ATL: IRMA - Models

[tolakram]

 https://twitter.com/EricBlake12/status/903190361388064768



Eric Blake ✔ @EricBlake12
As #Harvey exits the scene, all eyes turn to #Irma as it potentially sets its sights on the NE Caribbean and then...? Long week ahead!
5:38 AM - Aug 31, 2017

[gatorcane]

00Z UKMET looks to miss islands just to the north but passes through Hebert box as a significant cyclone

[jdjaguar]

00Z UKMET looks to miss islands just to the north but passes through Hebert box as a significant cyclone

Hebert Box

[USTropics]

 https://twitter.com/MJVentrice/status/903240235525529600




Michael Ventrice ✔ @MJVentrice
Major development: The best ECMWF EPS members via initialization score are west of ensemble mean track, taking #Irma into the Gulf of Mexico

[jlauderdal]

00Z UKMET looks to miss islands just to the north but passes through Hebert box as a significant cyclone

missing the shredder in this setup is really dangerous for the united states...going though the straits into the gulf is on the table with model support

[gatorcane]

Look at the NAVGEM's depiction of Irma at hour 180. It is an absolute monster! Oh by the way the track likely won't be where the NAVGEM has it since you can usually be guaranteed it is not going where the NAVGEM forecasts:

[KWT]

Yeah UKMO is a little to the north of the ECM but the general path is still not too dissimilar to the what the ECM forecasts. Also doesn't dive anywhere near as far WSW as some models are suggesting.

Track is likely to continue to the WNW/NW from that point onwards, like the GFS except further south.

Those ECM ensembles are certainly something to watch, especially as the ones that are verifying do go further west...

[gatorcane]

The Australian ACCESS model is not something discussed much on this board but it has actually done quite well in the past I remember as far as track. It is similar to the ECMWF track it looks like with the system around the NE Lesser Antilles next Wed. Link if anybody is interested in looking. It shows a weaker system though:

http://www.bom.gov.au/australia/charts/ ... fresh+View

[BensonTCwatcher]

Still some pretty interesting sets of variables in the models-

GFS- The low over the midwest is cutting off , combining with the surface low in the gulf, and retrograding - have to see if that happens- Look pretty plausible
EC- The low cuts off (no gulf low) but retrogrades much quicker - Also the ULL east of Irma seems to factor in as well, noting it fills in pretty quickly and is further SE

Given the NHC is on the southern side of the guidance so far (leaning EC over GFS), and rightly so, they didn't take any bait on the N movement - Looks like that will keep up through 48-72 hours at least

The concerning thing is how much in agreement they are on the overall synoptic setup- Pretty clear that the probability has increased for an islands impact followed by a US impact. Kind of nail-biting till Monday when we'll get further downstream. The setup looks too similar to Fran in that there were two distinct movements west or southwest that brought her to the US In 1996 Sept 6 was not a good day. Looks like we'll have a couple "hitches" in the overall recurve to deal with in any case, and we'll have a developed system as well. Still could go from the Gulf to Canadian Maritimes at this point, in my view, but I'm kind of hoping we get some help from that ULL depicted to weaken the ridge.

[SouthFLTropics]

00Z UKMET looks to miss islands just to the north but passes through Hebert box as a significant cyclone

[i mg]https://s26.postimg.org/yjpx5kz4p/ukm2.2017090700.168.lant.troplant.prp.fcst.gentr.png[/img]

missing the shredder in this setup is really dangerous for the united states...going though the straits into the gulf is on the table with model support

That is a prime time location for a SE Florida scare or strike. We've had many big ones approach from that location. However, it should be noted that we've had many in that position that curved north and avoided the peninsula as well. Whenever I see a track like that I think of Floyd and Frances.

[gatorcane]

The 00Z NASA model is also similar to the ECMWF track. 168 hour image below impacting the islands. It later moves the cyclone over the Greater Antilles. I am pretty sure the GFS will be shifting more to the south (left) in upcoming runs as we have the ECMWF, ACCESS, and NASA models in pretty good agreement:

[SouthDadeFish]

I've been impressed by how the HWRF has seemingly nailed the RI of Harvey and now Irma. Irma is even more impressive considering the statistical models were not as bullish for Irma as they were for Harvey.

[gatorcane]

Be careful looking at the spaghetti output right now. Notice the TVCN (consensus track in dark grey) is well south (left) of the other models. That is mainly due to the ECMWF (and ECMWF ensembles) weighting here. The GFS ensembles (all of the light grey lines) have not proven very accurate so far this season so wouldn't put too much faith in those at this point:

[JPmia]

The Australian ACCESS model is not something discussed much on this board but it has actually done quite well in the past I remember as far as track. It is similar to the ECMWF track it looks like with the system around the NE Lesser Antilles next Wed. Link if anybody is interested in looking. It shows a weaker system though:

http://www.bom.gov.au/australia/charts/ ... fresh+View

Yes, I recall it doing well with Matthew last year. Also, looking at the EPS colors.. the operational track is to the left of the highest probability shaded colors that keep Irma north of Hispainola and Cuba. But, the trend in the EURO and GFS has been west and south.

[p1nheadlarry]

00Z UKMET looks to miss islands just to the north but passes through Hebert box as a significant cyclone

missing the shredder in this setup is really dangerous for the united states...going though the straits into the gulf is on the table with model support

Pretty similar track to Georges, except for the landfall in 6 or 7 countries.

[p1nheadlarry]

Look at the NAVGEM's depiction of Irma at hour 180. It is an absolute monster! Oh by the way the track likely won't be where the NAVGEM has it since you can usually be guaranteed it is not going where the NAVGEM forecasts:

If I woke up to that in real life before my first cup of coffee, I'd put on a pot just to spit it out.

[WeatherEmperor]

Here is this mornings NAO forecast update. Notice the vast majority of red forecast lines are in positive territory. Maybe 2 or 3 only are nagative. Appears very likely the NAO stays positive the next 7-10 days. This may explain why the overnight Euro run had more ridging at the end of the run. We need to keep watching the NAO careful in the upcoming days IMO


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[KWT]

I've been impressed by how the HWRF has seemingly nailed the RI of Harvey and now Irma. Irma is even more impressive considering the statistical models were not as bullish for Irma as they were for Harvey.

Yeah, the hurricane models really latched onto the strengthening quite quickly, much more so than the global models. No reason not to believe it will go down into the 940mbs like the hurricane models suggest.

[kidcuba]

Hello! I see that southwest turn by day 6 gets Irma close to the Caribbean islands. Could it hit the Dominican Republic and Puerto Rico? What's the ridge forecasts say?

[RL3AO]

Hello! I see that southwest turn by day 6 gets Irma close to the Caribbean islands. Could it hit the Dominican Republic and Puerto Rico? What's the ridge forecasts say?

Both the DR and PR should watch this very closely. Any impact, if it were to occur, would be in about 8 days.