Advisories

000
WTPZ44 KNHC 120849
TCDEP4
 
Tropical Storm Norbert Discussion Number  11
NWS National Hurricane Center Miami FL       EP142026
1100 PM HST Fri Sep 11 2026
 
Deep convection associated with an earlier well-established curved 
band has deteriorated over the past several hours, likely due to 
some mid-level dry air entrainment. A 0442 UTC scatterometer pass 
indicated peak winds just above 40 kt within the northwest quadrant. 
Additionally, the latest subjective Dvorak intensity estimate from 
TAFB is T3.0/45 kt, with objective estimates from UW-CIMSS ranging 
from 45 to 50 kt. Given these data and the degraded convective 
structure, the initial intensity is lowered to a generous 50 kt.

The initial motion is west-northwestward, or 285/8 kt. The track 
guidance has come into much better agreement this cycle and shows 
Norbert continuing generally westward through the weekend as a low- 
to mid-level subtropical ridge remains north of the cyclone. A 
gradual turn toward the west-southwest is then forecast during the 
early to middle portion of next week. Despite the improved agreement 
among the track guidance this cycle, there has been considerable 
run-to-run variability, and confidence in the forecast beyond the 
weekend remains lower than normal. The NHC track forecast is largely 
an update of the previous advisory and lies close to the multi-model 
consensus (HCCA) and Google DeepMind ensemble mean.

Environmental conditions remain favorable for some strengthening 
over the weekend, and Norbert is forecast to approach hurricane 
intensity by 24 to 36 h. Thereafter, a gradual weakening trend is 
forecast through the remainder of the period, likely due to a 
combination of mid-level dry air entrainment and weakening 
upper-level divergence. Simulated satellite imagery from both the 
GFS and ECMWF broadly support this and depict Norbert struggling to 
maintain organized deep convection as it moves westward to 
west-southwestward next week. The latest NHC intensity forecast has 
been lowered slightly from the previous advisory. It remains above 
the intensity guidance envelope through the weekend, then trends 
toward the middle to upper end of the guidance next week. 

 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  12/0900Z 17.1N 127.4W   50 KT  60 MPH
 12H  12/1800Z 17.4N 128.8W   55 KT  65 MPH
 24H  13/0600Z 17.8N 130.6W   60 KT  70 MPH
 36H  13/1800Z 18.1N 132.6W   60 KT  70 MPH
 48H  14/0600Z 18.4N 134.7W   55 KT  65 MPH
 60H  14/1800Z 18.4N 137.0W   50 KT  60 MPH
 72H  15/0600Z 18.3N 139.4W   50 KT  60 MPH
 96H  16/0600Z 17.4N 144.0W   45 KT  50 MPH
120H  17/0600Z 15.6N 148.1W   45 KT  50 MPH
 
$$
Forecaster Pierce/Gibbs