kibishi0515

06Z升格20E

t02436

NHC初報巔峰上望颶風下限。

000
WTPZ45 KNHC 230846
TCDEP5

TROPICAL DEPRESSION TWENTY-E DISCUSSION NUMBER   1
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202016
400 AM CDT SUN OCT 23 2016

Conventional and microwave satellite data indicate that deep
convection associated with the low pressure area located south of
Mexico has become much better organized overnight.  A fortuitous
0526 UTC GPM microwave overpass revealed a significant increase in
banding and was also very helpful in determining the center
location.  Based on these data, and an earlier partial ASCAT pass
which indicated that the circulation had become sufficiently well
defined, advisories are being initiated on the twentieth tropical
depression of the 2016 eastern North Pacific hurricane season.  The
initial intensity has been set at 30 kt, which is in agreement with
Dvorak T-numbers of 2.0 from both TAFB and SAB.

The depression is forecast to move over SSTs of 29-30 degrees
Celsius and remain in an area of vertical shear of around 10 kt or
less during the next 2 to 3 days, which should allow for
steady strengthening.  Despite these seemingly favorable
conditions, the global and regional hurricane models show much less
strengthening than the statistical SHIPS/LGEM guidance which show a
peak intensity of around 70-75 kt in about 3 days.  Given the
expected favorable conditions, the NHC intensity forecast is above
the dynamical guidance and model consensus, but is lower than the
SHIPS and LGEM.  Late in the forecast period, cooler SSTs and
increasing southwesterly vertical wind shear are expected to weaken
the cyclone.

Since the depression is still in the formative stage, the initial
motion is a somewhat uncertain 290/14.  A strong mid- to upper-
level ridge that is forecast to shift westward over the Baja
California peninsula should steer the cyclone west-northwestward
during the next several days.  By day 4, the cyclone is forecast
to turn northwestward when it approaches the western periphery of
the ridge.  The track guidance is in good agreement on this overall
scenario, but there are some differences in the forward speed of the
cyclone and exactly when the northwestward turn will materialize.
The NHC forecast track is slightly faster than the model consensus
and is in best agreement with the latest ECMWF model.


FORECAST POSITIONS AND MAX WINDS

INIT  23/0900Z 13.1N 103.6W   30 KT  35 MPH
12H  23/1800Z 13.8N 105.6W   40 KT  45 MPH
24H  24/0600Z 14.7N 107.8W   45 KT  50 MPH
36H  24/1800Z 15.4N 110.2W   55 KT  65 MPH
48H  25/0600Z 16.1N 112.6W   65 KT  75 MPH
72H  26/0600Z 17.0N 117.1W   65 KT  75 MPH
96H  27/0600Z 18.8N 120.5W   55 KT  65 MPH
120H  28/0600Z 20.5N 122.5W   45 KT  50 MPH

$$
Forecaster Brown

t02436

21Z命名Seymour

000
WTPZ45 KNHC 232046
TCDEP5

TROPICAL STORM SEYMOUR DISCUSSION NUMBER   3
NWS NATIONAL HURRICANE CENTER MIAMI FL       EP202016
400 PM CDT SUN OCT 23 2016

The cyclone has become better organized during the last several
hours.  Visible satellite images suggest that an inner core is
forming, with a few curved bands surrounding this central
convection. The latest Dvorak classifications from TAFB and SAB are
2.5/35 kt, and automated values from CIMSS at the University of
Wisconsin are slightly higher.  In addition, an ASCAT pass around
1600 UTC showed maximum winds in the 30 to 35 kt range.  Based on
these data, the initial wind speed is increased to 35 kt.

The global models are in agreement that Seymour should remain in
a favorable upper-level wind pattern during the next few days.
These light upper-level winds, combined with very warm water and
high mid-level moisture values should allow Seymour to steadily, or
perhaps rapidly, strengthen during the next 72 hours. Beyond that
time, a significant increase in southwesterly shear, cooler waters,
and a decrease in moisture should end the strengthening trend and
induce weakening.  The NHC intensity forecast is raised from the
previous one, and is near the middle of the guidance envelope.

The tropical storm is moving west-northwestward at 12 kt.  A
mid-level ridge over Mexico should continue to steer Seymour
west-northwestward at a slightly slower pace during the next few
days.  After that time, the ridge is likely to erode as a deep-
layer low pressure moves eastward toward California.  This pattern
change will likely cause Seymour to turn northwestward and then
northward in 4 to 5 days.   The models have shifted considerably to
the right at the longer range points, and the new NHC track forecast
has been adjusted in that direction.

FORECAST POSITIONS AND MAX WINDS

INIT  23/2100Z 13.9N 105.9W   35 KT  40 MPH
12H  24/0600Z 14.5N 107.8W   40 KT  45 MPH
24H  24/1800Z 15.2N 110.2W   50 KT  60 MPH
36H  25/0600Z 15.8N 112.7W   60 KT  70 MPH
48H  25/1800Z 16.4N 115.1W   70 KT  80 MPH
72H  26/1800Z 17.8N 119.0W   75 KT  85 MPH
96H  27/1800Z 20.8N 121.1W   55 KT  65 MPH
120H  28/1800Z 23.1N 120.7W   35 KT  40 MPH

$$
Forecaster Cangialosi

s6815711

這OHC少的好可憐
目前還是在相對高的地方
看置換後的狀況了

蜜露

GFS看好西摩的發展 , Cat.3 有機會挑戰

底層大致置換完成 , 高層準備開眼