ATL: DORIAN - Post-Tropical - Discussion

[Hurrilurker]

Estimating at 72.4 W at 4 AM and him reaching 72.8 W at 6 AM vs 8 AM NHC prog. Moving 14 mph avg over last 5 hrs vs NHC prog of 11. Got to watch this because faster would mean further W at expected stall. Has already moved 15 miles more west vs prog over just last 5 hours or 3 per hour. If this were to keep up for 24, that would be 72 crucial miles. Maybe it will slow later but certainly not yet.

But, could the ridge also not break down faster than forecast, still allowing an earlier turn?

[KWT]

Estimating at 72.4 W at 4 AM and him reaching 72.8 W at 6 AM vs 8 AM NHC prog. Moving 14 mph avg over last 5 hrs vs NHC prog of 11. Got to watch this because faster would mean further W at expected stall. Has already moved 15 miles more west vs prog over just last 5 hours or 3 per hour. If this were to keep up for 24, that would be 72 crucial miles. Maybe it will slow later but certainly not yet.

But, could the ridge also not break down faster than forecast, still allowing an earlier turn?

Anything is possible at this stage, the ridge could just as easily hold on for longer, indeed typically that is what tends to happen in these set-ups. Still 24hrs or so could make a huge difference to what the situation is for the Bahamas, I still fear its going to end up south of where the models expect, enough to bring northern islands of the Bahamas into play in a big way.

Near due west in the last 2hrs, just a slight stair step here and there.

[Hurrilurker]

Last few frames it looks like the eye may be getting ragged again. We probably missed the max intensity for tonight, a few hours ago I would say it must have been sub-940mb and probably close to Cat-5.

[CourierPR]

Estimating at 72.4 W at 4 AM and him reaching 72.8 W at 6 AM vs 8 AM NHC prog. Moving 14 mph avg over last 5 hrs vs NHC prog of 11. Got to watch this because faster would mean further W at expected stall. Has already moved 15 miles more west vs prog over just last 5 hours or 3 per hour. If this were to keep up for 24, that would be 72 crucial miles. Maybe it will slow later but certainly not yet.

But, could the ridge also not break down faster than forecast, still allowing an earlier turn?

Anything is possible at this stage, the ridge could just as easily hold on for longer, indeed typically that is what tends to happen in these set-ups. Still 24hrs or so could make a huge difference to what the situation is for the Bahamas, I still fear its going to end up south of where the models expect, enough to bring northern islands of the Bahamas into play in a big way.

Near due west in the last 2hrs, just a slight stair step here and there.

I am watching nervously in SoFla, about 30 miles south of West Palm Beach. Will this bring more of South Florida into play?

[senorpepr]

NOAA 42 just departed and is headed to check out Dorian.

[wxman57]

The NW quad looks like it's getting hit with a bit of shear or dry air, probably nothing major, but a bit of that section is getting eroded.

Was about to post the same thing. Definitely looks weaker. Cloud pattern on west side not looking as good. Looking more like Dorian may miss the East U.S. Coast (at least the center). May pass a little north of the Bahamas, too.

[wxman57]

I am watching nervously in SoFla, about 30 miles south of West Palm Beach. Will this bring more of South Florida into play?

I think you're going to be OK there.

Time go head to the office...

[Bad_Hurricane]

000
WTNT45 KNHC 310848
TCDAT5

Hurricane Dorian Discussion Number 28
NWS National Hurricane Center Miami FL AL052019
500 AM EDT Sat Aug 31 2019
...
It should be noted that the new forecast track does not preclude
Dorian making landfall on the Florida coast, as large portions of
the coast remain in the track cone of uncertainty. Also,
significant impacts could occur even if the center stays offshore.
...
$$
Forecaster Beven

[NDG]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

[jlauderdal]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

if the models cant resolve this ridge with all the data that has been ingested, that would be a major bust

[hurricaneCW]

The NW quad looks like it's getting hit with a bit of shear or dry air, probably nothing major, but a bit of that section is getting eroded.

