241 
WTPZ44 KNHC 120250
TCDEP4
 
Tropical Storm Norbert Discussion Number  10
NWS National Hurricane Center Miami FL       EP142026
500 PM HST Fri Sep 11 2026

Satellite imagery indicates that the convective organization 
associated with Norbert has changed little over the past several 
hours. A well-defined curved band of deep convection continues to 
wrap into the circulation around the western semicircle from the 
north, although cloud-top temperatures within the band have warmed 
slightly during the past few hours. The latest subjective Dvorak 
intensity estimate from TAFB maintains T3.5/55 kt, which harmonizes 
well with the objective intensity estimates from UW-CIMSS ranging 
between 45 and 55 kt. Given these data and only modest changes in 
the convective structure, the initial intensity is held at 55 kt.

The initial motion is west-northwestward, or 285/10 kt. This general 
westward to west-northwestward motion is expected to persist through 
the weekend as a low- to mid-level subtropical ridge remains 
positioned north of the cyclone. Thereafter, confidence on Norbert's 
general motion is reduced as track models diverge significantly, as 
the evolution of the mid-level ridge plays a vital role in the track 
forecast over the next several days. The GFS shows the ridge 
shifting eastward, causing Norbert to generally prevail westward, 
while remaining on the north side of the guidance envelope. On the 
other hand, the ECMWF showcases the aforementioned ridge building 
southward, steering Norbert more southwestward. The consensus aids 
sit snug in between these two solutions. The NHC track forecast 
sides largely with the previous forecast, which lies near the Google 
DeepMind ensemble mean. 

Environmental conditions appear favorable for some strengthening, 
and Norbert is forecast to become a hurricane within the next 24 h. 
Thereafter, Norbert's intensity is expected to remain relatively 
consistent, shuffling 5 to 10 kt difference throughout the forecast 
period. This will depend ultimately on the track, as discussed 
above. A more northward track, more in line with the GFS, would find 
Norbert in a less favorable environment, where increasing vertical 
shear would weaken the system considerably. Conversely, the more 
southern track similar to the ECMWF, would bring Norbert into a more 
favorable environment with less vertical wind shear, allowing 
Norbert to potentially strengthen. Given the competing scenarios 
thereafter, little change has been made to the previous intensity 
forecast, with some weakening still indicated early next week. The 
NHC intensity forecast is generally an update to the previous 
advisory.

 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0300Z 17.2N 126.6W   55 KT  65 MPH
 12H  12/1200Z 17.4N 127.9W   60 KT  70 MPH
 24H  13/0000Z 17.8N 129.8W   65 KT  75 MPH
 36H  13/1200Z 18.2N 131.5W   65 KT  75 MPH
 48H  14/0000Z 18.5N 133.3W   65 KT  75 MPH
 60H  14/1200Z 18.7N 135.5W   55 KT  65 MPH
 72H  15/0000Z 18.6N 137.3W   55 KT  65 MPH
 96H  16/0000Z 18.0N 141.9W   55 KT  65 MPH
120H  17/0000Z 16.3N 146.1W   55 KT  65 MPH
 
$$
Forecaster Pierce/Gibbs