je.st
news
Tropical Storm Odalys Forecast Discussion Number 1
2020-11-03 21:41:09| National Hurricane Center (East Pacific)
Issued at 200 PM PDT Tue Nov 03 2020 000 WTPZ45 KNHC 032041 TCDEP5 Tropical Storm Odalys Discussion Number 1 NWS National Hurricane Center Miami FL EP202020 200 PM PDT Tue Nov 03 2020 The low pressure area well south-southwest of the southern tip of the Baja California Peninsula has become significantly better organized today. A curved band of deep convection is noted to the northwest of the low-level center, and a second weaker band is located to its southeast. Satellite-derived wind data indicate the low-level center is still somewhat broad, but it appears to have enough definition to justify starting advisories as a tropical cyclone. Recent ASCAT-B data show numerous 30+ kt wind barbs, with a couple barbs peaking at 33-34 kt in the eastern semicircle of the cyclone. Considering known under-sampling issues with this data source, the initial intensity is set at 35 kt, which is consistent with a T2.5 subjective Dvorak classification from TAFB. Thus, the system has become a tropical storm, and advisories are initiated on Tropical Storm Odalys. Weak to moderate vertical wind shear and sufficient oceanic heat content may support modest strengthening during the next 12 h or so. By 24-36 h, strong southwesterly deep-layer shear associated with an approaching shortwave trough to the northwest, along with intrusions of drier mid-level air, will induce a steady and perhaps rapid weakening trend. The system is forecast to weaken to a depression by 48 h and a remnant low by 96 h, but this could occur even sooner if the stronger shear values noted in the SHIPS guidance are realized. The GFS simulated satellite imagery suggests the system could be devoid of deep convection as early as day 3 of the forecast period. The storms estimated motion is a somewhat uncertain 295/11 kt. A slight increase in forward speed is expected during the next couple of days as Odalys is steered northwestward by a low- to mid-level ridge centered over southern Texas and northern Mexico. Then, the cyclone should gradually slow down and turn westward as this ridge weakens due to the aforementioned shortwave trough. By 72 h, the storm will be steered southwestward by another low- to mid-level ridge building to its northwest. The track models are in decent agreement, and the official NHC track forecast lies near the center of the guidance envelope closest to the track consensus aids. FORECAST POSITIONS AND MAX WINDS INIT 03/2100Z 14.1N 116.1W 35 KT 40 MPH 12H 04/0600Z 15.2N 117.9W 40 KT 45 MPH 24H 04/1800Z 16.8N 120.1W 40 KT 45 MPH 36H 05/0600Z 17.9N 122.0W 35 KT 40 MPH 48H 05/1800Z 18.5N 123.7W 30 KT 35 MPH 60H 06/0600Z 18.5N 125.4W 25 KT 30 MPH 72H 06/1800Z 18.0N 126.5W 25 KT 30 MPH 96H 07/1800Z 16.0N 128.5W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 08/1800Z...DISSIPATED $$ Forecaster Reinhart/Beven
Tags: number
discussion
storm
tropical
Category:Transportation and Logistics