老農民版夜神月

  三級颶風  
編號：27 L
名稱：Epsilon

  基本資料  
擾動編號日期：2020 年 10 月 16 日 20 時
命名日期　　：2020 年 10 月 20 日 00 時
撤編日期　　：2020 年 10 月 27 日 08 時
登陸地點　　：無

  巔峰時期資料  
近中心最強風速 ：100 kt ( Cat.3 )
海平面最低氣壓 ：952 百帕
  擾動編號資料  
94L.INVEST.20kts-1013mb-31.1N-54.2W.
  NHC：20%  

1. Shower activity associated with a broad non-tropical low pressure
system located about 600 miles east-southeast of Bermuda has
become a little better organized this morning.  Additional gradual
tropical or subtropical development of this system is possible
through the middle of next week while the low meanders over the
central Atlantic well to the southeast of Bermuda.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...40 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%/60%

1. Shower activity associated with a broad non-tropical low pressure
system located about 600 miles east-southeast of Bermuda is
continuing to become better organized, and satellite wind data
indicates that the circulation has become somewhat better defined.  
Additional development of this system is expected, and a
subtropical or tropical depression could form during the next
few days while the low meanders over the central Atlantic well to
the southeast of Bermuda.
* Formation chance through 48 hours...medium...40 percent.
* Formation chance through 5 days...medium...60 percent.

dom

展望提升至High 70%/80%

1. Showers and thunderstorms continue to gradually become better
organized in association with a non-tropical low pressure
system located about 500 miles east-southeast of Bermuda.  Although
the circulation is still somewhat elongated, the center appears
better defined than it was yesterday. Continued slow development
is expected, and a subtropical depression or storm is likely to
form during the next couple of days while the low meanders well to
the southeast of Bermuda.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

老農民版夜神月

FWC-N1300Z發布TCFA

SUBJ/TROPICAL CYCLONE FORMATION ALERT//
WTNT21 KNGU 171300
RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE
WITHIN 100 NM EITHER SIDE OF A LINE FROM 30.4N 55.5W TO 28.1N 56.7W
WITHIN THE NEXT 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 30 TO 40 KNOTS. METSAT
IMAGERY AT 171300Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 30.3N 55.5W. THE SYSTEM IS MOVING SOUTHWESTWARD AT 06 KNOTS.
2. REMARKS: EARLIER SATELLITE DERIVED WIND DATA INDICATE THAT A
NON-TROPICAL LOW PRESSURE SYSTEM LOCATED ABOUT 450 NM EAST-SOUTHEAST
OF BERMUDA HAS BECOME BETTER DEFINED OVERNIGHT. SUBSEQUENT RAIN SHOWER
AND THUNDERSTORM ACTIVITTY IS GRADUALLY DEVELOPING NEAR THE CENTER
OF CIRCULATION. IF THESE CONVECTIVE TRENDS CONTINUE, A SUBTROPICAL
DEPRESSION OR STORM WILL LIKELY FORM DURING THE NEXT 24 HOURS AS
IT DRIFTS SOUTHWARD.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 181300Z.//

老農民版夜神月

數值目前還是比較支持94L能有所發展的

老農民版夜神月

NHC展望提升至90%,即將升格

1. Showers and thunderstorms have increased in organization in
association with a large non-tropical low pressure system located
about 700 miles southeast of Bermuda.  Although environmental
conditions are expected to be only marginally conducive for
development during the next day or so, a subtropical or tropical
depression could still develop later today or on Tuesday. However,
upper-level winds are forecast to become more favorable for tropical
cyclone formation by late Tuesday and Wednesday while the low
meanders well to the southeast of Bermuda. See NOAA High Seas
Forecast products for more details on this system.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

老農民版夜神月

NHC12Z升格27L,初報上望75節不封頂

743
WTNT42 KNHC 191205
TCDAT2

Tropical Depression Twenty-Seven Special Discussion Number   1
NWS National Hurricane Center Miami FL       AL272020
800 AM AST Mon Oct 19 2020

Deep convection associated with the area of low pressure over the
central Atlantic has become significantly better organized
overnight.  The low-level center is located near the western edge of
the convection, but the system has enough organization to be
declared a tropical cyclone.  Therefore, advisories are being
initiated at this time.  The system appears to be near
tropical-storm strength, but since earlier classifications were just
below that intensity the system is being started as a 30-kt tropical
depression.  The system appears more tropical than subtropical
since it is no longer co-located with an upper-level low and it
appears to have a fairly small radius of maximum winds. Therefore,
it has been designated a tropical cyclone.  Scatterometer data
later this morning should provide a better assessment of the
system's intensity.  The depression is located over SSTs over 27-28
degrees Celsius and within an area of moderate westerly shear.  
These conditions should allow for gradual strengthening over the
next day or so.  After that time, the shear is expected to decrease
and continued strengthen is anticipated. The NHC intensity
forecasts calls for the system to become a hurricane within 72
hours, and is in best agreement with the HCCA and ICON intensity
consensus models.

