霧峰追風者

基本資料  
編號　　　　：91 L
擾動編號日期：2022 年 08 月 28 日 08 時
撤編日期　　：2022 年 00 月 00 日 00 時
91L.INVEST.20kts-1009mb-13.9N-44.9W

1. Central Tropical Atlantic:
Shower activity associated with an elongated area of low pressure
over the central tropical Atlantic Ocean has become a little better
organized since yesterday. Environmental conditions are forecast to
be generally favorable for additional gradual development over the
next several days, and a tropical depression could form by the
middle of next week as it moves west-northwestward at 10 to 15 mph
toward the waters east of the Leeward Islands.
* Formation chance through 48 hours...low...20 percent.
* Formation chance through 5 days...medium...50 percent.

霧峰追風者

1. Central Tropical Atlantic:
Shower and thunderstorm activity associated with an elongated area
of low pressure located several hundred miles east of the Lesser
Antilles has increased since yesterday.  Although environmental
conditions are only marginally conducive, additional gradual
development of this system is expected and a tropical depression
is likely to form within the next few days.  The disturbance is
forecast to move slowly toward the west and then west-northwest
at 5 to 10 mph, toward the adjacent waters of the northern Leeward
Islands. Additional information on this system can be found in High
Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...medium...60 percent.
* Formation chance through 5 days...high...80 percent.

霧峰追風者

000
WTNT41 KNHC 030236
TCDAT1

Tropical Storm Earl Discussion Number   1
NWS National Hurricane Center Miami FL       AL062022
1100 PM AST Fri Sep 02 2022

Air Force Reserve and NOAA Hurricane Hunter aircraft each flew
missions into the area of low pressure east of the Leeward Islands
this afternoon into this evening, and the data from those flights
indicated that the circulation and center of the low became well
defined today.  Deep convection has also persisted with the low,
albeit sheared near and to the east of the center, which means the
system has finally met the criteria of a tropical cyclone.
Flight-level, surface, and dropsonde data from the reconnaissance
flights all indicate that the system is producing
tropical-storm-force winds in the convection well to the east of the
center, and for good measure TAFB provided a Dvorak estimate of
T2.5/35 kt.  The low is therefore being designated as Tropical Storm
Earl with maximum winds of 35 kt.  The minimum pressure is estimated
to be 1005 mb based on an Air Force dropsonde that measured a
surface pressure of 1007 mb with 23-kt winds.

Earl is moving toward the west-northwest, or 295/12 kt.  The track
guidance is in fairly good agreement during the next 3 days, with a
low- to mid-level ridge expected to steer Earl west-northwestward
and then northwestward at decreasing forward speed.  The ridge to
the north is forecast to weaken and shift westward around day 3,
which should cause Earl to slow down to less than 5 kt and turn
northward by day 4, and then north-northeastward by day 5 as it
begins to feel the influence of the mid-latitude westerlies to the
north.  The biggest outliers on days 4 and 5 are the GFS and HMON,
which show a stronger Earl moving faster toward the northeast.  For
now, the NHC official forecast favors a slower scenario on days 4
and 5, closer to the ECMWF, HWRF, HCCA, and TVCN.

Moderate to strong shear is likely to continue affecting Earl for
much of the next 5 days, possibly peaking in 3 to 4 days according
to the SHIPS guidance.  Mid-level relative humidity ahead of the
system also remains lower than what is ideal for strengthening, and
as a result, the NHC intensity forecast shows only modest
intensification through the forecast period.  This forecast is very
close to the IVCN and HCCA consensus aids.

Tropical-storm-force winds are forecast to remain on the northern
and eastern side of the circulation, and as a result, are not
expected to move across the northern Leeward Islands, the Virgin
Islands, or Puerto Rico.  However, any southward shift of Earl's
center would increase the risk of tropical-storm-force winds in
those areas.


KEY MESSAGES:

1.  Tropical storm Earl is forecast to pass near or just to the
north of the northern Leeward Islands, the Virgin Islands, and
Puerto Rico over the weekend.  Gusty winds, especially in squalls,
area possible on those islands over the next day or two.

2.  Heavy rainfall from Earl is expected to lead to limited flash,
urban, and small stream flooding over the Leeward Islands, U.S. and
British Virgin Islands, and Puerto Rico this weekend.  Rapid rises
on rivers are possible in Puerto Rico.


