ATL: DORIAN - Models

[chris_fit]

Not much on the new GFS this morning...

[toad strangler]

6z GFS takes Hispaniola head on again. Ouch. Overall track similar to 0z Euro. Still so many variables / uncertainties. What no global has done yet is show a strong system before or after interaction with the Greater Antilles.

[NDG]

Majority of Euro ensembles track now show it north of greater Antilles and not dying off over the Caribbean like it was showing the last couple of runs.

[ronjon]

Pretty much all models keep Dorian a TS or Hurricane approaching Florida this weekend except for GFS. And most importantly, all show amazing consistency on the forecast track through this weekend. Most now take it into Florida moving W-NW or NW from the east coast. It will be a fun labor day weekend as usual tracking a tropical cyclone possibly impacting the US. So much for the slow season.

[NDG]

00z position of operational models (GFS/ECMWF/UKMET/ICON) at 144 hours:
https://i.ibb.co/6Nz4FYh/Webp-net-gifmaker-7.gif

That's a pretty tight track consensus that far out.

There is no consensus whatsoever. Each model is still significantly different each run.

Consensus is different from consistency which you are probably trying to refer to, two different things.
Hammy is right in saying that that based on last night’s 0z runs there’s is good consensus, not that they have been consistent on that solution, at least not yet.

[toad strangler]

That's a pretty tight track consensus that far out.

There is no consensus whatsoever. Each model is still significantly different each run.

Consensus is different from consistency which you are probably trying to refer to, two different things.
Hammy is right in saying that that based on last night’s 0z runs there’s is good consensus, not that they have been consistent on that solution, at least not yet.

Yeah that’s fine. In terms of wx forecasting though most people refer to the word consensus as a determined outcome. That isn’t remotely the case. That’s all I’m saying.

[SFLcane]

 https://twitter.com/raleighwx/status/1165938170342584322

[WAcyclone]

It will be interesting to see how NOAA's next generation hurricane model, the Hurricane Analysis and Forecast System (HAFS), performs with this storm. Currently, Version 0.B of this model has it very weak in the eastern Caribbean before quickly developing into a hurricane north of Hispaniola. Verson 0.A is quite similar.

[chaser1]

Fascinating. So much rides on whether the GFS is underplaying Dorian's nearer term increase in intensity. It would seem that a far weaker Dorian would suggest a bit more of a westward trek and greater interaction with "the rock". I don't see how that wouldn't wreck the small storm to shreds. On the flip side though, if the majority of other models suggest an increased level of consistency towards a track that would threaten P.R., then the greater question up to that point will be to what degree dry air and/or upper level shear might impact the storm prior to it's approach to Puerto Rico. Hard to imagine Dorian serving up a big threat here, but it seems clear that what ever increased risk to P.R. could well suggest a significant risk to the Bahamas and Florida. Even still, I'm not entirely sold on environmental conditions being that much more conducive once north of the Greater Antilles...... but intensification here (east of the Bahamas) would seem to fall within this season's overall paradigm. Let's put it this way...... Dorian seems to be a far more potential threat to the U.S. then I would have thought 24 hours ago. Let's first see if it'll survive the E. Caribbean shredder. I would be a bit shocked if RI were to really occur during the upcoming 48 hours but small storms are far more capable of such swings. That, and a better maintained intensity however would seem to really imply that environmental conditions overall are quickly becoming less adverse and a real wake up call that the switch were flipped and the lights all on. Will be curious to see how consistent the HWRF is with this one - especially with forecast track.

[stormlover2013]

should be interesting the next week are so, still have a lot of time to see what Dorian will do, Models will keep going back and forth

[chaser1]

It will be interesting to see how NOAA's next generation hurricane model, the Hurricane Analysis and Forecast System (HAFS), performs with this storm. Currently, Version 0.B of this model has it very weak in the eastern Caribbean before quickly developing into a hurricane north of Hispaniola. Verson 0.A is quite similar.

https://i.imgur.com/8BOG3aj.gif

Interesting model; had not seen/heard of it up to know. An upgrade of the HWRF or a tool less "connected" to the GFS itself?

[SFLcane]

It's rare to see the Euro pick a storm back up like that. Watching this closely now

[jlauderdal]

Pretty much all models keep Dorian a TS or Hurricane approaching Florida this weekend except for GFS. And most importantly, all show amazing consistency on the forecast track through this weekend. Most now take it into Florida moving W-NW or NW from the east coast. It will be a fun labor day weekend as usual tracking a tropical cyclone possibly impacting the US. So much for the slow season.

NHC is outstanding on track even out to 4 days now, even 5 day is getting to the point where you dont want to be at the 5 day point like a few years ago when it usually meant you were "ok". Intensity on this one is really a low confidence bet with the islands in play...24 hours from now Floridians will have a handle on what they can reasonably expect.

[Frank2]

Ugh - I hate living in South Florida at this time of year. I'm too old to be walking on eggs.

