ZCZC MIATCDEP5 ALL
TTAA00 KNHC DDHHMM

TROPICAL STORM DARBY DISCUSSION NUMBER   5
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP052016
300 PM MDT TUE JUL 12 2016

Although there is still some northeasterly shear present, the
low-level center of Darby has been migrating closer to the deep
convection during the day.  Recent ASCAT data indicate that maximum
winds are now near 45 kt, and this is supported by T3.0 Dvorak
classifications from TAFB and SAB.  The ocean near Darby is very
warm, with SSTs on the order of 29-30 degrees Celsius, but vertical
shear is expected to be 10-15 kt for another 24 hours or so.
Therefore, steady strengthening is anticipated, with Darby possibly
becoming a hurricane on Wednesday.  The cyclone will likely reach
its maximum intensity around day 3 before it reaches cooler waters
and begins to weaken.  Because Darby is starting out about 10 kt
stronger than previously estimated, the NHC intensity forecast has
been bumped up during the entire forecast period, and it is very
close to the SHIPS and LGEM guidance.

Darby has been moving just south of due west, or 265/10 kt.  The
subtropical ridge to the north of the cyclone is expected to
strengthen during the next 2-3 days, which will force Darby on a
westward course during that time.  The GFS continues to erode the
western extent of the ridge more than the ECMWF and UKMET models on
days 4 and 5, allowing Darby to make a stronger northwestward turn
at the end of the forecast period.  The NHC track forecast favors
the ridge remaining strong and only shows a slight west-
northwestward motion on days 4 and 5.  This forecast is a little
south of the TVCE model consensus and not too different from the
previous forecast.

FORECAST POSITIONS AND MAX WINDS

INIT  12/2100Z 15.7N 109.8W   45 KT  50 MPH
 12H  13/0600Z 15.6N 111.3W   55 KT  65 MPH
 24H  13/1800Z 15.5N 113.5W   65 KT  75 MPH
 36H  14/0600Z 15.4N 115.8W   75 KT  85 MPH
 48H  14/1800Z 15.6N 118.2W   80 KT  90 MPH
 72H  15/1800Z 16.2N 122.7W   85 KT 100 MPH
 96H  16/1800Z 17.0N 126.5W   75 KT  85 MPH
120H  17/1800Z 18.0N 130.5W   65 KT  75 MPH

$$
Forecaster Berg

NNNN