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Subtropical Storm Beryl Discussion Number  21
NWS National Hurricane Center Miami FL       AL022018
500 PM AST Sun Jul 15 2018

Beryl is less organized than 24 h ago, with the cyclone currently
comprised of a swirl of low- to mid-level clouds and occasional
puffs of convection in the southeastern quadrant.  The low-level
center has also become completely detached from a large-scale cloud
band farther to the east.  The initial intensity of 35 kt is based
mainly on earlier scatterometer data, and this data was also used to
revise the initial wind radii.

Beryl has been moving slowly eastward most of the day.  However, the
last few satellite images suggest a more northward motion is
beginning, so the initial motion is an uncertain 075/5.  A broad
deep-layer mid-latitude trough moving eastward across eastern Canada
and the northeastern United States should cause the cyclone to
turn northeastward with some acceleration tonight, with a faster
northeastward motion expected on Monday and Monday night.  The
track guidance has shifted to the east on this advisory, so the new
forecast track has been adjusted in that direction.  However, the
new track lies to the west of the center of the guidance envelope
and the various consensus models.

The new forecast track again keeps the center over the Gulf Stream
for 12 h, and the intensity forecast maintains the initial intensity
during that time.  After that, a quick decay over cold water should
occur, and the new intensity forecast now calls for Beryl to
dissipate completely between 36-48 h in agreement with the dynamical
guidance.  The low-level center is still under strong northwesterly
vertical shear, and microwave data suggests that dry air has wrapped
around the circulation.  If these factors prevent the quick
re-development of convection, the system could dissipate even
earlier than currently forecast.


FORECAST POSITIONS AND MAX WINDS

INIT  15/2100Z 38.2N  63.8W   35 KT  40 MPH
 12H  16/0600Z 39.2N  62.3W   35 KT  40 MPH
 24H  16/1800Z 41.3N  59.7W   30 KT  35 MPH...POST-TROP/REMNT LOW
 36H  17/0600Z 44.0N  56.8W   25 KT  30 MPH...POST-TROP/REMNT LOW
 48H  17/1800Z...DISSIPATED

$$
Forecaster Beven

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