FORECAST POSITIONS AND MAX WINDS

INIT  03/0300Z 18.4N  60.3W   35 KT  40 MPH
12H  03/1200Z 18.9N  62.0W   35 KT  40 MPH
24H  04/0000Z 19.5N  63.8W   40 KT  45 MPH
36H  04/1200Z 20.2N  65.3W   40 KT  45 MPH
48H  05/0000Z 20.9N  66.4W   40 KT  45 MPH
60H  05/1200Z 21.5N  67.2W   40 KT  45 MPH
72H  06/0000Z 22.2N  67.7W   40 KT  45 MPH
96H  07/0000Z 23.3N  67.8W   40 KT  45 MPH
120H  08/0000Z 24.7N  67.0W   45 KT  50 MPH

$$
Forecaster Berg

霧峰追風者

000
WTNT41 KNHC 042056
TCDAT1

Tropical Storm Earl Discussion Number   8
NWS National Hurricane Center Miami FL       AL062022
500 PM AST Sun Sep 04 2022

The large bursting pattern that was observed this morning with Earl
has evolved more into a shear pattern this afternoon, with the
low-level center becoming partially exposed to the west of the
coldest cloud tops that are displaced about 50 n mi east of the
center. An Air Force Reconnaissance aircraft conducted an
afternoon mission through the storm and found the highest 850 mb
flight-level winds of 51 kt with SFMR winds up to 48 kt. Satellite
intensity estimates remain unchanged from this morning, and the
initial intensity will remain 45 kt for this advisory.

The last several fixes from the aircraft indicate Earl has resumed a
slow northwestward motion at 310/4 kt. The forecasting reasoning has
not changed much from the previous forecast cycle, as a mid-level
ridge is expected to result in Earl turning to the north-northwest
over the next 12 to 24 hours. This slow motion should continue
thereafter as the ridge continues to slowly break down and shift
gradually eastward through the early part of this week. Towards the
end of the forecast, the strongest ridging is expected to be east of
Earl, allowing the cyclone to slowly recurve to the north-northeast.
The latest track guidance this cycle has narrowed somewhat, with the
latest ECMWF forecast shifting east, while the most recent GFS
shifted a touch west. Thus, little change was made to the NHC track
forecast this advisory, which lies quite close to the latest TVCN
and HCCA consensus aids.

It appears that this morning's convective burst was unsuccessful in
helping to vertically align Earl's vortex, and the mid-level center
noted on Puerto Rico radar is still located east of the aircraft
fixes. This failure was likely due to continued westerly vertical
wind shear undercutting the outflow layer and importing dry air into
Earl's core. However, most of the global and regional hurricane
models suggest that additional convective bursts will continue over
the next 24-48 hours, resulting in gradual intensification as the
cyclone becomes better vertically aligned. Thus, the latest NHC
intensity forecast continues to show slow intensification in the
short-term, with Earl possibly attaining hurricane intensity in a
couple of days. After 72 hours, both the GFS and ECMWF suggest the
shear will decrease, while the cyclone may also undergo a favorable
trough interaction. The guidance responds to this pattern by
indicating more significant intensification, and the latest advisory
shows a somewhat higher peak intensity of 105 kt by day 5.

While tropical-storm-force winds are still forecast to stay north of
the northern Leeward Islands, the Virgin Islands, and Puerto Rico,
training rain-bands are producing heavy rainfall over these islands.
Users should refer to products issued by local weather offices in
these areas.


KEY MESSAGES:

1.  Heavy rainfall from Earl is expected to lead to limited flash,
urban, and small stream flooding impacts over the Leeward Islands,
U.S. and British Virgin Islands, and Puerto Rico today. Rapid rises
on rivers and mudslides in areas of steep terrain are possible in
Puerto Rico. Locally considerable flood impacts cannot be ruled out
in areas that receive heavier rainfall totals.

2.  Earl is forecast to pass to the north of the the Virgin Islands
and Puerto Rico tonight, but gusty winds, especially in squalls,
remain possible on those islands overnight.


FORECAST POSITIONS AND MAX WINDS

INIT  04/2100Z 20.0N  65.2W   45 KT  50 MPH
12H  05/0600Z 21.1N  65.2W   50 KT  60 MPH
24H  05/1800Z 22.3N  65.4W   55 KT  65 MPH
36H  06/0600Z 23.5N  65.5W   60 KT  70 MPH
48H  06/1800Z 24.6N  65.6W   65 KT  75 MPH
60H  07/0600Z 25.4N  65.5W   70 KT  80 MPH
72H  07/1800Z 26.4N  65.1W   75 KT  85 MPH
96H  08/1800Z 28.2N  64.0W   85 KT 100 MPH
120H  09/1800Z 31.4N  61.5W  105 KT 120 MPH

$$
Forecaster Papin