Eastern Pacific Basin Tropical Cyclones

Tropical Depression Sandra Forecast Discussion


000
WTPZ44 KNHC 090835
TCDEP4

Tropical Depression Sandra Discussion Number   8
NWS National Hurricane Center Miami FL       EP192021
100 AM PST Tue Nov 09 2021

Satellite classifications and recent scatterometer surface wind 
data indicate that Sandra is barely hanging on a tropical cyclone. 
The closest convection, which has been waning over the past few 
hours, is located about 75 nmi east of the fully exposed low-level 
circulation center. That distance barely meets the Dvorak criteria 
for classifying Sandra as a tropical depression. The intensity has 
been lowered to 25 kt based on 0235Z ASCAT-A scatterometer data 
that revealed a few 25-kt surface wind vectors located about 50 nmi 
north of the cyclone's center. Additional weakening is anticipated 
due to the continued combination of strong southerly vertical wind 
shear of 25-30 kt and intrusions of dry mid-level air. As a result, 
Sandra is forecast to degenerate into a remnant low later today and 
dissipate by Wednesday.

Sandra is now moving a little south of due west, or 260/12 kt. A 
strong ridge to the north of the cyclone should keep Sandra moving 
westward to west-southwestward through Wednesday. The new NHC track 
forecast is very similar to the previous advisory, and lies close 
to the middle of the various consensus track models.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 14.8N 119.7W   25 KT  30 MPH
 12H  09/1800Z 14.5N 121.3W   25 KT  30 MPH...POST-TROP/REMNT LOW
 24H  10/0600Z...DISSIPATED

$$
Forecaster Stewart



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