2016 Global Model Runs Discussion (Out to Day 16)

[TheAustinMan]

@RL3AO I love the mid-level RH product... it's probably one of the best tools for sniffing out tropical waves as they track across the tropics (speaking of waves, pouch tracking by the Navy's Dept. of Meteorology begins July 18, and you can read more about it at http://www.met.nps.edu/~mtmontgo/storms2016-atlantic.html).

Although tropical development isn't really conclusive within the next two weeks, there are two tropical waves of interest in the Atlantic tropics that might have some, albeit minor, potential for developing. The first is a tropical wave currently over the Lesser Antilles. The models have that particular wave tracking westward into Nicaragua by about July 18-19, though a fragment of the moisture may track further north and may poke its head into the Bay of Campeche around July 21 while the rest of the wave may contribute to a possible EPac tropical cyclone. That said, the BoC fragment will probably stick around Central America without developing. The atmospheric conditions are there, but the geographical ones aren't.

The other disturbance of note is the tropical wave coming off of Africa right now. Although it looks fairly decent on entry into the Atlantic, given the strong presence of the Saharan Air Layer, it'll probably end up being a sacrificial wave to help slowly moisten up the environment. However, the GFS does have it bringing some gusty 25-30kt winds to the Leeward Islands next week. Looking at the RH, it appears possible (given the GFS solution) that the wave might cause some mischief in the Bay of Campeche/Western Gulf of Mexico later down the road (in around two weeks) but that is way too far in the future to be something of concern, at least for now.

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[stormwise]

Little weak closed off disturbance on the monsoon trough out there now.

https://s32.postimg.org/b79fwtjh1/WMBds26.png

[Hammy]

Euro is showing a large amount of weak vorticity extending pretty far north at day 10--could this indicate the moisture/instability being pulled north off the ITCZ to pave way for stronger waves and possible development?

[cycloneye]

Healthy waves rolling in Africa on long range and as someone mentioned in another thread,the African wave train will be robust in the coming weeks as the MJO signal is enhancing them.

[ninel conde]

I look for the east pac to remain active and the atlantic dead for some time. Pressures are quite low in the east pac. Lots of fertile green, none in the atlantic tropics. High remains perfectly positioned for tons of cane killing atlantic dust.

[blp]

GFS ensembles long range starting to bite on development.

http://www.tropicaltidbits.com/analysis/models/gfs-ens/2016071712/gfs-ememb_lowlocs_watl_62.png

[Yellow Evan]

Just 1 ensemble member though.

[tarheelprogrammer]

Looking at this model. The 240 out frame shows dust at a TC killing size across the entire MDR. Massive amount of dust if true.

http://www.map.nasa.gov/cgi-bin/viewer.cgi?project=GEOS.fp.fcst.inst1_2d_hwl_Nx&service=Go&year=2016&month=07&day=16&hour=00&minutes=00&fhour=240&expand=100&width=720&height=360&vproj=latlon&maxy=40.5&minx=-76&maxx=14&miny=-4.5&transparent=FALSE&bgcolor=0x000000&layers=countries&layers=e5131.inst1_2d_hwl_Nx-duexttau&nav=zin&factor=2&e5131.inst1_2d_hwl_Nx-duexttau-style=hyperwall&e5131.inst1_2d_hwl_Nx-duexttau-ct=IDL22&e5131.inst1_2d_hwl_Nx-duexttau-min=&e5131.inst1_2d_hwl_Nx-duexttau-max=&e5131.inst1_2d_hwl_Nx-duexttau-delta=&e5131.inst1_2d_hwl_Nx-duexttau-amax=

[Hammy]

Looking at this model. The 240 out frame shows dust at a TC killing size across the entire MDR. Massive amount of dust if true.

http://www.map.nasa.gov/cgi-bin/viewer.cgi?project=GEOS.fp.fcst.inst1_2d_hwl_Nx&service=Go&year=2016&month=07&day=16&hour=00&minutes=00&fhour=240&expand=100&width=720&height=360&vproj=latlon&maxy=40.5&minx=-76&maxx=14&miny=-4.5&transparent=FALSE&bgcolor=0x000000&layers=countries&layers=e5131.inst1_2d_hwl_Nx-duexttau&nav=zin&factor=2&e5131.inst1_2d_hwl_Nx-duexttau-style=hyperwall&e5131.inst1_2d_hwl_Nx-duexttau-ct=IDL22&e5131.inst1_2d_hwl_Nx-duexttau-min=&e5131.inst1_2d_hwl_Nx-duexttau-max=&e5131.inst1_2d_hwl_Nx-duexttau-delta=&e5131.inst1_2d_hwl_Nx-duexttau-amax=

Seems less than the last few, I think there were large areas of white on previous ones.

