Global model runs discussion

[Hurricaneman]

Well,despite all the noise from the models,NHC remains quiet.

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT SUN OCT 5 2014

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

Tropical cyclone formation is not expected during the next 5 days.

$$
Forecaster Berg

The NHC isn't believing what the GFS is selling because the GFS has shown a lot of phantom storms the last year or 2 but this also could be a case where if convection persists that the %s start soon or it could be a case where the GFS can no longer even get a 72hr forecast right

[gatorcane]

06Z GFS continues to show another Florida hit from this Caribbean system though in the long-range. How many runs in a row is this now?

[gatorcane]

Here is the 06Z GFS 192 hour frame before the resolution drops. This is a classic October system as far as where it forms and track that the GFS is showing:

[blp]

Starting to see some blue show up.

[NDG]

Question, how many times are you guys going to get burned by the GFS's medium to long range forecast before you start ignoring it?

[cycloneye]

@MJVentrice · 29m

GFS loves the idea of a Gulf Storm and western sub-tropical Atlantic TC later this week into next. Euro not so much.

[Dean4Storms]

Question, how many times are you guys going to get burned by the GFS's medium to long range forecast before you start ignoring it?

This is getting close to short range. 06Z GFS closing off the Low in the SW Carib at 114hrs...Thursday from where the eventual Gulf system comes from.


http://www.instantweathermaps.com/GFS-php/showmap-natlsfc.php?run=2014100506&time=INSTANT&var=PRMSL&hour=114

[LarryWx]

06Z GFS continues to show another Florida hit from this Caribbean system though in the long-range. How many runs in a row is this now?

11 hits in a row and about 20 total runs of a SW Caribbean TC genesis near 10/10 ever since that Friday 9/26 run for which Luis posted that 384 hour map that I replied to last night. So, one thing that is totally different from the Model U debacle of May/June is that there has been no time slippage as we've moved forward in run time. However, one thing that is similar is the lack of Euro support. It has shown just one run with a very weak low.

[hurricanetrack]

In reference to the post that said NHC is not buying the GFS...I would simply say that since development is not really progged to happen in the GFS until after day 5, then we need a couple of more days before it pops up in the graphical TWO. Interesting times ahead or we all get very angry with the GFS, well not all of us, but you get the point.

[Ntxw]

Model Uccellini is also developing this in a bubble surrounded by very high shear. In fact there is currently blasting shear down there right now like in May/June in the range of 30-50 knots. The Western Carib will actually see some shear as high as 60-70 kts later this week in the W Carib.

[LarryWx]

Model Uccellini is also developing this in a bubble surrounded by very high shear. In fact there is currently blasting shear down there right now like in May/June in the range of 30-50 knots. The Western Carib will actually see some shear as high as 60-70 kts later this week in the W Carib.

Yes, I see that. The key is that it develops it within a bubble of low (<10 knots) shear south of the very high shear as you mentioned. IF the GFS is incorrect in showing low shear in that bubble below the very high shear, then it very likely is out to lunch with the TC genesis. OTOH, if it is correct with the low shear bubble, is it possible that low shear just below an area of very high shear could actually be extra favorable for genesis?
Regardless, I still think we're within the "for mainly entertainment" timeframe due to the unreliability of Model U though this may change pretty soon if this keeps up and especially if the Euro starts giving consistent support.

[blp]

[Ntxw]

Yes, I see that. The key is that it develops it within a bubble of low (<10 knots) shear south of the very high shear as you mentioned. IF the GFS is incorrect in showing low shear in that bubble below the very high shear, then it very likely is out to lunch with the TC genesis. OTOH, if it is correct with the low shear bubble, is it possible that low shear just below an area of very high shear could actually be extra favorable for genesis?
Regardless, I still think we're within the "for mainly entertainment" timeframe though this may change pretty soon if this keeps up and especially if the Euro starts giving consistent support.

I'm not sure, but if the GFS is going to be right the more likely scenario, in my personal opinion, is something that sits around and is struggling being surrounded by all that shear then maybe some kind of frontal system picks it up and baroclinic enhancement as it rides N/NE along the front into something subtropical or extratropical.

