霧峰追風者

  熱帶風暴  
編號：04 L
名稱：Chantal

  基本資料  
擾動編號日期：2019 年 08 月 18 日 02 時
命名日期　　：2019 年 08 月 21 日 11 時
撤編日期　　：2019 年 08 月 25 日 07 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速 ：35 kt
海平面最低氣壓 ：1009 百帕

  過去路徑圖  

  擾動編號資料  
97L.INVEST.25kts-1013mb-32.8N-80.0W


  NHC:10%  

1. A surface trough is producing a band of cloudiness and showers
extending from the northeast Gulf of Mexico northeastward across the
coasts of Georgia, South Carolina, and North Carolina. The shower
activity is currently most concentrated near a small area of low
pressure located along the trough near the South Carolina coast.
Tropical development of this system, if any, is likely to be slow as
the disturbance moves northeastward along the eastern coast of the
United States with increasing forward speed during the few days.
Regardless of development, the disturbance is forecast to produce
heavy rainfall along with a threat of flash flooding in that region.
Please see products from your local National Weather Service office
or the Weather Prediction Center's Excessive Rainfall Outlook for
more information.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

以上資料來自：NHC、颱風論壇整理製作

霧峰追風者

NHC 展望提升至30%。

1. A small low pressure system located along the North Carolina coast
near Wilmington is producing a compact area of showers and
thunderstorms.  Any tropical development today is expected to be
limited due to the system's proximity to land. By Sunday night, the
low is expected to move northeastward over the warmer Atlantic
waters offshore of the Outer Banks, where some further organization
could occur before the system encounters cooler waters on Tuesday.
The low is forecast to produce heavy rainfall along with a threat of
flash flooding in coastal portions of South and North Carolina
through this evening.  Please see products from your local National
Weather Service office or the Weather Prediction Center's Excessive
Rainfall Outlook for more information.
* Formation chance through 48 hours...low...30 percent.
* Formation chance through 5 days...low...30 percent.

霧峰追風者

展望降低至10%。

1. A low pressure area located about 100 miles east of Norfolk,
Virginia, is producing limited shower and thunderstorm activity.
This low is moving northeastward, away from the United States, and
has only a slight chance to significantly organize through Monday
before upper-level winds become unfavorable for further
development.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

霧峰追風者

NHC 展望維持10%。

1. An area of low pressure located more than 200 miles southeast of
Cape Cod, Massachusetts, is producing a small area of thunderstorm
activity northeast of the center.  Significant development of this
system is unlikely as it moves eastward at 15 to 20 mph, away from
the United States. Additional information on this low can be 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
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...10 percent.

霧峰追風者

NHC 展望提升至40，高緯發展？

1. A small low pressure system is located more than 400 miles
southeast of Halifax, Nova Scotia. Associated thunderstorm activity
continues to shows signs of organization, and recent satellite data
indicate that the circulation has become a little better defined.
Although environmental conditions are only marginally conducive, any
further development of this low could result in the formation of a
tropical cyclone while it moves eastward at 15 to 20 mph across the
open north Atlantic.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...40 percent.

霧峰追風者

NHC 升格熱帶風暴，命名"Chantal"。

000
WTNT44 KNHC 210232
TCDAT4

Tropical Storm Chantal Discussion Number   1
NWS National Hurricane Center Miami FL       AL042019
1100 PM AST Tue Aug 20 2019

Recent scatterometer wind data and passive microwave satellite
images indicate that the small low pressure system that the NHC has
been monitoring for the past few days has developed a well-defined
surface wind circulation and contains tropical-storm-force winds
south of the cyclone's center. Therefore, the low has become
Tropical Storm Chantal.

The initial motion estimate is 085/19 kt. NHC model guidance is in
excellent agreement that Chantal will move eastward around the
northern periphery of the Bermuda-Azores high and gradually slow
down during the next 48 hours. Thereafter, the cyclone is forecast
to drop southward around the eastern portion of the ridge, possibly
stalling over warmer waters. The NHC forecast track lies close to
the consensus models HCCA and TVCN.

Chantal is expected to remain in a moderate southwesterly to
westerly vertical wind shear regime for the next 48 hours or so,
followed by a significant decrease in the shear through 120 h. After
48 hours, the southward motion is also expected to move Chantal over
warmer water with SSTs around 27C. However, mid-level moisture is
expected to be quite sparse with humidity values forecast to be less
than 40 percent based on the GFS and ECMWF SHIPS intensity guidance.
Therefore, little or no significant intensification is expected
throughout the forecast period, and the official intensity forecast
closely follows a blend of the HCCA and IVCN consensus models.
Although the official forecast calls for Chantal to remain a
tropical cyclone through the 120 h, the abundance of dry air that
the cyclone will be moving through could result in erosion of the
deep convection sooner than currently expected.

FORECAST POSITIONS AND MAX WINDS

INIT  21/0300Z 40.2N  56.2W   35 KT  40 MPH
12H  21/1200Z 40.3N  52.6W   35 KT  40 MPH
24H  22/0000Z 40.2N  48.5W   35 KT  40 MPH
36H  22/1200Z 39.0N  44.7W   35 KT  40 MPH
48H  23/0000Z 37.4N  42.3W   35 KT  40 MPH
72H  24/0000Z 34.9N  42.5W   35 KT  40 MPH
96H  25/0000Z 34.6N  44.8W   35 KT  40 MPH
120H  26/0000Z 36.0N  44.8W   35 KT  40 MPH

$$
Forecaster Stewart

霧峰追風者

減弱為TD。

000
WTNT44 KNHC 220232
TCDAT4

Tropical Depression Chantal Discussion Number   5
NWS National Hurricane Center Miami FL       AL042019
1100 PM AST Wed Aug 21 2019

Chantal's cloud pattern has become quite ragged during the past
several hours with a shrinking intermittently bursting convective
mass remaining sheared to the east of the surface center.  The
initial intensity is lowered to 30 kt and is in agreement with a
recent 0020 UTC ASCAT-A overpass and the subjective satellite
intensity estimates from TAFB and SAB.

There are no changes to the philosophy of the intensity forecast.
Further weakening is forecast through the period as the depression
continues moving through an inhibiting, high statically stable
surrounding environment.  The official forecast calls for Chantal
to degenerate into a remnant low by Friday night, if not sooner,
and is based primarily on the deterministic models.

The initial motion is estimated to be east-southeastward, or 105/16
kt, within the deep-layer mid-latitude westerlies.  Chantal is
forecast to turn southeastward to southward, around the
eastern periphery of a subtropical high, with a reduction in
forward speed, over the next couple of days.  By Saturday night, the
remnants of Chantal is likely to turn toward the west-northwest as
high pressure near the Azores Islands builds to the east of the
cyclone.  The NHC track forecast is a compromise of the TVCA
multi-model guidance and the NOAA HFIP corrected consensus.

FORECAST POSITIONS AND MAX WINDS

INIT  22/0300Z 39.4N  47.4W   30 KT  35 MPH
12H  22/1200Z 38.8N  44.9W   30 KT  35 MPH
24H  23/0000Z 37.9N  42.6W   30 KT  35 MPH
36H  23/1200Z 36.8N  41.4W   30 KT  35 MPH
48H  24/0000Z 35.9N  41.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  25/0000Z 35.8N  42.9W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  26/0000Z...DISSIPATED

$$
Forecaster Robert