老農民版夜神月

  一級颶風  
編號：14 L
名稱：Nicholas

  基本資料  
擾動編號日期：2021 年 09 月 11 日 14 時
命名日期　　：2021 年 09 月 12 日 23 時
撤編日期　　：2021 年 09 月 18 日 02 時
登陸地點　　：美國-德州

  巔峰時期資料  
近中心最強風速 ：65  kt ( Cat.1 )
海平面最低氣壓 ：988 百帕

  擾動編號資料  
94L.INVEST.15kts.1010mb.16.5N.87W


  NHC：70%

1. Disorganized showers and thunderstorms over portions of Central
America, southeastern Mexico, and the adjacent waters of the
northwestern Caribbean Sea and southern Gulf of Mexico are
associated with a tropical wave interacting with an upper-level
trough.  Upper-level winds over the western Gulf of Mexico are
expected to become more conducive for development over the weekend,
and a tropical depression is likely to form on Sunday or Monday
while the system moves northwestward and then northward near the
coast of northeastern Mexico.  Further development of this system
will be possible through the middle of next week if it remains over
water, and interests along the western and northwestern Gulf coast
should monitor the progress of this system.

Regardless of development, this disturbance is expected to produce
heavy rain across portions of Central America and the Yucatan
Peninsula today, which may lead to flash flooding and mudslides.  
By late this weekend, heavy rain will likely reach portions of the
western Gulf coast, including coastal Texas and Louisiana through
the middle of next week.  Localized significant rainfall amounts
will be possible, resulting in limited flash and urban flooding.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 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90%

1. Showers and thunderstorms over the Bay of Campeche and southern
Gulf of Mexico have been increasing during the past several hours
near and east of a surface trough of low pressure.  A tropical
depression is expected to form later today or tonight while the
system moves northwestward and then northward near the coast of
northeastern Mexico.  Additional development is possible through
the middle of next week if the system remains over water, and
interests along the western and northwestern Gulf coast should
monitor the progress of this disturbance.  An Air Force Hurricane
Hunter aircraft is scheduled to investigate the system this
morning, and potential tropical cyclone advisories could be
initiated later today.

Regardless of development, the disturbance will continue to produce
heavy rain across portions of southern Mexico today, including the
western Yucatan Peninsula, which may lead to flash flooding and
mudslides.  By late today, heavy rain is expected to reach portions
of the Texas and Louisiana coasts with a heavy rain threat
continuing across those coasts through the middle of the week.
Localized significant rainfall amounts are possible, potentially
resulting in areas of flash, urban, and isolated river flooding.
* Formation chance through 48 hours...high...90 percent.
* Formation chance through 5 days...high...90 percent.

老農民版夜神月

FWC-N發布TCFA

SUBJ/TROPICAL CYCLONE FORMATION ALERT (94L)//
WTNT21 KNGU 112000
RMKS/1. FORMATION OF A SIGNIFICANT TROPICAL CYCLONE IS POSSIBLE WITHIN
100 NM EITHER SIDE OF A LINE FROM 18.6N 93.3W TO 22.3N 96.6W
WITHIN THE NEXT 00 TO 24 HOURS. AVAILABLE DATA DOES NOT JUSTIFY
ISSUANCE OF NUMBERED TROPICAL CYCLONE WARNINGS AT THIS TIME.
WINDS IN THE AREA ARE ESTIMATED TO BE 15 TO 20 KNOTS. METSAT
IMAGERY, SYNOPTIC DATA AND RADAR DATA AT 110340Z INDICATE THAT A
CIRCULATION CENTER IS LOCATED NEAR 18.6N 93.2W. THE SYSTEM IS
MOVING NORTHWESTWARD AT 12 KNOTS.
2. A BROAD AREA OF LOW PRESSURE LOCATED ALONG THE COAST OF SOUTHEASTERN MEXICO IS PRODUCING A LARGE AREA OF SHOWERS AND THUNDERSTORMS THAT ARE EXTENDING OVER THE BAY OF CAMPECHE. ENVIRONMENTAL CONDITIONS OVER THE SOUTHERN GULF OF MEXICO ARE EXPECTED TO BECOME MORE FAVORABLE FOR DEVELOPMENT OF THE SYSTEM AS IT EMERGES OVER THE BAY BY TONIGHT. AS THE DISTURBANCE MOVES GENERALLY NORTHWESTWARD AT 5 TO 10 KT SUNDAY, FURTHER DEVELOPMENT IS EXPECTED AND A TROPICAL DEPRESSION IS LIKELY TO FORM OVER THE SOUTHERN GULF OF MEXICO BY SUNDAY NIGHT, OR EARLY MONDAY.
3. THIS ALERT WILL BE REISSUED, UPGRADED TO WARNING OR CANCELLED BY 122000Z.//
BT
NNNN

