霧峰追風者

基本資料  
編號　　　　：15 L
擾動編號日期：2020 年 08 月 31 日 07 時
撤編日期　　：2020 年 08 月 00 日 00 時
90L.INVEST.25kts-1010mb-36N-73W

2. Satellite and radar images indicate that an area of low pressure is
developing a couple of hundred miles east of Jacksonville, Florida.
Environmental conditions appear conducive for some additional
development, and a tropical depression is likely to form by the
middle of the week while the system moves northeastward or
east-northeastward, initially parallel to the southeastern coast
of the U.S. and then away from land.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...70 percent.

霧峰追風者

NHC 展望提升至70趴。

2. An area of low pressure is located about 150 miles south-southeast
of Wilmington, North Carolina. This system has become better
organized overnight, and a tropical depression is likely to form
within a day or so while the system moves northeastward, near but
offshore of the southeastern coast of the United States, and then
away from land.  An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate the system this afternoon if necessary.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...70 percent.

老農民版夜神月

FWC-N發布TCFA

WTNT22 KNGU 311300
SUBJ/TROPICAL CYCLONE FORMATION ALERT//
REF/A/FLEWEACEN NORFOLK VA/301900Z AUG 20//
AMPN/REF IS TROPICAL CYCLONE FORMATION ALERT (WTNT21 KNGU 301900)//
RMKS/ 1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 30.4N 78.4W TO 32.8N 74.6W
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 25 TO 30 KNOTS. METSAT
IMAGERY AT 311300Z INDICATES THAT A CIRCULATION CENTER IS LOCATED
NEAR 31.6N 77.4W. THE SYSTEM IS MOVING NORTHEASTWARD AT 10
KNOTS.
2. REMARKS: A BROAD AREA OF LOW PRESSURE IS LOCATED ABOUT 150 MILES
SOUTH-SOUTHEAST OF WILMINGTON, NORTH CAROLINA. THE SURFACE
CIRCULATION HAS BECOME A LITTLE BETTER DEFINED THIS MORNING AND THE
ASSOCIATED SHOWERS AND THUNDERSTORMS HAVE EXPANDED IN COVERAGE.
SUBSEQUENTLY, A TROPICAL DEPRESSION IS LIKEY TO DEVELOP DURING THE
NEXT 24 HOURS AS IT MOVES GENERALLY NORTHEASTWARD WELL OFFSHORE OF
THE SOUTHEASTERN AND MID-ATLANTIC COAST OF THE UNITED STATES.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY
011300Z.
4. SEE REF A FOR DETAILS ON A TROPICAL CYCLONE FORMATION ALERT
LOCATED NEAR 12.6N 64.0W.//
BT
#0001
NNNN

老農民版夜神月

NHC21Z升格TD15L

1. 000
   
2. WTNT45 KNHC 312044
   
3. TCDAT5
   
4. 
   
5. Tropical Depression Fifteen Discussion Number   1
   
6. NWS National Hurricane Center Miami FL       AL152020
   
7. 500 PM EDT Mon Aug 31 2020
   
8. 
   
9. Satellite images indicate that the area of low pressure offshore of
   
10. the Carolinas has had convection organized in bands since before
    
11. dawn, and scatterometer plus an Air Force Reserve Hurricane
    
12. Hunter mission data confirm that the circulation is closed.  Thus,
    
13. this is now a tropical depression, and the initial wind speed is
    
14. set to 30 kt in accordance with 25-30 kt ASCAT-A data plus buoy
    
15. 42001 readings which earlier had an adjusted 10-m peak of 30 kt.
    
16. 
    
17. The depression is moving northeastward at about 10 kt.  The system
    
18. should gradually turn toward the east-northeast by Wednesday due to
    
19. it moving around the northwest side of the subtropical ridge, then
    
20. move eastward in a few days around the flat ridge.  By late week,
    
21. the cyclone could slow and eventually turn back toward the northeast
    
22. around a rather strong mid-latitude high pressure system over the
    
23. northeast Atlantic.  There is considerable spread in the guidance,
    
24. which really seems to depend upon whether the system stays coherent,
    
25. like the official forecast, or would become a shallow low-level
    
26. swirl by 120h and end up slower and south of forecast track. This
    
27. forecast is near the corrected-consensus guidance, leaning toward
    
28. the ECMWF-based models, and it should be considered of low
    
29. confidence.
    
30. 
    
31. Gradual strengthening is expected over the next day or so while the
    
32. depression remains in a low-to-moderate shear environment. Although
    
33. the depression is expected to be traversing the warm Gulf Stream for
    
34. the next several days, wind shear is expected to greatly increase by
    
35. Wednesday, which should limit intensification.  In fact there's
    
36. some chance the system could decay and lose any deep convection in
    
37. rather strong shear in a few days. However, since it likely will be
    
38. moving near the Gulf Stream, I suspect it will continue to pulse
    
39. thunderstorm activity and stay alive throughout the period. The NHC
    
40. intensity forecast is near or just above the model consensus on
    
41. that reasoning, closest to the HWRF model.  The cyclone could
    
42. become extratropical (or a remnant low) by the end of the forecast,
    
43. but this is very uncertain.
    
44. 
    
45. 
    
46. FORECAST POSITIONS AND MAX WINDS
    
47. 
    
