Tropical Storm DOUGLAS
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TROPICAL STORM DOUGLAS DISCUSSION NUMBER 16
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 AM PDT WED JUL 02 2014
Douglas's structure has changed little since the last advisory.
Deep convection associated with the storm is losing a bit of
organization but remains compact near the low-level center. A
blend of Dvorak final-T and CI numbers from TAFB, SAB, and the
objective ADT supports maintaining an initial intensity of 40 kt.
Douglas is trapped in an environment of weak steering and is
drifting northwestward...or 325/2 kt...toward a break in the
subtropical ridge. The subtropical high to the west of Douglas is
expected to remain in place for another 48 hours or so, which will
continue a slow northwestward motion. After 48 hours, the western
subtropical high weakens while mid-level ridging strengthens over
the western United States. This pattern evolution should cause
Douglas to turn west-northwestward and accelerate between 72-120
hours. The track guidance has shifted noticeably to the right of
the previous NHC forecast, especially through 24 hours and again
between 96-120 hours. The updated forecast is also moved to the
right, lying near the ECMWF and just to the left of the model
consensus TVCE.
Given Douglas's slow motion in the short term, sea surface
temperatures will only gradually decrease along the forecast track
during the next 24-36 hours. Vertical shear is forecast to remain
low, and as a result, Douglas should be able to hang on as a
tropical storm for another day or so. The ocean becomes much colder
once Douglas accelerates to the west-northwest, and the cyclone is
expected to become a remnant low by 48 hours. The new NHC intensity
forecast is very similar to the previous one.
FORECAST POSITIONS AND MAX WINDS
INIT 02/1500Z 19.7N 116.0W 40 KT 45 MPH
12H 03/0000Z 20.0N 116.1W 35 KT 40 MPH
24H 03/1200Z 20.4N 116.4W 35 KT 40 MPH
36H 04/0000Z 20.9N 117.0W 30 KT 35 MPH
48H 04/1200Z 21.4N 118.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
72H 05/1200Z 22.6N 120.8W 25 KT 30 MPH...POST-TROP/REMNT LOW
96H 06/1200Z 24.0N 124.0W 20 KT 25 MPH...POST-TROP/REMNT LOW
120H 07/1200Z 24.5N 127.5W 20 KT 25 MPH...POST-TROP/REMNT LOW
$$
Forecaster Berg
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