Track:
https://www.nhc.noaa.gov/refresh/graphics_at3+shtml/l?cone#contents
Tropical Storm Laura Discussion Number 16
NWS National Hurricane Center Miami FL AL132020
500 PM EDT Sun Aug 23 2020
Satellite imagery and radar data from eastern Cuba show that the
center of Laura has been moving over water between Haiti and eastern
Cuba this afternoon. There has been a recent uptick in convection
near the center and the radar imagery has shown an increase in
banding. An Air Force reconnaissance aircraft investigating Laura
this afternoon has reported a minimum pressure that has fallen to
around 1000 mb, and winds to support an intensity of 50 kt. The
plane very recently found a small area of stronger flight-level
winds, but these winds may be associated with mesocyclone, and not
representative of the large scale circulation.
Laura continues to move briskly west-northwestward or 285/18 kt. The
track forecast reasoning remains the same as the previous advisory.
Laura should continue to move west-northwestward to the south of a
deep-layer ridge that is forecast to build westward across Florida
and the eastern Gulf of Mexico during the next day or two. The track
guidance has continued to edge southward for the portion of the
forecast near Cuba, and the NHC forecast has again been moved in
that direction. Laura should continue moving west-northwestward
over the southeastern Gulf on Tuesday, but a turn toward the
northwest is expected Tuesday night as the cyclone nears the western
portion of the ridge. A northwestward to north-northwestward motion
should then continue around the western portion of the ridge until
the cyclone reaches the northwestern Gulf coast. The latest run of
the ECMWF has shifted significantly eastward, however its ensemble
mean and many of the stronger ensemble members remain farther west
as a stronger cyclone is likely to be steered more westward by the
deep-layer ridge. The GFS, UKMET, and HWRF remain close to the
previous NHC track, so little change was made to the official
forecast was made after 48 hours.
The intensity forecast during the next 24 hours is highly dependent
on the track and the amount of interaction Laura has with Cuba. If
the storm stays along the southern coast or just offshore, the
environment of warm water and low vertical wind shear could allow
for some slight strengthening, but little overall change in
intensity is indicated during the next 24 hours. After the center
clears western Cuba, the upper-level wind pattern is predicted to
quite favorable while the storm traverses the warm waters of the
Gulf of Mexico. The GFS, UKMET, and regional hurricane models all
indicate significant deepening, and the NHC intensity forecast has
been adjusted slightly upward. Although not explicitly shown, Laura
could threaten the northwestern Gulf coast near major hurricane
strength.
Users are again reminded to not to focus on the exact details of
the track or intensity forecast at the longer range as winds, storm
surge, and rainfall hazards will extend far from the center.
Key Messages:
1. Tropical storm conditions are expected across portions of the
Haiti, the southeastern Bahamas, and Cuba through Monday. Heavy
rainfall is likely across Haiti, Cuba, and Jamaica through Monday
and these rains could cause mudslides and life-threatening flash and
urban flooding.
2. Tropical storm conditions are possible over the Middle and Lower
Florida Keys and the Dry Tortugas on Monday.
3. While the details of the long-range track and intensity forecasts
remain uncertain, Laura is forecast to strengthen over the Gulf of
Mexico and there is an increasing risk of dangerous storm surge,
wind, and rainfall impacts along portions of the U.S. Gulf Coast by
the middle of the week. This could result in a prolonged period of
hazardous weather for areas that are likely to be affected by Marco.
Interests along the Gulf Coast should monitor the progress of Laura
and Marco and updates to the forecast during the next few days.
FORECAST POSITIONS AND MAX WINDS
INIT 23/2100Z 19.5N 75.2W 50 KT 60 MPH
12H 24/0600Z 20.6N 78.3W 50 KT 60 MPH...NEAR CUBA
24H 24/1800Z 21.8N 81.7W 50 KT 60 MPH...NEAR CUBA
36H 25/0600Z 23.3N 84.9W 55 KT 65 MPH...OVER WATER
48H 25/1800Z 24.7N 87.7W 60 KT 70 MPH
60H 26/0600Z 26.1N 90.2W 75 KT 85 MPH
72H 26/1800Z 28.0N 92.5W 90 KT 105 MPH
96H 27/1800Z 32.7N 93.5W 45 KT 50 MPH...INLAND
120H 28/1800Z 37.0N 88.0W 25 KT 30 MPH...POST-TROPICAL
$$
Forecaster Brown
Tropical Storm Laura Advisory Number 16
NWS National Hurricane Center Miami FL AL132020
500 PM EDT Sun Aug 23 2020
...AIR FORCE HURRICANE HUNTER AIRCRAFT FINDS A SLIGHTLY STRONGER
LAURA JUST SOUTH OF EASTERN CUBA...
