Tropical Depression Three Forecast Discussion Number 3

By | July 23, 2019

Issued at 500 AM EDT Tue Jul 23 2019

000
WTNT43 KNHC 230836
TCDAT3
Tropical Depression Three Discussion Number   3
NWS National Hurricane Center Miami FL       AL032019
500 AM EDT Tue Jul 23 2019
Although deep convection has redeveloped near and to the northeast
of the low-level center, the overall convective appearance is
somewhat ragged. However, curved rain bands have been evident in
Doppler radar data from Miami and Melbourne since around 0300 UTC,
and Doppler velocity values of 35-40 kt have been detected in those
bands between 15,000-20,000 ft. In addition, three ships located
about 50 nmi northeast and east of the center have reported 28-29 kt
wind speeds. Although those wind reports were elevated at 30-60
meters above the surface, they were reported outside of the rain
bands. Based on this wind speed and radar information, the initial
intensity has been increased to 30 kt. An Air Force Reserve
reconnaissance aircraft will investigate the depression later this
morning to provide a better estimate of the cyclone's intensity.
The depression is now moving northward or 360/10 kt. There is
essentially no change to the previous track or reasoning. The 06Z
track model guidance continues to indicate that the cyclone will
continue to move around western periphery of the sprawling
Bermuda-Azores high pressure ridge.  A northward motion is expected
through today, followed by a turn toward the north-northeast with
an increase in forward speed tonight. A northeastward motion is
forecast on Wednesday, which will keep the center and strongest
winds away from the coast of the southeastern United States. The new
NHC track forecast is similar to the previous advisory and lies
close to the various consensus models.
Although significant strengthening of the depression is not
expected, it is certainly possible that the cyclone could briefly
reach tropical storm status in the 12-to-24-hour period when the
system will be accelerating and the vertical wind shear decreases
to less than 5 kt. However, in the event that the cyclone should
become a tropical storm, the rapid northeastward motion will act to
keep the strongest winds to the east of the center, well offshore
of the U.S. coastal areas. By Wednesday afternoon, the combination
of strong southwesterly vertical wind shear and interaction with an
approaching cold front is expected to result in rapid weakening and
dissipation of the cyclone. The official intensity forecast is
similar to the previous advisory and shows dissipation by 36 hours.
Direct impacts from the depression are expected to be limited to
1 to 3 inches of rainfall across the Bahamas today.
FORECAST POSITIONS AND MAX WINDS
INIT  23/0900Z 27.0N  79.5W   30 KT  35 MPH
12H  23/1800Z 29.6N  79.4W   30 KT  35 MPH
24H  24/0600Z 34.0N  76.5W   30 KT  35 MPH
36H  24/1800Z...DISSIPATED
$$
Forecaster Stewart

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