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Tropical Storm Norbert
Tropical Storm Norbert Forecast Discussion
Advisory Number: 15
1100 PM HST Sat Sep 12 2026
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