Official Discussion issued by the National Hurricane Center

Laura (AL132020) DATA RELEASED: 8/25/2020 3:00:00 AM UTC

Copy of official data

Tropical Storm Laura Discussion Number  21
NWS National Hurricane Center Miami FL       AL132020
1100 PM EDT Mon Aug 24 2020

Tropical Storm Laura made landfall on the Pinar del Rio province in
western Cuba around 0000 UTC with maximum winds of about 55 kt.
Around that time, a wind gust of 56 kt was reported in Havana.
Since then the storm has moved across western Cuba and is now
coming off the island and over the extreme southeastern Gulf of
Mexico. Radar data from Cuba and satellite images indicate that
the storm has become better organized with deep convection
beginning to wrap around the center with persistent thunderstorms
on the south side.  Data from the NOAA and Air Force Hurricane
Hunters indicate that the pressure has fallen to 996 mb and that
the winds are around 55 kt.

Laura continues to move fairly steadily to the west-northwest with
the latest initial motion estimated to be 290/17 kt.  The track
forecast reasoning is generally unchanged from previous discussions.
Laura should continue to move west-northwestward at about the same
forward speed through Tuesday as it remains in the flow on the
southwest side of the Atlantic subtropical ridge.  By early
Wednesday, Laura will likely slow down and turn northwestward and
then northward as it moves into a break in the ridge, caused by a
weak trough over the south-central U.S.  This motion should cause
the system to make landfall in either southwestern Louisiana or the
Upper Texas coast Wednesday night or early Thursday.  After
landfall, Laura is forecast to continue moving northward before
turning eastward on Friday as it becomes embedded in the
mid-latitude westerlies.   Although the global models are in
relatively good agreement, there remains some spread in the ensemble
members, especially in the ECMWF.  Therefore, confidence in the
track forecast is still not high.  The NHC track forecast is
slightly to the left of the previous one, trending toward the
latest consensus aids.

The storm is starting to pull away from the western portion of Cuba,
and it should be over the warm Gulf of Mexico waters for about 2
days.  Since Laura will have a notable amount of time over waters
with high oceanic heat while moving through a low wind shear and
high moisture air mass, significant strengthening seems quite likely
until the storm makes landfall.  The intensity models all show Laura
making landfall as a hurricane, but there are differences on exactly
how strong it will be.  The NHC intensity forecast continues to
stay near the consensus aids, which usually perform best, and
Laura could be near major hurricane strengthen when it reaches the
coast.

Users are again reminded not to focus on the exact details of the
track or intensity forecasts as the average NHC track error at 48 h
is around 80 miles and the average intensity error is close to 15
mph. In addition, wind, storm surge, and rainfall hazards will
extend far from the center.

Key Messages:

1. Laura is forecast to reach the northwestern Gulf Coast as a
hurricane late Wednesday and early Thursday. Do not focus
on the details of the official forecast given the typical
uncertainty in NHC's 2 to 3 day track and intensity predictions. In
addition, storm surge, wind, and rainfall hazards will extend well
away from Laura's center along the Gulf Coast.

2. There is a risk of life-threatening storm surge from San Luis
Pass, Texas, to Ocean Springs, Mississippi, within the next 48
hours, and a storm surge watch is in effect for these areas
outside of the southeast Louisiana Hurricane and Storm Damage Risk
Reduction System. Residents in these areas should follow any advice
given by local officials.

3. Hurricane conditions are possible by late Wednesday from Port
Bolivar, Texas, to west of Morgan City, Louisiana, with tropical
storm conditions possible by Wednesday afternoon, and a hurricane
watch is in effect. Additional hurricane watches may be needed
farther south along the Texas coast if the track forecast shifts
toward the south and west tonight and Tuesday.

4. Tropical storm conditions and heavy rainfall are expected across
central and western Cuba for several more hours. These rains could
cause mudslides and life-threatening flash and urban flooding.


FORECAST POSITIONS AND MAX WINDS

INIT  25/0300Z 22.7N  84.0W   55 KT  65 MPH
12H  25/1200Z 23.7N  86.3W   65 KT  75 MPH
24H  26/0000Z 25.2N  89.1W   75 KT  85 MPH
36H  26/1200Z 26.8N  91.6W   85 KT 100 MPH
48H  27/0000Z 28.8N  93.0W   95 KT 110 MPH
60H  27/1200Z 31.3N  93.6W   65 KT  75 MPH...INLAND
72H  28/0000Z 33.8N  93.0W   40 KT  45 MPH...INLAND
96H  29/0000Z 36.7N  89.1W   25 KT  30 MPH...INLAND
120H  30/0000Z 36.9N  77.1W   25 KT  30 MPH...POST-TROP/REMNT LOW

$$
Forecaster Cangialosi