je.st
news
Tropical Depression Norbert Forecast Discussion Number 11
2020-10-08 10:44:08| National Hurricane Center (East Pacific)
Issued at 300 AM MDT Thu Oct 08 2020 000 WTPZ44 KNHC 080843 TCDEP4 Tropical Depression Norbert Discussion Number 11 NWS National Hurricane Center Miami FL EP192020 300 AM MDT Thu Oct 08 2020 Norbert was very close to becoming a remnant low overnight. A recent burst of deep convection to the southeast of the partially exposed low-level center was sufficient to keep Norbert as a tropical depression for this advisory. Water vapor imagery indicates the depression is still battling dry mid-level air on the northern periphery of the circulation. The initial intensity has been lowered to 25 kt based on a 04 UTC ASCAT-B overpass that showed max winds of 25 kt in the southwest quadrant of Norbert. Norbert is presently drifting east-southeastward under weak steering currents, and the cyclone may continue meandering erratically for the next 6-12 h. Then, Norbert is forecast to move slowly west-southwestward or westward through 48 h. Thereafter, a mid-level ridge is expected to build to the north and northeast of Norbert, which should steer the system northwestward at a slightly faster speed. The NHC forecast track is shifted slightly to the right of the previous one based on the guidance consensus aids including TVCE and HCCA. Although drier mid-level air continues to impinge on the northern side of Norbert's circulation, the depression remains in an otherwise favorable environment of high oceanic heat content and light vertical wind shear. If Norbert can survive the slight increase in deep-layer shear depicted by the SHIPS guidance during the next 24 h, improving environmental conditions thereafter could allow Norbert to at least remain a depression for several days. Alternatively, moderate shear and additional dry air intrusions could cause Norbert to degenerate into a remnant low at almost any time. The NHC intensity forecast assumes the first scenario and keeps Norbert as a 25-30 kt depression for the next several days. By 96-120 h, GFS simulated satellite imagery suggests the cyclone will be devoid of convection as it moves into a drier mid-level environment. Thus, the official forecast depicts a transition to remnant low status by day 4. FORECAST POSITIONS AND MAX WINDS INIT 08/0900Z 13.2N 106.3W 25 KT 30 MPH 12H 08/1800Z 13.0N 106.2W 25 KT 30 MPH 24H 09/0600Z 13.0N 106.5W 25 KT 30 MPH 36H 09/1800Z 13.2N 107.0W 30 KT 35 MPH 48H 10/0600Z 13.5N 107.6W 30 KT 35 MPH 60H 10/1800Z 14.4N 108.2W 30 KT 35 MPH 72H 11/0600Z 15.3N 108.6W 30 KT 35 MPH 96H 12/0600Z 16.0N 109.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 120H 13/0600Z 16.5N 110.5W 25 KT 30 MPH...POST-TROP/REMNT LOW $$ Forecaster Reinhart/Zelinsky
Tags: number
discussion
tropical
depression
Category:Transportation and Logistics
Latest from this category |
All news |
||||||||||||||||||
|
|||||||||||||||||||