Tropical Storm Norbert Forecast Discussion
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Español: Aviso Publico Discusión |
000 WTPZ44 KNHC 130849 TCDEP4 Tropical Storm Norbert Discussion Number 15 NWS National Hurricane Center Miami FL EP142026 1100 PM HST Sat Sep 12 2026 Norbert's convective organization has improved during the past several hours. A renewed burst of deep convection, with cloud-top temperatures as cold as -80 C, has been expanding over the circulation. Recent ASCAT-A and ASCAT-B scatterometer passes showed an asymmetric wind field, with peak winds of around 45 kt north of the center. Given these new data and the improving convective presentation, the initial intensity is raised to 45 kt. The initial motion is estimated to be about 280/10 kt. The storm continues to be steered generally west-northwestward to westward south of a low- to mid-level subtropical that should persist through the forecast period. The track guidance remains in good agreement, although the latest guidance has continued to shift slightly northward. The updated NHC track forecast is largely unchanged, blending the previous advisory, the multi-model consensus (HCCA), and the Google DeepMind ensemble mean. Little change in strength is expected during the next 24 h while Norbert remains in a marginal environment tempered by mid-level dry air and some west-southwesterly vertical wind shear. Some fluctuations in intensity are possible during this period as intermittent bursts of deep convection develop near the circulation. Thereafter, increasingly unfavorable conditions will induce a steady weakening trend. The NHC intensity forecast is largely an update of the previous advisory and shows Norbert degenerating into a post-tropical remnant low by 60 h and dissipating as it opens into a trough by 72 h. FORECAST POSITIONS AND MAX WINDS INIT 13/0900Z 18.0N 131.7W 45 KT 50 MPH 12H 13/1800Z 18.3N 133.5W 45 KT 50 MPH 24H 14/0600Z 18.8N 135.8W 45 KT 50 MPH 36H 14/1800Z 19.1N 138.5W 40 KT 45 MPH 48H 15/0600Z 19.4N 141.1W 35 KT 40 MPH 60H 15/1800Z 19.5N 144.0W 30 KT 35 MPH...POST-TROP/REMNT LOW 72H 16/0600Z...DISSIPATED $$ Forecaster Pierce/Gibbs