Tropical Storm Cosme Winds: 45 kt
Pressure: 999 mbar
Advisory 2 / 2:00 PM PDT July 9, 2019

Cosme is rather ugly looking this afternoon. Little attempt has been made in organizing the storm's displaced convective activity remotely near the elongated center of circulation, and thus the low-level cumulus clouds around the surface vortex remain exposed. A 1722z quality-controlled ASCAT pass showed a field of 40 kt winds northeast of the broad center, and these winds were not in particularly deep convection. The associated AMSU microwave pass was in agreement in revealing the rather poor organizational nature of Cosme, and a rather wide region of sinking air west of the system may be to blame. Still, the sampled winds are higher across the board than any infrared assessments so the intensity for Cosme remains at 45 kt this advisory.

Cosme's broad circulation continues to lumber to the west-northwest away from the monsoon trough that spanwed it. No changes have been introduced to this advisory with regard to the forecast track. The California upper-trough and a restrengthening mid- to lower-level ridge will be tagteaming to produce the same sort of west-northwest curving to west track we saw with Barbara, this time farther north and farther east. We have the luxury this time around of this westward glide occurring well north of the sharp East Pacific thermocline where cooler waters commence.

As expected, there was no change in Cosme's intensity this morning due to its ill-defined structure. A dominant upper convergent regime was analyzed by CIMSS across the western periphery of the circulation, which is doubtless suppressing convective activity and organization despite supportive thermodynamics. Whatever favorable parameters exist fade away quite rapidly in roughly 24 hours as cooler waters and dry air settle firmly in place, inducing weakening. Most guidance - the HWRF being the lone exception - shows a steady-state or slight weakening today followed by weakening over the rest of the forecast window. This is in line with our previous forecasts, and thus the intensity forecast remains mostly unchanged from the previous advisory.


INIT 06/2100Z 45 KT 50 MPH

12H 07/0600Z 45 KT 50 MPH

24H 07/1800Z 40 KT 45 MPH

36H 08/0600Z 35 KT 40 MPH

48H 08/1800Z 30 KT 35 MPH

72H 09/1800Z 20 KT 25 MPH...POST-TROP/REMNT LOW

96H 10/1800Z 20 KT 25 MPH...POST-TROP/REMNT LOW


Forecaster TheAustinMan
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