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Tropical Storm Emilia Discussion Number 3
NWS National Hurricane Center Miami FL EP052024
800 PM MST Sun Aug 04 2024
The organization of the tropical cyclone has improved on satellite
imagery since the previous advisory. The subjective CI numbers from
TAFB and SAB are both T-2.5/35 kt, and the CIMSS objective intensity
estimates range from 33 to 35 kt. Earlier ASCAT data from around 17
UTC had peak wind vectors of 31 kt, and the organization on
satellite imagery has certainty improved since that time, with the
cyclone becoming more compact. Based on the Dvorak estimates, the
depression is upgraded to Tropical Storm Emilia with an initial
intensity of 35 kt.
The track forecast for Emilia is very dependent on a disturbance to
the east of the system (Invest 96E), which has a high chance of
becoming a tropical cyclone over the next day or so. Most of the
global models show both systems interacting with and rotating
cyclonically around each other. Emilia should move to the
south-southwest for the next 24 h, while it is located to the west
of 96E. After that time, the larger circulation of 96E should pull
the smaller Emilia toward the northwest or north-northwest. Only
minor changes were made to the previous NHC track forecast. 96E
and Emilia should merge together into one cyclone over the next
couple of days, but it is uncertain which cyclone will be dominant
and which cyclone will be absorbed. This forecast assumes that 96E
will absorb Emilia, with Emilia dissipating beyond 48 h. However,
it is quite possible that the opposite occurs, with Emilia absorbing
96E. Either way, I expect a tropical cyclone (the merged system) to
be moving west-northwestward in 3 to 4 days, spreading tropical
storm conditions across the open waters of the Pacific. The ECMWF
model shows the two systems merging in 36-48 h, but the latest GFS
model predicts a longer binary interaction, with the merger
occurring in 3 to 4 days.
Until the disturbance to the east starts to interact with Emilia,
the environment appears favorable for intensification, and the
intensity guidance has trended upward this cycle. The new NHC
forecast shows Emilia strengthening to a 55 kt tropical storm in 36
h. This is near, or slightly below the middle of the intensity
guidance envelope. The thinking is that Emilia will merge with 96E
after that time, and 96E will likely be a tropical storm at the
time of the merger.
FORECAST POSITIONS AND MAX WINDS
INIT 05/0300Z 15.0N 113.2W 35 KT 40 MPH
12H 05/1200Z 14.2N 113.4W 40 KT 45 MPH
24H 06/0000Z 13.8N 113.5W 50 KT 60 MPH
36H 06/1200Z 14.3N 113.8W 55 KT 65 MPH
48H 07/0000Z 15.6N 114.8W 55 KT 65 MPH
60H 07/1200Z...DISSIPATED
$$
Forecaster Hagen/Roberts
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