2015 Global model runs discussion

[LarryWx]

This will for the record go down as the 2nd Oct. in a row (at least two in a row because I can't say off the top of my head if the GFS did this in the prior Octobers) with a good # of runs with what turned out to be a phantom western Caribbean tropical cyclone genesis. This Oct's GFS bust was pretty bad but actually not nearly as bad as last Oct.'s horrendous GFS bust. Also, the Euro only had two runs this Oct. with a WC genesis and had essentially no runs last Oct. with that. So, between the GFS and Euro, the Euro far exceeded the quite poor GFS in terms of accurately portraying the lack of Oct. WC based tropical geneses these last two Octobers to this point.

[Hammy]

This will for the record go down as the 2nd Oct. in a row (at least two in a row because I can't say off the top of my head if the GFS did this in the prior Octobers) with a good # of runs with what turned out to be a phantom western Caribbean tropical cyclone genesis.

I distinctly recall at least two systems in 2013 as well (one middle and one later), so this would be the third consecutive. Especially with the GFS, for years there was also the problem of this occurring about the middle of June as well.

[LarryWx]

Thanks, Hammy, for the Oct. 2013 GFS info. I think it is important to keep track of these things on this forum for the benefit of coming up with the chance of something similar on future runs being another phantom (learn from history). So, if the GFS repeatedly insists on a WC genesis in Oct. of 2016 with no Euro support, we'll be able to point to 2013-5 GFS phantoms there as an extra reason to take with a grain.

[blp]

To be fair, the Euro showed it for two runs and CMC, FIM and Navgem had it for many runs. In the past it was ususally the GFS alone.

[LarryWx]

To be fair, the Euro showed it for two runs and CMC, FIM and Navgem had it for many runs. In the past it was ususally the GFS alone.

Duly noted. Although I did note the 2 Euro phantom runs, I didn't mention the CMC/NAVGEM, which both did worse due to more phantom runs. The NAVGEM had phantom runs for 2-3 days after the GFS stopped them! It may have been the worst performer though we know it is quite inferior to the GFS. I didn't track the FIM closely but do recall a number of its runs showing a WC TC.

I should add that the GEFS and CMC ensemble members also did quite poorly this time as a good number of both of them had some runs with a strong majority of members having a WC TC genesis. So, that tells me to be quite wary of the GFS and CMC even with ensemble support when the Euro isn't on board.

I think that all of this tells me that the Euro was easily the best of these models and the one model one should want for support more than any other in this region, especially in October.

[TheStormExpert]

From Ryan Maue on Twitter.

@RyanMaue: I predict a 10% yellow X in Gulf of Mexico soon for 5-day Tropical Cyclone development off Texas coast. Perhaps a weak TD ?

[Hammy]

To be fair, the Euro showed it for two runs and CMC, FIM and Navgem had it for many runs. In the past it was ususally the GFS alone.

FIM is GFS-based, and Navy/CMC models are two of the most notorious over-developers so I don't even bother counting them.

[Steve]

GFS on ncep is only 4 days out but an Atlantic low forms a few hundred miles east of the U.S. east coast (sts????) and moves up and out while a small low off comes off the SE TX coast, so it's continuing with small time development although this run takes the low into the gulf alread spinning off mexico. Who knows?

[Steve]

Fwiw, 10.5 in the metroplex (or a hair west) and another 10.5 just a hair southeast of Corpus Christi per qpf 00z

[NDG]

From Ryan Maue on Twitter.

@RyanMaue: I predict a 10% yellow X in Gulf of Mexico soon for 5-day Tropical Cyclone development off Texas coast. Perhaps a weak TD ?

With forecasted 50-70 knot UL winds it will have a hard time organizing.
GFS shows it will be subtropical and or extra tropical in nature.

[blp]

To be fair, the Euro showed it for two runs and CMC, FIM and Navgem had it for many runs. In the past it was ususally the GFS alone.

FIM is GFS-based, and Navy/CMC models are two of the most notorious over-developers so I don't even bother counting them.

Can you elaborate on the FIM being GFS based? I had heard before that it got data from GFS for its initalization but not sure.

Also, I agree the Navy/CMC are poor performers but the point was that all the models showed something in WC even the Euro and if not for the super strong High Pressure that has been in place the last few days something would have developed in WC. The evidence was Patricia which developed on the EPAC side. So the GFS was off only on the strength of the ridge unlike the past where it blindly was developing a system for weeks at a time. So I would say IMO it has improved.

