2018 Tropics: Global Model Runs Discussion (Out to day 16)

[blp]

00z GFS finally looks to be back to reality much weaker than previous run.

[LarryWx]

The 0Z MU (GFS) has totally backed off of an open W Caribbean genesis with a further delay and genesis now further west close to C America. Oh MU, how we love you for W Car TC genesis accuracy....not!

[cycloneye]

Is going to end up being a EPAC system.

[AutoPenalti]

I would think that with a monsoonal gyre we might get fluctuations in model runs, whether they verify will be up to timing.

[chaser1]

EURO 0Z 240 hr. just decided to drink a little of the GFS's kool-aid by tossing in a 1008 closed feature to the N.W. Caribbean. Will be interesting to see if/how this might evolve over the next one or two runs.

[Dylan]

European is now beginning to warm up to the idea of a disturbance in the Western Caribbean Sea in the 8 to 10 day range with CAG genesis. The one thing I’ve learned over the years is that when the European speaks, you listen. This has my attention, though these types of events usually take longer than what the models depict in the early stages, and that the models have tremendous difficulties handling them while it’s ongoing. Time will tell!

[Kingarabian]

There could be room for development next week with potentially favorable WWB induced convergence in the far eastern Pacific/western Caribbean sea.

[NDG]

The GFS may not have been that crazy after all.

[stormlover2013]

Gfs has been crazy it’s been showing stuff but keeps prolonging it, so yeah it’s been crazy

[Florida1118]

It would appear we have some consensus ladies and gentleman:

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[northjaxpro]

Yeah, indeed it is looking more probable now we will have a system to monitor moving out of the Caribbean in the next week.

[TheStormExpert]

00z EPS support growing.

[LarryWx]

The GFS may not have been that crazy after all.

I think it has been crazy in that it had been showing a cat 2 H (bordering on cat 3 in some cases) going into FL on run after run. Also, the progged genesis date has been slipping again. It was originally just 4-5 days from now in the W Caribbean (5/18-19).

So, originally it was a tight genesis 5/18-9 and now on today's 6Z it is only a broad low with genesis on 5/24 with only a much more believable 1000 mb low hitting FL instead of a 970 mb cat 2 H. Is that even the same thing? Even if it is, that's a massive change in strength and timing. And we still don't know if there will be a May W Caribbean TC at all yet.

[NDG]

The GFS may not have been that crazy after all.

I think it has been crazy in that it had been showing a cat 2 H (bordering on cat 3 in some cases) going into FL on run after run. Also, the progged genesis date has been slipping again. It was originally just 4-5 days from now in the W Caribbean (5/18-19).

So, originally it was a tight genesis 5/18-9 and now on today's 6Z it is only a broad low with genesis on 5/24 with only a much more believable 1000 mb low hitting FL instead of a 970 mb cat 2 H. Is that even the same thing? Even if it is, that's a massive change in strength and timing. And we still don't know if there will be a May W Caribbean TC at all yet.

Whoever has been taking seriously the GFS's Cat 2 phantom in its 10-14 day range is crazy, but lets not forget that weather models are nothing more than mathematical calculations that many times are way off in timing, even in their short range. What I have been saying since day one is that it may not be that crazy factoring the fact that conditions are not that hostile over the Caribbean and a strong MJO is currently over our part of the world so tropical development in the western Caribbean over the next 7-14 days is not out of the question and that's what GFS has been hinting for the past several days, IMO.

[blp]

Not surprised by the Euro run now on board since it was hinting at it in the 850mb vorticity on the last few runs. I think the GFS is finally more realistic with the intensity. I still think their are differences where the origins of this will come from. I see the Euro leaning more toward more EPAC energy being driven North versus the GFS which want to develop the energy from the Carribean. We will see.

[LarryWx]

The GFS may not have been that crazy after all.

I think it has been crazy in that it had been showing a cat 2 H (bordering on cat 3 in some cases) going into FL on run after run. Also, the progged genesis date has been slipping again. It was originally just 4-5 days from now in the W Caribbean (5/18-19).

So, originally it was a tight genesis 5/18-9 and now on today's 6Z it is only a broad low with genesis on 5/24 with only a much more believable 1000 mb low hitting FL instead of a 970 mb cat 2 H. Is that even the same thing? Even if it is, that's a massive change in strength and timing. And we still don't know if there will be a May W Caribbean TC at all yet.

