Tropical Storm Norbert

000
WTPZ44 KNHC 112033
TCDEP4
 
Tropical Storm Norbert Discussion Number   9
NWS National Hurricane Center Miami FL       EP142026
1100 AM HST Fri Sep 11 2026

Norbert's satellite presentation has changed little over the past 
few hours. The cyclone continues to be defined by a shield of deep 
convection, with an outflow band evident across its northern 
quadrants. The latest subjective Dvorak estimate from TAFB is 
T3.5/55 kt, and objective intensity estimates from UW-CIMSS range 
between 50 and 61 kt. With satellite imagery and Dvorak estimates 
suggesting a relatively steady trend, the initial intensity is 
maintained at 55 kt.

The initial motion is estimated to be 275/12 kt. Norbert is expected 
to turn west-northwestward as a mid-level ridge to its north begins 
to weaken slightly. This general motion should continue through late 
this weekend, after which the track models diverge significantly. 
The track forecast is highly sensitive to the evolution of this 
ridge over the next several days. The GFS shows the ridge shifting 
eastward, allowing Norbert to turn northward into a more hostile 
environment. Conversely, the ECMWF depicts the ridge building 
southward, steering Norbert southwestward into a more favorable 
environment. Given the large spread in the track guidance, neither 
scenario is strongly favored at this time, and confidence in the 
extended track forecast is lower than normal. The official track 
forecast leans toward the southwestward solution early next week, in 
agreement with highly-skilled aids, HCCA and Google DeepMind. 
Overall, the latest NHC track forecast is little changed from the 
previous advisory.

Uncertainty in the track forecast results in lower-than-normal 
confidence in the intensity forecast. Should Norbert take a more 
northwestward track, it would likely weaken substantially as it 
moves into a highly sheared environment with cooler SSTs. 
Conversely, a southwestward track, as suggested by some guidance 
early next week, would bring Norbert into a low shear environment 
over warmer waters that would favor steady strengthening. Given that 
reliable guidance currently favors the southwestward shift early 
next week, the latest intensity forecast shows steady strengthening 
into the weekend, followed by a brief period of weakening during 
Norbert's west-northwestward motion. This solution closely follows 
the HCCA and lies generally above the intensity model consensus 
IVCN. 
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  11/2100Z 16.8N 125.7W   55 KT  65 MPH
 12H  12/0600Z 16.9N 127.2W   60 KT  70 MPH
 24H  12/1800Z 17.3N 129.1W   65 KT  75 MPH
 36H  13/0600Z 17.7N 131.0W   70 KT  80 MPH
 48H  13/1800Z 18.1N 132.9W   70 KT  80 MPH
 60H  14/0600Z 18.3N 134.8W   65 KT  75 MPH
 72H  14/1800Z 18.4N 136.8W   60 KT  70 MPH
 96H  15/1800Z 18.2N 141.2W   55 KT  65 MPH
120H  16/1800Z 16.7N 145.5W   55 KT  65 MPH
 
$$
Forecaster Evans/Hagen