2015 Global model runs discussion

[stormlover2013]

Euro is showing tons of moisture in gulf next week though

[Hammy]

GFS showing a system developing midway between Africa and the Caribbean in a week. Despite being quite a ways out and the model being notorious for phantom storms, it's not developing it instantly upon hitting water like it normally does so it's caught my attention at least.

[Alyono]

0Z MU shows 3 TCs from the 7-16 day time frame in the Atlantic

[LarryWx]

0Z MU shows 3 TCs from the 7-16 day time frame in the Atlantic

Here we go again. We had to get all of the way to within like 72 hours for MU to stop showing those phantom E MDR storms early in the month! I will, however, stick to my earlier feeling that there may actually be one storm that really, really forms in the MDR though with little chance to make it to the CONUS. I'm also sticking to my earlier prediction of one named storm to form somewhere in the basin this month. Also, I currently think that the biggest threat(s) to the CONUS will come between mid-Sep and early Oct. and probably not from MDR geneses. We'll see.

[gatorcane]

Looks quite robust on the 06Z GFS run where you can see the storm halfway between the Leewards and Africa at a low latitude, 198 hours shown below:

[blp]

Saw the below posted on another thread from Levi. I agree September is usually the active month looking at history during El Nino as I think LarryWx has pointed out before. I think with the African wave train has been strong this year. The question moving into the active part of the season is can we get a good MJO pulse and a reprieve from the dry conditions to allow something to get going. I think we will get at least one system developing.


@TropicalTidbits 49 minutes ago
Relative to other months, September especially stands out as the active Atlantic TC genesis period for El Nino years:

[wxman57]

The area south of 20N from the Caribbean to Africa looks extremely hostile toward development this season. However, with the ridge that has been over TX/LA and much of the Gulf tracking west to California by Sunday, any disturbance tracking across the Caribbean might have a shot of turning NW into the Gulf, which is a much more hospitable place for development this season. I doubt there will be a single Caribbean TS this season, and possibly none east of the Caribbean south of 20N.

[Steve]

The area south of 20N from the Caribbean to Africa looks extremely hostile toward development this season. However, with the ridge that has been over TX/LA and much of the Gulf tracking west to California by Sunday, any disturbance tracking across the Caribbean might have a shot of turning NW into the Gulf, which is a much more hospitable place for development this season. I doubt there will be a single Caribbean TS this season, and possibly none east of the Caribbean south of 20N.

Mid-summer pattern is evolving. One question is do we continue to have these wide, deep troughs typical of El Nino or will we get more amplification with narrower axis? Despite the retrograde of the southern heat high, will the overall pattern north remain progressive and if not, could a blocking pattern set up in the NE/Canada possibly with ridging into the SE? Some models are hinting that mid-Atlantic highs behind fronts will link up with Atlantic ridging. Are they right? We obviously haven't hit pattern high-tide yet this summer, so it's anyone's guess if timing will be there with energy potentially aimed at the SE US Coast. But I wouldn't write this particular season off until after October. People want to say this is 1997 again. There are similarities for sure, but it's not the same El Nino. There were only 3 storms (1H, 2TS) after July with none in August. The water is substantially warmer off the US West Coast, and with all the atmospheric variables in play (El Nino being only one influence albeit a strong one this year), who knows what's in store for the US East and Gulf Coasts? This hurricane season could just peter out, or we could end up with a series of close-in potential weaker-end hits. No one knows, and anyone who says they do definitively should be brushed off IMHO.

[wxman57]

1997 is a fair analog for 2015. I was looking at mid-level moisture across the deep tropics over the past month and thought it would be interesting to compare moisture levels to 1997. I was quite surprised to find how much drier 2015 is compared to 1997. There's plenty of dry, sinking air all across the tropics this season and I see no signs of a change.

Of course, that doesn't preclude the possibility of development "close-in" - in the Gulf or near the East U.S. Coast. I think we might see one storm in the Gulf, and it could be a hurricane. As things look now, I wouldn't be surprised if there were only 2-3 more named storms this season, all in September.