Bastardi has backed off his comment of 8 hours ago and thinks perhaps it could pose a threat to the "SE US" by Labor Day. Of course for us down here there's a big difference in a storm going to the east of the Bahamas, or to it's west.

Some models are showing a track to the outside and towards the SE US as Bastardi mentioned, but I agree that 24 hours from now we should have a better idea of where it will go.

One wildcard - some models initially did show it continuing west towards the GOM, and since it's going south of Barbados that is a chance, if high pressure to the north is stronger than forecast.

Frank

[northjaxpro]

Pretty much all models keep Dorian a TS or Hurricane approaching Florida this weekend except for GFS. And most importantly, all show amazing consistency on the forecast track through this weekend. Most now take it into Florida moving W-NW or NW from the east coast. It will be a fun labor day weekend as usual tracking a tropical cyclone possibly impacting the US. So much for the slow season.

This is what I am favoring to happen at this juncture. It is looking more and more probable that Dorian may just only skirt the tip of Hispaniola or miss it completely to their north.

Bahamas and Florida has a good probability of dealing with Dorian late this week and into this upcoming.Labor Day weekend, possibly as a potential formidable tropical cyclone.

[USTropics]

00z ECMWF/GFS/UKMET ensemble members:

[Hypercane_Kyle]

Both the operational GFS and ECMWF have terrible initialization, IMO. ECMWF starts Dorian off at 1010mb; GFS at 1006mb.

[chaser1]

Pretty much all models keep Dorian a TS or Hurricane approaching Florida this weekend except for GFS. And most importantly, all show amazing consistency on the forecast track through this weekend. Most now take it into Florida moving W-NW or NW from the east coast. It will be a fun labor day weekend as usual tracking a tropical cyclone possibly impacting the US. So much for the slow season.

NHC is outstanding on track even out to 4 days now, even 5 day is getting to the point where you dont want to be at the 5 day point like a few years ago when it usually meant you were "ok". Intensity on this one is really a low confidence bet with the islands in play...24 hours from now Floridians will have a handle on what they can reasonably expect.

A pretty salient point here. All in all, a greater threat to a Ponce (P.R.) hit along with a continued NHC track bending Dorian back to the West to WNW once south and east of the Bahamas..... , is a real signal to Floridians to pay serious attention

[northjaxpro]

Fascinating. So much rides on whether the GFS is underplaying Dorian's nearer term increase in intensity. It would seem that a far weaker Dorian would suggest a bit more of a westward trek and greater interaction with "the rock". I don't see how that wouldn't wreck the small storm to shreds. On the flip side though, if the majority of other models suggest an increased level of consistency towards a track that would threaten P.R., then the greater question up to that point will be to what degree dry air and/or upper level shear might impact the storm prior to it's approach to Puerto Rico. Hard to imagine Dorian serving up a big threat here, but it seems clear that what ever increased risk to P.R. could well suggest a significant risk to the Bahamas and Florida. Even still, I'm not entirely sold on environmental conditions being that much more conducive once north of the Greater Antilles...... but intensification here (east of the Bahamas) would seem to fall within this season's overall paradigm. Let's put it this way...... Dorian seems to be a far more potential threat to the U.S. then I would have thought 24 hours ago. Let's first see if it'll survive the E. Caribbean shredder. I would be a bit shocked if RI were to really occur during the upcoming 48 hours but small storms are far more capable of such swings. That, and a better maintained intensity however would seem to really imply that environmental conditions overall are quickly becoming less adverse and a real wake up call that the switch were flipped and the lights all on. Will be curious to see how consistent the HWRF is with this one - especially with forecast track.

Good analysis Chaser. I could not have laid this out any better.

Most definitely interesting times ahead this week with Dorian. What a week this could end up being into the holiday weekend!!

[WAcyclone]

It will be interesting to see how NOAA's next generation hurricane model, the Hurricane Analysis and Forecast System (HAFS), performs with this storm. Currently, Version 0.B of this model has it very weak in the eastern Caribbean before quickly developing into a hurricane north of Hispaniola. Verson 0.A is quite similar.

https://i.imgur.com/8BOG3aj.gif

Interesting model; had not seen/heard of it up to know. An upgrade of the HWRF or a tool less "connected" to the GFS itself?

It is a new high-resolution hurricane model based on the FV3 core. I'm not sure if it is eventually going to replace the HWRF or if both will continue to run in parallel. Here is a quick description provided by the HFIP website:

The HAFS is NOAA's next-generation multi-scale numerical model and data assimilation package, which will provide an operational analysis and forecast out to seven days, with reliable and skillful guidance on Tropical Cyclone (TC) track and intensity (including rapid intensification), storm size, genesis, storm surge, rainfall and tornadoes associated with Tropical Cyclones within the framework of the Unified Forecast System (UFS) and its rolling three-year Strategic Implementation Plan (SIP). Central to the development of HAFS will be the FV3 dynamical core with embedded moving nest capable of tracking the inner core region of the hurricane at 1-2 km resolution.