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Hurricane Norman Forecast Discussion Number 11
2018-08-30 22:37:54| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Thu Aug 30 2018 167 WTPZ41 KNHC 302037 TCDEP1 Hurricane Norman Discussion Number 11 NWS National Hurricane Center Miami FL EP162018 200 PM PDT Thu Aug 30 2018 Norman is a very impressive hurricane in visible and infrared satellite imagery. The hurricane's CDO is very symmetric and has a well-defined 20-nmi-wide eye. The surrounding ring of cold cloud tops have warmed slightly, but the various satellite intensity estimates are still catching up to the improved satellite presentation and range from 127 kt to 135 kt. Based on a blend of these data, the initial intensity is set at 130 kt, and it appears that Norman's rapid strengthening phase is easing. There is still a potential for some additional increase in intensity within the next 12 hour or so, however, eyewall replacement probabilities from UW/CIMSS indicate a very high likelihood of an eyewall replacement beginning within the next 12-24 hours which will probably lead to some fluctuations in intensity. Slightly lower sea surface temperatures and a subtle increase in northeasterly shear are expected to cause a gradual decrease in wind speed over the weekend. The NHC intensity forecast shows gradual weakening but it does not weaken Norman as quickly as the statistical guidance, and it is in best agreement with the HFIP corrected consensus model. Recent satellite fixes indicated that Norman is moving slightly south of due west. A strong mid- to upper-level ridge that extends west-southwestward from the Baja California peninsula should steer Norman west-southwestward during the next 36 hours. After that time, the ridge changes orientation which is expected to cause Norman to turn back toward the west or west-northwest by early next week. The track guidance is once again tightly clustered but the overall model enveloped has shifted slightly southward. As a result, the NHC forecast has been nudged in that direction to be closer to the various consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 30/2100Z 17.5N 118.8W 130 KT 150 MPH 12H 31/0600Z 17.2N 120.0W 135 KT 155 MPH 24H 31/1800Z 16.8N 121.5W 130 KT 150 MPH 36H 01/0600Z 16.3N 123.2W 120 KT 140 MPH 48H 01/1800Z 16.2N 125.1W 115 KT 130 MPH 72H 02/1800Z 17.1N 129.4W 105 KT 120 MPH 96H 03/1800Z 18.9N 135.2W 85 KT 100 MPH 120H 04/1800Z 20.2N 140.5W 65 KT 75 MPH $$ Forecaster Brown
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