ATL: LAURA - Post-Tropical - Discussion

[gatorcane]

Without even looking at the models, continues to look like a tough road ahead of Laura over the next several days. Land interaction seems almost certain now, dry air is surrounding her and is ahead of her (look at the oranges).

http://rammb.cira.colostate.edu/ramsdis ... display=24

[msbee]

SPECIAL WEATHER BULLETIN #6 - Friday, August 21, 2020 - 11:30AM **

…TROPICAL DEPRESSION #13 BECOMES TROPICAL STORM LAURA…
…A TROPICAL STORM WARNING IS IN EFFECT FOR ST.MAARTEN….

At 11AM (1500 UTC), Tropical Storm Laura was located near latitude 17.0 North,
longitude 60.2 West or about 210 miles east southeast of St. Maarten. Laura is moving
toward the west near 18 mph (30 km/h). A general west-northwestward motion at a faster
forward speed is expected over the next couple days.

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 from the center.

The estimated minimum central pressure is 1007 mb (29.74 inches).

On the current forecast track, the center of tropical storm Laura is expected at its closest
about 35 miles to the south southwest of St. Maarten late tonight.

HAZARDS AFFECTING LAND:

RAINFALL: Laura could produce up to 4 inches of rainfall through Sunday over the
local area. Shower activity associated with rain bands from Laura is already affecting St.
Maarten. Moderate to heavy showers accompanied by thunderstorms are expected to
continue and intensify as the day progresses with most intense showers expected this
evening through Saturday morning. This rainfall will result in flooding/flash flooding in
low-lying areas and rock falls along hillsides, especially in areas that are already
saturated.

WIND: Storm force winds of 45 mph with higher gusts are expected across the local area
from this afternoon through Saturday morning.

SEAS: Sea conditions will continue to deteriorate today peaking near 10 feet overnight.
As a result a small craft warning is in effect for St. Maarten. Small craft operators and
swimmers should stay out of the water until the all clear is given.

The Meteorological Department of St. Maarten will continue to monitor the progress of this
system and keep the public updated accordingly.

If Laura is passing south of St Maarten, does that mean we will see more wind and rain than if she passes north?

[chris_fit]

Without even looking at the models, continues to look like a tough road ahead of Laura over the next several days. Land interaction seems almost certain now, dry air is surrounding her and is ahead of her (look at the oranges).

http://rammb.cira.colostate.edu/ramsdis ... display=24

Off topic a little but, but look at all the dry air engulfing the MDR. No one models show no major development for the next 1-2 weeks.

[Dean4Storms]

Looks like a new center forming out near 17N 59W and is moving WNW. Think this takes over.

[aspen]

Without even looking at the models, continues to look like a tough road ahead of Laura over the next several days. Land interaction seems almost certain now, dry air is surrounding her and is ahead of her (look at the oranges).

http://rammb.cira.colostate.edu/ramsdis ... display=24

Off topic a little but, but look at all the dry air engulfing the MDR. No one models show no major development for the next 1-2 weeks.

What is going on? I thought everything was pointing towards a favorable Atlantic starting right about now, but there’s dry air and struggling systems.

[AtlanticWind]

Looks like a new center forming out near 17N 59W and is moving WNW. Think this takes over.

https://www.star.nesdis.noaa.gov/GOES/s ... &length=24

See that too
Could make a difference on whether this clears Hispanola

[hipshot]

here is something interesting.. the overall vorticity is east to west orientated. that east lobe will swing around later and possibly see the center relocate with that.. earlier HWRF runs had something similar.

oh man yeah that west lobe will drop south and the east lobe will shoot north of the islands. I will be watching that intently today as that east lobe has a lot of rotational energy..

center reformation to the NE if convection build there is probably quite likely.

Load the loop below

https://re.ssec.wisc.edu/s/r1wqjC

I think you have a really good point there. My hunch will be that the rotational process will be a bit slower though like possibly well into the evening. Won't be a directional change, just a "stair-step" jump that'll result in a bit of a jump in latitude. Boy, that would shake things up a tad lol.

So, Aric, are you indicating that Laura could split at the east and west lobes? Not sure what you meant in that post.

[StPeteMike]

Looks like a new center forming out near 17N 59W and is moving WNW. Think this takes over.

And this has been discussed quite a bit on here and why I have said don’t place too much emphasis on the models today. Being a still weak end TS and still somewhat unorganized, anything can change with the trajectory of the track. I’m still thinking this will miss the islands but not 100% confident with that.

[Aric Dunn]

here is something interesting.. the overall vorticity is east to west orientated. that east lobe will swing around later and possibly see the center relocate with that.. earlier HWRF runs had something similar.

oh man yeah that west lobe will drop south and the east lobe will shoot north of the islands. I will be watching that intently today as that east lobe has a lot of rotational energy..

center reformation to the NE if convection build there is probably quite likely.

Load the loop below

https://re.ssec.wisc.edu/s/r1wqjC

I think you have a really good point there. My hunch will be that the rotational process will be a bit slower though like possibly well into the evening. Won't be a directional change, just a "stair-step" jump that'll result in a bit of a jump in latitude. Boy, that would shake things up a tad lol.

So, Aric, are you indicating that Laura could split at the east and west lobes? Not sure what you meant in that post.

No, just that some rotational motions to WNW are likely bringing closer to the north side of PR>

[ConvergenceZone]

I think the NHC is just because cautionary. There’s no way a struggling system intensifies while crossing that much land. My only thinking is that they think it will be just slightly north of the islands..

If the forecast dips south even the slightest, they will probably go with either a depression or dissipation as it enters the gulf

[SFLcane]

Looks like a new center forming out near 17N 59W and is moving WNW. Think this takes over.

Potentially....Looks so ragged on satellite .

[hipshot]

If it goes down the middle of the cone, it’s toast, a goner! A barely established tropical storm will fall apart even with that much partial land interaction,

Why?

[psyclone]

Nice to see reducing wind probs over Florida. The trend has definitely been favorable for us..hopefully that continues.

[ConvergenceZone]

If it goes down the middle of the cone, it’s toast, a goner! A barely established tropical storm will fall apart even with that much partial land interaction,

Why?

For obvious reasons. She will be visiting Mr. Shredder

[wx98]

If it goes down the middle of the cone, it’s toast, a goner! A barely established tropical storm will fall apart even with that much partial land interaction,

Why?

For obvious reasons. She will be visiting Mr. Shredder

Maybe, but it could also skirt around PR or take the Mona Passage or reform further north and miss everything.

[chris_fit]

Any more recon today?

[drezee]

https://twitter.com/andretrotter/status/1296805555022045185

Exactly as suggested, collasped

[DestinHurricane]

Tonight should be a key night. If she stays just to the north of PR then she should miss the other islands. We have seen many systems dance around to the north of PR. I don’t necessarily think this is shredded bound, especially if the center reforms a little N.

[ConvergenceZone]

You can tell when a Florida landfall probably decreases, as this forum gets much less active. Tons of folks from Florida on here

[Canelaw99]

So far I have not heard any official statement or plan of action from Monroe county or the City of Key West.

This was posted a little while ago:
https://www.nbcmiami.com/news/local/monroe-county-announces-emergency-order-evacuations-ahead-of-tropical-storm-lauras-potential-track/2281350/