Eastern Pacific Basin Tropical Cyclones

Tropical Depression Eight-E Forecast Discussion


000
WTPZ43 KNHC 271459
TCDEP3

Tropical Depression Eight-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP082022
900 AM MDT Wed Jul 27 2022

The area of low pressure we have been monitoring more than 500 miles
southwest of the Baja California peninsula has continued to become
better organized this morning. First light visible imagery shows
cold convective cloud tops near the estimated center that also
appear to be rotating cyclonically. While we haven't had any recent
C-band scatterometer passes near the center of this system, a
recent KU-band scatterometer showed plenty of non-rain contaminated
winds to help confirm that a closed circulation exists. Subjective
Dvorak classifications were up to T2.0/30-kt from TAFB and
T1.5/25-kt from SAB. A recently arriving SSMIS pass at 1159 UTC
also showed a well-defined curve band wrapping at least 75 percent
around the northwestern side of the system. All these data indicate
a new tropical depression has formed, and the initial intensity
will be set at 30 kt this advisory.

Currently the depression is moving westward at 275/6 kt. A large 
deep-layer ridge is situated north of the cyclone which should steer 
it on a general westward to west-southwestward heading over the next 
day or so. Afterwards, the larger circulation of Tropical Storm 
Frank is expected to get close enough to initiate binary interaction 
with the depression. The net result of this interaction is that the 
depression is likely to bend even more southward than the 
larger-scale steering flow would initially suggest, and there is 
some chance that Frank may capture the smaller depression. For now, 
the track forecast keeps Frank and TD Eight-E separate, showing a 
very slow west-northwestward motion towards the end of the forecast 
period. This track forecast is roughly follows the TVCE aid early 
on, but is slower later in the  forecast period due to uncertainty 
with interaction with Frank to the east. This initial track forecast 
is of low confidence.

The intensity forecast is also challenging and strongly related to
how much interaction this depression has with the larger circulation
of Frank. Assuming the depression remains separate, environmental
conditions only appear marginally favorable for intensification in
the short-term, with moderate easterly vertical wind shear, and
plenty of nearby dry air that could get ingested into the small
circulation at any time. For these reasons, the intensity forecast
only shows modest intensification over the next 24-48 hours and
caps the storm at 40 kt thereafter due to uncertainty in its future
evolution near Frank. This is roughly in line with the latest SHIPS
guidance, but is lower than the HCCA and other consensus intensity
aids which are biased by the larger and stronger wind field of
Frank later on in the forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  27/1500Z 16.3N 114.8W   30 KT  35 MPH
 12H  28/0000Z 16.0N 115.8W   35 KT  40 MPH
 24H  28/1200Z 15.2N 117.2W   40 KT  45 MPH
 36H  29/0000Z 14.4N 118.2W   40 KT  45 MPH
 48H  29/1200Z 14.0N 118.6W   40 KT  45 MPH
 60H  30/0000Z 14.0N 119.0W   40 KT  45 MPH
 72H  30/1200Z 14.3N 119.5W   40 KT  45 MPH
 96H  31/1200Z 15.0N 121.5W   40 KT  45 MPH
120H  01/1200Z 16.1N 124.0W   40 KT  45 MPH

$$
Forecaster Papin



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