老農民版夜神月

  熱帶風暴  
編號：12 L
名稱：Karen

  基本資料  
擾動編號日期：2019 年 09 月 20 日 20 時
命名日期　　：2019 年 09 月 22 日 17 時
撤編日期　　：2019 年 09 月 29 日 01 時
登陸地點　　：波多黎各

  巔峰時期資料  
近中心最強風速 ：40 kt
海平面最低氣壓 ：1003 百帕

  過去路徑圖  

  擾動編號資料  
99L INVEST 190920 1200 10.0N 47.5W ATL 25 1011


  NHC：20%  

1. A tropical wave located about 700 miles east of the Windward
Islands continues to produce disorganized showers and thunderstorms.
The wave is expected to move quickly westward at about 20 mph during
the next few days, and some development is possible while it
approaches and moves across the Windward Islands this weekend.
Upper-level winds are forecast to become less conducive for
development once the wave moves over the eastern Caribbean Sea early
next week.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...low...30 percent.

以上資料來自：NHC、颱風論壇整理製作

老農民版夜神月

NHC展望提升至Medium,40%/40%

1. A tropical wave located several hundred miles east of the Windward
Islands continues to produce a large area of disorganized showers
and thunderstorms.  Environmental conditions are currently conducive
for some development, and a tropical depression could form over the
weekend while the system moves quickly westward to west-
northwestward at 15 to 20 mph, crossing the Windward Islands
Saturday night and Sunday.  Upper-level winds are forecast to become
less conducive for development early next week once the wave moves
over the eastern Caribbean Sea.  A NOAA Hurricane Hunter aircraft
is scheduled to investigate this system tomorrow afternoon, if
necessary.  Regardless of development, heavy rainfall is possible
over the Windward Islands over the weekend, and interests on those
islands should monitor the progress of this system.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

老農民版夜神月

NHC展望再進一步提升至High,70%/70%

1. Updated: A strong tropical wave, accompanied by a broad low pressure
area located between Barbados and Tobago, is producing showers and
thunderstorms that are showing signs of organization.  In addition,
recent satellite-derived surface wind data and observations from
Barbados indicate that the disturbance is producing winds to near
tropical storm force in the eastern portion of the system. Further
development of this disturbance is expected over the next couple of
days, and a tropical depression or tropical storm will likely form
while it moves westward and then northwestward at 10 to 15 mph
across the Windward Islands and over the eastern Caribbean Sea.  The
system is then expected to turn northward, moving near Puerto Rico
and the Virgin Islands on Tuesday. Regardless of development, heavy
rainfall and strong gusty winds are likely over much of the Lesser
Antilles during the next couple of days and will likely spread
across Puerto Rico and the Virgin Islands by Monday night or
Tuesday.  Interests across the eastern Caribbean should monitor the
progress of this disturbance since tropical storm watches and
warnings could be required for portions of the Lesser Antilles and
Puerto Rico and the Virgin Islands on Sunday.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent.

老農民版夜神月

NHC22/09Z直接升格TS,命名Karen,並預測進入加勒比海後將逐漸轉為向北移動

WTNT42 KNHC 220900
TCDAT2

Tropical Storm Karen Discussion Number   1
NWS National Hurricane Center Miami FL       AL122019
500 AM AST Sun Sep 22 2019

Scatterometer surface wind data and observations from the Windward
Islands indicate that the low pressure system just east of Tobago
has become better defined. Infrared and microwave satellite imagery
also show that deep convection has increased and has become better
organized around the center. Barbados recently reported a 10-minute
wind of 32 kt gusting to 39 kt, and the earlier scatterometer data
showed a large field of 30-32 kt winds in the eastern semicircle.
Based on these data, the low has been upgraded to Tropical Storm
Karen. Tropical Storm Warnings have been issued for the southern
Windward Islands as a result.

The initial motion estimate is an uncertain 285/10 kt. The latest
NHC model guidance is in very good agreement on Karen moving
northwestward around the southwestern periphery of a deep-layer
ridge for the next 24-36 hours, followed by a turn toward the north
into a break in the ridge currently located over the northern
Leeward Islands and Puerto Rico. In the 72-96 hour period, Karen is
forecast to slow down and possibly even stall and turn westward on
day 5 as another large ridge moves eastward across the southeastern
United States and builds to the north of the cyclone. The official
track forecast lies close to the tightly packed consensus track
models TVCN, NOAA-HCCA, and TVCX.

Little, if any, change in intensity is expected for the next 48
hours due to strong northeasterly vertical wind shear. However, the
upper-level flow is expected to be difluent, which should help Karen
maintain its current intensity despite the otherwise unfavorable
shear conditions. By 72 hours and beyond, Karen is forecast to move
underneath an upper-level anticyclone, which should result in a
significant decrease in the shear and also enhance the upper-level
outflow, allowing for some strengthening to occur. The NHC intensity
forecast closely follows a blend of the the intensity consensus
models IVCN and HCCA, and the Decay-SHIPS model.

A Tropical Storm Watch will likely be required for Puerto Rico and
the Virgin Islands later today, and Tropical Storm Warnings may be
issued for other areas in the Windward Islands later this morning.

FORECAST POSITIONS AND MAX WINDS

INIT  22/0900Z 11.9N  60.2W   35 KT  40 MPH
12H  22/1800Z 12.5N  61.6W   35 KT  40 MPH
24H  23/0600Z 13.4N  63.1W   35 KT  40 MPH
36H  23/1800Z 14.7N  64.1W   35 KT  40 MPH
48H  24/0600Z 16.1N  65.1W   35 KT  40 MPH
72H  25/0600Z 19.9N  65.5W   45 KT  50 MPH
96H  26/0600Z 23.4N  65.0W   50 KT  60 MPH
120H  27/0600Z 25.6N  65.6W   55 KT  65 MPH

$$
Forecaster Stewart