730 
WTNT42 KNHC 231431
TCDAT2

Tropical Storm Kirk Discussion Number   5
NWS National Hurricane Center Miami FL       AL122018
1100 AM AST Sun Sep 23 2018

Kirk's cloud pattern has a figure 6 configuration, with most of the
deep convective bands over the western semicircle of the
circulation.  Microwave imagery indicates that the center is near
the eastern side of the main area of deep convection, as before.
Dvorak classifications from both TAFB and SAB support keeping the
intensity at 35 kt.  The storm will be moving over warmer waters
with fairly low shear for the next day or two, so some strengthening
is anticipated in the short term.  Later in the forecast period,
increasing westerly shear should cause weakening. The official
intensity forecast is similar to the model consensus through 48
hours, and follows the trends shown by the ECMWF and GFS global
guidance thereafter.  The latter models suggest that Kirk could open
up into a trough when it nears the Caribbean.

Center fixes indicate that Kirk has been accelerating westward and
the initial motion estimate is now 280/18 kt.  A well-defined
mid-level ridge to the north of the cyclone should cause an even
faster westward motion over the next few days.  Near the end of the
forecast period, a weakness in the ridge is likely to lead to a
slowing of the forward speed.  The official forecast is a blend of
the latest simple and corrected model consensus forecast tracks and
is also similar to the previous NHC track.

FORECAST POSITIONS AND MAX WINDS

INIT  23/1500Z  9.3N  30.2W   35 KT  40 MPH
 12H  24/0000Z  9.8N  33.2W   40 KT  45 MPH
 24H  24/1200Z 10.2N  37.3W   45 KT  50 MPH
 36H  25/0000Z 10.5N  41.5W   50 KT  60 MPH
 48H  25/1200Z 10.7N  45.6W   50 KT  60 MPH
 72H  26/1200Z 11.2N  52.4W   45 KT  50 MPH
 96H  27/1200Z 12.3N  57.5W   40 KT  45 MPH
120H  28/1200Z 13.5N  62.0W   35 KT  40 MPH

$$
Forecaster Pasch