On the note of the GFS being void of anything of note, I wouldn't really look to them at the moment for hope of later storms--all recieved upgrades this year and have been pushed to the conservative side of the forecasting spectrum. They seem to behave differently in the Atlantic for some reason, and that said, we aren't having the phantom storms any longer which is making the quiet period seem longer than it may be (but at the same time things aren't being "pushed back" either, like the last few seasons), and of the storms we've had so far only the Canadian model correctly showed anything forming more than three days out, and even then, it was only about a week or so that it showed any of them. Should something form around say August 5, I wouldn't expect the models to actually sniff it out until July 29-30. Until then the models will be void of anything.

(And personally I'm betting on >Aug 15 before we get another storm.)

Edit: one sign of change is the Euro having the ITCZ more defined, and further north, in the Atlantic while bringing the waves off Africa a tad further south.

[WPBWeather]

I look for the east pac to remain active and the atlantic dead for some time. Pressures are quite low in the east pac. Lots of fertile green, none in the atlantic tropics. High remains perfectly positioned for tons of cane killing atlantic dust.

Not true. Dust levels are declining as normal near end of July. Rain is increasing in Africa (we had this discussion last week, remember?) You'll have to come up with something other than "killer SAL."

[Hammy]

I look for the east pac to remain active and the atlantic dead for some time. Pressures are quite low in the east pac. Lots of fertile green, none in the atlantic tropics. High remains perfectly positioned for tons of cane killing atlantic dust.

Not true. Dust levels are declining as normal near end of July. Rain is increasing in Africa (we had this discussion last week, remember?) You'll have to come up with something other than "killer SAL."

My question is, are the waves/ITCZ in Africa too far north and is this contributing to the problem, or is the location normal and still waiting for the monsoon trough that's present there to moisten? I noticed last night but don't have model/surface data to know if it's normally at 18-20N.

And to ninel: The models are indicating the Epac slowing down over the coming weeks. No longer are we getting a storm forming every 3-4 days and only the current system over Central America is shown to form there now.

Edit: Latest GFS shows no storms in either basin through August 2, but shows a large deep monsoonal flow out of the west off of Africa, something I haven't seen in quite a few years.



And again some previous seasons come to mind.

[ninel conde]

for the first time pressures relaxing in the atlantic tropics and the high is not as well placed to surge out dust. trend or just temporary?

[srainhoutx]

Interestingly the ECMWF for the past couple of cycles is suggesting a fairly decent weakness with lowering pressures rounding the Eastern flank of the Upper Ridge and moving West across the Gulf around the 26th to 28th of July. The GFS does show this Easterly wave, but is not as aggressive as the ECMWF...but it does merit monitoring as the general Hemispheric Pattern may favor such a feature in the longer range.

[Alyono]

latest MU keeps the EPAC very active through the next 16 days

[Dean4Storms]

They don't refer to the "Cape Verde Season" for nothing, on average the TW train doesn't usually become favorable for long tracking robust TW's going on to develop into TC's out in the MDR until early to mid August. Yes, there have been years where that happened sooner and those years were generally well above normal in TC numbers in the Atlantic basin and especially the MDR, I don't think anybody is expecting an above normal season on the Atlantic side. I do believe we'll begin to see relaxing pressures across the MDR and north Africa come early to mid August resulting in more robust TW's with some development out there considering everything and by that point our biggest concern will not be development but the overall pressure pattern over Eastern NA extending out into the Atlantic! The MJO will become a big factor for waves once they reach the Western Atlantic and Carib. Sea!

[Siker]

Strong wave emerging off of Africa in 9 days on the GFS and Euro (the one that was being picked up on by a few GEFS members).

[gatorcane]

Finally looks like something of significance on the 12Z GFS rolling off Africa by day 10

[tarheelprogrammer]

Finally looks like something of significance on the 12Z GFS rolling off Africa by day 10

Very strong wave. TS almost right off the coast of Africa. Can it make it across the Atlantic? Or is it a fish storm?

[RL3AO]

IMO anything that comes off the coast like that will weaken/open up over the eastern Atlantic. It's not very hospitable out there. A strong wave like that would move west and possibly try to develop near islands/Bahamas.

[tarheelprogrammer]

IMO anything that comes off the coast like that will weaken/open up over the eastern Atlantic. It's not very hospitable out there. A strong wave like that would move west and possibly try to develop near islands/Bahamas.

It has the storm weaken over the Atlantic. Possibly dying out/doing nothing. Just too much stability and dry air for that matter.