老農民版夜神月

NHC04/09Z正式升格08L為TS,命名Gabrielle

ZCZC MIATCDAT3 ALL
TTAA00 KNHC DDHHMM

Tropical Storm Gabrielle Discussion Number   3
NWS National Hurricane Center Miami FL       AL082019
500 AM AST Wed Sep 04 2019

A late-arriving ASCAT-C scatterometer pass revealed peak surface
winds of 33 kt in the northwestern quadrant, and satellite imagery
since then indicates a marked increase in the deep convection,
albeit sheared to the northeast of the well-defined low-level center
noted in the scatterometer data.  Based on these wind data and a
satellite intensity estimate of T2.5/35 kt from TAFB and UW-CIMSS
ADT, the depression has been upgraded to Tropical Storm Gabrielle,
the seventh named storm of the 2019 Atlantic hurricane season.

The initial motion is 310/09 kt.  The initial position was adjusted
slightly to the southwest of the previous positions based on the
aforementioned scatterometer data.  This has resulted in the new
forecast track being shifted a little to the left of the previous
advisory track at all forecast times.  For the next 5 days,
Gabrielle is forecast to move generally northwestward toward a break
in the Bermuda-Azores high pressure ridge located between 40W-50W
longitude. The official forecast track lies close to a blend of the
tightly packed consensus models TVCN, TVCX, and NOAA-HCCA.

During the entire forecast period, Gabrielle is forecast to remain
in a marginally conducive environment characterized by moderate
southwesterly vertical wind shear of 15-20 kt, SSTs of 26-27 deg C,
and dry mid-level air with humidity values less than 50 percent.  As
a result, only slight strengthening is forecast through 72 hours.
The new NHC intensity forecast is similar to the previous advisory,
and closely follows the HCCA consensus intensity model.

FORECAST POSITIONS AND MAX WINDS

INIT  04/0900Z 19.6N  33.6W   35 KT  40 MPH
12H  04/1800Z 20.3N  34.4W   40 KT  45 MPH
24H  05/0600Z 21.1N  35.3W   40 KT  45 MPH
36H  05/1800Z 22.1N  36.4W   45 KT  50 MPH
48H  06/0600Z 23.4N  37.7W   45 KT  50 MPH
72H  07/0600Z 27.5N  41.0W   50 KT  60 MPH
96H  08/0600Z 31.5N  44.5W   50 KT  60 MPH
120H  09/0600Z 35.5N  47.2W   50 KT  60 MPH

$$
Forecaster Stewart

NNNN

老農民版夜神月

NHC08/15Z新報,預測一天內將在高緯再度微幅增強後發展至巔峰,並於大約三日後加速並轉化

WTNT43 KNHC 081452
TCDAT3

Tropical Storm Gabrielle Discussion Number  21
NWS National Hurricane Center Miami FL       AL082019
1100 AM AST Sun Sep 08 2019

Gabrielle continues to show signs of becoming better organized.
Deep convection now wraps about two-thirds of the way around the
center of circulation, and microwave imagery shows a distinct curved
band on the western semicircle.  A blend of the various satellite
intensity estimates support holding the initial intensity at 50 kt.
However, this value may be a little conservative.

The tropical storm will continue to be in a moderately favorable
environment for intensification over the next 24 hours or so. And,
based on the improving presentation of Gabrielle since late
last night, some intensification seems likely during that time.
After 24 to 36 hours, increasing southwesterly shear will begin to
impact the cyclone as a mid-latitude trough approaches the region,
and the system will move over cooler waters.  This should cause a
gradual weakening trend to begin. After 48 hours, Gabrielle is
expected to merge with a cold front and become an extratropical
cyclone. The official forecast intensity has been increased slightly
through 36 hours out of respect for the near term likelihood for
intensification. Otherwise, the forecast is similar to the previous
one, and is in agreement with the various consensus aids.

The initial motion is 330/10kt. Gabrielle will turn to the north
later today and then northeast by Monday as the system rounds the
western periphery of a mid-level ridge centered near the Azores.
Once Gabrielle turns northeastward, it will become embedded in the
increasing southwesterly flow ahead of the approaching mid-latitude
trough, which will accelerate the cyclone's forward motion. The
official forecast is little changed from the previous one, and is
near the tightly clustered track guidance.


FORECAST POSITIONS AND MAX WINDS

INIT  08/1500Z 33.8N  49.0W   50 KT  60 MPH
12H  09/0000Z 35.6N  49.1W   60 KT  70 MPH
24H  09/1200Z 38.4N  47.5W   60 KT  70 MPH
36H  10/0000Z 41.2N  43.8W   60 KT  70 MPH
48H  10/1200Z 43.7N  39.0W   55 KT  65 MPH
72H  11/1200Z 50.1N  24.7W   45 KT  50 MPH...POST-TROP/EXTRATROP
96H  12/1200Z 57.8N   5.3W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  13/1200Z...DISSIPATED

$$
Forecaster Latto