Tropical Storm LOWELL
ZCZC MIATCDEP2 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM LOWELL DISCUSSION NUMBER 7
NWS NATIONAL HURRICANE CENTER MIAMI FL EP122014
800 AM PDT TUE AUG 19 2014
The structure of Lowell has not changed much over the past few
hours, with most of the deep convection located south and southeast
of the center. The initial intensity remains 45 kt based on the
earlier ASCAT pass, which is also in agreement with the latest
Dvorak classification from TAFB. Some strengthening is forecast in
the short term, as Lowell will be in an environment of moderate
vertical shear and over warm waters. After that time, Lowell will
be moving over cooler waters and into a drier and more stable
airmass, which should result in steady weakening to remnant low
status by the end of the forecast period. The NHC intensity
forecast is similar to the previous one and is close to the latest
IVCN intensity consensus.
There is a fair bit of spread in the satellite fixes, which is not
surprising given the sprawling structure of the circulation. The
initial motion estimate of 300/06 is based on a blend of the fixes
and continuity from the previous advisory. The track forecast
reasoning remains unchanged. The subtropical ridge currently
steering Lowell will weaken as a shortwave trough digs southward
along the California coast in the next 24 to 36 hours. After that
time, some ridging rebuilds to the north, which should turn a
weakening Lowell back toward the west-northwest by the end of the
period. The new NHC track forecast is similar to the previous one
and close to the TVCE consensus.
FORECAST POSITIONS AND MAX WINDS
INIT 19/1500Z 17.7N 119.7W 45 KT 50 MPH
12H 20/0000Z 18.2N 120.5W 50 KT 60 MPH
24H 20/1200Z 18.8N 121.0W 55 KT 65 MPH
36H 21/0000Z 19.4N 121.3W 55 KT 65 MPH
48H 21/1200Z 20.1N 121.8W 55 KT 65 MPH
72H 22/1200Z 22.5N 124.0W 50 KT 60 MPH
96H 23/1200Z 25.0N 127.0W 40 KT 45 MPH
120H 24/1200Z 26.5N 130.0W 30 KT 35 MPH...POST-TROP/REMNT LOW
$$
Forecaster Brennan
NNNN