000
WTPZ41 KNHC 182032
TCDEP1
 
TROPICAL DEPRESSION ALETTA DISCUSSION NUMBER  18
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP012012
200 PM PDT FRI MAY 18 2012
 
THE CENTER OF ALETTA REMAINS EXPOSED TO THE SOUTHWEST OF SEVERAL
CLUSTERS OF DISORGANIZED CONVECTION DUE TO 25 KT OF SOUTHERLY
VERTICAL WIND SHEAR.  SATELLITE INTENSITY ESTIMATES ARE 30 KT FROM
SAB AND 35 KT FROM TAFB...AND A RECENT ASCAT OVERPASS SHOWS A FEW
25-30 KT VECTORS EAST OF THE CENTER.  BASED ON THIS...THE INITIAL
INTENSITY IS AGAIN 30 KT FOR THIS ADVISORY.  THE COMBINATION OF
CONTINUED SHEAR AND MID/UPPER-LEVEL DRY AIR SEEN IN WATER VAPOR
IMAGERY SHOULD CAUSE ALETTA TO DECAY INTO A REMNANT LOW IN THE NEXT
12-24 HOURS...WITH THE REMNANTS BEING ABSORBED BY A LARGER
DISTURBANCE TO THE EAST IN 48-72 HOURS.
 
THE INITIAL MOTION IS 040/3.  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 ARE EXPECTED TO MOVE SLOWLY EASTWARD AND THEN SOUTHWARD
DURING THE NEXT 48 HOURS AS THE DISTURBANCE TO THE EAST BECOMES THE
PRIMARY STEERING MECHANISM.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  18/2100Z 14.4N 113.5W   30 KT  35 MPH
 12H  19/0600Z 14.5N 113.1W   25 KT  30 MPH
 24H  19/1800Z 14.2N 112.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 36H  20/0600Z 13.6N 112.7W   20 KT  25 MPH...POST-TROP/REMNT LOW
 48H  20/1800Z 12.7N 112.8W   20 KT  25 MPH...POST-TROP/REMNT LOW
 72H  21/1800Z...DISSIPATED
 
$$
FORECASTER BEVEN