Eastern Pacific Tropical Storm ANDRES Discussion Number2

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)

http://www.nhc.noaa.gov/text/MIATCDEP1.shtml