Tropical Storm Dorian Advisory Number 3
NWS National Hurricane Center Miami FL AL052019
1100 PM AST Sat Aug 24 2019
...DORIAN MOVING STEADILY WESTWARD...
...WATCHES WILL LIKELY BE NECESSARY FOR PORTIONS OF THE LESSER
ANTILLES ON SUNDAY...
SUMMARY OF 1100 PM AST...0300 UTC...INFORMATION
-----------------------------------------------
LOCATION...10.9N 50.4W
ABOUT 635 MI...1020 KM ESE OF BARBADOS
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 14 MPH...22 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES
WATCHES AND WARNINGS
--------------------
There are no coastal watches or warnings in effect.
Interests in the central and northern Lesser Antilles should
monitor the progress of Dorian.
DISCUSSION AND OUTLOOK
----------------------
At 1100 PM AST (0300 UTC), the center of Tropical Storm Dorian was
located near latitude 10.9 North, longitude 50.4 West. Dorian is
moving toward the west near 14 mph (22 km/h). The tropical storm is
forecast to move generally west-northwestward at a similar forward
speed for the next several days. On the forecast track, Dorian is
expected to be near the central Lesser Antilles on Tuesday.
Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Gradual strengthening is forecast during the next few days, and
Dorian could be near hurricane strength when it approaches the
central Lesser Antilles on Tuesday.
Tropical-storm-force winds extend outward up to 25 miles (35 km)
from the center.
The estimated minimum central pressure is 1008 mb (29.77 inches).
HAZARDS AFFECTING LAND
----------------------
None.
NEXT ADVISORY
-------------
Next complete advisory at 500 AM AST.
$$
Forecaster Zelinsky
NWS NATIONAL HURRICANE CENTER MIAMI FL AL052019
0300 UTC SUN AUG 25 2019
THERE ARE NO COASTAL WATCHES OR WARNINGS IN EFFECT.
INTERESTS IN THE CENTRAL AND NORTHERN LESSER ANTILLES SHOULD
MONITOR THE PROGRESS OF DORIAN.
TROPICAL STORM CENTER LOCATED NEAR 10.9N 50.4W AT 25/0300Z
POSITION ACCURATE WITHIN 30 NM
PRESENT MOVEMENT TOWARD THE WEST OR 280 DEGREES AT 12 KT
ESTIMATED MINIMUM CENTRAL PRESSURE 1008 MB
MAX SUSTAINED WINDS 35 KT WITH GUSTS TO 45 KT.
34 KT....... 20NE 0SE 0SW 20NW.
12 FT SEAS.. 30NE 0SE 0SW 30NW.
WINDS AND SEAS VARY GREATLY IN EACH QUADRANT. RADII IN NAUTICAL
MILES ARE THE LARGEST RADII EXPECTED ANYWHERE IN THAT QUADRANT.
REPEAT...CENTER LOCATED NEAR 10.9N 50.4W AT 25/0300Z
AT 25/0000Z CENTER WAS LOCATED NEAR 10.8N 49.9W
FORECAST VALID 25/1200Z 11.2N 52.0W
MAX WIND 40 KT...GUSTS 50 KT.
34 KT... 30NE 0SE 0SW 30NW.
FORECAST VALID 26/0000Z 11.7N 54.1W
MAX WIND 45 KT...GUSTS 55 KT.
34 KT... 30NE 30SE 0SW 30NW.
FORECAST VALID 26/1200Z 12.5N 56.2W
MAX WIND 50 KT...GUSTS 60 KT.
50 KT... 20NE 0SE 0SW 20NW.
34 KT... 40NE 30SE 20SW 40NW.
FORECAST VALID 27/0000Z 13.2N 58.2W
MAX WIND 55 KT...GUSTS 65 KT.
50 KT... 20NE 0SE 0SW 20NW.
34 KT... 40NE 40SE 20SW 40NW.
FORECAST VALID 28/0000Z 15.0N 62.3W
MAX WIND 65 KT...GUSTS 80 KT.
