Official Discussion issued by the National Hurricane Center

Debby (AL042018) DATA RELEASED: 8/9/2018 5:00:00 AM UTC

Copy of official data

Tropical Storm Debby Discussion Number   8
NWS National Hurricane Center Miami FL       AL042018
500 AM AST Thu Aug 09 2018

Debby is still hanging on to tropical storm status with a new burst
of deep convection having recently developed just south of the
low-level center. However, the cyclone's overall cloud pattern has
deteriorated significantly since the previous advisory, and there
are no longer any convective bands in the region where earlier
40-plus-kt ASCAT winds were observed. As a result, the initial
intensity has been lowered slightly to 40 kt, which is consistent
with an average of consensus current T-number and current intensity
estimates of T2.5 and T3.0, respectively, from both TAFB and SAB.

Debby has begun to accelerate northeastward, and the motion
estimate is now 055/15 kt. A faster northeastward motion is expected
as Debby gets caught up in the high-latitude westerlies ahead of a
fast-moving shortwave trough. The small cyclone is forecast to open
up into a surface trough by 24 h or so due to Debby moving faster
than 20 kt and steady weakening of the circulation over the cold
waters of the far north Atlantic. The new NHC track forecast is
similar to the previous advisory and basically lies down the middle
of the tightly packed guidance envelope.

Although Debby has been and is forecast to continue straddling a
tight SST gradient with 26+ deg C water just to the southeast and
south of the center, the ingestion of drier and more stable air
from the north is expected to induce gradual weakening until
dissipation or absorption occurs in about 24 h. Debby could briefly
become extratropical in about 18 h, followed by dissipation shortly
thereafter.

FORECAST POSITIONS AND MAX WINDS

INIT  09/0900Z 43.6N  45.1W   40 KT  45 MPH
12H  09/1800Z 45.4N  41.4W   35 KT  40 MPH
24H  10/0600Z...DISSIPATED

$$
Forecaster Stewart