ATL: LAURA - Post-Tropical - Discussion

[jlauderdal]

I don't see the GAs being a huge problem. Maybe just a hinderance for strengthening though. With all the weather north of the center, I would not be surprised by a center relocation further north under the convection, especially if it gets close to the big islands. And like we saw with Isaias, "the shredder" is not a storm destroyer, especially if it's still on the weak side by then.

Isaias, Fay (2008), and other storms have proven that the islands, if anything, help weaker systems via frictional convergence.

these systems can bounce off those islands especially hispanola or reform centers away from the mountians..be on the lookout for that and these weaker systems dont feel the effects as much as the deep ones

[drezee]

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

Why tonight’s 0z euro? Last couple runs on the HWRF seem to have a decent handle on the broad nature of the system, and all of the models have had yesterday’s recon data fed into them overnight.

No model can accurately predict mesoscale center reformations. I believe the convective chaos will be more resolved by 0z. At that time, the models will have a better handle. The Euro is superior synoptically...go with the horse that brought you.

[toad strangler]

I don't see the GAs being a huge problem. Maybe just a hinderance for strengthening though. With all the weather north of the center, I would not be surprised by a center relocation further north under the convection, especially if it gets close to the big islands. And like we saw with Isaias, "the shredder" is not a storm destroyer, especially if it's still on the weak side by then.

Isaias, Fay (2008), and other storms have proven that the islands, if anything, help weaker systems via frictional convergence.

these systems can bounce off those islands especially hispanola or reform centers away from the mountians..be on the lookout for that and these weaker systems dont feel the effects as much as the deep ones

It just happened with Isaias. Stronger systems get hurt much more from interaction with the GA's than weaker systems do. Unless of course you go E to W right down the spine of all three islands.

[ObsessedMiami]

Putting a lot of faith in a set of model runs at this point of formation is like banking on a kids career goals when they are 13. I'll wait and see

[abajan]

000
WTNT63 KNHC 211305
TCUAT3

Tropical Storm Laura Tropical Cyclone Update
NWS National Hurricane Center Miami FL AL132020
905 AM AST Fri Aug 21 2020

...NOAA HURRICANE HUNTER AIRCRAFT FINDS THAT THE DEPRESSION HAS
STRENGTHENED TO TROPICAL STORM LAURA...

Data from a NOAA Hurricane Hunter aircraft indicate that Tropical
Depression Thirteen has strengthened and is now Tropical Storm
Laura with maximum sustained winds of around 45 mph (75 km/h). The
aircraft also found that the center of Laura is located south of the
previously estimated position. These changes will be reflected in
the track and intensity forecasts with the upcoming advisory that
will be issued at 1100 AM AST (1500 UTC).


SUMMARY OF 905 AM AST...1305 UTC...INFORMATION
---------------------------------------------------
LOCATION...17.0N 59.8W
ABOUT 230 MI...375 KM ESE OF THE NORTHERN LEEWARD ISLANDS
MAXIMUM SUSTAINED WINDS...45 MPH...75 KM/H
PRESENT MOVEMENT...W OR 280 DEGREES AT 21 MPH...33 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES

$$
Forecaster Brennan/Pasch

Source

I must admit this came as a total surprise to me. My TV just happened to be tuned to FOX's Today in Florida while I was in another room on my PC, when I heard an anchor saying something like "... is now Tropical Storm Laura." But knowing how poorly organized TD13 was said to have been just a few hours earlier, I assumed it was TD14 that was upgraded.

[Jr0d]

Wow, the model shifts South and the board's consensus seems to think it will now go through the shredder and South of Florida.

The models indicate a weak system until it gets to Hispaniola. We saw how the mountains there helped spin up Isaias. This could be a similar scenario with Laura.

Obviously best case scenario for me will be for it to move South of Puerto Rico and South or on top of Hispaniola, what the GFS, HMON, and ICON are showing.

I still think it is highly lily to go just north of the shredder and be a major problem for the Keys.

