2020 Global Model Runs Discussion (Out thru day 16)

[AutoPenalti]

00z Canadian...

https://i.imgur.com/aaEFdxM.gif

Is that forming from a CAG or the tail end of that front?

[gfsperpendicular]

00z Canadian...

https://i.imgur.com/aaEFdxM.gif

Is that forming from a CAG or the tail end of that front?

I think it's from a weak wave, possibly emerging off Africa in about 36 hours. It kinda slows in the Caribbean and starts to organize.

[aspen]

06z GFS is back to forming a bunch of EPac storms from the CA vorticity. Looks like it’s going to have to be force-fed an Atlantic TC now.

[Blown Away]

06z GFS is back to forming a bunch of EPac storms from the CA vorticity. Looks like it’s going to have to be force-fed an Atlantic TC now.

It continues showing a Low with TD/TS pressure in the NW Caribbean and/or GOM moving from long range into the mid range which gives the model more credibility. Flopping from Hurricane to TD from one model run to the next in mid to long range, I don’t think you can draw any conclusions except the model continues to see disturbed area in the NW Caribbean in early October, bears watching!

[LarryWx]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

[cheezyWXguy]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

[chris_fit]

Whoa, did you guys see the 06Z GFS ENS?

[chris_fit]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I think you're 24 hours late with this post. Last 24 hours have trended towards development. Previous 24 hours was a bit quieter. We even have the EPS showing over 50% chance of TD now.

[LarryWx]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

1. GFS runs had been showing 50%+ with a H for several days. Now none have done so recently.

2. GFS has had a history of fake Oct W Caribbean storms for at least several years.

3. The GEFS appears to be too genesis happy in relation to the operational.

4. The Euro suite continues to have very little. The 0Z EPS has backed off that slight uptick the 12Z EPS has and is now back to hardly anything.

5. The ICON and CMC have a history of being genesis happy. For example, the ICON had a fake 94L storm hitting NC on many runs whereas no other model had this.

6. I’m not so sure either. I’m not saying zero chance, especially in deference to the climo of the ENSO based-analogs. But the trend of the GFS toward no development in the W Caribbean is obvious.

7. The bias on weather forums is toward more development chances than reality because most members want development because no development is boring vs development being interesting. This is notwithstanding exceptions like 57 and Frank2, who tend to downplay most of the time.

[SFLcane]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

1. GFS runs had been showing 50%+ with a H for several days. Now none have done so recently.

2. GFS has had a history of fake Oct W Caribbean storms for at least several years.

3. The GEFS appears to be too genesis happy in relation to the operational.

4. The Euro suite continues to have very little. The 0Z EPS has backed off that slight uptick the 12Z EPS has and is now back to hardly anything.

5. The ICON and CMC have a history of being genesis happy. For example, the ICON had a fake 94L storm hitting NC on many runs whereas no other model had this.

6. I’m not so sure either. I’m not saying zero chance, especially in deference to the climo of the ENSO based-analogs. But the trend of the GFS toward no development in the W Caribbean is obvious.

7. The bias on weather forums is toward more development chances than reality because most members want development because no development is boring vs development being interesting. This is notwithstanding exceptions like 57 and Frank2, who tend to downplay most of the time.

EPS probability for a TD is almost near 60%. It has been trending up and I am curious to see if it continues. I do agree I would like to see more deterministic runs pick it up. We shall see

[Ubuntwo]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

1. GFS runs had been showing 50%+ with a H for several days. Now none have done so recently.

2. GFS has had a history of fake Oct W Caribbean storms for at least several years.

3. The GEFS appears to be too genesis Happy in relation to the operational.

4. The Euro suite continues to have very little. The 0Z EPS has backed off that slight uptick the 12Z EPS has and is now back to hardly anything.

5. The ICON and CMC have a history of being genesis happy. For example, the ICON had a fake 94L storm hitting NC on many runs whereas no other model had this.

6. I’m not so sure either. I’m not saying zero chance, especially in deference to the climo of the ENSO based-analogs. But the trend of the GFS toward no development in the W Caribbean is obvious.

7. The bias on weather forums is toward more development chances than reality because most want members want development because no development is boring vs development being interesting.

Not sure what your angle is with this. The latest EPS is the most active thus far in the West Caribbean (more systems in general, though less get intense), and the operational run ends with a couple closed, concentrated areas of vorticity in the Caribbean and along a frontal boundary - more than in any recent run.

