2015 Global model runs discussion

[wxman57]

I plotted the 00Z Euro surface pressure in 1mb increments along with 10m winds (knots) and wind contours (starting at 20kts). Euro has a low west of the Cape Verde Islands at the end of the run. It moves off west Africa early on the 22nd. Central pressure is 1006mb. GFS is about 500nm farther west with a weaker low at the same time.

Environment from the Caribbean to Africa is quite hostile, though. The low may be mostly convection-free by that time. I think it will have to reach a more favorable environment to strengthen/develop (should the EC be correct).

[gatorcane]

The GEM is starting to spit out systems. Good sign even though 9 out of 10 times, it is wrong.

[gatorcane]

I plotted the 00Z Euro surface pressure in 1mb increments along with 10m winds (knots) and wind contours (starting at 20kts). Euro has a low west of the Cape Verde Islands at the end of the run. It moves off west Africa early on the 22nd. Central pressure is 1006mb. GFS is about 500nm farther west with a weaker low at the same time.

Environment from the Caribbean to Africa is quite hostile, though. The low may be mostly convection-free by that time. I think it will have to reach a more favorable environment to strengthen/develop (should the EC be correct).

http://home.comcast.net/~cgh57/euro.gif

Here is the 384 hour position of the GFS/ECMWF system that off Africa around the 22nd and the GFS shows something behind it. Seems like the GFS is thinking active end of August. Of course in early August it was thinking active mid August and so far that is not the case.

[Alyono]

and the MU looks to show troughing off of the East Coast. Even if development were to occur, which the chances of are quite low, it is unlikely this affects the USA

[LarryWx]

and the MU looks to show troughing off of the East Coast. Even if development were to occur, which the chances of are quite low, it is unlikely this affects the USA

Notwithstanding the troughing setup suggested by the GFS, storms with genesis well out in the MDR during a strong El Nino have hardly ever gotten to the CONUS per climo going back many years. They'd have a significantly higher chance if they first become an actual TD much closer to the L.A.'s than to the CV's. Nevertheless, there is an exception:

http://weather.unisys.com/hurricane/atl ... /track.gif

Edit: During oncoming or current strong Ninos:
- 5 out of 18 that first became a TD+ between 40 W and the L.A.'s later hit the CONUS.
- In contrast, only 1 out of 10 that formed into a TD+ east of 40W within the MDR later hit the CONUS. The odds may even be a bit lower if some others that formed way out there are totally not known.

[Hammy]

Interesting changes to the main model runs today:
Navy no longer developing either wave, but having two large (and possibly convection-free as a few have pointed out) gyres
Canadian developing both systems around the 150 hour mark, sending the western one into Central America and the eastern one northwest over cooler waters
GFS showing the same as the Navy and once again pushed any development of any kind back to the 270+ hour mark
Euro (i.e. GFS Jr. lately) seems to be possibly developing a storm briefly in 144 hours and sending it NW, similar to the Canadian.

What we can take away from this is that there is not (and probably won't be) any solid model consensus, as the models are likely having a difficult time properly resolving the dry air and cooler water temps beyond a day or two, and further indicates August will very likely be storm-free.

[LarryWx]

Interesting changes to the main model runs today:
Navy no longer developing either wave, but having two large (and possibly convection-free as a few have pointed out) gyres
Canadian developing both systems around the 150 hour mark, sending the western one into Central America and the eastern one northwest over cooler waters
GFS showing the same as the Navy and once again pushed any development of any kind back to the 270+ hour mark
Euro (i.e. GFS Jr. lately) seems to be possibly developing a storm briefly in 144 hours and sending it NW, similar to the Canadian.

What we can take away from this is that there is not (and probably won't be) any solid model consensus, as the models are likely having a difficult time properly resolving the dry air and cooler water temps beyond a day or two, and further indicates August will very likely be storm-free.

I still am educatedly guessing that there will be one August storm forming somewhere (not necessarily in the MDR) based on longterm strong Nino climo.

[Alyono]

Interesting changes to the main model runs today:
Navy no longer developing either wave, but having two large (and possibly convection-free as a few have pointed out) gyres
Canadian developing both systems around the 150 hour mark, sending the western one into Central America and the eastern one northwest over cooler waters
GFS showing the same as the Navy and once again pushed any development of any kind back to the 270+ hour mark
Euro (i.e. GFS Jr. lately) seems to be possibly developing a storm briefly in 144 hours and sending it NW, similar to the Canadian.

What we can take away from this is that there is not (and probably won't be) any solid model consensus, as the models are likely having a difficult time properly resolving the dry air and cooler water temps beyond a day or two, and further indicates August will very likely be storm-free.

I still am educatedly guessing that there will be one August storm forming somewhere (not necessarily in the MDR) based on longterm strong Nino climo.

however, with conditions much more hostile than 1997, the only comparable Niño to this one, are your stats based upon weaker niños valid?

[LarryWx]

Interesting changes to the main model runs today:
Navy no longer developing either wave, but having two large (and possibly convection-free as a few have pointed out) gyres
Canadian developing both systems around the 150 hour mark, sending the western one into Central America and the eastern one northwest over cooler waters
GFS showing the same as the Navy and once again pushed any development of any kind back to the 270+ hour mark
Euro (i.e. GFS Jr. lately) seems to be possibly developing a storm briefly in 144 hours and sending it NW, similar to the Canadian.

What we can take away from this is that there is not (and probably won't be) any solid model consensus, as the models are likely having a difficult time properly resolving the dry air and cooler water temps beyond a day or two, and further indicates August will very likely be storm-free.

