老農民版夜神月

03Z報出爐,定強維持100節,並持續上望120KT

078
WTNT42 KNHC 040237
TCDAT2

Hurricane Larry Discussion Number  14
NWS National Hurricane Center Miami FL       AL122021
1100 PM AST Fri Sep 03 2021

Larry has had a distinct but slightly ragged 15 n mi wide eye
during the past few hours, while convective cloud tops within the
eyewall have been gradually cooling.  Intensity estimates have
responded, somewhat significantly, to the improved structure, and
TAFB and SAB Dvorak fixes at 0000 UTC were T5.5/102 kt and T5.0/90
kt, respectively.  In addition, objective UW-CIMSS ADT and SATCON
estimates are near 105 kt.  Larry has become a major hurricane, the
third of the Atlantic season, with estimated 100-kt sustained winds.

The hurricane is located due south of a mid-tropospheric high
centered over the central Atlantic, and continues to move toward
the west-northwest (285/14 kt).  Larry is generally expected to move
around the southwestern periphery of the high, turning northwestward
at a slower speed by Sunday and then north-northwestward by
Wednesday as a deep-layer trough moves eastward across the eastern
United States.  There is fairly high confidence in the track
forecast, with model guidance showing a below- to near-normal amount
of spread through day 5.  The new NHC track forecast is right along
the forecast from the previous advisory through day 3, and then
nudged slightly westward on days 4 and 5.  It should be noted that a
few of the consensus aids, including HCCA, are still a little bit
west of the official forecast at day 5, which might portend
additional westward nudges in future advisories.

By strict definition, Larry hasn't quite rapidly intensified since
this time yesterday, but it has still strengthened quickly over
waters that are considered only marginally warm (26-27 degrees
Celsius).  For the next couple of days, low shear, higher oceanic
heat content, and a more unstable environment should favor
additional intensification.  However, there are still indications
that Larry could run into an environment of higher shear and less
upper-level divergence in 2-3 days as it approaches a
mid-/upper-level trough currently located north and northeast of
the Leeward Islands.  In addition, internal processes within the
hurricane's core itself, such as eyewall replacement cycles, could
affect the intensity.  In light of all these factors, the NHC
intensity forecast relies on persistence to show additional
strengthening during the next 36 hours, and then holds Larry steady
through 60 hours at an intensity that is near the upper end of the
guidance.  Very gradual weakening is anticipated on days 3 through
5 while Larry heads in the direction of higher latitudes, yet the
hurricane is forecast to remain at major hurricane intensity for
the entire 5-day forecast period.

Significant ocean swells generated by Larry's growing wind field
are expected to reach the Lesser Antilles on Sunday, and then
spread westward to portions of the Greater Antilles, the Bahamas,
and Bermuda on Monday and Tuesday.  These swells could cause
life-threatening rip currents and high surf conditions.  Large
swells are also likely to spread to the east coast of the United
States by midweek.


FORECAST POSITIONS AND MAX WINDS

INIT  04/0300Z 15.5N  43.3W  100 KT 115 MPH
12H  04/1200Z 16.2N  45.3W  110 KT 125 MPH
24H  05/0000Z 17.4N  47.6W  115 KT 130 MPH
36H  05/1200Z 18.7N  49.7W  120 KT 140 MPH
48H  06/0000Z 20.0N  51.7W  120 KT 140 MPH
60H  06/1200Z 21.2N  53.6W  120 KT 140 MPH
72H  07/0000Z 22.4N  55.3W  115 KT 130 MPH
96H  08/0000Z 25.4N  58.5W  115 KT 130 MPH
120H  09/0000Z 29.5N  61.5W  105 KT 120 MPH

$$
Forecaster Berg

老農民版夜神月

NHC00Z升格MH

AL, 12, 2021090400,   , BEST,   0, 152N,  427W, 100,  964, HU,

老農民版夜神月

NHC升格C2

FORECAST POSITIONS AND MAX WINDS

INIT  03/2100Z 15.0N  42.0W   85 KT 100 MPH
12H  04/0600Z 15.8N  44.1W   95 KT 110 MPH
24H  04/1800Z 16.9N  46.5W  105 KT 120 MPH
36H  05/0600Z 18.1N  48.7W  110 KT 125 MPH
48H  05/1800Z 19.4N  50.8W  120 KT 140 MPH
60H  06/0600Z 20.7N  52.8W  120 KT 140 MPH
72H  06/1800Z 21.9N  54.5W  115 KT 130 MPH
96H  07/1800Z 24.7N  57.6W  115 KT 130 MPH
120H  08/1800Z 28.7N  60.5W  105 KT 120 MPH

