ATL: PETER - Remnants - Discussion

[Teban54]

This may be trying to consolidate around 12.5-13.0N, based on visible/IR imagery. Let’s see if this keeps up.

Looks much better than yesterday. I can realistically see this spinning up to a TS before the islands if the trend continues.

[ElectricStorm]

I still think this one develops at some point. Whether we see weak development before the TUTT or it waits until after remains to be seen. But I think there's a solid chance we see Odette out of this. Still not convinced on 96L developing and I think there's a good chance this is the only one out of the three AOI's that develops.

[aspen]

The vorticity signature on the CIMSS map has improved as well, and is lined up with the blob of convection on satellite imagery.

[Nimbus]

I still think this one develops at some point. Whether we see weak development before the TUTT or it waits until after remains to be seen. But I think there's a solid chance we see Odette out of this. Still not convinced on 96L developing and I think there's a good chance this is the only one out of the three AOI's that develops.

The trough is forecast to cut off and probably roll SW but that process will take some time and the low will be putting 95L under shear for a couple days. So I'm starting to think even if we get Odette it will stay sheared and probably track north of the islands. Could get completely torn up if it tracks west with the ULL but I'm haunted by the possibility of an Andrew type scenario. Similar setup with a trough splitting and Andrew at about 990 mb's north of Puerto Rico. Computers couldn't predict that back then and computer hardware doesn't get haunted so its pretty unlikely to be modeled.

[cycloneye]

The vorticity signature on the CIMSS map has improved as well, and is lined up with the blob of convection on satellite imagery.

Do you have graphic?

[aspen]

The vorticity signature on the CIMSS map has improved as well, and is lined up with the blob of convection on satellite imagery.

Do you have graphic?

No, I’m on mobile. Here’s the site: http://tropic.ssec.wisc.edu/real-time/w ... oom=&time=

They judged updated it with the 15z map, and 95L’s vort signature looks a little better.

[Sciencerocks]

[grapealcoholic]

Shear vector is forecast to move from SE to SW tonight. We should see it take off as SW shear will be much more favorable in preventing dry air from advecting into downshear vortex.

[grapealcoholic]

Shear really starts to become detrimental at 00z 9/20 (60h). Assuming it starts developing tonight that gives it 35-40 hours, most of which will be over 28+ waters, to strengthen into a low-mid level hurricane.

[tolakram]

Shear really starts to become detrimental at 00z 9/20 (60h). Assuming it starts developing tonight that gives it 35-40 hours, most of which will be over 28+ waters, to strengthen into a low-mid level hurricane.

I'm not convinced we even get a TD out of this. We'll see.

[Nimbus]

Shear vector is forecast to move from SE to SW tonight. We should see it take off as SW shear will be much more favorable in preventing dry air from advecting into downshear vortex.

The northeasterly trade winds have been over running 95L and the trough shear may offset some of that over running shear initially, but that is a tall stack of airmass and there it will likely continue to be some shear vectoring from the south. I personally don't see it going below 990 mb's unless it misses the islands but the official cone was just moved south almost to Guadeloupe.

[cycloneye]

Showers and thunderstorms associated with a tropical wave and broad
area of low pressure located about midway between the Lesser
Antilles and the Cabo Verde Islands have become a little better
organized since yesterday. Environmental conditions are expected
to be conducive for further development during the next couple of
days, and a tropical depression is likely to form over the weekend
or early next week while moving toward the west-northwest at about
15 mph across the central tropical Atlantic and then near the
northern Leeward Islands by Monday and Tuesday. Upper-level winds
could become less conducive for development over the southwestern
Atlantic by the early to middle part of next week. Interests in
the Leeward Islands should monitor the progress of this system
during the next few days.
* Formation chance through 48 hours...high...70 percent.
* Formation chance through 5 days...high...80 percent.

[grapealcoholic]

Shear vector is forecast to move from SE to SW tonight. We should see it take off as SW shear will be much more favorable in preventing dry air from advecting into downshear vortex.

