840
WTPZ44 KNHC 130248
TCDEP4

Tropical Storm Norbert Discussion Number  14
NWS National Hurricane Center Miami FL       EP142026
500 PM HST Sat Sep 12 2026

Satellite imagery indicates that Norbert`s convective organization
has degraded during the past several hours. The convective mass over
and north of the circulation center has diminished in coverage, with
cloud-top temperatures also warming. This appears to be due, at
least in part, to some mid-level dry air becoming entrained into the
circulation along with some southwesterly vertical wind shear. An
earlier scatterometer pass showed an asymmetric system with peak
winds just above 40 kt located over the northern semicircle. The
subjective Dvorak intensity estimate from TAFB and objective
estimates from UW-CIMSS remain in decent agreement, ranging from 35
to 50 kt. Given these data and the decreased organization, the
initial intensity is lowered to 40 kt.

Norbert`s initial motion is estimated to be westward, or 280/10 kt.
The storm remains positioned south of a subtropical ridge extending
westward from northern Mexico, which should steer Norbert on a
general west-northwestward to westward track for the remainder of
the forecast period. The track guidance remains in fairly good
agreement, and the NHC track forecast is largely unchanged,
reflecting a blend of the previous forecast and the latest
multi-model consensus (HCCA) and Google DeepMind ensemble, which lie
slightly north of the previous track.

The track will bring the cyclone deeper into a hostile environment
dominated by strong westerly vertical wind shear and dry mid-level
air. These environmental conditions will induce a steady weakening
trend by 36 h. Model guidance unanimously reflects this hostile
setup showing Norbert opening into a trough of low pressure east of
Hawaii by middle portion of next week. Consequently, the updated NHC
intensity forecast accelerates the decay timeline, degenerating
Norbert to a remnant low by 72 h and dissipating it by 96 h.

FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 17.9N 130.5W   40 KT  45 MPH
 12H  13/1200Z 18.3N 132.0W   40 KT  45 MPH
 24H  14/0000Z 18.7N 134.2W   40 KT  45 MPH
 36H  14/1200Z 19.1N 136.6W   35 KT  40 MPH
 48H  15/0000Z 19.3N 139.4W   35 KT  40 MPH
 60H  15/1200Z 19.4N 142.0W   35 KT  40 MPH
 72H  16/0000Z 19.3N 144.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  17/0000Z...DISSIPATED

$$
Forecaster Pierce/Gibbs