Tropical Storm DOUGLAS
ZCZC MIATCDEP4 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DOUGLAS DISCUSSION NUMBER 8
NWS NATIONAL HURRICANE CENTER MIAMI FL EP042014
800 AM PDT MON JUN 30 2014
Douglas has changed little in organization during the past 6 hours.
The cyclone has maintained a broad inner core with most of the
convective banding features being well removed from the center.
The current intensity has been held at 35 kt, which is in agreement
with satellite intensity estimates from TAFB, SAB, and UW-CIMSS ADT.
The initial motion estimate is 305/08 kt. There is no significant
change to the previous track forecast or reasoning. Douglas is
expected to move west-northwestward for the next 48 hours or so
toward a weakness in the subtropical ridge to the north of the
cyclone, which will result in a gradual decrease in Douglas'
forward speed. By late in the forecast period, the ridge is
expected to strengthen, which should turn the cyclone more westward
as it comes under the influence of moderate low-level trade wind
flow. This motion will bring Douglas over cooler waters, causing the
cyclone to gradually weaken. The official forecast track is a
little to the right of the previous advisory track, but only to
account for the more northward initial position. Otherwise, the new
forecast track closely follows the multi-model consensus TCVE.
Although the vertical wind shear is expected to remain weak at less
than 10 kt for the next 3 days or so, the broad inner-core wind
field and sea-surface temperatures decreasing to less than 27C
argues for only slight intensification over the next couple of days.
After that, Douglas will be moving over sub-26C SSTs and into a
drier and more stable thermodynamic environment, which should
result in steady weakening. The NHC intensity forecast is similar
to the previous advisory and follows the consensus model IVCN.
FORECAST POSITIONS AND MAX WINDS
INIT 30/1500Z 17.4N 114.0W 35 KT 40 MPH
12H 01/0000Z 18.1N 115.1W 40 KT 45 MPH
24H 01/1200Z 18.7N 115.9W 40 KT 45 MPH
36H 02/0000Z 19.1N 116.6W 40 KT 45 MPH
48H 02/1200Z 19.3N 117.1W 35 KT 40 MPH
72H 03/1200Z 19.5N 117.9W 30 KT 35 MPH
96H 04/1200Z 19.5N 119.1W 25 KT 30 MPH
120H 05/1200Z 19.5N 121.1W 25 KT 30 MPH...POST-TROP/REMNT LOW