老農民版夜神月

命名Nicholas

000
WTNT44 KNHC 121502
TCDAT4

Tropical Storm Nicholas Discussion Number   1
NWS National Hurricane Center Miami FL       AL142021
1000 AM CDT Sun Sep 12 2021

Showers and thunderstorms associated with a broad area of low
pressure over the southern Bay of Campeche have increased overnight
and very recently become better organized with a loose band of
convection around the northeastern portion of the circulation. An
Air Force Reserve reconnaissance aircraft that has been
investigating the system has found 44-kt flight-level winds and
SFMR winds that support a 35-kt initial intensity.  Based on the
recent increase in organization and the 35-kt initial intensity,
advisories are being initiated on Tropical Storm Nicholas, the
fourteenth named storm of the Atlantic hurricane season.

The storm is located within an environment of moderate
south-southwesterly vertical wind shear, over warm waters, and in a
moist and unstable atmosphere. These conditions should allow gradual
strengthening over the next 24 to 48 hours.  The NHC intensity
forecast follows suit and calls for gradual strengthening until
the system reaches the coast of Texas.  The official wind speed
forecast is near the higher end of the guidance in best agreement
with the SHIPS statistical guidance, the HFIP corrected consensus,
and the HWRF.  In this case, the intensity forecast is highly
dependent on eventual track of the system.  A track to the east of
the NHC forecast could result in a lower wind shear environment
and slightly more time over water for the system to strengthen.  
Conversely a track to the west of the forecast track would result
in the system interacting with land much sooner.

Since the system is still in its formative stage the initial motion
estimate is a somewhat uncertain 330/11 kt.  A north-northwestward
motion around the western portion of a mid-level ridge that is
sliding east near the coast of the Carolinas, should continue to
steer Nicholas in that direction for the next 24 to 48 hours.  
After that time, steering currents weaken and the cyclone is
expected to move slowly north-northeastward between a couple of
mid-level ridges located to the east and west of Nicholas.  The
track guidance generally agrees with this overall scenario but
there is some cross-track spread with the UKMET along the left side
of the guidance envelope taking the storm into northeastern Mexico,
while the GFS, HWRF, and HMON are along the right side.  The NHC
track is near the various consensus models and both the EC and GFS
ensemble means.

Key Messages:

1. Tropical storm conditions are expected along portions of the
northeastern coast of Mexico and the coast of south Texas
beginning on Monday.  Nicholas is forecast to approach the middle
Texas coast as a strong tropical storm on Tuesday, and tropical
storm conditions are possible along portions of the middle and upper
Texas coasts late Monday night and Tuesday.

2. There is the possibility of life-threatening storm surge along
the coast of Texas from the Mouth of the Rio Grande to High Island.
Residents in these areas should follow any advice given by local
officials.

3.  Periods of heavy rainfall are expected to impact portions of the
Texas and Louisiana coasts today through the middle of the week.
Significant rainfall amounts are possible, potentially resulting in
areas of flash, urban, and isolated river flooding.


FORECAST POSITIONS AND MAX WINDS

INIT  12/1500Z 20.5N  94.8W   35 KT  40 MPH
12H  13/0000Z 21.9N  95.7W   40 KT  45 MPH
24H  13/1200Z 24.1N  96.6W   45 KT  50 MPH
36H  14/0000Z 26.4N  96.9W   50 KT  60 MPH
48H  14/1200Z 28.2N  96.5W   55 KT  65 MPH
60H  15/0000Z 29.4N  95.9W   40 KT  45 MPH...INLAND
72H  15/1200Z 30.3N  95.2W   30 KT  35 MPH...INLAND
96H  16/1200Z 31.0N  94.8W   25 KT  30 MPH...INLAND
120H  17/1200Z 32.0N  94.5W   20 KT  25 MPH...POST-TROP/REMNT LOW

$$
Forecaster Brown

老農民版夜神月

沿墨西哥東部近海北上,即將登陸

000
WTNT44 KNHC 131436
TCDAT4

Tropical Storm Nicholas Discussion Number   6
NWS National Hurricane Center Miami FL       AL142021
1000 AM CDT Mon Sep 13 2021

Doppler radar data from Brownsville and Corpus Christi, Texas, along
with reconnaissance aircraft flight-level wind data, indicate that
Nicholas' inner-core structure has undergone some radical changes
since the previous advisory. The earlier near-eyewall pattern
dissipated a few hours ago, and has been replaced with what appears
to be an ongoing reformation of a new center abut 90 nmi
north-northeast of the old center. The aircraft recently found a
pressure of 1000 to 1002 mb with the dissipating original center,
while Doppler radar velocity data show a pronounced mid- to
upper-level circulation forming farther north as previously
mentioned. The Air Force Reserve Hurricane Hunter aircraft is going
to be concentrating its reconnoiter mission in Nicholas'
northeastern quadrant to see if reformation of the low-level center
is occurring beneath the mid-level circulation noted in radar data.
The initial wind speed remains 50 kt based on recent aircraft 850-mb
flight-level winds of 59 kt, which equates to about 47 kt equivalent
surface winds.

