ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
 
Tropical Storm Norbert Discussion Number  21
NWS National Hurricane Center Miami FL       EP192020
900 PM MDT Tue Oct 13 2020
 
Norbert has increased in organization this evening, with a pair of
microwave passes as well as infrared satellite imagery showing a
tightly curved band of convection wrapping about halfway around the
low-level center. In addition, a well-defined outflow pattern is
surrounding the cyclone in the current low-shear environment. Based
on these developmental trends, the initial intensity has been
increased to 35 kt, which is in agreement with the latest Dvorak
intensity estimate from TAFB.
 
There is only about a 12-18 h opportunity for Norbert to maintain
its current strength or perhaps intensify a little more before it
reaches a hostile environment just to its north. By 24 h, the
cyclone is forecast to encounter strong southwesterly shear and a
dry and stable atmospheric environment, while moving over cooler
waters. Therefore, the cyclone should start weakening by 24 h and
should degenerate into a remnant low devoid of deep convection by
48 h. The model guidance indicates the remnant low should dissipate
very soon thereafter. The latest NHC intensity forecast is close to
the latest consensus intensity guidance, and is only higher than the
previous NHC forecast due to the increase in the initial intensity.
 
Norbert has been moving northwestward at around 13 kt since this
afternoon as the cyclone has been steered between a deep-layer ridge
centered over northern Mexico and an upper-level low offshore of
Baja California. As the upper low shifts westward over the next day
or so, Norbert's forward speed should decrease. What remains of
Norbert should then turn northward on Thursday within the low-level
flow.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  14/0300Z 21.0N 112.7W   35 KT  40 MPH
 12H  14/1200Z 22.4N 113.8W   35 KT  40 MPH
 24H  15/0000Z 24.2N 115.0W   30 KT  35 MPH
 36H  15/1200Z 25.5N 115.6W   25 KT  30 MPH
 48H  16/0000Z 26.5N 115.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
 60H  16/1200Z...DISSIPATED
 
$$
Forecaster Latto
 
NNNN