The northeasterly trade winds have been over running 95L and the trough shear may offset some of that over running shear initially, but that is a tall stack of airmass and there it will likely continue to be some shear vectoring from the south. I personally don't see it going below 990 mb's unless it misses the islands but the official cone was just moved south almost to Guadeloupe.

It also looks like it might be broad at least initially, and then develops a small core. It's probably going to rearing it's head for RI and then runs smack into the heavier shear

[Nimbus]

Shear vector is forecast to move from SE to SW tonight. We should see it take off as SW shear will be much more favorable in preventing dry air from advecting into downshear vortex.

The northeasterly trade winds have been over running 95L and the trough shear may offset some of that over running shear initially, but that is a tall stack of airmass and there it will likely continue to be some shear vectoring from the south. I personally don't see it going below 990 mb's unless it misses the islands but the official cone was just moved south almost to Guadeloupe.

It also looks like it might be broad at least initially, and then develops a small core. It's probably going to rearing it's head for RI and then runs smack into the heavier shear

I've heard this forecast before, but after the trough splits

[AutoPenalti]

The northeasterly trade winds have been over running 95L and the trough shear may offset some of that over running shear initially, but that is a tall stack of airmass and there it will likely continue to be some shear vectoring from the south. I personally don't see it going below 990 mb's unless it misses the islands but the official cone was just moved south almost to Guadeloupe.

It also looks like it might be broad at least initially, and then develops a small core. It's probably going to rearing it's head for RI and then runs smack into the heavier shear

I've heard this forecast before, but after the trough splits


https://pbs.twimg.com/media/ECM2C-2XkAA-fXl.jpg

The shortwave that's been modeled to steer this away has become shallower and shallower each run.

[grapealcoholic]

The northeasterly trade winds have been over running 95L and the trough shear may offset some of that over running shear initially, but that is a tall stack of airmass and there it will likely continue to be some shear vectoring from the south. I personally don't see it going below 990 mb's unless it misses the islands but the official cone was just moved south almost to Guadeloupe.

It also looks like it might be broad at least initially, and then develops a small core. It's probably going to rearing it's head for RI and then runs smack into the heavier shear

I've heard this forecast before, but after the trough splits


https://pbs.twimg.com/media/ECM2C-2XkAA-fXl.jpg

Definitely, it could easily become diffluent especially over warm water

[grapealcoholic]

Even a low end hurricane would barrel thru this PV

[Nimbus]

It also looks like it might be broad at least initially, and then develops a small core. It's probably going to rearing it's head for RI and then runs smack into the heavier shear

I've heard this forecast before, but after the trough splits


https://pbs.twimg.com/media/ECM2C-2XkAA-fXl.jpg

The shortwave that's been modeled to steer this away has become shallower and shallower each run.

The first trough is digging south and will become an ULL to the west or SW of 95L where it could eventually ventilate the outflow. So after some temporary shear the track should turn more westward north of the islands.
The trough split didn't happen to Andrew till it was north of Puerto Rico but the current trough ahead of 95L will be splitting and rolling away earlier.

https://www.tropicaltidbits.com/sat/sat ... uct=wv-mid

[grapealcoholic]

Time of the essence and I think DMAX will be crucial tonight to at least get a TD closed up. I like how HWRF lets us do a little now-casting; for example it has some decent convection firing by 8pm

[AutoPenalti]

I've heard this forecast before, but after the trough splits


https://pbs.twimg.com/media/ECM2C-2XkAA-fXl.jpg

The shortwave that's been modeled to steer this away has become shallower and shallower each run.

The first trough is digging south and will become an ULL to the west or SW of 95L where it could eventually ventilate the outflow. So after some temporary shear the track should turn more westward north of the islands.
The trough split didn't happen to Andrew till it was north of Puerto Rico but the current trough ahead of 95L will be splitting and rolling away earlier.

https://www.tropicaltidbits.com/sat/sat ... uct=wv-mid

It's progressive as well.