ATL: FIONA - Models

[artist]

Gonna leave us in suspense??

so, what are those possibilites? at least in your opinion.

Honestly, my initial gut would be that Early would be more safely between Bermuda and the EC (well, as safely as you can get in there), with 97L as Fiona become a very real concern for the Carolinas, particularly OBX.

Now, with Earl trending towards the west, it more takes the place of 97L in my gut scenario. What will be important is how quickly 97L decides to get its act together, how quickly Earl gets out of there, and what the ridge decides to do in Earl's wake. For the moment, I think That Earl will stay far enough off the EC that it won't be a huge concern, and at a speed that will be enough to induce 97L/Fiona to follow a similar path up and out. For the islands, it may almost look like a replay of Earl, though this time may be close enough to feel more direct effects. As the ridge builds in, it could rake along the coast or perhaps even make landfall in the Carolinas.

Now, there's a lot that can mess that up royally, and I'm not particularly confident in that. If Earl's slow or 97L is fast, it could go up and out more quickly, with little or no concern for many. On the flip side, the ridge could build in enough to force 97L west and become a Florida/Gulf/Cuba(????) issue. 97L's development will be key, too. We can see now that the low level flow would force a weaker system farther west like Earl has done somewhat, but quicker development shows a bigger window to play with.

thanks thetruesm. So, it is a matter of watch and wait! I hate it that no matter what, more than likely someone could get hit from this one as well.

[Steve]

>>if the ECM is showing a solution at 144hr of a GOM threat then I would be worried...

It's worth noting for sure. It's got landfall 11 days in SC LA? UKMET that I have access to doesn't go out that far but does show 97L north of the Bahamas at 120. Canadian/GEM 12z out to 144 is north of the Bahamas (00z eventual landfall was +/- NC/SC border. 12Z Wharf is north of the Bahamas following Earl and 12Z GFDL is trailing Earl to the east which would be my least likely scenario. 12Z GFS shows recurve beginning a couple hundred miles east of the South Carolina coast just out in front of high pressure moving down off the coast in the Mid-Atlantic. Who knows this far out if we get a reinforcing high (albeit small), but if it does have that pattern close, I suspect timing would be the thing to watch.

[Portastorm]

I think I have seen enough (as have my colleagues) in this thread today where many well-intended folks are begging our pro mets to chime in on the situation and when they do, they (the pro mets) have to read posts which either criticize their comments or attempt to reduce them to a few basic sentences which demean the pro met's efforts at educating folks.

The warnings are going to start flying here fast and furious and after warnings come board vacations.

[CYCLONE MIKE]

>>if the ECM is showing a solution at 144hr of a GOM threat then I would be worried...

It's worth noting for sure. It's got landfall 11 days in SC LA? UKMET that I have access to doesn't go out that far but does show 97L north of the Bahamas at 120. Canadian/GEM 12z out to 144 is north of the Bahamas (00z eventual landfall was +/- NC/SC border. 12Z Wharf is north of the Bahamas following Earl and 12Z GFDL is trailing Earl to the east which would be my least likely scenario. 12Z GFS shows recurve beginning a couple hundred miles east of the South Carolina coast just out in front of high pressure moving down off the coast in the Mid-Atlantic. Who knows this far out if we get a reinforcing high (albeit small), but if it does have that pattern close, I suspect timing would be the thing to watch.

Steve, do any of those show any kind of bending back west at anytime? Just think with those models you spoke of they are to slow with Earl moving out or to quick catching 97L up to Earl. Either way basically has 97L catching the weakness Earl leaves behind before the high has a chance to build back in. Just think the Euro has a better handle on things right now than the GFS and its brothers do.

[Steve H.]

Throw out the idea that 97L will catch Earl and join to his hip. Ain't gonna happen that way and the GFDL and the HWRF feed from the same trough of GFS slop (no pun intended). I like the westward progression of the Euro with both systems, but it is some day out before we get a handle as to whether it sends up in the GOM or makes the turn before that. The solution is probably in the middle somewhere, but the timing will be critical. Make sure you've got you're hurricane stuff together for later this week (heck, I don't). But we may need it.

[Steve]

>>Steve, do any of those show any kind of bending back west at anytime? Just think with those models you spoke of they are to slow with Earl moving out or to quick catching 97L up to Earl. Either way basically has 97L catching the weakness Earl leaves behind before the high has a chance to build back in. Just think the Euro has a better handle on things right now than the GFS and its brothers do.

