of convection around the center. Subjective and objective satellite intensity estimates range from 65-75 kt, so the initial intensity is increased to a possibly conservative 70 kt. Conservative or not, this is a 35 kt increase from this time yesterday. The initial motion is a little south of west or 260/10, with part of the southward component possibly due to some reformation of the center as the cyclone intensified. During the next 48 h, a deep-layer ridge to the north of Fernanda should steer the hurricane generally westward, and the new forecast is similar to the previous forecast. After that time, a large mid- to upper-level trough over the central Pacific north of Hawaii should cause the ridge to weaken, and the track guidance shows Fernanda turning west-northwestward in response. The guidance is forecasting a greater northward component of motion from 72-120 h than on the previous runs, and thus the latter part of the track forecast is nudged northward as well. Overall, the new forecast lies close to the various consensus models. While satellite imagery suggests that some shear continues to affect Fernanda, so far it has done little to slow the development. The hurricane should remain over warm water and in a light shear environment for the next 72 h, and the SHIPS model Rapid Intensification Index shows better than a 50 percent chance of a 35-kt increase in strength in the next 24 hours and a 45-kt increase in 36 h. Based on this, the intensity forecast calls for 36 h more of rapid strengthening. Given the lack of negative factors, except for the possibility of eyewall replacement cycles, the new intensity forecast could still be conservative even though it lies above the intensity guidance. After 72 h, Fernanda should encounter decreasing sea surface temperatures and drier air, and this is expected to cause a steady weakening. The new intensity forecast is again increased considerably over the previous forecast during the first 36 h, and it is decreased below for previous forecast at 120 h. FORECAST POSITIONS AND MAX WINDS INIT 13/2100Z 11.2N 116.0W 70 KT 80 MPH 12H 14/0600Z 11.1N 117.5W 85 KT 100 MPH 24H 14/1800Z 10.9N 119.4W 100 KT 115 MPH 36H 15/0600Z 10.9N 121.3W 115 KT 130 MPH 48H 15/1800Z 11.3N 123.5W 120 KT 140 MPH 72H 16/1800Z 12.5N 128.0W 125 KT 145 MPH 96H 17/1800Z 14.0N 132.5W 115 KT 130 MPH 120H 18/1800Z 15.5N 136.0W 95 KT 110 MPH $$ Forecaster Beven
Tags: number
discussion
forecast
hurricane
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||