Whoever has been taking seriously the GFS's Cat 2 phantom in its 10-14 day range is crazy, but lets not forget that weather models are nothing more than mathematical calculations that many times are way off in timing, even in their short range. What I have been saying since day one is that it may not be that crazy factoring the fact that conditions are not that hostile over the Caribbean and a strong MJO is currently over our part of the world so tropical development in the western Caribbean over the next 7-14 days is not out of the question and that's what GFS has been hinting for the past several days, IMO.

Point taken. I just don't think the GFS deserves praise. It has been laughable imo. Moreover, we still don't yet know if there will even be a W Caribbean TC genesis.

[tolakram]

Remember what the models are best for, even the GFS. It observed something that it developed into a hurricane long range. That something is there, the mistake was developing it as the GFS almost always does. The extended range may be useless for genesis prediction but it does have other merits. So when the GFS creates a phantom storm I think we can conclude that conditions will be at least marginal for some type of development, just not to the extent that the GFS sees. Or something like that.

[Shell Mound]

If the current Gulf low were to somehow become Alberto (as seems increasingly possible) and Beryl were to follow in its wake, the back-to-back pre-season storms would very likely presage an inactive peak season. While pre-season activity in itself does not necessarily imply a dead heart of the season, El Niño years are almost always associated with an anomalously active pre-season/early season and a correspondingly dead peak season. La Niña is often the opposite: a slow start followed by a hyperactive peak season, with activity continuing well into late season (and sometimes beyond, even after New Year's Eve). So I think that the increasing prospects of both multiple pre-season storms and the increasing likelihood of El Niño by peak season go together nicely. Thus the odds of a very inactive season, with activity weighted toward pre-season/early season rather than peak/late season, are going way up at this time. So the model trends and sensible weather/climate trends both tend to support this outcome. Additionally, the fact that Alberto may very well turn out to be a subtropical system in the Gulf could indicate unfavourable conditions for classic tropical storm structures even in the subtropics, which would imply a season that is even more hostile than I may have thought. I could be wrong, but data are data. Hmm...

[Alyono]

If the current Gulf low were to somehow become Alberto (as seems increasingly possible) and Beryl were to follow in its wake, the back-to-back pre-season storms would very likely presage an inactive peak season. While pre-season activity in itself does not necessarily imply a dead heart of the season, El Niño years are almost always associated with an anomalously active pre-season/early season and a correspondingly dead peak season. La Niña is often the opposite: a slow start followed by a hyperactive peak season, with activity continuing well into late season (and sometimes beyond, even after New Year's Eve). So I think that the increasing prospects of both multiple pre-season storms and the increasing likelihood of El Niño by peak season go together nicely. Thus the odds of a very inactive season, with activity weighted toward pre-season/early season rather than peak/late season, are going way up at this time. So the model trends and sensible weather/climate trends both tend to support this outcome. Additionally, the fact that Alberto may very well turn out to be a subtropical system in the Gulf could indicate unfavourable conditions for classic tropical storm structures even in the subtropics, which would imply a season that is even more hostile than I may have thought. I could be wrong, but data are data. Hmm...

the last time we had 2 storms before June we ended up with 19 total storms.

Multiple storms does not mean a quiet season. May actually raise an alarm of a more active season as one of them would come from the deep tropics

[ronjon]

If the current Gulf low were to somehow become Alberto (as seems increasingly possible) and Beryl were to follow in its wake, the back-to-back pre-season storms would very likely presage an inactive peak season. While pre-season activity in itself does not necessarily imply a dead heart of the season, El Niño years are almost always associated with an anomalously active pre-season/early season and a correspondingly dead peak season. La Niña is often the opposite: a slow start followed by a hyperactive peak season, with activity continuing well into late season (and sometimes beyond, even after New Year's Eve). So I think that the increasing prospects of both multiple pre-season storms and the increasing likelihood of El Niño by peak season go together nicely. Thus the odds of a very inactive season, with activity weighted toward pre-season/early season rather than peak/late season, are going way up at this time. So the model trends and sensible weather/climate trends both tend to support this outcome. Additionally, the fact that Alberto may very well turn out to be a subtropical system in the Gulf could indicate unfavourable conditions for classic tropical storm structures even in the subtropics, which would imply a season that is even more hostile than I may have thought. I could be wrong, but data are data. Hmm...

CSU disagrees - so far indicates a slight-above average season. But forecasts made this far out are pretty speculative. The one thing they predict is that neutral conditions will prevail on ENSO during the peak of the season.

https://tropical.colostate.edu/media/sites/111/2018/04/2018-04.pdf