Not really. The closest anything else I've looked at comes is from the 00Z GEM (runs to 240 hours) where Earl slides a little west north of Puerto Rico then recurves. (By that time, named storm) Fiona comes in a slightly more northerly latitude on a westerly-wnw heading straight to the SC/NC border. What GEM does is nudges a piece of the Atlantic High back toward the west (in the wake of Earl) and the reinforcing high pressure coming off the mid-Atlantic acts to keep it blocked and on that trajectory. You can see what it's doing at 500mb.

http://raleighwx.easternuswx.com/models ... MLoop.html

Other than that, I haven't looked at the GFS Ensembles at all today, but most of the tracks are pretty tightly clustered on a recurve scenario through 12-18Z (as per SWFMD plots). It's something to watch, but I'd have to agree with the pros who say it's too early but would appear that the initial U.S. target area to watch would be the SE Coast. If things change (and 7-8 days is forever in the tropics as everyone knows), we'll have plenty of time to watch the evolution of the pattern and how the models latch onto things.

[Ivanhater]

Euro Ensemble hot off the presses

[Steve]

Weird how it has the Gulf solution where the 12z NAO pro is more negative than it has been in forever. Of course if there's a blocking subtropical high (or other more local indicators), it's not as important. But it's been flipping back and forth from its 12z-00z runs every day.

2010082912z ECMWF RUN NAO Values
NAO value for forecast hour 000: -120.355087
NAO value for forecast hour 024: -81.0095596
NAO value for forecast hour 048: -58.0232697
NAO value for forecast hour 072: -62.1287041
NAO value for forecast hour 096: -50.8557663
NAO value for forecast hour 120: -37.3647156
NAO value for forecast hour 144: -96.9747314
NAO value for forecast hour 168: -132.931549
NAO value for forecast hour 192: -156.384201
NAO value for forecast hour 216: -160.936096
NAO value for forecast hour 240: -194.482574
NAO value for Day 1-5: -57.8764038
NAO value for Day 6-10: -148.341827

12Z GFS joins in tanking it, but has an exception in the 204-216 which may be similar to what the Euro is seeing at lower latitudes in that bend west.

2010082912z GFS RUN NAO Values
NAO value for forecast hour 000: -124.83374
NAO value for forecast hour 006: -119.521149
NAO value for day 1 (f00-f06): -122.177444
NAO value for forecast hour 012: -108.214249
NAO value for forecast hour 018: -101.147461
NAO value for forecast hour 024: -87.8982697
NAO value for forecast hour 030: -84.473526
NAO value for day 2 (f12-f30): -95.4333801
NAO value for forecast hour 036: -76.2230682
NAO value for forecast hour 042: -78.6893311
NAO value for forecast hour 048: -74.2573166
NAO value for forecast hour 054: -76.943428
NAO value for day 3 (f36-f54): -76.5282898
NAO value for forecast hour 060: -74.822525
NAO value for forecast hour 066: -87.071991
NAO value for forecast hour 072: -84.8923645
NAO value for forecast hour 078: -93.5323639
NAO value for day 4 (f60-f78): -85.0798111
NAO value for forecast hour 084: -92.353096
NAO value for forecast hour 090: -96.9192886
NAO value for forecast hour 096: -79.962326
NAO value for forecast hour 102: -70.742836
NAO value for day 5 (f84-f102): -84.9943848
NAO value for forecast hour 108: -55.7121811
NAO value for forecast hour 114: -54.687355
NAO value for forecast hour 120: -46.8791656
NAO value for forecast hour 126: -50.5031738
NAO value for day 6 (f108-126): -51.9454689
NAO value for forecast hour 132: -47.233757
NAO value for forecast hour 138: -55.9718552
NAO value for forecast hour 144: -52.3820763
NAO value for forecast hour 150: -58.8366241
NAO value for day 7 (f132-f150): -53.6060791
NAO value for forecast hour 156: -57.920208
NAO value for forecast hour 162: -65.2909164
NAO value for forecast hour 168: -53.5947838
NAO value for forecast hour 174: -48.173851
NAO value for day 8 (f156-f174): -56.2449417
NAO value for forecast hour 180: -33.0807457
NAO value for forecast hour 192: 14.4986038
NAO value for day 9 (f180-f192): -9.29107094
NAO value for forecast hour 204: 16.4094887
NAO value for forecast hour 216: 14.9436951
NAO value for day 10 (f204-f216): 15.6765919
NAO value for forecast hour 228: -1.45330811
NAO value for forecast hour 240: -20.7859421
NAO value for day 11 (f228-f240): -11.1196251
NAO value for forecast hour 252: -34.3646736
NAO value for forecast hour 264: -54.109642
NAO value for day 12 (f252-f264): -44.2371597
NAO value for forecast hour 276: -75.9381256
NAO value for forecast hour 288: -87.0435944
NAO value for day 13 (f276-f288): -81.49086
NAO value for forecast hour 300: -89.5662918
NAO value for forecast hour 312: -88.5006943
NAO value for day 14 (f300-f312): -89.033493
NAO value for forecast hour 324: -92.1392593
NAO value for forecast hour 336: -106.41861
NAO value for day 15 (f324-f336): -99.2789307
NAO value for forecast hour 348: -124.963531
NAO value for forecast hour 360: -149.272903
NAO value for day 16 (f348-f360): -137.118225
NAO value for forecast hour 372: -167.895599
NAO value for forecast hour 384: -176.116684
NAO value for day 16 (f372-f384): -28.6676903
NAO value for Day 1-5: -92.842659
NAO value for Day 6-10: -31.0821934
NAO value for Day 11-15: -65.0320129

