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Tropical Storm Selma Discussion Number 3
NWS National Hurricane Center Miami FL EP202017
400 PM CDT Fri Oct 27 2017
The center of Selma became exposed shortly after the issuance of the
previous advisory, however, deep convection has redeveloped near and
just south of the center this afternoon. The system is feeling the
affects of moderate northeasterly shear and does not appear to have
strengthened. Subjective Dvorak T-numbers from both TAFB and SAB
are 2.0 (30 kt), however, the initial intensity is maintained at
35 kt in agreement with the overnight ASCAT data. Unfortunately,
the ASCAT satellites did not pass over the tropical cyclone today.
Satellite and microwave fixes show that Selma has turned more
poleward and is now moving north-northwestward or 345/6 kt. A
large mid-latitude trough is forecast to move over the Gulf of
Mexico tonight and Saturday which should cause Selma to turn
northward later today or tonight. The 12Z track guidance has come
into better agreement and brings Selma onshore in El Salvador
or eastern Guatemala on Saturday, and little change was made to the
previous NHC forecast track.
Moderate to strong northeasterly shear is expected to remain over
the tropical cyclone during the next 24 hours, and little overall
change in strength is expected before landfall. Selma should
rapidly weaken and dissipate over the mountains of Central America
Saturday night or Sunday.
It should be noted that the primary threat associated with Selma
is heavy rainfall, with totals possibly as high as 10 inches
over portions of El Salvador and Guatemala. This rainfall could
cause life-threatening flash floods and mudslides.
FORECAST POSITIONS AND MAX WINDS
INIT 27/2100Z 11.7N 89.4W 35 KT 40 MPH
12H 28/0600Z 12.5N 89.7W 35 KT 40 MPH
24H 28/1800Z 13.6N 89.8W 35 KT 40 MPH...INLAND
36H 29/0600Z 14.8N 89.5W 25 KT 30 MPH...POST-TROP/REMNT LOW
48H 29/1800Z...DISSIPATED
$$
Forecaster Brown
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