The initial motion is an uncertain 005/10 kt due to the erosion and
ongoing reformation of the center. Despite the recent inner-core
erosion, the latest NHC model guidance remains in fairly good
agreement on Nicholas moving northward through a weakness in the
subtropical ridge. The GFS model has been performing exceptionally
well with predicting the recent erosion and more northward
reformation of the Nicholas' center. The new NHC track forecast is
similar to but slightly east or right of the previous advisory
track, and lies along the eastern edge of the track consensus model
envelope, which is to the left of the GFS track prediction.

Although the inner-core convective pattern has been disrupted,
recent trends in the radar data suggest that a new center should
reform farther northeast into the convective cloud shield. The
latest GFS- and ECMWF-based SHIPS shear analyses indicate that
westerly shear of near 20 kt is allegedly affecting Nicholas.
However, water vapor satellite imagery suggests that the upper-level
shear vector is actually from a south-southwesterly direction, which
is more along than across the cyclone's forward motion, thus
reducing the magnitude and negative effects of the vertical wind
shear. Therefore, strengthening is still expected until landfall
as Nicholas continues to move over slightly warmer Gulf waters. It
is possible that Nicholas could become a hurricane just before
landfall, and that's the reason for the northeastward extension of
the hurricane watch area.  Nicholas should rapidly weaken after
landfall due to increased frictional effects, strong southwesterly
shear, and entrainment of mid-level dry air, resulting in
degeneration into a tropical depression by late Tuesday and a
remnant low on Wednesday.  Otherwise, no significant changes were
made to the previous advisory intensity forecast.

Key Messages:

1. Heavy rainfall will impact portions of the Texas and Louisiana
coasts through the middle of the week. Significant rainfall amounts
are possible, potentially resulting in areas of life-threatening
flash and urban flooding, especially in highly urbanized
metropolitan areas. Minor to isolated moderate river flooding is
also expected.

2. There is the danger of life-threatening storm surge inundation
along the coast of Texas from Port Aransas to Sabine Pass.
Residents in these areas should follow any advice given by
local officials.

3. Nicholas is forecast to approach the middle Texas coast as a
strong tropical storm by this evening, and could be near hurricane
intensity at landfall.  Tropical storm conditions are expected
along portions of the middle Texas coast beginning this afternoon,
with hurricane conditions possible from Port Aransas to San Luis
Pass by late afternoon through tonight.

4. Tropical storm conditions are expected along portions of the
coast of south Texas into the afternoon.

FORECAST POSITIONS AND MAX WINDS

INIT  13/1500Z 26.4N  96.8W   50 KT  60 MPH
12H  14/0000Z 27.5N  96.7W   60 KT  70 MPH
24H  14/1200Z 29.1N  96.3W   45 KT  50 MPH...INLAND
36H  15/0000Z 30.2N  95.4W   30 KT  35 MPH...INLAND
48H  15/1200Z 31.0N  94.0W   25 KT  30 MPH...INLAND
60H  16/0000Z 31.5N  92.5W   20 KT  25 MPH...INLAND
72H  16/1200Z 32.0N  91.1W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  17/1200Z...DISSIPATED

$$
Forecaster Stewart

king111807

NHC升格C1

019
WTNT44 KNHC 140305
TCDAT4

Hurricane Nicholas Discussion Number   8
NWS National Hurricane Center Miami FL       AL142021
1000 PM CDT Mon Sep 13 2021

Very recently, a WeatherFlow Station at Matagorda Bay, Texas,
reported sustained winds of 66 kt with a gust to 83 kt.  Based on
this observation, Nicholas is being upgraded to a hurricane on this
advisory, and a Hurricane Warning is issued.  No additional
strengthening is anticipated until the system makes landfall, and
gradual weakening is expected during the next 2-3 days while
Nicholas moves over southeastern Texas and southwestern Louisiana.

Nicholas is moving north-northeastward, or around 020/10 kt.  The
system is currently moving through a weakness in the mid-level
subtropical ridge.  Within 12 to 24 hours, after Nicholas has moved
inland, the ridge is forecast to weaken and leave Nicholas in an
area of light steering currents.  As a result, during the next
couple of days, the cyclone is expected to turn eastward and slow to
a crawl near southwestern Louisiana.  The official forecast is
slower than the previous one, but not as slow as the new model
consensus.


