000
WTPZ41 KNHC 181432
TCDEP1
 
TROPICAL DEPRESSION ALETTA DISCUSSION NUMBER  17
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012012
800 AM PDT FRI MAY 18 2012

FIRST-LIGHT VISIBLE IMAGERY SHOWS THAT THE CENTER OF ALETTA IS
EXPOSED TO THE SOUTHWEST OF THE CONVECTION DUE TO 20-25 KT OF
SOUTHERLY VERTICAL WIND SHEAR.  SATELLITE INTENSITY ESTIMATES ARE
30 KT FROM SAB AND 35 KT FROM TAFB...AND THE INITIAL INTENSITY
REMAINS AT 30 KT.  THE COMBINATION OF CONTINUED SHEAR AND MID/
UPPER-LEVEL DRY AIR ENTRAINMENT SHOULD CAUSE ALETTA TO DECAY INTO A
REMNANT LOW IN THE NEXT 12-24 H...WITH THE REMNANTS BEING ABSORBED
BY A LARGER DISTURBANCE TO THE EAST IN 72-96 H.

THE INITIAL MOTION IS 045/5.  ALETTA REMAINS IN AN AREA OF WEAK
STEERING CURRENTS SOUTH OF A LOW/MID-LEVEL TROUGH OVER NORTHWESTERN
MEXICO AND THE ADJACENT PACIFIC WATERS.  THE DEPRESSION OR ITS
REMNANTS IS EXPECTED TO MOVE SLOWLY EASTWARD AND THEN SOUTHWARD
DURING THE NEXT 72 H AS THE DISTURBANCE TO THE EAST BECOMES THE
PRIMARY STEERING MECHANISM.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/1500Z 14.2N 113.6W   30 KT  35 MPH
 12H  19/0000Z 14.4N 113.1W   25 KT  30 MPH
 24H  19/1200Z 14.4N 112.6W   20 KT  25 MPH...POST-TROP/REMNT LOW
 36H  20/0000Z 14.0N 112.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  20/1200Z 13.1N 112.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  21/1200Z 11.5N 112.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
 96H  22/1200Z...DISSIPATED
 
$$
FORECASTER BEVEN