Tropical Depression Seven Discussion Number 1
NWS National Hurricane Center Miami FL AL072024
Issued by the NWS Weather Prediction Center College Park MD
200 PM CVT Wed Sep 11 2024
Tropical Depression Seven has formed in the eastern Atlantic
today. This formation is based on scatterometer depicting a
closed circulation center, and organized deep convection based on
TAFB/SAB satellite classifications. Satellite imagery also
indicates that the low-level circulation has consolidated beneath
the mid-level center based upon visible imagery The initial
intensity is set to 30 kt, based on the scatterometer data.
The depression is estimated to be moving 285/16 kt. The system
should move to the west or west-northwest over the next few days
with the storm being steered by a subtropical ridge to the north of
the Azores. Confidence in the depression's track gradually lessens
beyond forecast hour 72 as the synoptic scale flow becomes more
complex. The depression will probably gradually slow down between
hours 72-120 as it becomes caught between a pair of upper level
ridges; one north of the Azores and another north of the Lesser
Antilles. Meanwhile, an amplifying upper trough in the North
Atlantic will attempt to deepen far enough south to steer the
depression northward. How much the upper trough digs southward
will determine if and when the storm takes on a more northerly
track, or if it remains at a lower latitude longer. The forecast
was placed just south of consensus this forecast period.
Wind shear is not expected to be a big hindrance in its
development initially while SSTs along its forecast path will
generally be around 27C. Thus gradually intensification is shown
for the first couple of days. However, shear is forecast to
increase thereafter along with more marginal dry air conditions.
This forecast leans more heavily on the regional hurricane models
which show more modest intensification than the statistical
dynamical tools but could be conservative at the end depending on
how much latitude the system gains.
FORECAST POSITIONS AND MAX WINDS
INIT 11/1500Z 16.0N 28.7W 30 KT 35 MPH
12H 12/0000Z 16.6N 31.2W 35 KT 40 MPH
24H 12/1200Z 17.5N 34.1W 40 KT 45 MPH
36H 13/0000Z 18.6N 36.7W 45 KT 50 MPH
48H 13/1200Z 19.3N 39.3W 45 KT 50 MPH
60H 14/0000Z 19.9N 41.9W 45 KT 50 MPH
72H 14/1200Z 20.3N 43.9W 45 KT 50 MPH
96H 15/1200Z 20.6N 46.6W 45 KT 50 MPH
120H 16/1200Z 21.0N 48.8W 45 KT 50 MPH
$$
Forecaster Mullinax/Blake