Tropical Cyclone Discussion
Issued by NWS

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4
000
WTPZ41 KNHC 281453
TCDEP1

TROPICAL STORM ANDRES DISCUSSION NUMBER   2
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012015
900 AM MDT THU MAY 28 2015

Deep convection associated with the tropical cyclone has continued
to expand this morning with a large area of cloud top temperatures
colder than -70 degrees Celsius.  The convection has also become
better organized with an increase in banding and a developing
central dense overcast.  Dvorak data T-numbers from both SAB and
TAFB were T2.5, which support upgrading the depression to a 35-kt
tropical storm.

The initial motion estimate is 295/12. Andres is located to the
south and southwest of a mid-level ridge that extends from
south-central Mexico west-southwestward over the eastern Pacific.
This ridge is expected to be the main steering influence during the
next several days, and should cause Andres to move
west-northwestward to northwestward.  After 48 hours, track guidance
spread increases, with the GFDL, HWRF, and ECMWF models taking
Andres on a more northerly track, while the GFS and GFS ensemble
maintain a northwesterly motion.  The NHC track forecast remains
near the multi-model consensus for now.

Warm water and low shear during the next 2-3 days should allow for
steady strengthening.  In fact, the SHIPS RI index indicates a 60%
chance of at least a 30-kt increase during the next 24 hours. The
updated NHC forecast calls for a faster rate of intensification over
the next 36 h than the previous one. In 2 to 3 days, the cyclone
will be approaching slightly cooler waters which should induce
weakening by the end of the forecast period.

FORECAST POSITIONS AND MAX WINDS

INIT  28/1500Z 11.6N 111.3W   35 KT  40 MPH
 12H  29/0000Z 12.3N 112.4W   45 KT  50 MPH
 24H  29/1200Z 13.0N 113.3W   60 KT  70 MPH
 36H  30/0000Z 13.8N 114.0W   70 KT  80 MPH
 48H  30/1200Z 14.8N 114.6W   80 KT  90 MPH
 72H  31/1200Z 16.7N 115.6W   80 KT  90 MPH
 96H  01/1200Z 18.0N 117.0W   65 KT  75 MPH
120H  02/1200Z 19.0N 118.0W   50 KT  60 MPH

$$
Forecaster Brown and Barack Obama (PRESIDENT)



USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.