In this case development appears to be attributable to a trackable wave, not some random phantom. The GFS could've been overamplifying it, but that doesn't mean the energy is nonexistent.

Fact of the matter is, this is *the most* active region as we move into October - and we're in an already extremely active season. Statistically and climatologically speaking, eventual development in the west Caribbean looks more likely than not.

(notwithstanding, point 7 is all too true sometimes.)

[cheezyWXguy]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

1. GFS runs had been showing 50%+ with a H for several days. Now none have done so recently.

2. GFS has had a history of fake Oct W Caribbean storms for at least several years.

3. The GEFS appears to be too genesis happy in relation to the operational.

4. The Euro suite continues to have very little. The 0Z EPS has backed off that slight uptick the 12Z EPS has and is now back to hardly anything.

5. The ICON and CMC have a history of being genesis happy. For example, the ICON had a fake 94L storm hitting NC on many runs whereas no other model had this.

6. I’m not so sure either. I’m not saying zero chance, especially in deference to the climo of the ENSO based-analogs. But the trend of the GFS toward no development in the W Caribbean is obvious.

7. The bias on weather forums is toward more development chances than reality because most members want development because no development is boring vs development being interesting. This is notwithstanding exceptions like 57 and Frank2, who tend to downplay most of the time.

All fair points, especially 7 haha. Agreed the gefs May be genesis happy, especially since the upgrade. To counter though, the timeframe has moved up somewhat consistently. The gfs also has given into a clear bias this season to over produce in the epac, which, if those storms did verify, would directly suppress development in the Caribbean. However if those currently depicted are phantoms, then it would be falsely be underdoing the Caribbean development.

Also, how do we define phantom? Is a phantom any storm the gfs depicts at a given time that never pans out, or is it a system the gfs depicts in a pattern that never pans out? If the gfs models a pattern that has, say, a 30% chance of producing a system, and ends up correct but a storm never develops, does that count as a phantom?

All in all, I feel like my chances are higher than yours that this isn’t a phantom (by the latter definition above), and maybe a little higher than yours in development at all, but I haven’t left my comfortable spot on the fence yet.

[DestinHurricane]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

First off, it is not a "phantom" as it is a trackable wave. Second, EPS has jumped aboard so not sure about that.

[Emmett_Brown]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

First off, it is not a "phantom" as it is a trackable wave. Second, EPS has jumped aboard so not sure about that.

And the CMC has a big fat area of lowering pressures in the W Caribbean at 240 hours, so multiple models are sniffing out something.

[LarryWx]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

First off, it is not a "phantom" as it is a trackable wave. Second, EPS has jumped aboard so not sure about that.

1. IF there ends up not being a W Caribbean storm by 10/5 (2/3 chance of no named storm in my mind right now...I’m not talking about after 10/5), it will be another in a long list of GFS October fake storms. Let’s see what happens. And even I’m not saying near zero chance. I’m near 33% chance. I gave plenty of supporting reasons to drop it from 67% chance though.

2. I keep seeing EPS support posts for a TD but my source actually shows fewer TCs with sub 1004 mb on the 0Z vs the 12Z. It shows only a very few of the 51 members getting to lower than 1004 mb during early October. Something seems off about that 50-55% chance of a TD per “weathermodels.com”. I don’t subscribe to them and am going by what I see on my provider’s objective output. Perhaps most of the members that get to TD don’t become a named storm.

3. It is not surprising that a somewhat bearish post on genesis generates so much discussion opposing it for reason #7 in my list. Also, posts with even just some bearishness tend to get fewer likes than bullish posts for the same reason.

[Ubuntwo]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

First off, it is not a "phantom" as it is a trackable wave. Second, EPS has jumped aboard so not sure about that.

1. IF there ends up not being a W Caribbean storm by 10/5 (2/3 chance of no named storm in my mind right now...I’m not talking about after 10/5), it will be another in a long list of GFS October fake storms. Let’s see what happens. And even I’m not saying near zero chance. I’m near 33% chance. I gave plenty of supporting reasons to drop it from 67% chance though.

2. I keep seeing EPS support posts for a TD but my source actually shows fewer TCs with sub 1004 mb on the 0Z vs the 12Z. It shows only a very few of the 51 members getting to lower than 1004 mb during early October. Something seems off about that 50-55% chance of a TD per “weathermodels.com”. I don’t subscribe to them and am going by what I see on my provider’s objective output.

