034 
 WTPZ42 KNHC 111437
 TCDEP2
 
 Tropical Depression Aletta Discussion Number  24
 NWS National Hurricane Center Miami FL       EP022018
 800 AM PDT Mon Jun 11 2018
 
 Aletta has been devoid of any significant convection for about 8
 hours due to the cyclone ingesting dry mid- and upper-level air
 along with an abundance of stable, low-level cold-air stratocumulus
 clouds. The combination of these unfavorable thermodynamic
 conditions and SSTs less than 26C beneath the cyclone should result
 in Aletta degenerating into a remnant low pressure system later
 today, possibly as early as the next advisory cycle. The initial
 intensity of 30 kt is based on an average of Dvorak T- and CI-
 numbers from TAFB, and an assumed spin down from the 35-kt winds
 noted in 0532 UTC ASCAT data.
 
 Microwave satellite fixes indicate that Aletta has been moving
 westward at about 10 kt since the previous advisory. However, this
 is likely just a temporary motion due to the decoupling of the
 low- and upper-level circulations owing to the loss of convection.
 As a result, the advisory motion is estimated to be a slower 270/06
 kt. Aletta is expected to move westward today, followed by a turn
 toward the west-southwest by Tuesday due to the shallow cyclone
 being steered by the low-level easterly to northeasterly tradewind
 flow. By days 3 and 4, the steering flow is forecast to weaken
 significantly, causing Aletta to possibly stall, due to the remnant
 low coming under the influence of major Hurricane Bud's expanding
 circulation. The NHC track guidance is in good agreement on this
 developing track scenario, and the new forecast track is similar to
 the previous advisory and the consensus models HCCA and TVCN.
 
 FORECAST POSITIONS AND MAX WINDS
 
 INIT  11/1500Z 16.8N 117.8W   30 KT  35 MPH
  12H  12/0000Z 16.7N 118.7W   25 KT  30 MPH...POST-TROP/REMNT LOW
  24H  12/1200Z 16.5N 119.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
  36H  13/0000Z 16.3N 120.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
  48H  13/1200Z 16.1N 120.2W   20 KT  25 MPH...POST-TROP/REMNT LOW
  72H  14/1200Z 16.0N 120.2W   15 KT  15 MPH...POST-TROP/REMNT LOW
  96H  15/1200Z 16.0N 120.0W   15 KT  15 MPH...POST-TROP/REMNT LOW
 120H  16/1200Z...DISSIPATED
 
 $$
 Forecaster Stewart