[Ntxw]

To be fair, the Euro showed it for two runs and CMC, FIM and Navgem had it for many runs. In the past it was ususally the GFS alone.

FIM is GFS-based, and Navy/CMC models are two of the most notorious over-developers so I don't even bother counting them.

Can you elaborate on the FIM being GFS based? I had heard before that it got data from GFS for its initalization but not sure.

FIM is experimental and was developed intended to possibly replace the GFS down the road. Uses GFS physics.

http://fim.noaa.gov/

[Alyono]

models seem like they will have done quite well with the upcoming Gulf low

[Hammy]

Is the Gulf system likely to be non-tropical in nature or is there a chance of it getting named briefly similar to Allison in 2001?

edit: rechecking the models, it appears the GoM low may actually be a redevelopment of Patricia's remnants.

[CrazyC83]

Is the Gulf system likely to be non-tropical in nature or is there a chance of it getting named briefly similar to Allison in 2001?

edit: rechecking the models, it appears the GoM low may actually be a redevelopment of Patricia's remnants.

What are the chances the low actually survives and Patricia makes it to the GOM intact as at least a TD?

[AutoPenalti]

Is the Gulf system likely to be non-tropical in nature or is there a chance of it getting named briefly similar to Allison in 2001?

edit: rechecking the models, it appears the GoM low may actually be a redevelopment of Patricia's remnants.

What are the chances the low actually survives and Patricia makes it to the GOM intact as at least a TD?

Very low. Whatever is left will be crushed by the mountains and dragged along by the next trough that arrives.

[Steve]

According to the models, the chances are actually very good that Patricia reforms in the NW Gulf. Of the major globals, only the GFDL keeps the remnant circulation over land in south and southeast texas. The CMC GFS hwrf ecmwf etc all spin up a solid regeneration. Looks like a mostly tropical feature (surface and aloft) that meets up with the flow into the front, but as the high reinforces north, the system hangs up in the nw gulf. Looks like all models have lots of rain for tx and north central Gulf as the system slows at or near the Coast. Based on the moisture in the pattern, globals could be underdoing some of the localized rainfall amounts. I haven't followed Patricia much except to know it broke some records. I'm going to have to go to the thread and see what everyone thinks.

If the general model consensus is right, and Patricia's circation was over water for 2-3 days in the nw gulf, td would be 95% (could be partially hybrid and/or frontal obviously), TS would be about 75% and a H probably 10-15%. 100% chance of whatever is there hits the US coast.

Whatever threats we end up having in the US are in the short term. Regardless of whether the remnants get back over water or not, it looks like the possibility of serious flash flooding across texas and then a lot of rain for Louisiana and points north and east.

This isn't a forecast, point was the model acknowledgement.

[AutoPenalti]

According to the models, the chances are actually very good that Patricia reforms in the NW Gulf. Of the major globals, only the GFDL keeps the remnant circulation over land in south and southeast texas. The CMC GFS hwrf ecmwf etc all spin up a solid regeneration. Looks like a mostly tropical feature (surface and aloft) that meets up with the flow into the front, but as the high reinforces north, the system hangs up in the nw gulf. Looks like all models have lots of rain for tx and north central Gulf as the system slows at or near the Coast. Based on the moisture in the pattern, globals could be underdoing some of the localized rainfall amounts. I haven't followed Patricia much except to know it broke some records. I'm going to have to go to the thread and see what everyone thinks.

If the general model consensus is right, and Patricia's circation was over water for 2-3 days in the nw gulf, td would be 95% (could be partially hybrid and/or frontal obviously), TS would be about 75% and a H probably 10-15%. 100% chance of whatever is there hits the US coast.

Whatever threats we end up having in the US are in the short term. Regardless of whether the remnants get back over water or not, it looks like the possibility of serious flash flooding across texas and then a lot of rain for Louisiana and points north and east.

This isn't a forecast, point was the model acknowledgement.

Any FL threat?

[Weatherwatcher98]

Nope.

[gatorcane]

The GFS is trying to develop something near the NE Leewards in the medium to long range and has been doing so for the past few days of its runs. The CMC and NAVGEM shows it as well while the ECMWF shows an area of disturbed weather developing but no development.

GFS:


EC: