Track:
https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/?cone#contents
Tropical Storm Laura Discussion Number 7
NWS National Hurricane Center Miami FL AL132020
1100 AM AST Fri Aug 21 2020
A NOAA Hurricane Hunter aircraft has been investigating the system
this morning and found that the maximum winds have increased to near
40 kt, and therefore the cyclone is being named. The Hurricane
Hunters also found that the center of the storm is located somewhat
to the south of previous estimates. The system is better organized
than it was yesterday, but still lacks well-defined banding
features. However, some upper-level outflow is now noted over the
southern portion of the circulation. The official forecast calls
for some slow strengthening during the next couple of days, but the
intensity forecast is quite uncertain and depends on how much
interaction with land will occur. For now, we will assume that the
northern part of the circulation will remain over water so that the
system will not be too disrupted by Hispaniola and Cuba. The
official intensity forecast remains close to the model consensus
except at days 4 and 5 where it is a little lower due to these
uncertainties.
With the repositioning of the center, the motion is very uncertain
but is estimated to be 270/16 kt. Laura is expected to move mainly
west-northwestward on the south side of a subtropical high pressure
system over the next couple of days. Later in the forecast period,
the tropical cyclone should turn toward the northwest as it moves
around the western periphery of the high. The official track
forecast has been adjusted to the south of the previous one and is
on the northern side of the guidance suite.
Tropical storm warnings have been issued for the northern Leeward
Islands, Puerto Rico, and the Virgin Islands.
Key Messages:
1. Tropical storm conditions are expected across portions of the
northern Leeward Islands, the Virgin Islands, and Puerto Rico today
through Saturday, and Tropical Storm Warnings are in effect. Heavy
rainfall is likely across this area beginning today and could cause
mudslides and flash and urban flooding through Sunday.
2. Tropical storm conditions are possible along the northern coasts
of the Dominican Republic and Haiti, the southeastern Bahamas,
and the Turks and Caicos islands Saturday and Sunday, and Tropical
Storm Watches are in effect.
3. The details of the long-range track and intensity forecasts
remain more uncertain than usual since Laura is forecast to move
near or over portions of the Greater Antilles through Monday.
However, Laura could bring storm surge, rainfall, and wind impacts
to portions of Cuba, the Bahamas, and Florida early next week and
the northeast U.S. Gulf Coast by the middle of next week. Interests
there should monitor the progress of Laura and updates to the
forecast over the next few days.
FORECAST POSITIONS AND MAX WINDS
INIT 21/1500Z 17.0N 60.2W 40 KT 45 MPH
12H 22/0000Z 17.4N 62.7W 40 KT 45 MPH
24H 22/1200Z 18.3N 66.0W 45 KT 50 MPH
36H 23/0000Z 19.2N 69.5W 45 KT 50 MPH
48H 23/1200Z 20.2N 73.4W 45 KT 50 MPH
60H 24/0000Z 21.6N 77.1W 50 KT 60 MPH
72H 24/1200Z 23.2N 80.7W 55 KT 65 MPH
96H 25/1200Z 26.5N 85.5W 65 KT 75 MPH
120H 26/1200Z 29.5N 87.5W 65 KT 75 MPH
$$
Forecaster Pasch
Tropical Storm Laura Advisory Number 7
NWS National Hurricane Center Miami FL AL132020
1100 AM AST Fri Aug 21 2020
...TROPICAL STORM WARNINGS ISSUED FOR THE NORTHERN LEEWARD ISLANDS
AND PUERTO RICO...
SUMMARY OF 1100 AM AST...1500 UTC...INFORMATION
-----------------------------------------------
LOCATION...17.0N 60.2W
ABOUT 210 MI...335 KM ESE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 270 DEGREES AT 18 MPH...30 KM/H
MINIMUM CENTRAL PRESSURE...1007 MB...29.74 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
A Tropical Storm Warning has been issued for Puerto Rico, Vieques,
Culebra, and the U.S. Virgin Islands.
The government of Antigua has issued a Tropical Storm Warning for
Antigua, Barbuda, St. Kitts, Nevis, Anguilla, and the British
Virgin Islands.
The government of the Netherlands has issued a Tropical Storm
Warning for Saba and St. Eustatius.
The government of France has issued a Tropical Storm Warning for St.
Martin and St. Barthelemy.
The government of St. Maarten has issued a Tropical Storm Warning
for St. Maarten.
The government of the Dominican Republic has issued a Tropical
Storm Watch for northern coast of the Dominican Republic from Cabo
Cabron to the border with Haiti.
The government of Haiti has issued a Tropical Storm Watch for
northern coast of Haiti from Le Mole St. Nicholas to the border with
the Dominican Republic.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* Puerto Rico, Vieques and Culebra
* U.S. Virgin Islands
* British Virgin Islands
* Saba and St. Eustatius
* St. Maarten
* St. Martin and St. Barthelemy
* Antigua, Barbuda, St. Kitts, Nevis, and Anguilla
A Tropical Storm Watch is in effect for...
* The northern coast of the Dominican Republic from Cabo Cabron to
the border with Haiti
* The northern coast of Haiti from Le Mole St. Nicholas to the
border with the Dominican Republic
* The southeastern Bahamas and the Turks and Caicos Islands
A Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning, in this case within the next
12 to 24 hours.
A Tropical Storm Watch means that tropical storm conditions are
possible within the watch area, generally within 48 hours.
Interests in Cuba and the remainder of the Bahamas should monitor
the progress of Laura.
For storm information specific to your area in the United
States, including possible inland watches and warnings, please
monitor products issued by your local National Weather Service
forecast office. For storm information specific to your area
outside of the United States, please monitor products issued by
your national meteorological service.
DISCUSSION AND OUTLOOK
----------------------
At 1100 AM AST (1500 UTC), the center of Tropical Storm Laura was
located near latitude 17.0 North, longitude 60.2 West. Laura is
moving toward the west near 18 mph (30 km/h) and a generally
west-northwestward motion at a faster forward speed is expected
over the next couple of days. On the forecast track, the center of
Laura will move near or over the northern Leeward Islands later
today, near or over Puerto Rico Saturday morning, and near the
northern coast of Hispaniola late Saturday and early Sunday.
Maximum sustained winds are near 45 mph (75 km/h) with higher gusts.
Some slow strengthening is forecast during the next 48 hours.
Tropical-storm-force winds extend outward up to 150 miles (240 km)
from the center.
The minimum central pressure estimated from NOAA Hurricane Hunter
aircraft observations is 1007 mb (29.74 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: Laura is expected to produce 3 to 6 inches of rain over
Puerto Rico and the Virgin Islands, the Dominican Republic, and the
southern Haitian Peninsula through Sunday. Maximum amounts up to 8
inches are possible along eastern portions and the southern slopes
of Puerto Rico, as well as over Haiti and the Dominican Republic.
This heavy rainfall could lead to flash and urban flooding, as well
as an increased potential for mudslides with minor river flooding in
Puerto Rico.
1 to 3 inches of rain with isolated maximum totals of 5 inches is
expected over the remainder of Haiti, the northern Leeward Islands,
the Turks and Caicos and southeast Bahamas.
WIND: Tropical storm conditions are expected within portions of
the warning area area later today through Saturday. Tropical storm
conditions are possible within portions of the watch area Saturday
night and early Sunday.
NEXT ADVISORY
-------------
Next intermediate advisory at 200 PM AST.
Next complete advisory at 500 PM AST.
$$
Forecaster Pasch |