ATL: LAURA - Post-Tropical - Discussion

[Aric Dunn]

anyone notice the circ that was SE of barbados yesterday that was elongated and dry, but now has a massive blow up of convection.. and there is a convergence line between the two? looks like there will be some interaction between the two. HWRF and HMON were showing something similar to this. helping to swing Td13 westerly. where that happens exactly is key.

[NDG]

Very concerning with models keep trending in it tracking north of the Greater Antilles. I am sure the NHC will start trending upward with its strength forecast if the models remain persistent on its forecast track over the next 3-4 days.

[AutoPenalti]

There’s expectation that weakening will occur for about 12 hours before finally finding favorable conditions for the remainder of its journey.

[NDG]

For those hard headers, as we Cubans say "cabeziduro", who as of late last night were doubting the shear was going to get out of the way as all models have been persistently showing, here's the proof. There will still be some left but by no way destructive to TD 13, before conditions go perfect north of the Greater Antilles. Now lets move on.

[msbee]

Good morning
Not sure what to expect here in St Maarten. As some of you may know, even a tropical storm can cause big problems on our small islands.
Local Met Office says this morning:
"Regardless of development, gusty wind conditions and heavy rainfall are expected over parts of the local area from late Friday.
The current forecast track brings the closest point of approach at approximately 60 miles to the Northeast of St Maarten in about 48 hours."

[BensonTCwatcher]

Hmm seeing a LOT of confident statements in the blocking ridge setup, and I am not stating that that in any way that scenario is not the most likely one at this time. But own personal observations of many other synoptic scale setups 100 hours or more in the future has something nagging at me.

1. The "thumb" portion of the ridge that will be in place SW of Bermuda with the East/West axis is clearly the dominant steering feature ( sown on GFS 500 mb height)
2. I see in the GFS model upstream sampling (soundings) ahead of the storm the steering flow at 102 hours is WNW up through 500 mb height
3. I also notice the the flow is much more northerly both above 500 mb AND as you go up the FL east coast. There does not seem to be any wiggle room either. I see that if this storm is stronger than forecast at 102 hours, or if it is riding the right side of the forecast envelope it could be influenced by the change in the steering vector right at the "thumbnail" portion of the clockwise flow - somewhere around WPB.
4. The above factors combined with the angle of the FL coast makes a FL landfall point forecast slip up the coast as it approaches. Given we are still pretty far out from this point, I can see at least a possibility that this "misses the 2 a.m. Monday forecast point by being much stronger than a TS and being a tad on the right of the guidance. There are ensemble members showing this on the latest run. Not at all saying this re-curves OTS or anything like that, or even that this does not get into the Gulf - still most likely- just that clearly the intensity forecast confidence is low and if this at all a strong hurricane coming through the Bahamas it looks like the steering flow will be quite different. Some Dominoes stacked up here on this one. Won't be sure which way they will fall till the wee hours on Monday though.

[RT23]

Quick question here , that Vorticity in the SW quad just SE of Barbados, has spun up some convection overnight, any chance this can "break away" and be ripe for development?

[Aric Dunn]

Quick question here , that Vortex in the SW quad just SE of Barbados, has spun up some convection overnight, any chance this can "break away" and be ripe for development?

I mentioned this system on the previous page..

I dont think it will develop but it may very well help bend td 13 more westerly for a short time similar to the HWRF /HMON

[cycloneye]

Good morning
Not sure what to expect here in St Maarten. As some of you may know, even a tropical storm can cause big problems on our small islands.
Local Met Office says this morning:
"Regardless of development, gusty wind conditions and heavy rainfall are expected over parts of the local area from late Friday.
The current forecast track brings the closest point of approach at approximately 60 miles to the Northeast of St Maarten in about 48 hours."

Good morning Barbara. A TS watch issued for St Maarten.

The government of St. Maarten as issued a Tropical Storm Watch for
St. Maarten.

The government of Antigua has issued a Tropical Storm Watch for
Antigua, Barbuda, St. Kitts, Nevis, and Anguilla.

