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Tropical Depression Norbert Forecast Discussion Number 13
2020-10-08 22:33:20| National Hurricane Center (East Pacific)
Issued at 300 PM MDT Thu Oct 08 2020 000 WTPZ44 KNHC 082033 TCDEP4 Tropical Depression Norbert Discussion Number 13 NWS National Hurricane Center Miami FL EP192020 300 PM MDT Thu Oct 08 2020 Norbert has a ragged and disorganized appearance, with asymmetrical convection bursting intermittently around the center. Satellite imagery suggests that the system is now experiencing some southeasterly shear. A recent ASCAT overpass sampled peak winds of 24 kt, so the advisory intensity will remain 25 kt. The current environment surrounding Norbert is not forecast to change much over the next few days. Therefore, only minor fluctuations in intensity are expected to occur during that time. By 72 h, model guidance is indicating that the cyclone should encounter a more stable atmosphere, which would limit convection and cause Norbert to weaken. The cyclone is forecast to degenerate into a remnant low devoid of deep convection by day 4, but it is possible that the deep convection could dissipate long enough for Norbert to be declared a remnant low before that time. Another plausible scenario is that Norbert's low level circulation dissipates and opens up into a surface trough later in the forecast period. The only change to the latest NHC forecast is that no further strengthening is indicated, which is agreement with every available intensity model except the SHIPS guidance. Norbert has barely budged since early this morning due to a lack of steering currents. A weak mid-level ridge is forecast to build to the northeast of the cyclone Friday through Saturday, which should cause Norbert to eventually move west-northwest to northwest. By Sunday, however, a mid-upper level low digging across northern Mexico should weaken the ridge, and the model guidance has trended toward Norbert once again meandering for a couple of days. By day 5, low-level ridging building to the northwest of Norbert should cause the shallow system to begin a westward motion. Due to the lack of run-to-run model consistency in the 3-5 day period, that portion of the track forecast is of low confidence. The NHC forecast track was changed little through 48 h, then is slower at 60-96 h to reflect the second collapse of the steering currents. FORECAST POSITIONS AND MAX WINDS INIT 08/2100Z 13.1N 106.1W 25 KT 30 MPH 12H 09/0600Z 13.0N 106.2W 25 KT 30 MPH 24H 09/1800Z 13.3N 106.7W 25 KT 30 MPH 36H 10/0600Z 13.9N 107.3W 25 KT 30 MPH 48H 10/1800Z 14.5N 107.6W 25 KT 30 MPH 60H 11/0600Z 14.8N 107.6W 25 KT 30 MPH 72H 11/1800Z 14.9N 107.7W 25 KT 30 MPH 96H 12/1800Z 15.0N 107.9W 20 KT 25 MPH...POST-TROP/REMNT LOW 120H 13/1800Z 15.1N 109.6W 20 KT 25 MPH...POST-TROP/REMNT LOW $$ Forecaster Latto [ more ]
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