je.st
news
Tropical Storm Hilary Forecast Discussion Number 27
2017-07-28 04:54:46| National Hurricane Center (East Pacific)
Issued at 800 PM PDT Thu Jul 27 2017 000 WTPZ44 KNHC 280254 TCDEP4 Tropical Storm Hilary Discussion Number 27 NWS National Hurricane Center Miami FL EP092017 800 PM PDT Thu Jul 27 2017 Deep convection associated with Hilary has been decreasing during the last several hours, and the convective pattern is now limited to a ragged central dense overcast. This loss of convection appears to be associated with dry air that has wrapped into the circulation, as evident in microwave data. An average of the latest Final T- and CI-numbers from TAFB/SAB, along with ADT values from CIMSS at the University of Wisconsin, support lowering the initial intensity to 60 kt, making Hilary a tropical storm. Hilary still has another 18-24 hours over warm water, and the regional hurricane models respond to this by showing Hilary restrengthening during that time. Given the observed weakening trend over the past day or so and Hilary's current struggle with dry air, the NHC intensity forecast lies at the low end of the guidance during that time frame, and calls for the storm to remain steady in intensity. After 24 hours, Hilary is expected to cross the 26-deg C isotherm and it will be moving over even cooler waters and into a drier air mass during the next few days. These unfavorable conditions should cause weakening, and Hilary is forecast to become a post-tropical cyclone in about 4 days. The NHC intensity forecast is similar to the previous one, and it lies fairly close to the SHIPS and LGEM models. The tropical storm is moving west-northwestward at 7 kt on the south side of a mid-level ridge. This motion with a slight increase in forward speed is expected during the next couple of days as the mid-level ridge strengthens. When Irwin rotates around the eastern and northern sides of Hilary in the 48- to 72-h time frame, Hilary could turn briefly to the left before it absorbs Irwin. Thereafter, a slower motion to the west-northwest is predicted as the weakening storm moves in the low- to mid-level flow. The NHC track forecast is adjusted a little to the north of the previous one, to come into better agreement with the latest consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 28/0300Z 18.3N 117.3W 60 KT 70 MPH 12H 28/1200Z 18.8N 118.4W 60 KT 70 MPH 24H 29/0000Z 19.6N 120.0W 60 KT 70 MPH 36H 29/1200Z 20.5N 122.0W 55 KT 65 MPH 48H 30/0000Z 21.2N 124.3W 55 KT 65 MPH 72H 31/0000Z 22.1N 128.7W 45 KT 50 MPH 96H 01/0000Z 23.2N 132.1W 35 KT 40 MPH...POST-TROPICAL 120H 02/0000Z 24.5N 134.8W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Cangialosi
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||