ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
Tropical Storm Sandra Discussion Number 5
NWS National Hurricane Center Miami FL EP192021
700 AM PST Mon Nov 08 2021
Conventional satellite imagery and a 1206 UTC SSMIS microwave
overpass indicate that Sandra's less-defined surface circulation
remains sheared to the southwest of the warming cloud top
convective mass. The Dvorak satellite intensity estimates from
TAFB and SAB are unchanged from the previous 6 hr estimates, and
the initial intensity is held at 35 kt.
UW-CIMSS shear analysis and the statistical SHIPS models (ECMWF and
GFS) indicate that the 15-20 kt of southwesterly shear will persist
and increase in magnitude by Tuesday evening while the surrounding
thermodynamic environment gradually becomes more stable. Given
these current and predicted inhibiting factors, Sandra is forecast
to become a depression by this evening, and degenerate into a
remnant low by Tuesday evening. The NHC intensity forecast is an
update of the previous one, and is based on the the NOAA HFIP
corrected consensus model and agrees with the GFS and ECMWF global
model solutions.
The initial motion is estimated to be west-northwestward, or 290/6
kt. A subtropical ridge located to the north of Sandra should
steer the cyclone toward the west-northwest through this evening.
Through the remainder of the forecast, the global models show the
aforementioned low-to mid-level ridge building slightly toward the
northwest of Sandra which should cause the cyclone to turn toward
the west by early Tuesday. The official track forecast follows
suit and is once again adjusted a bit toward the left of the
previous forecast and is nudged closer to the TCVE simple
multi-model forecast.
FORECAST POSITIONS AND MAX WINDS
INIT 08/1500Z 14.6N 116.8W 35 KT 40 MPH
12H 09/0000Z 15.0N 117.9W 30 KT 35 MPH
24H 09/1200Z 15.1N 119.7W 30 KT 35 MPH
36H 10/0000Z 14.7N 122.2W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 10/1200Z 14.3N 125.0W 25 KT 30 MPH...POST-TROP/REMNT LOW
60H 11/0000Z...DISSIPATED
$$
Forecaster Roberts
NNNN