GG
原文：

000
WTPZ44 KNHC 130235
TCDEP4

Post-Tropical Cyclone Elida Discussion Number  17
NWS National Hurricane Center Miami FL       EP092020
800 PM PDT Wed Aug 12 2020

Elida has been devoid of deep convection for more than 12 hours, and
since it is over SSTs of 22-23 degrees Celsius, it is unlikely that
organized deep convection will return.  As a result, the system
has become a post-tropical cyclone, and this will be the last NHC
advisory on Elida.  The initial intensity has been set at 35 kt,
which is a blend of the latest Dvorak T- and CI-numbers from TAFB
and SAB.  The cyclone is heading toward even cooler waters and a
more stable environment.  Continued weakening is therefore
expected, and the remnant low is forecast to dissipate by Friday
morning.

The initial motion estimate is 315/8 kt. A low- to mid-level
trough located to the northwest of the cyclone has caused a break
in the subtropical ridge.  This has allowed the system to turn
northwestward, and a northwestward to north-northwestward motion is
expected to continue until dissipation occurs on Friday. The global
model guidance continues to suggest that the low-level center will
decelerate as the mid-level circulation is pulled northward ahead
of the aforementioned trough.  The new NHC track foreast is similar
to the previous advisory and again shows a slower forward motion
than the global model trackers.

This is the last NHC advisory on Elida.  For additional information
on this system please see High Seas Forecasts issued by the
National Weather Service, under AWIPS header NFDHSFEPI, WMO header
FZPN02 KWBC, and on the web at ocean.weather.gov/shtml/NFDHSFEPI.php


FORECAST POSITIONS AND MAX WINDS

INIT  13/0300Z 24.4N 120.2W   35 KT  40 MPH...POST-TROPICAL
12H  13/1200Z 25.3N 121.0W   25 KT  30 MPH...POST-TROP/REMNT LOW
24H  14/0000Z 26.6N 121.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
36H  14/1200Z...DISSIPATED

$$
Forecaster Brown

機器翻譯(翻譯品質差僅供參考)：

000
WTPZ44 KNHC 130235 TCDEP4
埃里達

熱帶風暴後討論編號17
NWS邁阿密颶風中心美國佛羅里達州EP092020
800 PM PDT 2020年8月12日星期三

Elida一直沒有深對流超過12個小時，並且
由於其SST超過22-23攝氏度，
有組織的深對流不太可能恢復。結果，該系統
已成為熱帶後氣旋，這將是
Elida 上最新的NHC 諮詢。初始強度設定為35 kt，
是TAFB
和SAB 的最新Dvorak T和CI編號的混合。旋風正朝著更涼的水和
更穩定的環境。因此，
預計將持續走弱，預計剩餘的低點將在周五
早上消散。

初始運動估計為315/8 kt。
旋风西北部的低至中層低谷造成了
亞熱帶海脊的破裂。這使系統可以向
西北轉動，並且從西北向北向西北的運動
預計將持續到星期五消散。全球
模型指南繼續表明，
隨著中層環流
在上述谷底之前向北拉動，低層中心將減速。新的NHC東方賽道類似
到先前的諮詢，並且再次顯示出
比全局模型跟踪器慢的前進速度。

這是NHC關於Elida的最新諮詢。有關
此系統的更多信息，請參閱
國家氣象局發布的“公海預報” ，位於AWIPS標頭NFDHSFEPI，WMO標頭
FZPN02 KWBC下，以及位於以下網址的網絡ocean.weather.gov/shtml/NFDHSFEPI.php


預測位置和最大風速

INIT 13 / 0300Z 24.4N 120.2W 35 KT 40 MPH ...後熱帶
12H 13 / 1200Z 25.3N 121.0W 25 KT 30 MPH ...後熱帶/短低
24H 14 / 0000Z 26.6N 121.5W 20 KT 25 MPH ...後低/後低
36H 14 / 1200Z ...已分發

$$
Forecaster Brown

15Z升格二級颶風,NHC認為此刻便是巔峰,定強85KT,中心最低氣壓975百帕

000
WTPZ44 KNHC 111439
TCDEP4

Hurricane Elida Discussion Number  11
NWS National Hurricane Center Miami FL       EP092020
900 AM MDT Tue Aug 11 2020

Elida continued to get better organized through about 12Z, with the
eye becoming better defined inside the cold overcast.  Since then,
the eye has become a little less distinct, suggesting that the
hurricane has peaked in intensity.  Satellite intensity estimates
from TAFB and SAB were 90 kt at 12Z, and based mainly on these the
initial intensity is increased to a possibly conservative 85 kt.