Was about to post the same thing. Definitely looks weaker. Cloud pattern on west side not looking as good. Looking more like Dorian may miss the East U.S. Coast (at least the center). May pass a little north of the Bahamas, too.

Could end up being all hype and bark with no bite, and we'd get some nice swells out of it.

Pattern's quite different this year vs last two with a lot of big troughs and strong highs coming south into the northern half of US.

[PandaCitrus]

This storm was supposed to never have formed, then it was supposed to dissipate over Hispaniola, then hit Puerto Rico. It did none of these things. And this was all in the 24-48 hour forecast period when they are supposed to be most reliable!

It's already been a major forecast bust as far as the models are concerned multiple times. We'll see how it goes but as of right now it is moving almost due west and seems to have picked up a little forward motion during the night. The models may change again today. We'll just have to see what happens.

[plasticup]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

if the models cant resolve this ridge with all the data that has been ingested, that would be a major bust

There is a lot of data, and I am sure the forecast is better than average accuracy because of it. But the difference between onshore and offshore here is only 50-100 miles. That’s tiny. Meteorologically only a small miss would have huge change in impact

[NDG]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

if the models cant resolve this ridge with all the data that has been ingested, that would be a major bust

There was not much data collected to the north of Dorian last night, it was only a few dropsondes by the NOAA recon on its way back to Lakeland along the 29th latitude which showed H50 heights at 592dm, a little stronger than what the models were showing.

[GCANE]

Eye is contracting. Very likely pinhole.
Seeing steady lightning on the NE eyewall.
Looking at cloud tops, appears some UL shear.

[jlauderdal]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

if the models cant resolve this ridge with all the data that has been ingested, that would be a major bust

There was not much data collected to the north of Dorian last night, it was only a few dropsondes by the NOAA recon on its way back to Lakeland along the 29th latitude which showed H50 heights at 592dm, a little stronger than what the models were showing.

good point on last nights data collection...trend is good for no florida strike but at the speed its moving, 6 hours of westward motion the models dont see could mean landfall

[wjs3]

The ridging to the north of Dorian will be very important to watch today along with its continuing forward speed, if the ridge stays stronger than what the models see it will keep pushing westward further west before the ridge starts weakening and a track to the NNW starts happening. I will not be letting my guards down and hopefully people along the FL east coast will not start celebrating too soon that the track is now offshore.

if the models cant resolve this ridge with all the data that has been ingested, that would be a major bust

IMO the model variability is not about resolving the ridge--it's about resolving the speed, location and depth of the trough that comes through in the westerlies and breaks down that ridge.

We're in a transitional season (fall has started in the north) and I think we've seen all models sort of struggle with just how deep, where and when the trof will come through. Earlier model runs were more summer-like. Now they're more fall-like (Chicago isn't forecast to get out of the 60s on Wednesday, e.g.).

[wjs3]

Eye is contracting. Very likely pinhole.
Seeing steady lightning on the NE eyewall.
Looking at cloud tops, appears some UL shear.

I'm not sure I see the eye contracting in IR. What I do see is that the CDO has gotten much less symmetrical. In WV there may be a little dry air it's ingesting that looks to have eroded some of the W side of the circ.

Edit: Maybe it is a little shear. Seeing some subtle signs of cloud tops blowing to the south. Or some combination (shear bringing dry air in).

[senorpepr]

I received more information about yesterday's recon mission. TEAL 77 had a cracked windshield. They returned to base. 307 then attempted a fix mission into Dorian, but cracked another windshield. So they aborted the fix mission and just completed the buoy drop.

Sent from my SM-T810 using Tapatalk

[txwatcher91]

I received more information about yesterday's recon mission. TEAL 77 had a cracked windshield. They returned to base. 307 then attempted a fix mission into Dorian, but cracked another windshield. So they aborted the fix mission and just completed the buoy drop.

Sent from my SM-T810 using Tapatalk

Interesting, thanks for sharing. What could have cracked the windshield in both of them?