老農民版夜神月

NHC上調上望至120KT

FORECAST POSITIONS AND MAX WINDS

INIT  02/2100Z 13.7N  35.8W   70 KT  80 MPH
12H  03/0600Z 14.0N  38.4W   80 KT  90 MPH
24H  03/1800Z 14.7N  41.3W   95 KT 110 MPH
36H  04/0600Z 15.7N  43.9W  105 KT 120 MPH
48H  04/1800Z 16.9N  46.3W  110 KT 125 MPH
60H  05/0600Z 18.3N  48.6W  120 KT 140 MPH
72H  05/1800Z 19.7N  50.6W  120 KT 140 MPH
96H  06/1800Z 22.2N  54.0W  115 KT 130 MPH
120H  07/1800Z 25.1N  57.0W  110 KT 125 MPH

老農民版夜神月

NHC06Z升格一級颶風

AL, 12, 2021090206, , BEST, 0, 129N, 314W, 65, 987, HU,

老農民版夜神月

已增強至TS上限60KT,即將升格C1

FORECAST POSITIONS AND MAX WINDS

INIT  01/2100Z 12.5N  29.4W   60 KT  70 MPH
12H  02/0600Z 12.6N  31.8W   70 KT  80 MPH
24H  02/1800Z 13.0N  34.9W   85 KT 100 MPH
36H  03/0600Z 13.7N  38.0W   95 KT 110 MPH
48H  03/1800Z 14.6N  40.9W  100 KT 115 MPH
60H  04/0600Z 15.6N  43.5W  105 KT 120 MPH
72H  04/1800Z 16.9N  46.2W  105 KT 120 MPH
96H  05/1800Z 19.5N  50.5W  105 KT 120 MPH
120H  06/1800Z 22.5N  54.0W  105 KT 120 MPH

老農民版夜神月

09Z命名Larry

042
WTNT42 KNHC 010858
TCDAT2

Tropical Storm Larry Discussion Number   3
NWS National Hurricane Center Miami FL       AL122021
800 AM CVT Wed Sep 01 2021

Deep convection with cloud tops colder than -80C have increased over
and to the west of the low-level center since the previous advisory.
Subjective satellite intensity estimates at 0600 UTC from TAFB and
SAB were T2.5/35 kt and T3.0/45 kt, while the most recent objective
intensity estimates from UW-CIMSS are T2.8/41 kt from ADT and 37 kt
from SATCON. An average of these intensity estimates support
increasing the advisory intensity to 40 kt, making the cyclone
Tropical Storm Larry. In addition, 0300 UTC and 0700 UTC
observations from ship VRNF3, which recently passed through the
center of Larry, reported a pressure of 1006.8 mb and winds near 25
kt. These data were the basis for the estimated central pressure of
1003 mb, a pressure value that also supports an intensity of 40 kt.

Larry has turned more westward over the past several hours, and the
new motion estimate is 280/17 kt. Larry is expected to move around
the southern and southwestern periphery of the sprawling
Bermuda-Azores ridge for the next 5 days, resulting in a general
west motion for the next 36 hours or so, followed by a turn toward
the west-northwest on Friday, and a northwestward motion over the
weekend and continuing into early next week. There has been a
pronounced westward shift in the track guidance for this cycle, with
the greatest shift coming from the GFS model. Over the past 36
hours, the GFS has shifted its track westward by more than 500 nmi,
and even the latest shift still keeps the GFS model the easternmost
track forecast in the guidance suite. In contrast, the ECMWF and
UKMET models, which lie along the westernmost portion of the
guidance envelope, have been fairly stable. Owing to the westward
shift in the overall guidance envelope, and considering the GFS
solution as an outlier model, the new NHC forecast track has also
been shifted westward, and lies between the NOAA-HCCA
corrected-consensus model to the south, and the tightly packed TVCA
simple-consensus model and FSSE corrected-consensus model to the
north. Given the poor handling of the ridge to the north of Larry by
the GFS, subsequent NHC forecast tracks may have to be shifted
farther west.

