000
WTPZ42 KNHC 192035
TCDEP2

TROPICAL STORM LOWELL DISCUSSION NUMBER   8
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP122014
200 PM PDT TUE AUG 19 2014

A recent ASCAT-B pass over Lowell around 1800 UTC confirmed that the
cyclone still has a large wind field, with 34-kt winds extended out
more than 100 nautical miles in all quadrants. ASCAT showed some 40
kt winds east of the center, and assuming a bit of a low bias, the
initial intensity remains 45 kt for this advisory. Lowell will
remain in a moderate shear environment for the next day or so while
still over SSTs above 27C, which could support a little
strengthening in short term, followed by little change through 48
hours. After that time, gradual weakening is expected as Lowell will
move over cooler waters and into a drier and more stable airmass,
and should become a remnant low by 5 days. In general the intensity
guidance has trended lower this cycle, and so has the official
forecast, which is close to the IVCN consensus.

The ASCAT pass and visible satellite imagery yield a little more
certainty with the center position and initial motion estimate of
310/07. Lowell is expected to move slowly northwestward to north-
northwestward over the next 48 hours while a shortwave trough
digs southward along the California coast and weakens the
subtropical ridge. As the trough moves eastward, some ridging will
rebuild to the north, which should result in the weakening cyclone
accelerating west-northwestward by the end of the period. The new
NHC track is once similar to the previous one and close to the TVCE
consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  19/2100Z 18.4N 120.3W   45 KT  50 MPH
 12H  20/0600Z 18.8N 120.8W   50 KT  60 MPH
 24H  20/1800Z 19.3N 121.3W   50 KT  60 MPH
 36H  21/0600Z 20.0N 121.7W   50 KT  60 MPH
 48H  21/1800Z 21.0N 122.5W   50 KT  60 MPH
 72H  22/1800Z 23.5N 125.0W   45 KT  50 MPH
 96H  23/1800Z 25.5N 128.0W   35 KT  40 MPH
120H  24/1800Z 27.5N 131.0W   30 KT  35 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brennan