[Tropical] Tropical Cyclone Discussion

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WTNT42 KNHC 281447
TCDAT2

TROPICAL DEPRESSION TWO DISCUSSION NUMBER   4
NWS NATIONAL HURRICANE CENTER MIAMI FL       AL022016
1100 AM EDT SAT MAY 28 2016

Satellite and NOAA WSR-88D radar data indicate that deep convection
has increased in the northern semicircle of the depression's
circulation since the previous advisory. However, the depression
remains a sheared tropical cyclone due to southeasterly upper-level
winds of 20-25 kt. An Air Force Reserve reconnaissance aircraft
investigated the cyclone this morning and obtained reliable SFMR
surface winds of at least 30 kt.  Satellite intensity estimates
were also T2.0/30 kt from both TAFB and SAB, so the intensity is
being maintained at 30 kt for this advisory.

Microwave satellite and recon fix positions indicate that the
cyclone has made a jog toward the west-northwest during the past six
hours. However, smoothing through these short-term wobbles yields a
12-hour motion of 310/11 kt. The ECMWF and GFS models actually did
quite well in predicting this recent short-term wobble, and both
models turn the depression more toward the right, accompanied by
a steady decrease in forward speed over the next 24 hours as the
cyclone nears the South Carolina coast. As a result, the new NHC
forecast track lies slightly to the left of the previous advisory
track through 12 hours, primarily to account for the more westward
initial position, and then is near the previous track and a blend
of the GFS-ECMWF model consensus track at 24 hours and beyond.

The depression is beginning to move over the eastern wall of the
Gulf Stream where sea-surface temperatures are 27-28 deg C. Outer
convective bands have also developed over the slightly cooler shelf
waters between the South Carolina coast and the Gulf Stream, which
implies that there might not be as much of a weakening effect by
those cooler waters as previously anticipated. However, southerly
vertical wind shear is forecast by the SHIPS model to increase to
more than 20 kt before the cyclone reaches the coast, and that is
expected to inhibit any significant strengthening. It is possible
that the cyclone could peak at around 40 kt while it is over the
Gulf Stream this afternoon and evening, followed by slight weakening
just before it reaches the coast. The official intensity forecast is
similar to the previous advisory and closely follows the Decay-SHIPS
intensity model.

FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 30.3N  78.5W   30 KT  35 MPH
 12H  29/0000Z 31.3N  79.5W   35 KT  40 MPH
 24H  29/1200Z 32.4N  80.3W   35 KT  40 MPH
 36H  30/0000Z 32.7N  80.3W   30 KT  35 MPH...INLAND
 48H  30/1200Z 33.0N  79.7W   30 KT  35 MPH...INLAND
 72H  31/1200Z 33.6N  78.0W   30 KT  35 MPH...POST-TROP/REMNT LOW
 96H  01/1200Z 34.4N  76.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  02/1200Z 34.9N  75.8W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Stewart
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