ZCZC MIATCMAT4 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DANNY FORECAST/ADVISORY NUMBER
5
NWS NATIONAL HURRICANE CENTER MIAMI FL
AL042015
1500 UTC WED AUG 19 2015
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.
TROPICAL STORM CENTER LOCATED NEAR 11.2N
POSITION ACCURATE WITHIN 20 NM
41.1W AT 19/1500Z
PRESENT MOVEMENT TOWARD THE WEST OR 275 DEGREES AT
10 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1000 MB
MAX SUSTAINED WINDS 45 KT WITH GUSTS TO 55 KT.
34 KT....... 60NE 30SE
0SW 40NW.
12 FT SEAS..100NE 50SE 20SW 40NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 11.2N 41.1W AT 19/1500Z
AT 19/1200Z CENTER WAS LOCATED NEAR 11.1N 40.7W
FORECAST VALID 20/0000Z 11.4N 42.6W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 20NE 20SE
0SW 20NW.
34 KT... 60NE 30SE
0SW 40NW.
FORECAST VALID 20/1200Z 11.9N 44.2W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 30NE 20SE
0SW 20NW.
34 KT... 60NE 50SE 20SW 50NW.
FORECAST VALID 21/0000Z 12.4N 45.8W
MAX WIND 60 KT...GUSTS 75 KT.
50 KT... 30NE 20SE 20SW 30NW.
34 KT... 70NE 50SE 40SW 70NW.
FORECAST VALID 21/1200Z 13.1N 47.5W
MAX WIND 70 KT...GUSTS 85 KT.
50 KT... 40NE 20SE 20SW 40NW.
34 KT... 70NE 60SE 50SW 70NW.
FORECAST VALID 22/1200Z 14.4N 51.5W
MAX WIND 80 KT...GUSTS 100 KT.
50 KT... 40NE 30SE 20SW 40NW.
34 KT... 80NE 70SE 60SW 70NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 200 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
OUTLOOK VALID 23/1200Z 15.6N 56.2W
MAX WIND 75 KT...GUSTS 90 KT.
OUTLOOK VALID 24/1200Z 16.6N 61.5W
MAX WIND 70 KT...GUSTS 85 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 11.2N
NEXT ADVISORY AT 19/2100Z
$$
41.1W
FORECASTER KIMBERLAIN
NNNN
ZCZC MIATCDAT4 ALL
TTAA00 KNHC DDHHMM
TROPICAL STORM DANNY DISCUSSION NUMBER
NWS NATIONAL HURRICANE CENTER MIAMI FL
1100 AM AST WED AUG 19 2015
5
AL042015
While there has not been much overall change to Danny's curved-band
cloud pattern, there is evidence in satellite imagery of
increased inner-core structural organization since yesterday. Cloud
top temperatures, however, have warmed in recent hours. The initial
intensity is held at 45 kt in agreement with the latest CI number
from TAFB.
There is nothing obvious that would impede gradual intensification
during the next few days, except for the possible entrainment of
dry air associated with a Saharan Air Layer following the cyclone
to the north. Around the time Danny approaches the Lesser Antilles
in 3 to 5 days, global models have divergent solutions regarding the
strength and position of the mid-oceanic trough, which will
ultimately affect Danny's intensity. The ECMWF shows upper-level
westerlies and even drier air associated with this feature holding
sway over the Caribbean region, while the GFS shows a relaxation
of the shear. The statistical guidance, strongly dependent on the
GFS forecast fields, continues to indicate a higher intensity, yet
the dynamical models suggest less overall intensification and even
weakening late in the forecast period. The GFS-based guidance seems
less likely relative to the other model solutions, especially given
the strength and persistence of the mid-oceanic trough thus far this
season. The intensity forecast is therefore reduced throughout
the forecast period but especially at later times and is close to or
just above the multi-model consensus ICON.
Recent fixes indicate that Danny's forward speed has decreased
slightly, and the initial motion estimate is 275/10. An enhanced
mid-oceanic trough, extending from the northeastern Atlantic to the
Caribbean Sea, is forecast to keep the subtropical ridge to the
north of Danny somewhat weak over the next few days. This should
result in Danny's continued movement toward the west or westnorthwest across the tropical Atlantic, albeit at a less than
climatological rate of speed. Later in the forecast period, largescale models are in agreement that there should be some restrengthening of the subtropical ridge, which would result in
Danny's moving at a slightly faster forward speed. The cyclone's
heading late in the forecast period should largely be a function of
the depth of the system. A weaker Danny would move westward faster,
as is the case in the ECMWF solution. A stronger system, like the
one that the GFS shows, would tend to gain more latitude. The
track forecast is adjusted southward this forecast cycle, based on
an initial re-positioning of the cyclone and with the expectation
that Danny could be somewhat weaker later in the forecast period.
FORECAST POSITIONS AND MAX WINDS
INIT
12H
24H
36H
19/1500Z
20/0000Z
20/1200Z
21/0000Z
11.2N
11.4N
11.9N
12.4N
41.1W
42.6W
44.2W
45.8W
45
50
55
60
KT
KT
KT
KT
50
60
65
70
MPH
MPH
MPH
MPH
48H
72H
96H
120H
21/1200Z
22/1200Z
23/1200Z
24/1200Z
13.1N
14.4N
15.6N
16.6N
$$
Forecaster Kimberlain
NNNN
47.5W
51.5W
56.2W
61.5W
70
80
75
70
KT
KT
KT
KT
80
90
85
80
MPH
MPH
MPH
MPH