Key Messages:

1. Heavy rainfall will impact portions of southeastern Texas,
Louisiana, and southern Mississippi through the middle of the week.
Significant rainfall amounts are expected, potentially resulting in
areas of life-threatening flash and urban flooding, along the
eastern Texas coast into southwestern Louisiana.  Minor to isolated
major river flooding is also possible in smaller river basins and
urban areas.

2. There is the danger of life-threatening storm surge inundation
along the coast of Texas from Port Aransas to Sabine Pass.
Residents in these areas should follow any advice given by
local officials.

3. Hurricane conditions are expected within the Hurricane
Warning area and Tropical storm conditions are expected with
the Tropical Storm Warning area along the Texas coast.


FORECAST POSITIONS AND MAX WINDS

INIT  14/0300Z 28.4N  95.8W   65 KT  75 MPH
12H  14/1200Z 29.6N  95.4W   50 KT  60 MPH...INLAND
24H  15/0000Z 30.2N  94.8W   35 KT  40 MPH...INLAND
36H  15/1200Z 30.3N  93.7W   30 KT  35 MPH...INLAND
48H  16/0000Z 30.3N  93.3W   25 KT  30 MPH...INLAND
60H  16/1200Z 30.3N  93.0W   25 KT  30 MPH...INLAND
72H  17/0000Z 30.5N  92.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  18/0000Z...DISSIPATED

$$
Forecaster Pasch

老農民版夜神月

登陸,NHC降TS,將於美國境內結束短暫而瀟灑的風生,如同駕雲翻騰照亮著二八年華

000
WTNT44 KNHC 140856
TCDAT4

Tropical Storm Nicholas Discussion Number   9
NWS National Hurricane Center Miami FL       AL142021
400 AM CDT Tue Sep 14 2021

Radar and surface observations indicate that Nicholas has continued
to move slowly inland and has weakened during the past few hours,
with the strongest winds now located near southern Galveston Bay.
The initial wind speed is set to 60 kt, perhaps generously.
Additional weakening is anticipated as Nicholas moves over land,
with increasing southwesterly shear also assisting this process.
No significant changes were made to the intensity forecast.

The storm is moving north-northeastward at about 8 kt, and should
gradually turn northeastward and eastward during the next day or so.
Nicholas is likely to slow to a crawl over Louisiana on Wednesday
as it loses any significant steering.  The new track forecast is
similar to the previous one, but a smidge faster. While the exact
track is tough to pin down due to inconsistent model forecasts,
most guidance shows a significant flash flood risk along the
Gulf Coast during the next couple of days.


Key Messages:

1. Heavy rainfall will impact areas from the upper coast of Texas,
across Louisiana, southern Mississippi and far southern Alabama
through the middle of the week. Significant rainfall amounts are
expected, potentially resulting in areas of life-threatening flash
and urban flooding across these areas.  Minor to isolated major
river flooding is also possible in smaller river basins and urban
areas.

2. There is the danger of life-threatening storm surge inundation
along the coast of Texas from Sargent to Sabine Pass. Residents in
these areas should follow any advice given by local officials.

3. Tropical storm conditions are expected in Tropical Storm Warning
area along the Texas coast today and along the southwestern
Louisiana coast by afternoon.


FORECAST POSITIONS AND MAX WINDS

INIT  14/0900Z 29.3N  95.6W   60 KT  70 MPH...INLAND
12H  14/1800Z 29.9N  95.1W   45 KT  50 MPH...INLAND
24H  15/0600Z 30.3N  94.0W   30 KT  35 MPH...INLAND
36H  15/1800Z 30.4N  93.4W   25 KT  30 MPH...INLAND
48H  16/0600Z 30.4N  92.8W   20 KT  25 MPH...INLAND
60H  16/1800Z 30.5N  92.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
72H  17/0600Z...DISSIPATED

$$
Forecaster Blake

老農民版夜神月

NHC降格TD

208
WTNT34 KNHC 142338
TCPAT4

BULLETIN
Tropical Depression Nicholas Intermediate Advisory Number 11A
NWS National Hurricane Center Miami FL       AL142021
700 PM CDT Tue Sep 14 2021

...NICHOLAS WEAKENS TO A TROPICAL DEPRESSION...
...LIFE-THREATENING FLASH FLOODS EXPECTED ACROSS PORTIONS OF THE
DEEP SOUTH DURING THE NEXT COUPLE OF DAYS...


SUMMARY OF 700 PM CDT...0000 UTC...INFORMATION
----------------------------------------------
LOCATION...29.9N 94.4W
ABOUT 25 MI...40 KM W OF PORT ARTHUR TEXAS
ABOUT 60 MI...95 KM ENE OF HOUSTON TEXAS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...ENE OR 70 DEGREES AT 6 MPH...9 KM/H
MINIMUM CENTRAL PRESSURE...1003 MB...29.62 INCHES