Atlantic - Laura forms August 21, 2020 (tornado, night, America, West)

[Cambium]

Laura will be a Major Hurricane hitting the gulf coast, then weaken to a Tropical Storm, then a Tropical Depression, then exit the East coast off NJ and become a Post Tropical Storm off NJ

[Psychoma]

Tue 25Aug 8aEDT/AST,7aCDT
Winds 75mph(120km/h)
Moving WNW 17mph(28km/h)
Pressure 991mb

Cat1 Hurricane and strengthening.

[Psychoma]

Tue 10aEDT/9aCDT - satellite shows slow steady organization continues. Storms continue to build and encircle the center more and more. No rapid intensification yet, but the possibility is there as crosses the Gulf.

Given model guidance, shift more West in forecast cone wouldn’t be surprising.

[Psychoma]

Tue 11aEDT/10aCDT
Winds 75mph(120km)
Moving WNW 16mph(26km/h)
Pressure 990mb.

Air recon and satellite indicate the center through the morning has been tilted slightly with the Low Level Center (LLC) just NE of the Mid Level Center (MLC). Very close to becoming vertically aligned (would = more healthy storm). The slight tilt would indicate steady intensification vs rapid for the time being is more likely. Continues to organize & intensify.

Reminder with a more powerful storm that power loss is likely across E TX, W LA and portions of OK and AR as storm heads inland (winds around 40+mph typically start see scattered power/tree issue begin). Large scale events can mean extended time without power as quipment and crews will be busy.

NHC slightly moved cone to the West slightly but is East of most model guidance currently.

There are indications that wind shear will begin to effect storm just before makes landfall but not expecting a big change/drop though. And unlike Marco, bigger more organized systems can fight off shear longer/better.

Surge values upped some to 9-13ft with waves on top, Sea Rim State Park, TX to Intracoastal City, LA including some adjacent lakes. Reminder surge will be great across a large distance of Gulf coast line, well away from the storm center.

Watch/Warning updates:
-Storm Surge Warning San Luis Pass, TX to Mouth of MS River including inside Port Arthur flood system.
-Hurricane Warning San Luis Pass, TX to Intracoastal City, LA
-TS Warning Sargent, TX to San Luis Pass, TX
-TS Warning for Cuba canceled.

[Psychoma]

NHC’s Surge Warning map and water heights, which can travel miles inland, up waterways, etc.
https://twitter.com/nhc_atlantic/sta...76758983045120

[Veritas Vincit]

With it currently forecast to hit between Houston and New Orleans..it looks like that would send the brunt of the winds and surge into the fairly thinly settled coastal areas of Western LA. Seems like that's where you'd want it to come in to avoid the worst issues for the Houston or NOLA areas.

[impala096]

Why was there no consistency in the models regarding intensity forecasts? These 5 models ranged from Laura being a TS to a Category 4 Hurricane. It looks like now it's likely to make landfall as a Category 3 hurricane. How helpful are these models if combined they run nearly the entire gauntlet of possibilities?

[Texas Ag 93]

Loaded up the kids and pets and left our house in Galveston County at 6 am. Glad I left when I did. Better safe than sorry. My husband stayed behind because he’ll have to work. At my in-laws place outside Tyler. Expect rain here, but no surge or wind as could be the case at home.

[Psychoma]

Originally Posted by impala096

Why was there no consistency in the models regarding intensity forecasts? These 5 models ranged from Laura being a TS to a Category 4 Hurricane. It looks like now it's likely to make landfall as a Category 3 hurricane. How helpful are these models if combined they run nearly the entire gauntlet of possibilities?

Intensity forecast are harder to get correct versus track. Dozens and dozens of models exist. Even the Euro is made up of 50 smaller sub-models essentially, each running slight different possibilities of things that could occur that affect storm track and intensity over time, to help cover most possibilities. They all have their good and bad traits though and some have known issues that are biased towards one thing or another so some are weighted more then others (ie: the NAM 3km likes to make unrealistic record breaking Cat5's with hurricanes typically). Seems like there's always at least some that always bring a storm to Cat5 and some that always make it fall apart. Also in modeling they have to start with the storm in the correct starting place which several got wrong while storm was over Hispaniola and Cuba which throws everything down stream off. Anyways, just my random 2 cents on the topic.

[Psychoma]

Originally Posted by Texas Ag 93

Loaded up the kids and pets and left our house in Galveston County at 6 am. Glad I left when I did. Better safe than sorry. My husband stayed behind because he’ll have to work. At my in-laws place outside Tyler. Expect rain here, but no surge or wind as could be the case at home.

Glad you made it! I have some family in Tyler & Longview. Hope no issues with the house back home.