50 KT... 30NE 20SE 10SW 30NW.
34 KT... 50NE 40SE 30SW 50NW.
EXTENDED OUTLOOK. NOTE...ERRORS FOR TRACK HAVE AVERAGED NEAR 150 NM
ON DAY 4 AND 175 NM ON DAY 5...AND FOR INTENSITY NEAR 15 KT EACH DAY
OUTLOOK VALID 29/0000Z 17.0N 66.5W
MAX WIND 70 KT...GUSTS 85 KT.
OUTLOOK VALID 30/0000Z 19.0N 70.0W...INLAND
MAX WIND 55 KT...GUSTS 65 KT.
REQUEST FOR 3 HOURLY SHIP REPORTS WITHIN 300 MILES OF 10.9N 50.4W
NEXT ADVISORY AT 25/0900Z
$$
FORECASTER ZELINSKY
NWS National Hurricane Center Miami FL AL052019
1100 PM AST Sat Aug 24 2019
Dorian's structure hasn't changed substantially since the last
advisory. Although southeasterly shear and surrounding dry air
appear to be limiting convection, the most recent available
microwave imagery showed that the small cyclone is maintaining
well-defined convective banding. The initial intensity is still
35 kt, based primarily on the most recent TAFB Dvorak fix.
Confidence in the intensity forecast is particularly low due to a
number of factors. The small size of Dorian could make it
susceptible to large short-term swings in intensity (up or down).
While SHIPS diagnostics suggest that the wind shear will be below 10
kt for at least the next 72 h, UW-CIMSS shear diagnostics indicate
that the current shear is higher, more like 15-20 kt. And the
intensity guidance spread is also notably large, further decreasing
confidence in the forecast. For now, the NHC intensity forecast has
not been significantly changed, and shows Dorian near hurricane
strength when it approaches the Lesser Antilles in a few days. This
is a little above the intensity consensus and it should be stressed
that it is still too soon to pinpoint potential wind impacts across
those islands, given the large uncertainty in the forecast. The
official forecast then shows Dorian maintaining hurricane strength
across the northeast Caribbean, but it is certainly possible that it
could be weaker, especially given the expected surrounding dry
environment and a possible increase in wind shear forecast by the
GFS and ECMWF models. By the end of the forecast period, the NHC
intensity forecast is very close to HCCA and IVCN.
An ASCAT-B overpass at 0024 UTC revealed that Dorian is moving
slightly faster than previously estimated, now 280/12 kt. Unlike the
intensity guidance, the track models are in quite good agreement on
the track of Dorian. The tropical storm should continue moving
westward to west-northwestward at a similar forward speed, steered
primarily by a mid-level ridge stretching across most of the central
Atlantic. The NHC forecast is nearly on top of the previous advisory
and remains very near the TVCN and HCCA consensus aids.
Key Messages:
1. Dorian is forecast to strengthen and could be near hurricane
strength when it approaches the Lesser Antilles on Tuesday.
2. It is too soon to determine the specific timing or magnitude of
impacts in the Lesser Antilles, but tropical storm or hurricane
watches will likely be needed for a portion of the islands on
Sunday.
FORECAST POSITIONS AND MAX WINDS
INIT 25/0300Z 10.9N 50.4W 35 KT 40 MPH
12H 25/1200Z 11.2N 52.0W 40 KT 45 MPH
24H 26/0000Z 11.7N 54.1W 45 KT 50 MPH
36H 26/1200Z 12.5N 56.2W 50 KT 60 MPH
48H 27/0000Z 13.2N 58.2W 55 KT 65 MPH
72H 28/0000Z 15.0N 62.3W 65 KT 75 MPH
96H 29/0000Z 17.0N 66.5W 70 KT 80 MPH
120H 30/0000Z 19.0N 70.0W 55 KT 65 MPH...INLAND
$$
Forecaster Zelinsky