000
WTPZ43 KNHC 062040
TCDEP3

Tropical Storm Cosme Discussion Number   2
NWS National Hurricane Center Miami FL       EP032019
200 PM PDT Sat Jul 06 2019

Cosme continues to have a lopsided appearance in satellite images,
with all of its associated deep convection east of the center.
While there have been some cells near the core of the cyclone, they
have not lasted long due to plentiful dry air in the mid-levels.
The initial wind speed is kept at 45 kt in agreement with recent
ASCAT data, again well above any Dvorak estimates.

While shear is clearly decreasing near the center, it will take
some time for the large cyclone to mix out the aforementioned
dry near and west of the core.  In addition, Cosme has only about 36
hours over marginal SSTs before reaching cool waters.  These factors
indicate little significant strengthening this weekend, and a
gradual weakening early next week due to cooler waters and higher
shear.  The HWRF shows some strengthening right before Cosme
crosses into the cool waters, but the rest of the models holds
Cosme's intensity flat or decreasing during the next few days. The
official intensity forecast is similar to the previous one, which
goes with the weaker solution provided by the bulk of the models.

The center has been difficult to track, but ASCAT and visible
satellite suggest it is moving a bit slower and poleward than
before, or 295/12.  The storm is expected to be steered to the west-
northwest during the next day or so due to a subtropical ridge over
Mexico.  However all of the models show a break in the ridge forming
between 120-130W, which should induce a motion more to the
northwest by Monday.  Guidance has shifted a bit to the north on
this cycle, and the ECMWF solution remains a bit of an outlier to
the southwest. The new NHC forecast is adjusted slightly to the
northeast of the previous one, but is southwest of the model
consensus.


FORECAST POSITIONS AND MAX WINDS

INIT  06/2100Z 16.2N 116.3W   45 KT  50 MPH
 12H  07/0600Z 16.9N 117.8W   45 KT  50 MPH
 24H  07/1800Z 17.8N 119.2W   45 KT  50 MPH
 36H  08/0600Z 18.8N 120.3W   40 KT  45 MPH
 48H  08/1800Z 19.8N 121.1W   35 KT  40 MPH
 72H  09/1800Z 21.0N 122.6W   25 KT  30 MPH...POST-TROP/REMNT LOW
 96H  10/1800Z 21.5N 125.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  11/1800Z...DISSIPATED

$$
Forecaster Blake