Tropical Depression Two-E Discussion Number 1

Wiki-Hurricanes Forecast Center

8:00 PM PDT Sat Jun 29 2019

A new tropical depression has formed in the East Pacific. Infrared satellite imagery shows a very large convective system, with deepest thunderstorm activity (on the order of -80C) positioned near the presumed location of the low-level circulation. An earlier ASCAT pass showed the center itself was closed and nearly sufficiently defined to be designated as a tropical depression. While there have been no new passes since that time, the increase in organization on conventional satellite imagery gives me strong reason to believe it has met that criteria at this time. The initial intensity is set to 30kt based on development since 0z satellite intensity estimates and the earlier ASCAT passes.

As a whole, the environment ahead of Two-E should favor further intensification. Upper-level winds are in the process of relaxing in the vicinity of the system and should fall under 10kt about a day from now. Sea surface temperatures are above 29C, and Two-E should remain south of the 26C isotherm for at least four days, if not longer. Mid-level relative humidity values are currently near 75 percent, only expected to become marginal for intensification after 72 hours. The biggest fly in the ointment as far as strengthening is concerned may be the storm's attachment to the Intertropical Convergence Zone. The GFS in particular shows only slight development over the next four days as Two-E competes with several different vorticity maxima. The ECMWF and HWRF too show slow organization over the next two days or so, but rapid organization takes place beyond that point. The SHIPS predicts a hurricane in three days, while the LGEM is slightly more conservative with a strong tropical storm through the period. Certain facets of each solution make sense, and the first forecast will show only slow development for the next two days, with a more rapid pace for days three and four. By day five, a more stable environment may cause the storm to at least level off. Obviously, this is a low-confidence intensity forecast.

As opposed to the intensity forecast, the track prediction is fairly straightforward. Two-E is being steered by an expansive and strong mid-level ridge over northern Mexico. The system should maintain a pretty steady west-northwest trajectory over the next four days as this ridge remains in place. By day five, model guidance shows the ridge sliding westward into the subtropical East Pacific, and this should force Two-E on a more westward track.


INIT 30/0300Z 30 KT 35 MPH

12H 30/1200Z 35 KT 40 MPH

24H 01/0000Z 40 KT 45 MPH

36H 01/1200Z 45 KT 50 MPH

48H 02/0000Z 55 KT 65 MPH

72H 03/0000Z 65 KT 75 MPH

96H 04/0000Z 80 KT 90 MPH

120H 05/0000Z 80 KT 90 MPH

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