Given the improved inner-core wind field based on earlier ASCAT wind
data and reports from ship VRNF3, along with warm sea-surface
temperatures of 28 deg C and light easterly to southeasterly
vertical shear of around 5 kt, steady strengthening is expected for
the next 24 hours or so. By 36 hours when Larry is expected to be a
hurricane and have a well-established and tighter inner-core wind
field and possibly an eye, rapid intensification is forecast, with
Larry becoming a major hurricane by 72 hour. This in large part due
to the massive equatorward upper-level outflow pattern that all
of the global and regional models are forecasting, which is the
same type of outflow pattern that recently occurred with Hurricane
Ida. The new official intensity forecast is above the previous
advisory forecast by about 10 kt at all forecast times, and
conservatively follows an average of the Decay-SHIPS, COAMPS-TC,
FSSE, and ECMWF models. This intensity forecast is near the upper
end of the guidance envelope and is above the other consensus
intensity models.


FORECAST POSITIONS AND MAX WINDS

INIT  01/0900Z 12.3N  24.8W   40 KT  45 MPH
12H  01/1800Z 12.5N  27.5W   50 KT  60 MPH
24H  02/0600Z 12.6N  30.6W   60 KT  70 MPH
36H  02/1800Z 13.1N  33.7W   70 KT  80 MPH
48H  03/0600Z 13.6N  36.8W   85 KT 100 MPH
60H  03/1800Z 14.4N  39.7W   95 KT 110 MPH
72H  04/0600Z 15.5N  42.0W  100 KT 115 MPH
96H  05/0600Z 18.2N  46.9W  105 KT 120 MPH
120H  06/0600Z 21.3N  50.6W  105 KT 120 MPH

$$
Forecaster Stewart

老農民版夜神月

初報上望90節不封頂

142
WTNT42 KNHC 312035
TCDAT2

Tropical Depression Twelve Discussion Number   1
NWS National Hurricane Center Miami FL       AL122021
800 PM CVT Tue Aug 31 2021

Satellite imagery, along with earlier scatterometer data, indicates
that the low pressure area over the eastern tropical Atlantic has
a well-defined circulation and sufficient organized convection to
be considered a tropical depression.  Thus, advisories are being
initiated on Tropical Depression Twelve.  The initial intensity is
set at 30 kt based on satellite intensity estimates from TAFB and
SAB as well as the scatterometer data.

The initial motion is a somewhat uncertain 285/14.  A strong low-
to mid-level ridge to the north should cause the cyclone to move
westward at a faster forward speed for the next 36 h or so,
followed by a gradual turn toward the west-northwest and northwest
by the end of the period as the depression moves along the
southwest side of the ridge.  There is some spread in the guidance
after 36-48 h, with the GFS and GFS ensemble mean showing a more
northward motion while the UKMET and the UKMET ensemble mean show a
more westward motion.  The official forecast is near the middle of
the guidance envelope and is close to the HFIP corrected consensus
model, which is a little to the south of the other consensus models.

Conditions appear favorable for intensification during the next 72
h or so as the cyclone is in a moist environment with light shear
and warm sea surface temperatures.  The intensity forecast thus
calls for the cyclone to become a tropical storm in 12 h or so and
reach hurricane strength in 48-60 h.  By the end of the forecast
period, the forecast track takes the cyclone over slightly cooler
water and into a drier air mass.  Based on this, the intensity
forecast calls for a slower development rate.  The official
intensity forecast is in the middle of the intensity guidance, and
it is possibly conservative given that many of the global models
are showing the development of a large and powerful tropical
cyclone.

FORECAST POSITIONS AND MAX WINDS

INIT  31/2100Z 11.2N  21.1W   30 KT  35 MPH
12H  01/0600Z 11.6N  23.9W   35 KT  40 MPH
24H  01/1800Z 12.0N  27.5W   40 KT  45 MPH
36H  02/0600Z 12.1N  30.7W   50 KT  60 MPH
48H  02/1800Z 12.5N  33.7W   60 KT  70 MPH
60H  03/0600Z 13.3N  36.5W   70 KT  80 MPH
72H  03/1800Z 14.3N  39.0W   80 KT  90 MPH
96H  04/1800Z 16.5N  43.5W   85 KT 100 MPH
120H  05/1800Z 19.5N  47.5W   90 KT 105 MPH

$$
Forecaster Beven