000
WTPZ43 KNHC 122033
TCDEP3

Tropical Storm Calvin Discussion Number   5
NWS National Hurricane Center Miami FL       EP032017
400 PM CDT Mon Jun 12 2017

The cloud pattern of the tropical cyclone has become a little better
organized today, with a convective band wrapping about halfway
around the southern portion of the circulation.  Accordingly,
Dvorak T-numbers from both TAFB and SAB have increased to 2.5,
corresponding to an intensity of 35 kt.  On this basis, the system
is being named.  Although a little more intensification is possible
before the center crosses the coast, no significant increase in
strength is anticipated.  After landfall, the tropical cyclone will
likely weaken rapidly over the mountainous terrain of southeastern
Mexico.

Although the system essentially stalled earlier today, visible
satellite images and the Puerto Angel radar from the meteorological
service of Mexico indicate that a slow west-northwestward motion
has resumed, and the motion is now about 300/02 kt.  Although
steering currents remain weak, the dynamical models indicate that
there should be enough mid-level ridging to the north of Calvin to
push the system west-northwestward into southeastern Mexico.  The
official track forecast is close to the latest ECMWF solution.

The main danger from Calvin will come from heavy rains, and the
associated threats of flash flooding and mudslides, particularly in
areas of mountainous terrain.

FORECAST POSITIONS AND MAX WINDS

INIT  12/2100Z 15.5N  95.5W   35 KT  40 MPH
 12H  13/0600Z 15.8N  96.0W   35 KT  40 MPH
 24H  13/1800Z 16.0N  96.5W   25 KT  30 MPH...INLAND
 36H  14/0600Z 16.2N  97.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  14/1800Z...DISSIPATED

$$
Forecaster Pasch