ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
 
Tropical Storm Norbert Discussion Number   4
NWS National Hurricane Center Miami FL       EP192020
900 AM MDT Tue Oct 06 2020
 
The overall appearance of Norbert has changed little since early
this morning, with a mass of deep convection pulsating over the
low-level center. A blend of the latest Dvorak intensity
estimates from TAFB and SAB support keeping the initial intensity
at 40 kt.
 
The environment appears conducive for Norbert to strengthen over
warm waters with low vertical wind shear. Despite this, most of the
global and hi-res dynamical models do not strengthen Norbert, and in
fact the HWRF and HMON both weaken the system over the next couple
of days. Therefore, the consensus aids also do not indicate that
the system will intensify. On the other end of the spectrum, the
SHIPS guidance favors strengthening over the next couple of days
and indicates that Norbert will be nearing hurricane strength
within a few days. The latest NHC forecast remains above the
consensus aids but below the SHIPS guidance, suggesting some
gradual strengthening over the next 48 h, prior to the increase in
shear.
 
Norbert continues to move northwestward at 6 kt, steered by a
weakening mid-level ridge centered over southern Mexico. The
steering currents are forecast to collapse by tonight, and the
cyclone is expected to meander through the middle of the week. By
late this week, a weak mid-level ridge should build north of the
cyclone which would result in a slow west-northwestward motion. Due
to the weak steering flow, there is a larger than normal spread in
the track guidance. The latest NHC forecast remains close to the
consensus aids, and is slightly faster then the previous forecast at
days 3-5.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  06/1500Z 14.2N 106.6W   40 KT  45 MPH
 12H  07/0000Z 14.4N 106.8W   45 KT  50 MPH
 24H  07/1200Z 14.5N 106.8W   50 KT  60 MPH
 36H  08/0000Z 14.7N 106.8W   50 KT  60 MPH
 48H  08/1200Z 14.8N 106.8W   55 KT  65 MPH
 60H  09/0000Z 15.0N 107.1W   55 KT  65 MPH
 72H  09/1200Z 15.2N 107.8W   55 KT  65 MPH
 96H  10/1200Z 15.7N 109.3W   55 KT  65 MPH
120H  11/1200Z 16.1N 110.4W   55 KT  65 MPH
 
$$
Forecaster Latto
 
NNNN