48. INIT  31/2100Z 32.6N  76.5W   30 KT  35 MPH
    
49. 12H  01/0600Z 33.8N  75.0W   35 KT  40 MPH
    
50. 24H  01/1800Z 34.9N  72.4W   40 KT  45 MPH
    
51. 36H  02/0600Z 35.8N  69.7W   40 KT  45 MPH
    
52. 48H  02/1800Z 36.7N  67.0W   40 KT  45 MPH
    
53. 60H  03/0600Z 37.6N  63.7W   35 KT  40 MPH
    
54. 72H  03/1800Z 38.2N  60.5W   35 KT  40 MPH
    
55. 96H  04/1800Z 39.0N  55.0W   35 KT  40 MPH
    
56. 120H  05/1800Z 41.5N  49.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
    
57. 
    
58. $
    
59. Forecaster Blake
    

複製代碼

霧峰追風者

NHC 命名"Omar"，有紀錄以來最早前15個命名風暴。

000
WTNT45 KNHC 012048
TCDAT5

Tropical Storm Omar Discussion Number   5
NWS National Hurricane Center Miami FL       AL152020
500 PM EDT Tue Sep 01 2020

Satellite images show that the system remains sheared with a
bursting pattern on satellite, occasionally exposing the center,
and a large area of curved bands in the southeastern quadrant of
the circulation. Almost all of the subjective and objective Dvorak
estimates, along with SATCON values, are between 35 to 40 kt, and
the lower number is chosen as the initial wind speed since
scatterometer data suggests 30 to 35 kt.  This makes Omar the 15th
named storm of the 2020 Atlantic hurricane season, and is the
earliest 15th storm on record, besting the previous mark by about
a week from Ophelia of 2005.

Any chance for strengthening should end by tomorrow afternoon due
to greatly increasing shear, and weakening is likely to commence by
then.  The persistence of the shear should cause the cyclone to
decay into a remnant low in about 48 hours, if not sooner.  No
significant changes were made to the previous forecast, which is
near the model consensus.

The initial motion remains east-northeast or 065/13 kt.  The
cyclone is being steered by the northern side of the subtropical
ridge, which is forecast to cause a similar motion through tomorrow
and an eastward turn late week due to the orientation of the ridge.
The only notable change to the forecast is a slow down at long
range in most of the guidance, probably due to a shallow system
no longer feeling the stronger deep-layer winds, so the NHC track
prediction follows suit.  The remnant low should dissipate in 4-5
days.


FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 35.3N  71.5W   35 KT  40 MPH
12H  02/0600Z 36.1N  69.4W   35 KT  40 MPH
24H  02/1800Z 36.7N  66.7W   35 KT  40 MPH
36H  03/0600Z 37.2N  63.9W   30 KT  35 MPH
48H  03/1800Z 37.2N  61.1W   25 KT  30 MPH...POST-TROP/REMNT LOW
60H  04/0600Z 37.0N  59.2W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  04/1800Z 37.0N  57.4W   25 KT  30 MPH...POST-TROP/REMNT LOW
96H  05/1800Z 39.5N  53.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
120H  06/1800Z...DISSIPATED

$$
Forecaster Blake

開梅

請問『有紀錄以來最早前15個命名風暴』意思是大西洋有紀錄以來，最早形成的第15號颶風嗎？

老農民版夜神月

NHC21Z降格TD,並預測24H後將減弱為殘餘低氣壓

243
WTNT45 KNHC 022038
TCDAT5

Tropical Depression Omar Discussion Number   9
NWS National Hurricane Center Miami FL       AL152020
500 PM AST Wed Sep 02 2020

Conventional satellite imagery shows that Omar's cloud pattern is
rapidly deteriorating, and the surface circulation center has
become quite ill-defined.  This morning's METOP-A/B scatterometer
passes revealed only a few 33 kt winds well to the southeast of
the center and it's reasonable to determine that those winds are no
longer present.  Therefore, the initial intensity is lowered to 30
kt for this advisory and is further supported by the subjective
satellite intensity T-numbers from TAFB and SAB.  The latest global
model runs agree with the depression degenerating to a remnant
low in 24 hours, or less, and the NHC intensity forecast follows
suit.  Dissipation of the remnant low should occur no later than
Saturday evening.

Omar's initial motion is estimated to be due east, or 090/13 kt,
within the mid-latitude westerlies north of a subtropical ridge
stretching east to west over the central Atlantic.  Omar should
continue moving eastward through Friday, although a couple of the
global models are showing a track a bit more east-southeastward.  
Around the 60 hour period, the remnant low is expected to reduce in
forward speed, and turn toward the east-northeast in response to an
approaching baroclinic system entering the northwest Atlantic.  The
NHC forecast is nudged just a little to the right of the previous
one, and lies close to the HCCA and TVCA consensus models.


FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 36.1N  65.7W   30 KT  35 MPH
12H  03/0600Z 36.1N  63.6W   30 KT  35 MPH
24H  03/1800Z 36.0N  61.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
36H  04/0600Z 35.7N  59.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
48H  04/1800Z 35.7N  57.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
60H  05/0600Z 35.9N  56.9W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  05/1800Z...DISSIPATED

$$
Forecaster Roberts