Tropical Storm Karen Advisory Number 1
NWS National Hurricane Center Miami FL AL122019
500 AM AST Sun Sep 22 2019
...TROPICAL STORM KAREN FORMS JUST EAST OF THE WINDWARD ISLANDS...
...TROPICAL STORM WARNING ISSUED FOR PORTIONS OF THE WINDWARD
ISLANDS...
SUMMARY OF 500 AM AST...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...11.9N 60.2W
ABOUT 100 MI...165 KM E OF GRENADA
ABOUT 120 MI...190 KM SE OF ST. VINCENT
MAXIMUM SUSTAINED WINDS...40 MPH...65 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 9 MPH...15 KM/H
MINIMUM CENTRAL PRESSURE...1005 MB...29.68 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
The government of Trinidad and Tobago has issued a Tropical Storm
Warning for Trinidad and Tobago. The Trinidad and Tobago
Meteorological Service has issued a Tropical Storm Warning for
Grenada and its dependencies.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* Trinidad and Tobago
* Grenada and its dependencies
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, in this case within the
next 12 hours.
Tropical Storm Warnings may be issued later today for other
portions of the Windward Islands. A Tropical Storm Watch will likely
be issued later today for Puerto Rico and the Virgin Islands.
Elsewhere, interests in the Leeward Islands should monitor the
progress of Karen.
For storm information specific to your area, please monitor
products issued by your national meteorological service.
DISCUSSION AND OUTLOOK
----------------------
At 500 AM AST (0900 UTC), the center of newly formed Tropical Storm
Karen was located near latitude 11.9 North, longitude 60.2 West.
Karen is moving toward the west-northwest near 9 mph (15 km/h) and
this general motion is expected to continue today. A turn toward
the northwest is forecast to occur on Monday, followed by a turn
toward the north on Tuesday. On the forecast track, Karen will move
across the Windward Islands this afternoon and tonight, and emerge
over the southeastern Caribbean Sea Monday morning. On Tuesday,
Karen is expected to approach Puerto Rico and the Virgin Islands.
Maximum sustained winds are near 40 mph (65 km/h) with higher gusts.
Little change in strength is forecast during the next 48 hours.
Tropical-storm-force winds extend outward up to 125 miles (205 km)
from the center. Barbados recently reported a sustained wind of
37 mph (59 km/h) and a gust to 45 mph (72 km/h).
The estimated minimum central pressure is 1005 mb (29.68 inches).
HAZARDS AFFECTING LAND
----------------------
WIND: Tropical storm conditions are expected to first reach those
islands within the warning area later this morning and afternoon,
making outside preparations difficult or dangerous.
RAINFALL: Karen is expected to produce the following rainfall
accumulations through Wednesday:
Windward Islands...3 to 6 inches, isolated 8 inches.
Leeward Islands...1 to 3 inches, isolated 5 inches.
Far northeastern Venezuela and Barbados...1 to 3 inches.
These rains may cause flash flooding and mudslides, especially in
mountainous areas.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 AM AST.
Next complete advisory at 1100 AM AST.
$$
Forecaster Stewart
NWS National Hurricane Center Miami FL AL122019
500 AM AST Sun Sep 22 2019
Scatterometer surface wind data and observations from the Windward
Islands indicate that the low pressure system just east of Tobago
has become better defined. Infrared and microwave satellite imagery
also show that deep convection has increased and has become better
organized around the center. Barbados recently reported a 10-minute
wind of 32 kt gusting to 39 kt, and the earlier scatterometer data
showed a large field of 30-32 kt winds in the eastern semicircle.
Based on these data, the low has been upgraded to Tropical Storm
Karen. Tropical Storm Warnings have been issued for the southern
Windward Islands as a result.
The initial motion estimate is an uncertain 285/10 kt. The latest
NHC model guidance is in very good agreement on Karen moving
northwestward around the southwestern periphery of a deep-layer
ridge for the next 24-36 hours, followed by a turn toward the north
into a break in the ridge currently located over the northern
Leeward Islands and Puerto Rico. In the 72-96 hour period, Karen is
forecast to slow down and possibly even stall and turn westward on
day 5 as another large ridge moves eastward across the southeastern
United States and builds to the north of the cyclone. The official
track forecast lies close to the tightly packed consensus track
models TVCN, NOAA-HCCA, and TVCX.
Little, if any, change in intensity is expected for the next 48
hours due to strong northeasterly vertical wind shear. However, the
upper-level flow is expected to be difluent, which should help Karen
maintain its current intensity despite the otherwise unfavorable
shear conditions. By 72 hours and beyond, Karen is forecast to move
underneath an upper-level anticyclone, which should result in a
significant decrease in the shear and also enhance the upper-level
outflow, allowing for some strengthening to occur. The NHC intensity
forecast closely follows a blend of the the intensity consensus
models IVCN and HCCA, and the Decay-SHIPS model.
A Tropical Storm Watch will likely be required for Puerto Rico and
the Virgin Islands later today, and Tropical Storm Warnings may be
issued for other areas in the Windward Islands later this morning.
FORECAST POSITIONS AND MAX WINDS
INIT 22/0900Z 11.9N 60.2W 35 KT 40 MPH
12H 22/1800Z 12.5N 61.6W 35 KT 40 MPH
24H 23/0600Z 13.4N 63.1W 35 KT 40 MPH
36H 23/1800Z 14.7N 64.1W 35 KT 40 MPH
48H 24/0600Z 16.1N 65.1W 35 KT 40 MPH
72H 25/0600Z 19.9N 65.5W 45 KT 50 MPH
96H 26/0600Z 23.4N 65.0W 50 KT 60 MPH
120H 27/0600Z 25.6N 65.6W 55 KT 65 MPH
$$
Forecaster Stewart