je.st
news
Tropical Storm HILDA Forecast Discussion Number 3
2015-08-06 16:49:57| National Hurricane Center (East Pacific)
Issued at 800 AM PDT THU AUG 06 2015 000 WTPZ45 KNHC 061449 TCDEP5 TROPICAL STORM HILDA DISCUSSION NUMBER 3 NWS NATIONAL HURRICANE CENTER MIAMI FL EP102015 800 AM PDT THU AUG 06 2015 The cyclone's cloud pattern has significantly increased in organization since late yesterday. There is now a small central mass of deep convection, with a band on the northern side of the circulation. The center, according to an 1132 UTC SSM/I pass, is also directly underneath this central convection, and the same pass indicates increasing symmetry to the overall convective structure. Satellite classifications from 1200 UTC were T2.0/30 kt and T2.5/35 kt from SAB and TAFB, respectively. The initial intensity estimate is set at the higher end of these estimates (35 kt), based on the even greater organization seen in satellite imagery since that time. The initial motion is toward the west or 275/11. The general forecast scenario is for a subtropical ridge north of the cyclone to steer Hilda westward for the next couple of days with a slight bend toward the west-northwest after 36 hours. In about 72 hours, the cyclone should move around the western end of the ridge and encounter a break in this feature at the end of the forecast period. This pattern should cause Hilda to turn northwestward with a decrease in forward speed by 96 hours. The GFS-based guidance shows a stronger ridge and a west-southwestward to westward track during the next 2 to 3 days, while the ECMWF has a weaker ridge and a track farther north. The official forecast is closer to the ECMWF solution and near but faster than the previous one through 72 hours. Overall, the NHC forecast lies to the right of the multi-model consensus, which is dominated by the GFS guidance. After 72 hours, the official track is near the multi-model consensus but not as far west as the GFS/ECMWF model solutions. Large-scale dynamic and thermodynamic factors are forecast to be conducive for intensification through for the next 72 hours or so, except for a somewhat drier lower to middle troposphere along Hilda's path in 2 to 3 days. When the cyclone gains latitude late in the forecast period, it should begin to weaken due to increasing southwesterly shear associated with a mid- to upper-level trough expected to be near the longitude of Hawaii. The official intensity forecast is higher than the previous one through 72 hours and is higher than the multi-model consensus, but little change was made to the intensity forecast late in the period. FORECAST POSITIONS AND MAX WINDS INIT 06/1500Z 12.7N 132.3W 35 KT 40 MPH 12H 07/0000Z 12.9N 133.6W 45 KT 50 MPH 24H 07/1200Z 13.0N 135.8W 50 KT 60 MPH 36H 08/0000Z 13.5N 137.9W 55 KT 65 MPH 48H 08/1200Z 14.1N 139.9W 60 KT 70 MPH 72H 09/1200Z 15.4N 144.2W 65 KT 75 MPH 96H 10/1200Z 17.1N 146.8W 65 KT 75 MPH 120H 11/1200Z 18.8N 149.4W 55 KT 65 MPH $$ Forecaster Kimberlain
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||