...HEAVY RAINFALL AND LIFE-THREATENING FLASH FLOODING LIKELY OVER
THE DOMINICAN REPUBLIC...HAITI...CUBA...AND JAMAICA...
SUMMARY OF 500 PM EDT...2100 UTC...INFORMATION
----------------------------------------------
LOCATION...19.5N 75.2W
ABOUT 50 MI...80 KM S OF GUANTANAMO CUBA
ABOUT 220 MI...350 KM SE OF CAMAGUEY CUBA
MAXIMUM SUSTAINED WINDS...60 MPH...95 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1000 MB...29.53 INCHES
WATCHES AND WARNINGS
--------------------
CHANGES WITH THIS ADVISORY:
The government of the Cayman Islands has issued a Tropical Storm
Warning for Little Cayman and Cayman Brac.
The Tropical Storm Watch for the the Florida Keys north of Craig
Key and for Florida Bay has been discontinued.
The government of the Dominican Republic has discontinued all
Tropical Storm Warnings for the Dominican Republic.
The government of the Bahamas has discontinued the Tropical Storm
Warning for the Turks and Caicos Islands, and for the southeastern
Bahamas except for Inagua and the Ragged Islands. The Tropical
Storm Watch for the central Bahamas and Andros Island has been
discontinued.
SUMMARY OF WATCHES AND WARNINGS IN EFFECT:
A Tropical Storm Warning is in effect for...
* Entire coast of the Haiti
* Inagua and the Ragged Islands in southeastern Bahamas
* Little Cayman and Cayman Brac
* Cuban provinces of Camaguey, Las Tunas, Holguin, Guantanamo,
Santiago de Cuba, Granma, Ciego De Avila, Sancti Spiritus, Villa
Clara, Cienfuegos, Matanzas, Mayabeque, La Habana, Artemisa, Pinar
del Rio, and the Isle of Youth
A Tropical Storm Watch is in effect for...
* Florida Keys from Craig Key to Key West and the Dry Tortugas
The Tropical Storm Warning means that tropical storm conditions are
expected somewhere within the warning area, 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, in this case within the next 24
hours.
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 500 PM EDT (2100 UTC), the center of Tropical Storm Laura was
located near latitude 19.5 North, longitude 75.2 West. Laura is
moving toward the west-northwest near 21 mph (33 km/h), and this
general motion with some decrease in forward speed is expected over
the next couple of days. A turn toward the northwest is foreast by
Wednesday. On the forecast track, the center of Laura will move
near or over southern coast Cuba tonight and Monday, and move over
the southeastern Gulf of Mexico Monday night and Tuesday. Laura is
expected to move over the central and northwestern Gulf of Mexico
Tuesday night and Wednesday.
Data from an Air Force Reserve reconnaissance aircraft indicate that
the maximum sustained winds are near 60 mph (95 km/h) with higher
gusts. Little change in strength is forecast while Laura moves near
the southern coast of Cuba tonight. However, strengthening is
forecast after the storm moves over the Gulf of Mexico, and Laura is
forecast to become a hurricane late Tuesday or Tuesday night.
Tropical-storm-force winds extend outward up to 140 miles (220 km)
from the center.
The minimum central pressure estimated from reconnaissance aircraft
data is 1000 mb (29.53 inches).
HAZARDS AFFECTING LAND
----------------------
RAINFALL: Laura is expected to produce the following storm total
rainfall accumulations through Tuesday:
Dominican Republic, Haiti, Jamaica, and Cuba: 4 to 8 inches, with
maximum amounts of 12 inches.
Cayman Islands: 2 to 4 inches, maximum amounts of 6 inches.
Florida Keys, Turks and Caicos and southeast Bahamas: 1 to 2 inches.
Across the Greater Antilles this heavy rainfall could lead to
life-threatening flash and urban flooding, and the potential for
mudslides.
WIND: Tropical storm conditions are expected within portions of the
warning area in Haiti through this evening. Tropical storm
conditions are expected within portions of the warning area in Cuba
later tonight through Monday. Tropical storm conditions are expected
in Little Cayman and Cayman Brac on Monday. Tropical storm
conditions are possible within portions of the watch area in the
Florida Keys Monday.
SURF: Swells generated by Laura are affecting portions of Puerto
Rico, Hispaniola, eastern Cuba, the southeastern Bahamas and the
Turks and Caicos Islands. These swells are expected to spread
across central and western Cuba, the central and northwestern
Bahamas, and the Florida Keys during the next couple of days.
Please consult products from your local weather office.
NEXT ADVISORY
-------------
Next intermediate advisory at 800 PM EDT.
Next complete advisory at 1100 PM EDT.
$$
Forecaster Brown |