霧峰追風者

000
WTNT41 KNHC 131453
TCDAT1

Tropical Storm Josephine Discussion Number   8
NWS National Hurricane Center Miami FL       AL112020
1100 AM AST Thu Aug 13 2020

A just-received ASCAT overpass showed an area of 35-40 kt winds
about 70 n mi north of the center of Tropical Depression Eleven,
and based on this the cyclone is being upgraded to Tropical Storm
Josephine with an initial intensity of 40 kt.  Satellite imagery
shows that the convective pattern associated with Josephine has
become a little better organized since the last advisory, with a
ragged central convective feature and a weak band in the northern
semicircle.

The initial motion is now west-northwestward or 295/13 kt.  
Josephine should continue this motion for the next several days as
it moves toward a weakness in the western portion of the Atlantic
subtropical ridge.  The global models forecast the western end of
the ridge to weaken even more after 72-96 h, which should cause
the cyclone, or what is left of it by that time, to turn
northwestward.  The track guidance is tightly clustered, and the
new forecast track lies a little to the right of the previous track
and a little to the left of the consensus models.

Some additional strengthening appears likely during the next 24-  
36 h as Josephine moves through an environment of light vertical
wind shear.  After that, the cyclone is expected to encounter
moderate to strong southwesterly shear as it approaches an
upper-level trough over the southwestern Atlantic, which should
cause at least some weakening.  The new intensity forecast is
adjusted upward for the first 72 h based on the current intensity.  
After 72 h, it shows weakening similar to the previous forecast, but
not as drastic as the global models that show the storm degenerating
to a tropical wave before 120 h.

Josephine is the earliest tenth tropical storm of record in the
Atlantic, with the next earliest tenth storm being Tropical Storm
Jose on August 22, 2005.


FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 13.7N  49.2W   40 KT  45 MPH
12H  14/0000Z 14.5N  51.1W   45 KT  50 MPH
24H  14/1200Z 15.8N  53.6W   50 KT  60 MPH
36H  15/0000Z 17.1N  56.3W   50 KT  60 MPH
48H  15/1200Z 18.5N  58.9W   50 KT  60 MPH
60H  16/0000Z 19.9N  61.3W   45 KT  50 MPH
72H  16/1200Z 21.3N  63.6W   40 KT  45 MPH
96H  17/1200Z 24.0N  67.0W   30 KT  35 MPH
120H  18/1200Z 27.0N  68.0W   25 KT  30 MPH

$$

老農民版夜神月

NHC21Z判定11L已減弱成為殘餘

000
WTNT41 KNHC 162033
TCDAT1

Remnants Of Josephine Discussion Number  21
NWS National Hurricane Center Miami FL       AL112020
500 PM AST Sun Aug 16 2020

The low-level swirl seen in visible satellite imagery has become
less defined this afternoon, and ASCAT surface wind data that
arrived shortly after the release of the previous advisory indicated
that Josephine had degenerated into a trough of low pressure.  As a
result, this will be the final NHC advisory on this system.  The
ASCAT revealed a small area of 30-kt winds along the northeast side
of the trough axis, and that will be the initial wind speed for
this advisory.  The remnants are forecast to continue encountering
a hostile upper-level wind environment over the next couple of days
and re-generation of the system is not expected during that time.
The strong upper-level winds are forecast to decrease later in the
week, but it appears that there will not be much left of the system
to take advantage of those conditions.

The remnants are moving west-northwestward at 10 kt, and should
turn northwestward and northward over the next couple of days as a
low- to mid-level trough moves near the southeastern U.S. coast.

This is the last NHC advisory on this system.  Future information
can be found in High Seas Forecasts issued by the National Weather
Service, under AWIPS header NFDHSFAT1, WMO header FZNT01 KWBC, and
online at ocean.weather.gov/shtml/NFDHSFAT1.php


FORECAST POSITIONS AND MAX WINDS

INIT  16/2100Z 20.9N  65.8W   30 KT  35 MPH
12H  17/0600Z...DISSIPATED

$$
Forecaster Brown