Tropical Cyclone Discussion

446
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