ATL: IRMA - Models

[floridasun78]

gfs want save islands past few runs

[meriland29]

[RL3AO]

Day 6 compare. The ball has been set in motion with the GFS and it will probably miss the US. The differences pile up slowly over the next five days, but its enough to lead to 1000 mile differences by day 10.

[SFLcane]

Looks like it might not even make it past 60-65w

[Kingarabian]

ECMWF control run:

[img]http://i.imgur.com/4ZOiE4F.gif[img]

Source: weather.us

Amatuer question... What is the ECMWF control run, and why is it so different than the standard ECMWF model run?
Thx...

The control is basically the operational/deterministic model run on a lower resolution with less horizontal and vertical grid points.

The individual ensemble runs are also the lower resolution control model but have added changes to the initial conditions.

The ensemble runs give forecasters a sense of direction if small changes were to affect the system, but at the same time can be very erroneous due to resolution issues. That's when the ensemble control comes in. The ensemble control helps identify when the Ensemble spread is due to initial condition variations as opposed to resolution issues.

[weathaguyry]

Irma and her son Jose, scooting across the Atlantic

[KWT]

GFS really ramping up that trough over the states, still looks overdone to me, looks more like a late September type trough and its probably the GFS most frustrating bias (I'm a winter lover here in the UK, that bias always causes what we like to call a 'downgrade', often it looks like you'll get a humbdinger of a dump of cold blast, and instead its like a leaky shower tap)

Anyway could be a NE threat from the 18z GFS if the cut-off low swings it round and holds off long enough to capture it.

[SouthFLTropics]

The Euro cuts off the trough whereas the GFS keeps it together and keeps the ridge eroded. The Euro is night and day different beyond 96 hours and as RL3AO said, the early differences add up to the big change later on.

[meriland29]

[stormreader]

Sure has gained a lot of latitude in recent pics. Seems like that would favor the GFS solution. Funny for me to say this, because I normally favor the Euro.

[SouthFLTropics]

Stop the press...I think the GFS just cut the trough off...

[RL3AO]

Sure has gained a lot of latitude in recent pics. Seems like that would favor the GFS solution. Funny for me to say this, because I normally favor the Euro.

Moving just as forecast by the Euro.

[RL3AO]

Big trof drapped across the SE..

Becomes cut-off low, MUCH stronger than the 12z ECM which has the same idea of making a cutoff low but hangs it back (maybe too far, I have heard the ECM does hang back cutoff lows too much).

My gut is this run swings Irma up towards NE states and Newfoundland.

I think you're right. The stronger trough will make this get closer to the US has the 500 mb flow is southerly along the coast instead of southwesterly.

[AxaltaRacing24]

Sure has gained a lot of latitude in recent pics. Seems like that would favor the GFS solution. Funny for me to say this, because I normally favor the Euro.

The euro has also foretasted this to happen. It has the storm at near 19N at one point. This is nothing unexpected.

[meriland29]

[stormreader]

Sure has gained a lot of latitude in recent pics. Seems like that would favor the GFS solution. Funny for me to say this, because I normally favor the Euro.

Moving just as forecast by the Euro.

Thanks. At this stage, I just look at general model trends. Didn't know there was a little bump northward in the early stages of the Euro.

[ronjon]

Does the trough or cut off low retrograde now on the GFS? If so, US in big trouble.

[KWT]

Big trof drapped across the SE..

Becomes cut-off low, MUCH stronger than the 12z ECM which has the same idea of making a cutoff low but hangs it back (maybe too far, I have heard the ECM does hang back cutoff lows too much).

My gut is this run swings Irma up towards NE states and Newfoundland.

I think you're right. The stronger trough will make this get closer to the US has the 500 mb flow is southerly along the coast instead of southwesterly.

Out to 192hrs, its going to be quite a close call, the cutoff low is just sitting there and slowly starting to weaken, any slight shift east will catch it, if it hangs there then it may well be a coastal raker in the end.

Just goes to how this situation isn't purely just an NW then out to sea situtation, there are other players that make this tricky.

[meriland29]

198

[weathaguyry]

This GFS run is literally giving me knots in my stomach, with the cutoff and a straight path up the east coast