The initial motion is now northwestward or 305/12 kt.  The track
guidance is in good agreement than Elida should move west-
northwestward for the next 36 h or so, and this part of the new
forecast track is similar to the previous track.  After that, there
is spread between the NAVGEM/UK Ensemble mean/COAMPS-TC models,
which show a more westward motion, and the bulk of the remaining
guidance which shows a northwestward motion with a decrease in
forward speed due to Elida interacting with an upper-level low off
of the coast of California.  The new forecast follows the
northwestward scenario and the various consensus models, and it has
been nudged to the right of the previous forecast.

Elida is moving toward colder sea surface temperatures, with the
center forecast to be over 24C water in 24 h and 23C in 48 h.  This
should lead to rapid weakening after 12 h or so.  The new intensity
forecast follows the trend of the guidance and the previous
forecast in calling for Elida to drop below hurricane strength in
just over 24 h and to degenerate to a remnant low by 48 h.  The new
forecast has the remnant low dissipating between 72-96 h, and the
global models suggest this could occur earlier than currently
forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  11/1500Z 21.3N 113.8W   85 KT 100 MPH
12H  12/0000Z 22.1N 115.9W   80 KT  90 MPH
24H  12/1200Z 23.1N 118.0W   65 KT  75 MPH
36H  13/0000Z 23.9N 119.6W   45 KT  50 MPH
48H  13/1200Z 24.8N 120.6W   30 KT  35 MPH...POST-TROP/REMNT LOW
60H  14/0000Z 25.8N 121.5W   25 KT  30 MPH...POST-TROP/REMNT LOW
72H  14/1200Z 27.0N 122.5W   20 KT  25 MPH...POST-TROP/REMNT LOW
96H  15/1200Z...DISSIPATED

$$
Forecaster Beven

NHC10/21Z升格09E為一級颶風，定強65節，上望+24H後80節

000
WTPZ44 KNHC 102033
TCDEP4

Hurricane Elida Discussion Number   8
NWS National Hurricane Center Miami FL       EP092020
300 PM MDT Mon Aug 10 2020

Elida continues to gradually gain strength.  Satellite images show
that the storm has a well organized central dense overcast and
curved bands that surround that feature.  Recent microwave images
show a partial eyewall, but dry slots appear to be preventing it
from completely closing off.  The satellite intensity estimates
have increased, and support upgrading Elida to a 65-kt hurricane.
The center of Elida is passing just north of Socorro Island.

The hurricane has about another day over warm water and in
generally favorable atmospheric conditions, so some additional
strengthening seems likely during that time period.  After that,
however, progressively cooler waters, drier air, and an increase in
southerly shear in a few days should cause a steady weakening
trend.  Elida will likely become a remnant low in 3 to 4 days when
it is forecast to be in quite dry conditions and over cool 23 C
waters.  The NHC intensity forecast continues to lie at the high
end of the guidance in the short term, but falls near the middle of
the guidance envelope beyond a couple of days.

Elida is moving west-northwestward at 12 kt.  A mid-level ridge
located over northern Mexico and the southwestern U.S. should steer
the hurricane west-northwestward at about the same forward speed
for another couple of days.  After that time, the models diverge
with the latest runs of the GFS and ECMWF showing a more northward
motion toward a mid- to upper-level trough.  Conversely, the HWRF,
UKMET, and other models show a more westward motion in the low-level
flow. As a compromise, the NHC track forecast has been adjusted
northward, but it still lies closer to the southern end of the
guidance.

FORECAST POSITIONS AND MAX WINDS

INIT  10/2100Z 19.6N 110.9W   65 KT  75 MPH
12H  11/0600Z 20.4N 112.9W   75 KT  85 MPH
24H  11/1800Z 21.4N 115.5W   80 KT  90 MPH
36H  12/0600Z 22.3N 117.8W   70 KT  80 MPH
48H  12/1800Z 23.0N 119.8W   55 KT  65 MPH
60H  13/0600Z 23.4N 121.3W   45 KT  50 MPH
72H  13/1800Z 23.8N 122.8W   35 KT  40 MPH
96H  14/1800Z 24.5N 125.0W   20 KT  25 MPH...POST-TROP/REMNT LOW
120H  15/1800Z...DISSIPATED

$$
Forecaster Cangialosi

周子堯@FB 發表於 2020-8-9 11:40
NHC 0809/02Z升格為TD-09E，首報上望Cat.1

命名和風速掃描

WTPZ44 KNHC 090849
TCDEP4

Tropical Storm Elida Discussion Number   2
NWS National Hurricane Center Miami FL       EP092020
400 AM CDT Sun Aug 09 2020

Deep convection associated with the cyclone has increased during the
past several hours, particularly in a band in the southeast
quadrant. Late-arriving ASCAT data valid around 0330 UTC revealed
that the cyclone's low-level wind structure was still somewhat
elongated in a SSW-NNE orientation. That said, the ASCAT data also
showed a few believable 30-35 kt vectors in the northeast quadrant
of the cyclone. That supports an intensity of 35 kt, making Elida
the 5th tropical storm of the 2020 eastern North Pacific season.

