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Tropical Storm BERYL


Tropical Storm Beryl Discussion Number   9
NWS National Hurricane Center Miami FL       AL022018
1100 AM AST Sat Jul 07 2018

Beryl's small size was always going to make it prone to wild and
unpredictable fluctuations in intensity, and that appears to have
come to fruition this morning.  The cyclone's low-level center is
now completely exposed with all associated deep convection displaced
to the east and southeast.  Dvorak estimates from TAFB and SAB have
decreased accordingly, and the initial intensity is set at 55 kt,
with Beryl being downgraded to a tropical storm.

Even though upper-level winds over the system remain light, and
upper-level cloud motions are still from east to west, strengthening
low-level flow is likely leading to an increase in the deep-layer
westerly shear.  In fact, analyses from UW-CIMSS indicate that
about 15 kt of westerly shear is now over the system.  The shear
and a very dry ambient environment have likely caused the small and
fragile cyclone to suddenly weaken.  Since the low-level flow is
expected to increase further, and Beryl will be running into
upper-level westerlies in 36-48 hours, the shear is only expected
to become more hostile.  This will make it extremely difficult for
Beryl to become more organized again, and its chances of being a
hurricane before reaching the Lesser Antilles have decreased
significantly.  The updated NHC intensity forecast has been lowered
from the previous advisory, and now keeps Beryl as a tropical storm
through the forecast period.  The forecast intensities could still
be a little high, and this prediction will remain low confidence
until we get a better handle on Beryl's initial intensity.  Even
though a 72-hour forecast is provided, it is entirely possible that
Beryl will open up into a trough over the eastern Caribbean Sea
before that time.  Regardless of whether the system has a closed
circulation, it is likely to continue producing strong gusty winds
and locally heavy rainfall over portions of the Greater Antilles
next week.

Beryl is now gaining more latitude and has an initial motion of
295/12 kt.  The cyclone is still expected to accelerate toward the
west-northwest during the next several days, and the track guidance
remains tightly clustered through the forecast period.  The new NHC
track forecast has been shifted slightly northward due to Beryl's
recent northwestward jog, and it lies relatively close to the HCCA

Key Messages:

1. Beryl is no longer forecast to be near hurricane strength when it
approaches the Lesser Antilles Sunday night or Monday, but the
chance of some islands receiving direct impacts from wind and
rainfall continues.  Tropical storm warnings and watches are in
effect for some of the countries in the Lesser Antilles, and
additional watches or warnings could be required for other islands
later today.

2. Due to its very small size, there is greater-than-usual
uncertainty in the analysis of Beryl's current intensity, and
confidence in the official intensity forecast is also lower than
normal.  Rapid changes in intensity, both up and down, that are
difficult to predict are possible during the next couple of days.


INIT  07/1500Z 12.1N  51.1W   55 KT  65 MPH
 12H  08/0000Z 12.6N  52.9W   50 KT  60 MPH
 24H  08/1200Z 13.6N  56.0W   50 KT  60 MPH
 36H  09/0000Z 14.8N  59.6W   50 KT  60 MPH
 48H  09/1200Z 15.9N  63.6W   45 KT  50 MPH
 72H  10/1200Z 18.3N  71.7W   35 KT  40 MPH...INLAND
 96H  11/1200Z...DISSIPATED

Forecaster Berg