I still am educatedly guessing that there will be one August storm forming somewhere (not necessarily in the MDR) based on longterm strong Nino climo.

however, with conditions much more hostile than 1997, the only comparable Niño to this one, are your stats based upon weaker niños valid?

Alyono, good question.
1) Are you saying that they are much more hostile than August of 1997? If so, how confident are you that conditions will remain much more hostile than 1997 through the end of the month? Can't they improve some?
2) Even so, 1997 had a very unusually active July for a strong Nino with 4 TC's and it had one form barely after the end of August (on 9/3). Could that August's timing have been handicapped somehow by so much activity the prior month as a reflection of cyclical factors?
3) How were conditions in Augusts of 1982, 1972, 1888, and 1877 as compared to this month? This is a rhetorical Q for 1888 and 1877 since nobody could answer, but al four of those were very strong Nino's with 1-2 August geneses each.

[Alyono]

Alyono, good question.
1) Are you saying that they are much more hostile than August of 1997? If so, how confident are you that conditions will remain much more hostile than 1997 through the end of the month? Can't they improve some?
2) Even so, 1997 had a very unusually active July for a strong Nino with 4 TC's and it had one form barely after the end of August (on 9/3). Could that August's timing have been handicapped somehow by so much activity the prior month as a reflection of cyclical factors?
3) How were conditions in Augusts of 1982, 1972, 1888, and 1877 as compared to this month? This is a rhetorical Q for 1888 and 1877 since nobody could answer, but al four of those were very strong Nino's with 1-2 August geneses each.

Wxman57 posted that the tropical Atlantic was significantly more moist in 1997 than it was this year. As for July's activity, that was ALL mid latitude development, aside from a weak TD. So, I would say the July activity had no bearing on August. I believe 1997 had some decent waves in terms of convection. The Caribbean at times, would experience periods of reduced shear. These are things we are NOT seeing this year. Even the wave that became Erika wouldn't have developed given the current environmental conditions.

With the worse conditions compared to 1997, and the fact that 1997 had 3 more storms from this date forward, I wouldn't be surprised to see 1 or 2 more for the remainder of the year. The x factors would be cross over systems from the EPAC and high latitude development

[NCSTORMMAN]

What is the chance that the models will keep showing phantom storms and nothing else forms this season. This might be the deadest season I can remember. Used to always be under the gun growing up and now nothing. A good thing for sure but we need tropical storms or depressions for rain in the south right now badly.

[Hammy]

What is the chance that the models will keep showing phantom storms and nothing else forms this season. This might be the deadest season I can remember. Used to always be under the gun growing up and now nothing. A good thing for sure but we need tropical storms or depressions for rain in the south right now badly.

I would say the chances are extremely low that nothing else forms the rest of the season, but it would not be at all surprising to see nothing form in the MDR, or even south of 25 for the rest of the season. In all likelihood the models (which I believe may be partially statistical) are probably going to keep showing phantom storms for the duration.

[ninel conde]

i think its safe to say the non major streak will continue. the real question is can even a weak sheared strung out minimal cat1 form.

[gatorcane]

The ECMWF is back to showing a Cape Verde storm, but it has pushed out the timeframe some, 240 hours below:

[Alyono]

What is the chance that the models will keep showing phantom storms and nothing else forms this season. This might be the deadest season I can remember. Used to always be under the gun growing up and now nothing. A good thing for sure but we need tropical storms or depressions for rain in the south right now badly.

I would say the chances are extremely low that nothing else forms the rest of the season, but it would not be at all surprising to see nothing form in the MDR, or even south of 25 for the rest of the season. In all likelihood the models (which I believe may be partially statistical) are probably going to keep showing phantom storms for the duration.

the global models are dynamical. The solutions are from numerically solving the equations of motion, not statistics

[jlauderdal]

i think its safe to say the non major streak will continue. the real question is can even a weak sheared strung out minimal cat1 form.

it going to be a very tough season for those that want systems...need it to form inside of 60W...conditions in the open atlantic are horrid and the carib isnt much better..welcome to a strong el nino pattern

[Steve]

Real time - seeing some lightning down by the coast. Surface trough in the Gulf.

Interesting Bastardi Saturday Summary if you live in the Gulf or Southeast. Longer range Jams tech (sp?) and European argue for strong ridging in the NE with a trough axis in the central US including much warmer than average for the Eastern US through September. An early teleconnection comes from the trailing storm in the WPAC. First storm hits near Taiwan and into China where the second one looks like it will drift north and recurve, but instead turns back to the west. That's ridging in the Eastrrn US 6-10 days later. That's late August/Early September. But when you figure those models have it warm in the SE through September, if they are right, then that pattern could persist before reversing into a colder and wetter pattern in the SEUS for the winter. What happens in the transition? Who knows. But 2002 was brushed on, and that's Lili and Isidore which by atmospheric circumstance and land interaction, didn't maintain their Cat 4 intensity. Who knows?

[Nederlander]

Yeah it looks to me like the best chance of anything forming would be something homegrown like a cut off low or something. If not for that chance I would say we are near zero chance for the rest of the season. Most of the basin is just brutal.



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[Steve]

Well I know he has overhyped in the past, but the message was don't sleep on the season. For now, it's mid August. Most similar seasons have been demonstrated to show in September. I thought 7-4-1 ish so I'm not saying there will be a chaotic onslaught, but a possibly dangerous setup could be in place for the southeast. It's probably a good thing the MDR isn't a breeding ground this year if the longer range Japanese or European models turn out to be accurate for September.

[gatorcane]

00Z GFS is lighting up the Atlantic in the long-range. What El Nino?