Even with the assistance of the ASCAT pass, it has been difficult to
track the center of the tropical storm this morning. The center of
Elida appears to have jumped somewhat northward since last night,
and further reformations of the center will be possible until the
system consolidates some more. The northward adjustment in the
position resulted in a slight adjustment to the track forecast in
that direction, but overall the tropical storm is still forecast to
move generally west-northwestward for the next several days, steered
by a mid-level ridge extending over northern Mexico and the
southwestern United States. A westward turn is likely near the end
of the forecast period as Elida weakens and low-level tradewinds
become the dominant steering mechanism. Overall the models are in
excellent agreement and confidence in the track forecast is fairly
high.

All of the statistical and regional hurricane intensity models
forecast Elida to strengthen and become a hurricane within 48 h.
Since the cyclone does not appear to have a tight inner-core yet,
only modest strengthening is forecast for the first 12 h, followed
by a faster rate after that. The extent of strengthening is still
highly uncertain, and the guidance ranges from a minimal to major
hurricane. The new NHC forecast is very similar to the previous one
and the multi-model consensus. Elida is forecast to weaken later
this week after it reaches cooler waters to the north.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 15.8N 104.1W   35 KT  40 MPH
12H  09/1800Z 16.8N 106.1W   40 KT  45 MPH
24H  10/0600Z 17.9N 108.8W   55 KT  65 MPH
36H  10/1800Z 18.8N 111.2W   65 KT  75 MPH
48H  11/0600Z 19.7N 113.8W   75 KT  85 MPH
60H  11/1800Z 20.6N 116.4W   75 KT  85 MPH
72H  12/0600Z 21.2N 119.0W   70 KT  80 MPH
96H  13/0600Z 21.9N 123.5W   55 KT  65 MPH
120H  14/0600Z 21.5N 127.0W   35 KT  40 MPH

$$
Forecaster Zelinsky

NHC 0809/02Z升格為TD-09E，首報上望Cat.1

775
WTPZ44 KNHC 090233
TCDEP4

Tropical Depression Nine-E Discussion Number   1
NWS National Hurricane Center Miami FL       EP092020
1000 PM CDT Sat Aug 08 2020

Deep convection associated with the area of disturbed weather that
we have been monitoring to the south of Mexico has persisted for
more than 12 hours.  Directional ambiguities from an earlier ASCAT-B
scatterometer overpass suggest that the system has a closed
circulation, and recent satellite imagery shows that convection is
increasing near the estimated center while banding features are
becoming better defined.  The system has sufficient convective
organization and circulation to be designated as a tropical
depression, and advisories are being initiated.  Based on a ship
report and the scatterometer data, the current intensity is
estimated to be near 30 kt.  Upper-level outflow from the tropical
cyclone is becoming better defined, and the system will be moving
over warm waters and in a low-shear environment through early next
week.  With these conducive factors for strengthening, the cyclone
is likely to become a tropical storm rather soon and a hurricane
within a couple of days.  The official forecast is similar to the
model consensus but given the anticipated environment, this may be
conservative.  By days 3-5, cooler waters will likely lead to
weakening.

Although the center is not yet very well defined, my best estimate
of initial motion is a fairly climatological 295/12 kt.  The
steering pattern looks quite straightforward for the next several
days.  A pronounced 500 mb ridge extending westward from the
southwest United States over the Pacific should maintain a
generally west-northwestward track for much of the forecast period.
Late in the period, as the cyclone weakens, the shallower
circulation should turn westward with the lower-level flow.  The
official track forecast is mainly a combination of the simple and
corrected multi-model consensus solutions.


FORECAST POSITIONS AND MAX WINDS

INIT  09/0300Z 14.7N 102.6W   30 KT  35 MPH
12H  09/1200Z 15.6N 104.5W   35 KT  40 MPH
24H  10/0000Z 16.7N 107.0W   45 KT  50 MPH
36H  10/1200Z 17.8N 109.5W   55 KT  65 MPH
48H  11/0000Z 18.8N 112.1W   65 KT  75 MPH
60H  11/1200Z 19.7N 114.7W   75 KT  85 MPH
72H  12/0000Z 20.5N 117.3W   70 KT  80 MPH
96H  13/0000Z 21.4N 122.7W   55 KT  65 MPH
120H  14/0000Z 21.0N 127.0W   40 KT  45 MPH

$$
Forecaster Pasch

NHC展望提升至70%

1. Showers and thunderstorms associated with a broad area of low
pressure located a few hundred miles southwest of the Gulf of
Tehuantepec continue to show some signs of organization.  
Environmental conditions are forecast to be conducive for further
development, and a tropical depression is likely to form during the
next couple of days while the system moves west-northwestward,
remaining offshore the coast of southwestern Mexico.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...90 percent.