3. It is not surprising that a somewhat bearish post on genesis generates so much discussion opposing it for reason #7 in my list. Also, posts with even just some bearishness tend to get fewer likes than bullish posts for the same reason.

Weathermodels has a ~50% chance for a TD, but only about a ~10% max chance for a TS. Not sure if this is a function of timeframe or only marginal conditions.

[Spacecoast]

The chances this is just another in a long line of GFS W Caribbean phantoms have increased markedly during the last 24 hours. I’d say it is now at 2:1 in favor of it being a W Caribbean phantom vs it being at 2:1 in favor of it being for real just 3 days ago.

First off, it is not a "phantom" as it is a trackable wave. Second, EPS has jumped aboard so not sure about that.

And the CMC has a big fat area of lowering pressures in the W Caribbean at 240 hours, so multiple models are sniffing out something.

The CMC shows that area @240...



The corresponding timeframeof the GEPS ens also shows it...



but ultimately only 1 member (out of 20) develops anything out of it, shooting the Yucatan channel,(I'm not sure whether that member is associated with the WCar system that the CMC displayed).


What I don't understand is why any of these ensemble members from any of of the models aren't massively blowing up anything drifting into the boiling hot waters of the West Carib.

[gatorcane]

My thought is that something is going to form of potential significance down there in the Western Caribbean in October if not this one the models are hinting at in the next 10 days but maybe one in mid to late October timeframe. Think it is just a matter of time. Models haven’t done well in the medium to long-range again this year so they may not pick up on it until it is closer to 5 days (or even less) out.

[Ubuntwo]

Potential genesis looks to be the result of interaction between a tropical wave and a trough. These setups often lead to strung out fast moving systems, especially if genesis is delayed. A weaker trough and earlier consolidation might be needed for an intense storm.

[LarryWx]

I'm not so sure. GEFS now shows a signal starting in 168 hours, and the CMC and Icon are showing signs of latching on too. It would seem the GFS only wants to show the system when it is not unreasonably pumping out epac storms. Would be interested to hear your reasoning though.

1. GFS runs had been showing 50%+ with a H for several days. Now none have done so recently.

2. GFS has had a history of fake Oct W Caribbean storms for at least several years.

3. The GEFS appears to be too genesis happy in relation to the operational.

4. The Euro suite continues to have very little. The 0Z EPS has backed off that slight uptick the 12Z EPS has and is now back to hardly anything.

5. The ICON and CMC have a history of being genesis happy. For example, the ICON had a fake 94L storm hitting NC on many runs whereas no other model had this.

6. I’m not so sure either. I’m not saying zero chance, especially in deference to the climo of the ENSO based-analogs. But the trend of the GFS toward no development in the W Caribbean is obvious.

7. The bias on weather forums is toward more development chances than reality because most members want development because no development is boring vs development being interesting. This is notwithstanding exceptions like 57 and Frank2, who tend to downplay most of the time.

All fair points, especially 7 haha. Agreed the gefs May be genesis happy, especially since the upgrade. To counter though, the timeframe has moved up somewhat consistently. The gfs also has given into a clear bias this season to over produce in the epac, which, if those storms did verify, would directly suppress development in the Caribbean. However if those currently depicted are phantoms, then it would be falsely be underdoing the Caribbean development.

Also, how do we define phantom? Is a phantom any storm the gfs depicts at a given time that never pans out, or is it a system the gfs depicts in a pattern that never pans out? If the gfs models a pattern that has, say, a 30% chance of producing a system, and ends up correct but a storm never develops, does that count as a phantom?

All in all, I feel like my chances are higher than yours that this isn’t a phantom (by the latter definition above), and maybe a little higher than yours in development at all, but I haven’t left my comfortable spot on the fence yet.

IF there ends up being no named storm by 10/5 in or near the W Caribbean/Gulf in the Atlantic basin, I’m going to retrospectively call it a “GFS phantom”, even if one forms later, which I’m still betting on based on ENSO based analogs (current weak to moderate La Niña following a weak to moderate El Niño the prior fall/winter.)

Keep in mind that one week ago today that I first brought up these particular analogs implying a significantly higher than normal chance for a CONUS H hit from the Caribbean once we get to early to mid October and I’m still not backing down from that idea. So, I’m not downplaying just for the heck of it like I think a few like to do. But I’m also not a cheerleader who likes to “upplay” (is that a word lol?) like many members like to do on any weather board.