Since there is only one road out, we have to think about evacuations. If this misses the mountains, the potential of RI is there and evacuations will be necessary by tomorrow morning at the latest.

[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

[eastcoastFL]

Nhc will probably stick with a week cat 1 through day 5 @ 11am with the recent intensity guidance

[lhpfish]

Aric - Good point. Visually you can totally see this potentially swinging around. I almost feel like the LLC they've located now looks like it's going to dive south/west and crash and burn.

Still don't think they have a good handle on what this storm is going to do. I expect more shifts in the cone to come...

[Gums]

Salute!

Not a good wakeup for DestinHurri and this old codger.

Looks like a replay of Erin track back in 95. So Ft Walton, Navarre, Destin take the brunt unless the other storm interferes.

Still hoping for strong turn into Big Bend, where life and property threat not so bad. Not good, but better for more folks.

Meanwhile, get gas, propane, beer and poptarts!

Gums sends...

[Aric Dunn]

Recon showing the center moved a little more the south maybe SE. to me that say its doing a cyclonic loop .. soon it will shift east then NE where there is greater momentum.. and thats when it could tighten up quite a bit more.

[Michele B]

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 see what you are saying there.

What I ALSO see is how Laura is "gaining" on TD14. Are you telling us that there WON'T be an impact (for good or bad, I don't know) from the interaction of these two storms so "close" to each other.

We here in SWFL are feeling some of the moisture from TD14 now, I think, looking at how long the moisture "train" is behind him. So how is it not going to impact Laura, too, as she gets closer to him?

[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 see what you are saying there.

What I ALSO see is how Laura is "gaining" on TD14. Are you telling us that there WON'T be an impact (for good or bad, I don't know) from the interaction of these two storms so "close" to each other.

We here in SWFL are feeling some of the moisture from TD14 now, I think, looking at how long the moisture "train" is behind him. So how is it not going to impact Laura, too, as she gets closer to him?

There will be plenty of moisture either way. but td14 will definitely spew out mid to upper level moisture to the east for Laura.

[AnnularCane]

Wow...I'm almost speechless (almost!). I was so sure TD 14 would be Laura. Guess this little one wasn't quite as badly off as everyone thought. The tropics really are full of surprises.

[Blow_Hard]

Oh yea big shift coming south 12z is almost near Cuba now. Mainland SFL " Dade and Broward" might be out the cone expect the keys.

Yep. Looking more like this is going to be less of a problem for S FL and more of a problem for the Panhandle.

Which ya’all don’t need.

Honestly, I expect the models will continue shifting south and west and as they do so, I feel a little better about our prospects up here in Panama City. We may get some fringe effects (which we can handle) but it's looking more and more likely that this will be more of a Ms to Pensacola problem and I wouldn't be surprised to see it ultimately end up near SE La. It kind of reminds me a little of both Ivan and Katrina in that we were initially right in the center of the cross hairs but as time went by we ended out of the cone in both cases. I'm certainly not letting my guard down and I am already stocked up, but I feel a little better today than I did yesterday.

[NDG]

Recon showing the center moved a little more the south maybe SE. to me that say its doing a cyclonic loop .. soon it will shift east then NE where there is greater momentum.. and thats when it could tighten up quite a bit more.

Yep, exactly what the 06z HWRF shows it doing all the way until it gets to PR tonight.

[FLpanhandle91]

I was discussing the Erin approach with my family earlier today.

Erin 1995 radar loop

[SFLcane]

Recon showing the center moved a little more the south maybe SE. to me that say its doing a cyclonic loop .. soon it will shift east then NE where there is greater momentum.. and thats when it could tighten up quite a bit more.

The whole envelope is rather far S though.

[MGC]

Hurricane Fredrick of 1979 might be a good analog. Tracked across all the GA islands then turned NW off western tip of Cuba and hit near MS/Al border...MGC

[EquusStorm]

Just came back from the AL coast on Monday. Might have to make a quick run back down there this upcoming Monday at this point.