[toad strangler]

 http://twitter.com/weatherprof/status/1296418644306661376

[aspen]

So far, TD13 is tracking a little to the south of the NHC’s forecast track. It could continue wobbling north and south, or it could end up tracking closer to the GAs.

[SFLcane]

 https://twitter.com/WeatherProf/status/1296417202527248384

[abajan]

Latest visibles:

[artist]

Good morning
Not sure what to expect here in St Maarten. As some of you may know, even a tropical storm can cause big problems on our small islands.
Local Met Office says this morning:
"Regardless of development, gusty wind conditions and heavy rainfall are expected over parts of the local area from late Friday.
The current forecast track brings the closest point of approach at approximately 60 miles to the Northeast of St Maarten in about 48 hours."

Good morning, msbee.
Right now the NHC shows winds should hit there late Fri, early Sat morning and last the day, with. 17% chance of winds between 34-50 knots during the day. Most of the heavier rain appears to stay north and ne of you there.
Anyone else able to give her a better idea?

[msbee]

Good morning
Not sure what to expect here in St Maarten. As some of you may know, even a tropical storm can cause big problems on our small islands.
Local Met Office says this morning:
"Regardless of development, gusty wind conditions and heavy rainfall are expected over parts of the local area from late Friday.
The current forecast track brings the closest point of approach at approximately 60 miles to the Northeast of St Maarten in about 48 hours."

Good morning, msbee.
Right now the NHC shows winds should hit there late Fri, early Sat morning and last the day, with. 17% chance of winds between 34-50 knots during the day. Most of the heavier rain appears to stay north and ne of you there.
Anyone else able to give her a better idea?

good morning. I think we just wait and watch and hopefully it will just be a squally day with no real serious problems.

[NDG]

For those that think that the set up is similar to Hurricane Matthew, and it could take a similar track to it. The set up was similar but different. Different trajectory and by the time the Bermuda ridge tried to retrograde westward again Matthew was already in the northern Bahamas.
With TD 13 the developing strong Bermuda ridge will be tracking westward along with it, keeping it from gaining much latitude.

[abajan]

Good morning
Not sure what to expect here in St Maarten. As some of you may know, even a tropical storm can cause big problems on our small islands.
Local Met Office says this morning:
"Regardless of development, gusty wind conditions and heavy rainfall are expected over parts of the local area from late Friday.
The current forecast track brings the closest point of approach at approximately 60 miles to the Northeast of St Maarten in about 48 hours."

Good morning, msbee.
Right now the NHC shows winds should hit there late Fri, early Sat morning and last the day, with. 17% chance of winds between 34-50 knots during the day. Most of the heavier rain appears to stay north and ne of you there.
Anyone else able to give her a better idea?

good morning. I think we just wait and watch and hopefully it will just be a squally day with no real serious problems.

Hi msbee

A squally day sounds about right, but we'll get a clearer picture as it progresses.
Praying all goes well for you and others potentially in harm's way.

[Aric Dunn]

For those that think that the set up is similar to Hurricane Matthew, and it could take a similar track to it. The set up was similar but different. Different trajectory and by the time the Bermuda ridge tried to retrograde westward again Matthew was already in the northern Bahamas.
With TD 13 the developing strong Bermuda ridge will be tracking westward along with it, keeping it from gaining much latitude.

https://i.imgur.com/X4WExg3.gif

and there is that distinct digging trough that was over the mid west for Matthew.. VS now where it will be a building ridge across the central US as well.

quite the contrast. and the same applies to Dorian that had a trough- ridge timing issue.

currently we are going to have a no trough and just ridge strength/orientation scenario.

[Blown Away]

Looking good this morning, a legit TD this morning.

https://i.imgur.com/pwV2aon.jpg

An hour and a half ago it looked "horrible" according to SFLcane.

At the surface much better, true LLC likely there. SFLCane I think meant appearance on the IR, doesn't tell the whole story.

[SFLcane]

Looking good this morning, a legit TD this morning.

https://i.imgur.com/pwV2aon.jpg

An hour and a half ago it looked "horrible" according to SFLcane.

At the surface much better, true LLC likely there. SFLCane I think meant appearance on the IR, doesn't tell the whole story.

Still think satellite appearance is meh this morning.