[KFDM Meteorologist]

Euro Ensemble hot off the presses

[AdamFirst]

One portion of the Euro ensemble right offshore from me.

That's cool, I guess.

[stormchazer]

One portion of the Euro ensemble right offshore from me.

That's cool, I guess.

Better then the earlier run with a Cat 5 going right down I-4 corridor. Seriously, all we have is to watch and ponder.

[CYCLONE MIKE]

Just curious about how the Euro has handled/handling Earl compared to the GFS. The reason I ask is because of such the large spread between the two so far with 97L.

[Wx_Warrior]

Historically speaking

[Vortex]

When comparing Daielle, I looked back at the 12Z(euro) last sunday and where danielle is today..Nearly dead on...

[artist]

When comparing Daielle, I looked back at the 12Z(euro) last sunday and where danielle is today..Nearly dead on...

what about the in between?

[Wx_Warrior]

Danielle, most were dead on.....EURO has stuck it's next out with this one.

[Steve]

Cyclone,

If you run GEM GFS & Euro at 500mb, you can see some of the reasons. ECMWF shows Earl brush by New England and noses in high pressure from the east north of Fiona similar to GEM. The difference between ECMWF and GEM is that the ridging to the north building back in the wake of Earl affects Fiona farther south. Euro has it in the southern Bahamas, GEM northeast of the Bahamas. Euro has the system farther west where the reinforcing high coming off the US still is in the great lakes region. Now the GFS comes up farther east than either the GEM or Euro, so it recurves behind Earl and out ahead of the high moving off the US Coast. They all time that high differently. They all time the ridging back into the SE Coast differently. And they all have Fiona in a different place in the week range. Again, run them at 500mb and watch the features I'm talking about.

ECMWF
http://raleighwx.easternuswx.com/models ... _loop.html

GFS
http://raleighwx.easternuswx.com/models ... SLoop.html

GEM
http://raleighwx.easternuswx.com/models ... MLoop.html

You might want to contrast at 200mb, 750 or whatever as well. GFS is east, Euro is south, Canadian is a compromise - closer to GFS by the Bahamas but without the recurve later.

[CYCLONE MIKE]

Appreciate that Steve but I was more or less looking for longer range accuracy(6-8 days or so) between the models such as how they have handled/handling Earl, Danielle, Alex. Basically did the Euro or the GFS do better with the synoptics and final landfalls from the longer range period.

[Steve]

I got you - you want to look at recent performance. One of the pros had a comment earlier today or yesterday saying GFS and Euro were about split. I dont remember which thread or which met.

Of course f you watch the main runs (00, 12) you can also judge for yourself. We have differences a week out now. I want to see which one handles it best (if any do).

[frederic79]

Also may be telling to watch how Euro handles 97L during the next day or two in regards to strength since strength can influence which steering layer is ultimately guiding the system. If Euro pegs the early development of Fiona, it could lend more credence to the current long-term sceneros it offering. It will be interesting to see how well it verifies for the next 48-72 hours.