[AL]巴哈马群岛东北四级飓风“华金”(11L.Joaquin) - 实测气压933mb，严重影响巴哈马 - MAX:135kt
楼主#更多 发布于：2015-09-26 08:05
AL, 98, 2015092600, , BEST, 0, 245N, 685W, 20, 1011, DB, 34, NEQ, 0, 0, 0, 0, 1012, 90, 70, 0, 0, L, 0, , 0, 0, INVEST, S, 0, , 0, 0, 0, 0, genesis-num, 034, SPAWNINVEST, al712015 to al982015,
Disorganized showers and a few thunderstorms over the western
Atlantic Ocean several hundred miles south-southwest of Bermuda are
associated with an upper-level low and a surface trough.
Development, if any, of this system is expected to be slow to occur
while it drifts toward the north. Upper-level winds are forecast to
become unfavorable for development after the weekend.
* Formation chance through 48 hours...low...10 percent
* Formation chance through 5 days...low...10 percent
2. Satellite imagery indicates that a weak area of surface low pressure
has formed about 450 miles south-southwest of Bermuda, and the
associated shower and thunderstorm activity has increased since
yesterday. Some additional gradual development of this system is
possible during the next couple of days while it moves toward the
north-northwest or northwest at 5 to 10 mph. After that time,
development is not expected due to unfavorable upper-level winds.
* Formation chance through 48 hours...medium...40 percent
* Formation chance through 5 days...medium...40 percent
2. Showers and thunderstorms are showing signs of organization in
association with an area of low pressure located about 425 miles
south-southwest of Bermuda. Some additional development of this
system is possible and this system could become a tropical
depression during the next day or so while it moves toward
the northwest at 5 to 10 mph. After that time, development is not
expected due to unfavorable upper-level winds. For additional
information on this system, see High Seas Forecasts issued by the
National Weather Service.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...medium...50 percent
Showers and thunderstorms have become better organized since
yesterday in association with an elongated area of low pressure
located about midway between the central Bahamas and Bermuda.
Additional slow development of this system is likely during the next
day or two while it moves toward the northwest at 5 to 10 mph. After
that time, development is not expected due to unfavorable
upper-level winds. For more information on this system, see High
Seas Forecasts issued by the National Weather Service.
* Formation chance through 48 hours...medium...60 percent
* Formation chance through 5 days...medium...60 percent
WTNT41 KNHC 280239
TROPICAL DEPRESSION ELEVEN DISCUSSION NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL112015
1100 PM AST SUN SEP 27 2015
Late-afternoon visible satellite imagery indicates that the
circulation of the low pressure area located midway between the
Bahamas and Bermuda has become well defined. Since the low has
already had persistent and organized deep convection, the system is
being declared a tropical depression. A 2312 UTC SSMI/S overpass
indicated that the center of the depression has become at least
partially exposed to the northwest of a large convective mass due to
moderate northwesterly shear. The initial wind speed is set to 30
kt, based on a T2.0/30 kt classification from TAFB. The depression
is expected to be blasted by strong north-northwesterly or northerly
winds associated with the tail of an upper-level trough over the
central Atlantic beginning on Monday. In fact, global models show
the shear being sufficiently strong enough to result in the cyclone
either becoming a remnant low or dissipating within a few days. The
intensity forecast is below the multi-model consensus through the
forecast period, closest to the HWRF solution.
A low- to mid- level ridge north and northeast of the cyclone is
steering the lower half of the depression's circulation
northwestward while increasing northwesterly winds aloft are
opposing this motion. The net deep-layer mean flow is therefore
providing for only a slow northwestward motion of 315/02 kt, a
rather uncertain estimate considering the scatter of recent fixes.
This synoptic pattern is expected to persist for the next couple of
days, resulting in a the cyclone's drifting west-northwestward or
northwestward. The low- to mid-level ridge is forecast to shift
eastward in 2-3 days as a trough reaches the eastern seaboard of the
United States, and the increasingly shallow system should turn
northwestward and north-northwestward at a faster forward speed if
it still exists. The track forecast is close to a blend of the GFS
and ECMWF model solutions.
FORECAST POSITIONS AND MAX WINDS
INIT 28/0300Z 27.5N 68.7W 30 KT 35 MPH
12H 28/1200Z 27.7N 69.4W 30 KT 35 MPH
24H 29/0000Z 27.9N 69.9W 30 KT 35 MPH
36H 29/1200Z 28.2N 70.4W 30 KT 35 MPH
48H 30/0000Z 28.8N 70.8W 30 KT 35 MPH
72H 01/0000Z 31.0N 71.6W 30 KT 35 MPH
...DEPRESSION STRENGTHENS TO TROPICAL STORM JOAQUIN...
...THE TENTH NAMED STORM OF THE SEASON...
ECMWF這報對米國東岸威脅甚大, 尤其是Chesapeake Bay......