je.st
news
Tropical Storm Kristy Forecast Discussion Number 10
2018-08-09 10:44:48| National Hurricane Center (East Pacific)
Issued at 200 AM PDT Thu Aug 09 2018 158 WTPZ43 KNHC 090844 TCDEP3 Tropical Storm Kristy Discussion Number 10 NWS National Hurricane Center Miami FL EP132018 200 AM PDT Thu Aug 09 2018 Deep convection has continued to increase near and to the north and east of Kristy's center, and cirrus outflow has expanded some in all quadrants. Satellite intensity estimates supported an intensity of 40 kt at 0600 UTC, but the recent increase in convection, along with a Dvorak estimate of T3.0/45 kt from TAFB and and a UW-CIMSS ADT estimate of T2.9/43 kt, justify increasing the advisory intensity to 45 kt. Kristy has turned to north-northwest and is now moving 345/05 kt. The cyclone is expected to turn toward the north later today, followed by a motion toward the north-northeast or northeast in the 24-48 h time period as Kristy and much larger Tropical Storm John undergo some weak binary interaction. However, the two cyclones separate by 72 h as John weakens over cold waters and its influence on Kristy diminishes, resulting in a turn to the north. By 96 h and beyond, Kristy will also be located over much colder water and is expected to have degenerated into a shallow remnant low pressure, becoming steered more westward by the deep-layer easterly trade wind flow. There remains considerable divergence among the global and regional hurricane models, with the GFS, HWRF, and HMON models keeping Kristy moving northward after 72 h, and the ECMWF and UKMET models moving Kristy westward. The guidance envelope has shifted markedly to the right of the previous forecast track, and the new official forecast track has also been shifted in that direction. However, the new track forecast was not shifted as far east as the consensus models HCCA and FSSE, out of respect for the reliable ECMWF model. There is a narrow window of opportunity of about 24 h for Kristy to strengthen a little more while the cyclone remains over SSTs of 26-26.5 deg C and in a low-shear environment. After that time, however, cooler waters and the entrainment of much drier mid-level air is expected to induce steady weakening through the remainder of the forecast period, with the cyclone becoming post-tropical by 72 h, if not sooner. The official intensity forecast is similar to the intensity consensus model IVCN through 24 h, and then is a little lower than IVCN after that due to Kristy moving over sub-25 deg C SSTs. FORECAST POSITIONS AND MAX WINDS INIT 09/0900Z 15.8N 130.1W 45 KT 50 MPH 12H 09/1800Z 16.5N 130.2W 45 KT 50 MPH 24H 10/0600Z 17.6N 129.9W 50 KT 60 MPH 36H 10/1800Z 18.7N 129.3W 45 KT 50 MPH 48H 11/0600Z 19.8N 128.9W 45 KT 50 MPH 72H 12/0600Z 21.4N 129.0W 35 KT 40 MPH...POST-TROPICAL 96H 13/0600Z 22.8N 129.9W 25 KT 30 MPH...POST-TROP/REMNT LOW 120H 14/0600Z 23.5N 132.0W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Stewart
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics