TROPICAL DEPRESSION ELEVEN-E DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL EP112015
900 PM MDT SAT AUG 15 2015
The last few hours of visible imagery indicated that the large low
pressure area located well to the south-southwest of the Baja
California peninsula had developed a sufficiently well-defined
center of circulation, even if the overall circulation itself was
still somewhat elongated. Also, deep convection has been forming
closer to this center over the past few hours, and Dvorak estimates
from TAFB and SAB were T2.0/30 kt and T2.5/35 kt, respectively.
Advisories have therefore been initiated, and the initial intensity
estimate is 30 kt.
Since the center has just recently become more apparent, the
initial motion estimate is an uncertain 300/10 kt. The depression
is being steered west-northwestward between a mid- to upper-level
low located to its southwest near 17N125W and a large mid-level
high centered over the southwestern United States. This pattern is
expected to cause the cyclone to accelerate northwestward within
the next 12 hours and continue that trajectory through day 4. The
cross-track spread among the track models is small, but there are
some speed differences. For example, the ECMWF is the fastest model
while the HWRF and GFDL are two of the slowest. The official track
forecast is a little faster than the TVCE model consensus and leans
closer toward the GFS and ECMWF solutions.
The depression only has another 24-36 hours before it reaches sea
surface temperatures colder than 26 degrees Celsius. In addition,
water vapor imagery shows a large area of mid-/upper-level dry air
impinging on the southwestern side of the circulation. Given the
system's large and asymmetric appearance, and the short window of
favorable conditions, significant strengthening is not likely, and
the official forecast shows the depression just reaching tropical
storm intensity within the next day or so. This forecast most
closely follows the intensity consensus. The cyclone should become
a remnant low by day 3 and dissipate by day 5, if not sooner.
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