The depression is located in an area of weak steering currents near
the base of a mid- to upper-level trough that extends southwestward
from the northeastern Atlantic.  As a result, little net motion is
expected through tonight.  A mid- to upper-level ridge is forecast
to build over the western and central Atlantic to the north of the
system by midweek.  As the ridge slides eastward later this week,
the cyclone should move west-northwestward to northwestward at a
faster rate of speed.  This motion will bring the system close to
Bermuda by late week and the interests on that island should
closely monitor the progress of the cyclone.  The dynamical models
are in relatively good agreement on the overall scenario and the
NHC track forecast is near the center of the guidance envelope.

FORECAST POSITIONS AND MAX WINDS

INIT  19/1200Z 25.8N  55.5W   30 KT  35 MPH
12H  19/1800Z 25.8N  55.4W   35 KT  40 MPH
24H  20/0600Z 26.0N  55.3W   45 KT  50 MPH
36H  20/1800Z 26.9N  55.9W   50 KT  60 MPH
48H  21/0600Z 28.0N  57.8W   55 KT  65 MPH
60H  21/1800Z 28.6N  59.3W   60 KT  70 MPH
72H  22/0600Z 29.5N  60.3W   65 KT  75 MPH
96H  23/0600Z 31.7N  62.3W   70 KT  80 MPH
120H  24/0600Z 33.5N  63.8W   75 KT  85 MPH

$$
Forecaster Brown

老農民版夜神月

NHC升格TS,命名Epsilon,命名報上望80節不封頂

000
WTNT42 KNHC 191456
TCDAT2

Tropical Storm Epsilon Discussion Number   2
NWS National Hurricane Center Miami FL       AL272020
1100 AM AST Mon Oct 19 2020

Although the center of the system has become exposed over the past
few hours, it is very well defined.  In addition, the convective  
banding over the northern and eastern portions of the circulation
has continued to improve.  Based on a Dvorak classification of T2.5
from TAFB, the system is upgraded to a 35-kt tropical storm. ASCAT-A
has missed the circulation, but ASCAT-B caught the far eastern edge
of the wind field and indicates winds of 30-35 kt in that area.  The
tropical storm is located within an environment of moderate
southwesterly to westerly vertical wind shear and over warm waters.  
These conditions should allow for gradual strengthening over the
next day or so. By 48 hours, decreasing vertical wind shear could
allow for more significant intensification, and there is increasing
spread in the intensity guidance by that time.  The statistical
guidance is at the upper-end of the envelope while the regional
hurricane models are lower.  The NHC forecast is a bit on the
conservative side for now, and lies just above the intensity
consensus aids.  Given the expected decrease in shear, some upward
adjustment in the intensity forecast may be required in subsequent
advisories.

Epsilon is meandering over the central Atlantic as it is located
within an area of weak steering currents near the base of a mid- to
upper-level trough that extends southwestward from the northeastern
Atlantic. A mid- to upper-level ridge is forecast to build over the
western and central Atlantic to the north of the system by midweek,
and this ridge should slide eastward later in the week.  These
changes in the synoptic pattern should cause Epsilon to begin moving
west-northwestward to northwestward at a faster rate of speed by
midweek. The models are again in fairly good agreement and the NHC
track is near the center of the guidance envelope.  

Key Message:

1. Epsilon is forecast to be at or near hurricane strength when
it approaches Bermuda late this week.  While it is too soon to
determine the exact details of Epsilon's track and intensity near
the island, there is a risk of direct impacts from wind, rainfall,
and storm surge on Bermuda, and interests there should closely
monitor the progress of Epsilon.

FORECAST POSITIONS AND MAX WINDS

INIT  19/1500Z 25.6N  55.3W   35 KT  40 MPH
12H  20/0000Z 25.8N  55.1W   40 KT  45 MPH
24H  20/1200Z 26.4N  55.4W   50 KT  60 MPH
36H  21/0000Z 27.6N  56.7W   55 KT  65 MPH
48H  21/1200Z 28.3N  58.5W   60 KT  70 MPH
60H  22/0000Z 29.1N  59.8W   65 KT  75 MPH
72H  22/1200Z 30.2N  60.8W   70 KT  80 MPH
96H  23/1200Z 32.3N  62.7W   75 KT  85 MPH
120H  24/1200Z 34.5N  63.3W   80 KT  90 MPH

$$
Forecaster Brown