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BULLETIN
HURRICANE DANNY ADVISORY NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 AM AST THU AUG 20 2015

...DANNY STRENGTHENS INTO THE FIRST HURRICANE OF THE 2015 ATLANTIC
HURRICANE SEASON...


SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...12.5N 44.8W
ABOUT 1090 MI...1755 KM E OF THE WINDWARD ISLANDS
MAXIMUM SUSTAINED WINDS...75 MPH...120 KM/H
PRESENT MOVEMENT...WNW OR 295 DEGREES AT 12 MPH...19 KM/H
MINIMUM CENTRAL PRESSURE...992 MB...29.30 INCHES


WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.


DISCUSSION AND 48-HOUR OUTLOOK
------------------------------
At 1100 AM AST (1500 UTC), the center of the eye of Hurricane Danny
was located by satellite near latitude 12.5 North, longitude 44.8
West. Danny is moving toward the west-northwest near 12 mph (19
km/h) and this general motion is expected to continue for the next
couple of days.

Maximum sustained winds have increased to near 75 mph (120 km/h)
with higher gusts. Some additional strengthening is forecast during
the next 48 hours.

Danny is a small tropical cyclone. Hurricane-force winds only
extend outward up to 10 miles (20 km) from the center and
tropical-storm-force winds extend outward up to 60 miles (95 km).

The estimated minimum central pressure is 992 mb (29.30 inches).


HAZARDS AFFECTING LAND
----------------------
None.


NEXT ADVISORY
-------------
Next complete advisory at 500 PM AST.

Discussion about how it may weaken:

HURRICANE DANNY DISCUSSION NUMBER 9
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042015
1100 AM AST THU AUG 20 2015

Danny's cloud pattern has continued to improve since the previous
advisory, and a 10 n mi diameter eye has become embedded in the
center of a small central dense overcast. Water vapor imagery
indicates that upper-level outflow has become more symmetrical. The
initial intensity of 65 kt is based on NHC objective Dvorak
classifications of T4.1-T4.2 using an eye feature. Conventional and
microwave satellite images indicate that Danny is an unusually small
tropical cyclone.

Satellite fixes indicate that Danny is now moving west-northwestward
or 295/10 kt. The latest model guidance remains in very good
agreement on Danny moving west-northwestward for the next 48-72
hours toward a weakness in the subtropical ridge along 60W
longitude. A mid- to upper-level trough north of Bermuda is forecast
by the global models to begin lifting out to the north in 96-120
hours, which should allow the subtropical ridge to the north of
Danny to build back westward, forcing Danny on a more westward track
on days 4 and 5. The NHC official forecast track is essentially an
update of the previous advisory through 72 hours, but was shifted a
little north of the previous track after that in agreement with the
consensus model TVCN.

Danny's compact size makes it subject to significant fluctuations in
strength, both up and down, and such fluctuations are notoriously
difficult to forecast. Low-shear conditions are expected to
continue for the next 36 hours or so, which argues for some further
strengthening during that time. However, the cyclone continues to be
surrounded by dry mid-level air, which could penetrate into the core
and disrupt the intensification process. By 48 hours and beyond, the
vertical wind shear is forecast to become southerly to southwesterly
and increase to near 15 kt. As a result, Danny is expected to be
weakening as it approaches the Leeward Island. The official
intensity forecast calls for a peak intensity somewhat higher and
earlier than the previous advisory, ending up close to the IVCN
consensus model.

FORECAST POSITIONS AND MAX WINDS

INIT 20/1500Z 12.5N 44.8W 65 KT 75 MPH
12H 21/0000Z 13.1N 46.0W 70 KT 80 MPH
24H 21/1200Z 14.0N 47.6W 75 KT 85 MPH
36H 22/0000Z 14.7N 49.4W 75 KT 85 MPH
48H 22/1200Z 15.2N 51.5W 70 KT 80 MPH
72H 23/1200Z 16.0N 56.4W 65 KT 75 MPH
96H 24/1200Z 16.9N 61.7W 65 KT 75 MPH
120H 25/1200Z 18.0N 66.6W 55 KT 65 MPH

Closest point of approach to Tortola now listed as 61 miles away, after some weakening, but nothing to sneeze at, at this point..