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Hurricane Laura Discussion Number  26
NWS National Hurricane Center Miami FL       AL132020
400 AM CDT Wed Aug 26 2020
 
Satellite images indicate that Laura has become a formidable 
hurricane since yesterday evening.  Deep convection has intensified 
and become more symmetric, with an eye now trying to clear out.  An 
earlier Air Force Hurricane Hunter mission found flight-level winds 
of 104 kt, along with peak SFMR values of 86 kt, which supported the 
90-kt intensity on the intermediate advisory.  Since that time, 
however, the cloud pattern has only continued to improve, so the 
initial wind speed is set to 95 kt for this advisory.  Notably, the 
aircraft also recorded that the extent of the hurricane-force winds 
have increased substantially northeast of the center. A pair of 
Hurricane Hunter planes should be in the area within a couple of 
hours.
 
The hurricane has intensified a remarkable 40 kt during the past 24 
hours, and there are no signs it will stop soon, with shear 
remaining low-to-moderate over the deep warm waters of the central 
Gulf of Mexico.  Guidance is noticeably higher than before, so the 
new peak intensity will be raised to 115 kt, and some models are 
even a little higher.  Increasing shear is expected to slightly 
weaken the hurricane close to landfall, so the new forecast keeps 
the previous 105-kt intensity near the coast.  Laura will 
weaken rapidly after landfall, but it will likely bring 
hurricane-force winds well inland over western Louisiana and 
eastern Texas.  In the extended range, there is some chance that 
Laura re-intensifies as a tropical cyclone off the Mid-Atlantic 
coast, instead of becoming part of a frontal system, but for now 
the forecast will stay extratropical at 96 hours and beyond.
 
Recent satellite shows that Laura has turned northwestward, now 
estimated at 13 kt.  There are no substantial changes to the track 
forecast to report.  The hurricane should gradually turn toward the 
northwest and north over the next day or two as it moves around the 
western periphery of a mid-level high. The models are in very good 
agreement on the center of Laura moving into extreme southwestern 
Louisiana or southeastern Texas in about 24 hours, so no changes 
were made to the previous NHC forecast. Later in the forecast period 
the weakened cyclone should turn toward the east-northeast and move 
with increasing forward speed while embedded within the mid-latitude 
westerlies. The official track forecast is shifted southward at 
longer range, not too far from the latest consensus track model 
predictions.
 
It should be mentioned Laura is now a large hurricane, and wind, 
storm surge, and rainfall hazards will extend far from the center. 
Do not use the cone graphic for any representation of these hazards, 
it is just for the center uncertainty.
 
Key Messages:
 
1. Life-threatening storm surge with large and dangerous waves is
expected to produce potentially catastrophic damage from San Luis
Pass, Texas, to the Mouth of the Mississippi River, including areas
inside the Port Arthur Hurricane Flood Protection system. This surge
could penetrate up to 30 miles inland from the immediate coastline
in southwestern Louisiana and southeastern Texas. Actions to protect
life and property should be rushed to completion as water levels
will begin to rise later today.
 
2. Hurricane-force winds are expected tonight in the warning area 
from San Luis Pass, Texas, to west of Morgan City, Louisiana, and 
the strongest winds associated with Laura's eyewall will occur 
somewhere within this area.  Hurricane-force winds and widespread 
damaging wind gusts are also expected to spread well inland into 
portions of eastern Texas and western Louisiana early Thursday.
 
3. Widespread flash flooding along small streams, urban areas, and 
roadways is expected to begin this afternoon into Thursday from far 
eastern Texas, across Louisiana and Arkansas.  This will also lead 
to minor to isolated moderate freshwater river flooding.  The heavy 
rainfall threat and localized flash and urban flooding potential 
will spread northeastward into the middle-Mississippi, lower Ohio 
and Tennessee Valleys Friday night and Saturday.
 
 
FORECAST POSITIONS AND MAX WINDS
 
INIT  26/0900Z 26.1N  90.7W   95 KT 110 MPH
 12H  26/1800Z 27.4N  92.4W  115 KT 130 MPH
 24H  27/0600Z 29.7N  93.5W  105 KT 120 MPH...NEAR COAST
 36H  27/1800Z 32.4N  93.7W   50 KT  60 MPH...INLAND
 48H  28/0600Z 34.8N  92.9W   30 KT  35 MPH...INLAND
 60H  28/1800Z 36.4N  91.0W   25 KT  30 MPH...INLAND
 72H  29/0600Z 37.3N  87.3W   30 KT  35 MPH...INLAND
 96H  30/0600Z 38.0N  74.5W   35 KT  40 MPH...POST-TROP/EXTRATROP
120H  31/0600Z 44.0N  60.0W   45 KT  50 MPH...POST-TROP/EXTRATROP
 
$$
Forecaster Blake
 
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