ATL: DANNY - Models

[tolakram]

Moving north.

[RL3AO]

You can use a dProg/dT loop to look at changes by model run. Here is next Tuesday morning for the last 5 or 6 GFS runs. You can see the model has trended slower and stronger for the Hudson Bay trough.

http://www.atmos.albany.edu/student/kgr ... dprog.html

[gatorcane]

GFS is showing the same pattern we have seen for so many years around this time which is a trough along the Eastern Seaboard of the U.S. I am not convinced yet this far out unless the European shows it too (which it is not yet)

[ronjon]

This is all very speculative 9-10 days out. What if the high bridges from the central plains to the western atlantic and the weakness remains in the NE GOM? Totally different track. Its fun to watch these models in the long range, but they're not really accurate at all.

[tolakram]

[emeraldislenc]

The next two days of models will be interesting. A lot has changed since last night. It will be interesting.

[RL3AO]

This is all very speculative 9-10 days out. What if the high bridges from the central plains to the western atlantic and the weakness remains in the NE GOM? Totally different track. Its fun to watch these models in the long range, but they're not really accurate at all.

They're more accurate then people give them credit for. I'd wager in 8 days, there will be a trough in SE Canada and a building ridge over the Central US. The inaccuracies will depend on how weak/strong and how fast/slow, which will make significant impacts on when/where it recurves.

[PTrackerLA]

Well not a total fish, hits Bermuda hr 312 then turns SE and makes a cyclonic loop aiming for Bermuda again at 384 .

[gatorcane]

12Z GEM drops the system. Initialization looks way off.

But if you look at the steering from the 12Z GEM (This is the CMC which is actually pretty decent at forecasting mid-latitude synoptics) for late next week into next week, it looks like it builds in more ridging with a 500MB ridge right off the SE United States coast and that would prevent a recurve for sure. Hmm:

[RL3AO]

The feature to watch over the next couple days will be the SE Canada trough. Do the models continue to make it stronger? If so, we would have a strong cold front sweeping off the East Coast ahead of Danny.

[gatorcane]

12Z NAVGEM is sending a strengthening Danny on a beeline WNW just north of the Leewards and Puerto Rico:



700MB steering shows the ridge to the north might be expanding west and flattening creating a narrow ridge above Danny?

[BigB0882]

The GFS shows something in the Gulf at 240 hours. I wonder if that may have potential to spin up into something should it sit there long enough?

Back on topic: I am not sure what to think, yet. Based on the last few years I would go with a recurve but who knows!

[blp]

Michael Ventrice ‏@MJVentrice
IMost models have been biased too far north and east of reality according to track biases for #Danny

[blp]

As some of the pros have been commenting. The picture is still far from settled with ridge pattern so really not worth putting too much effort on it right now.

Ryan Maue ‏@RyanMaue
Two Super Typhoons can really build downstream ridges.
GFS 12z has 600 dm contour touching Alaska next week (+3.8σ)

[tolakram]

12Z Euro initialized.

[tolakram]

[tolakram]

[tolakram]

Further north this run.

[tolakram]

I take that back. Looking at higher rez plots it's almost identical to the 0Z run.

[stormlover2013]

doesn't look that much if any north by looking at previous runs