[cycloneye]

Model Uccellini is also developing this in a bubble surrounded by very high shear. In fact there is currently blasting shear down there right now like in May/June in the range of 30-50 knots. The Western Carib will actually see some shear as high as 60-70 kts later this week in the W Carib.

Yes, I see that. The key is that it develops it within a bubble of low (<10 knots) shear south of the very high shear as you mentioned. IF the GFS is incorrect in showing low shear in that bubble below the very high shear, then it very likely is out to lunch with the TC genesis. OTOH, if it is correct with the low shear bubble, is it possible that low shear just below an area of very high shear could actually be extra favorable for genesis?
Regardless, I still think we're within the "for mainly entertainment" timeframe though this may change pretty soon if this keeps up and especially if the Euro starts giving consistent support.

Hi Larry and Ntxw. About the shear,GFS haves it is mainly north of 20N in the Western Caribbean so something can develop below that latitude.What we have to see is if the shear north of 20N may have an outflow channel that coud be favorable more north.

[SFLcane]

NASA GOES 5 wx model..

[gatorcane]

Model Uccellini is also developing this in a bubble surrounded by very high shear. In fact there is currently blasting shear down there right now like in May/June in the range of 30-50 knots. The Western Carib will actually see some shear as high as 60-70 kts later this week in the W Carib.

Yes, I see that. The key is that it develops it within a bubble of low (<10 knots) shear south of the very high shear as you mentioned. IF the GFS is incorrect in showing low shear in that bubble below the very high shear, then it very likely is out to lunch with the TC genesis. OTOH, if it is correct with the low shear bubble, is it possible that low shear just below an area of very high shear could actually be extra favorable for genesis?
Regardless, I still think we're within the "for mainly entertainment" timeframe though this may change pretty soon if this keeps up and especially if the Euro starts giving consistent support.

Hi Larry and Ntxw. About the shear,GFS haves it is mainly north of 20N in the Western Caribbean so something can develop below that latitude.What we have to see is if the shear north of 20N may have an outflow channel that coud be favorable more north.

The GFS builds an anticyclone right on top of it in the SW Caribbean by 144 hours with dual-channel outflow. This anticyclone moves northward in tandem with the low. This is a very good upper environment if it verifies:

[boca]

The 12z GFS has a closed low at 66 hours.Im not taking this seriously because of the boy who cried wolf senario.

[gatorcane]

12Z GFS is running and bringing the timeframe in more, now down to 1003MB at 114 hours.

[SFLcane]

morning 06z ensembles have quite the clustering in the northwestern Caribbean sea.

[LarryWx]

I'm not sure, but if the GFS is going to be right the more likely scenario, in my personal opinion, is something that sits around and is struggling being surrounded by all that shear then maybe some kind of frontal system picks it up and baroclinic enhancement as it rides N/NE along the front into something subtropical or extratropical.

One thing that doesn't help chances of genesis is general El Nino climo. Whereas non-Nino's have averaged near one TS/H and near 0.65 H forming during Oct.-Nov. in the Caribbean since 1900 per Hurricaneman's Friday night post, Nino's/oncoming Nino's have averaged only 0.54 TS/H and 0.37 H there. OTOH, 0.54/0.37 is still high enough to not ignore the possibility, especially with the GFS being so insistent and with no time slippage since that Luis posted run of nine days ago.
However, on the subject of MH's, alone, only one of the 28 majors in Hurricaneman's Oct./Nov. Caribbean list was during a Nino/oncoming Nino (I'm excluding 1952 as an oncoming Nino). This was Hurricane #4 of 1905 (120 mph). None of the strongest 17 were during Nino's/oncoming Nino's. So, whereas a development in the SW Caribbean in October moving slowly NNW to the SE Gulf would normally have a decent chance at becoming a major H, Nino climo suggests that that chance would be very low and far lower than the chance if it were non-Nino fwiw.