1997:


2015:

[gatorcane]

12Z GFS still going with a storm in the MDR

[blp]

Thanks for the graphics Wxman57. If you look at the last 10 days I see some of the dryer air migrating south around 50-60W and much more humidity entering the eastern Atlantic especially above 15N.You can certainly see in those graphics the nature of the problem and why the models are trending towards dissipating the strong waves as they move further West.

[TheStormExpert]

Weaker than the 06z run and much weaker than the 00z run. Wouldn't surprise me if the 18z run completely drops it.

[TheStormExpert]

Thanks for the graphics Wxman57. If you look at the last 10 days I see some of the dryer air migrating south and much more humidity entering the eastern Atlantic especially above 15N.You can certainly see in those graphics the nature of the problem and why the models are trending towards dissipating the strong waves as they move further West.

http://i57.tinypic.com/2w5re60.gif

IMO the problem is they are also having a hard time handling where the moist and dry air is exactly.

[gatorcane]

12Z GFS 500MB Height anomalies showing a big area of upper heights across Eastern North America / Canada / Newfoundland next week. This pattern could open the door if something can actually get going in the MDR. The past many seasons have shown just the opposite with a large trough over Eastern North America as we head into late August.

[gatorcane]

The GFS has another model showing the Cape Verde system for next week though it looks slower and more to the north than the GFS. 12Z NAVGEM (Navy) run below:

[NDG]

1997 is a fair analog for 2015. I was looking at mid-level moisture across the deep tropics over the past month and thought it would be interesting to compare moisture levels to 1997. I was quite surprised to find how much drier 2015 is compared to 1997. There's plenty of dry, sinking air all across the tropics this season and I see no signs of a change.

Of course, that doesn't preclude the possibility of development "close-in" - in the Gulf or near the East U.S. Coast. I think we might see one storm in the Gulf, and it could be a hurricane. As things look now, I wouldn't be surprised if there were only 2-3 more named storms this season, all in September.

1997:
http://home.comcast.net/~cgh57/1997.JPG

2015:
http://home.comcast.net/~cgh57/2015.JPG

I was reading your mind or vice versa this past Sunday I posted the same thing in the 2015 Indicators Thread.

viewtopic.php?f=31&t=117035&st=0&sk=t&sd=a&start=460

[gatorcane]

18Z GFS is more bullish on this run and continues to show the storm in the MDR and keeps it around through 12 days and actually shows it strengthening as it heads west in the MDR indicating it is seeing more favorable conditions out there next week. This is the longest I have seen the GFS keep something around this season in the MDR. Certainly bears watching as we head later into August. It has the feel it is not a phantom storm this time but we will see:

996MB at it's strongest point on this run, heading WNW:


Below I circled the wave the GFS thinks will be our next storm in the MDR next week. The wave behind it looks more impressive but the GFS is going with the first wave:

[Yellow Evan]

Disregard the GFS storm when it's having issues with MJO/CCKW forecasting and seems to having issues with AEW's like all models do. Conditions are downright toxic in the ATL.

The current atmospheric state does not favor much if any activity in the Atlantic. Only the NPAC is where conditions are favored right now.

[Hammy]

18Z GFS is more bullish on this run and continues to show the storm in the MDR and keeps it around through 12 days and actually shows it strengthening as it heads west in the MDR indicating it is seeing more favorable conditions out there next week. This is the longest I have seen the GFS keep something around this season in the MDR. Certainly bears watching as we head later into August. It has the feel it is not a phantom storm this time but we will see

I don't see any other model support as with the last several model storms, so it's a bit hard to take seriously (last night the GEM was at least showing something, but nothing now) so while it seems a bit interesting as it's not developing something right as it comes off, I'm still betting on no development until others show something.

[gatorcane]

Quite possibly a phantom but this time the GFS has at least one other model showing some development of this wave and that is the NAVGEM. It's not the best model but the GFS is not alone. The ECMWF is not good at forecasting genesis deep in the MDR. I would like to see the CMC showing development though to have some more confidence.

18Z NAVGEM shows something near the Cape Verde islands in 180 hours but it is much slower and further north than the GFS. In fact the last several runs of the NAVGEM is showing development.