Hurricane FELIX: Global & BAM Models

[Stratosphere747]

I'll stop taking this thread off-topic.

But I do feel much safer with your latest forecast...

A slower transgression across the YP will leave little inner core intact.

*edit*

Portastorm obviously reacts much quicker than I can....

[tolakram]

I was annoyed at the Dean speculation because there was high confidence in the forecast track. I'm concerned about Felix, though, because you can sense the uncertainty the NHC has plus the models seem to be very in denial about this storm.

By tomorrow this time I hope the models have a better handle on Felix and the steering so we will know, with more confidence, where he will end up.

[Berwick Bay]

Well my point about a "slow" transit. Its true if that pans out, I would look for a much weaker storm entering the GOM. But I'm thinking that you could get a stationary type situation along the NE coast of the Yucatan. So there could very well be good regeneration in the Gulf. I do expect the storm to be broken down, but I also expect a hurricane in the Gulf. Won't speculate yet on intensity in Gulf. But I think a rapid build up again would be very possible.

[Portastorm]

Well my point about a "slow" transit. Its true if that pans out, I would look for a much weaker storm entering the GOM. But I'm thinking that you could get a stationary type situation along the NE coast of the Yucatan. So there could very well be good regeneration in the Gulf. I do expect the storm to be broken down, but I also expect a hurricane in the Gulf. Won't speculate yet on intensity in Gulf. But I think a rapid build up again would be very possible.

Fair enough ... and it's certainly not out of the question. Stranger things have happened in the tropics.

[LAwxrgal]

Well my point about a "slow" transit. Its true if that pans out, I would look for a much weaker storm entering the GOM. But I'm thinking that you could get a stationary type situation along the NE coast of the Yucatan. So there could very well be good regeneration in the Gulf. I do expect the storm to be broken down, but I also expect a hurricane in the Gulf. Won't speculate yet on intensity in Gulf. But I think a rapid build up again would be very possible.

That depends on the condition of the storm's inner core once it gets off the Yucatan.

[jhamps10]

I don't know if anyone is reading the other thread, but we OFFICALLY have a cat 5 on our hands people, just in 145 kts, 165 MPH!

[Thunder44]

249
WHXX01 KWBC 030042
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0042 UTC MON SEP 3 2007

DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.
PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE
AND SUBTROPICAL CYCLONE INFORMATION.

ATLANTIC OBJECTIVE AIDS FOR

TROPICAL CYCLONE FELIX (AL062007) 20070903 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
070903 0000 070903 1200 070904 0000 070904 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 13.8N 73.0W 14.8N 76.5W 15.4N 79.7W 16.0N 82.8W
BAMD 13.8N 73.0W 14.5N 76.6W 15.2N 79.8W 15.7N 82.5W
BAMM 13.8N 73.0W 14.6N 76.9W 15.2N 80.4W 15.5N 83.7W
LBAR 13.8N 73.0W 14.6N 76.8W 15.6N 80.3W 16.5N 83.5W
SHIP 145KTS 155KTS 149KTS 143KTS
DSHP 145KTS 155KTS 149KTS 143KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
070905 0000 070906 0000 070907 0000 070908 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 16.6N 85.4W 17.7N 90.0W 19.4N 94.2W 21.0N 97.6W
BAMD 16.2N 85.1W 17.3N 90.1W 18.3N 94.6W 18.4N 98.4W
BAMM 15.7N 86.5W 16.4N 91.6W 16.8N 96.1W 17.1N 99.5W
LBAR 17.4N 86.2W 19.6N 90.8W 22.0N 94.1W 21.2N 98.5W
SHIP 139KTS 120KTS 105KTS 112KTS
DSHP 139KTS 92KTS 50KTS 57KTS

...INITIAL CONDITIONS...
LATCUR = 13.8N LONCUR = 73.0W DIRCUR = 280DEG SPDCUR = 18KT
LATM12 = 13.1N LONM12 = 69.4W DIRM12 = 282DEG SPDM12 = 17KT
LATM24 = 12.6N LONM24 = 66.1W
WNDCUR = 145KT RMAXWD = 10NM WNDM12 = 90KT
CENPRS = 930MB OUTPRS = 1012MB OUTRAD = 150NM SDEPTH = D
RD34NE = 100NM RD34SE = 75NM RD34SW = 40NM RD34NW = 100NM

$$
NNNN

Still winds at 145kts but pressure down to 930mb.

[vaffie]

The 18Z GFDL and GFS drift it through Central America, though as we've said before, the GFS barely even sees it, and the GFDL is using the initialization data of the GFS, so both are very flimsy predictions right now. The latest 18Z WRF has it crossing into the Bay of Campeche and drifting northward at the end of the run. The 18Z NOGAPS slows it down considerably just before it reaches the Yucatan, and then races it across the peninsula on a nnw track towards the Mexico/Texas border. I think we're still waiting on the 18Z UKMET model, but the 12Z is similar to the NOGAPS but further south. More disparate tracks I don't think we could see. It appears that the models (GFDL and GFS) that have it hit south--Honduras--end up taking it towards the Pacific. Those that miss Honduras--head northwestward through the Yucatan towards northern Mexico.

https://my.sfwmd.gov/portal/page?_pagei ... ema=PORTAL

[Extremeweatherguy]

What is interesting is the fact that the NOGAPS is one of the furthest south models in the short term and then is one of the furthest north in the long term.

[wxman57]

I was just talking to one of my hurricane team members about the track. After our track being well south of the NHC and most guidance for the past 24 hours, I finally relented and adjusted the track closer to the NHC’s 21Z track (we issue the track an hour before NHC so I didn't know what their track would look like). Kind of aiming for Tampico or just north of there. But I was thinking about the weather pattern and the models while out on my bike this evening and I think that the big problem has been that the GFS was developing a spurious “hurricane” near Florida on Wed/Thu. This resulted in a significantly weaker ridge north of Felix and the NW turn we’ve seen projected over the Yucatan. The European never developed this low and kept a strong ridge across the northern Gulf. I knew the European hit Dean perfectly and I shouldn’t have strayed from the European’s more southern track for Felix.

Now the GFS appears to be giving up the idea of that Bahamas low and it’s developing a stronger ridge across the northern Gulf - very much like the ECMWF. As a result, there has been a significant southward shift in the models. The consensus models, like the CONU the NHC likes to follow had been fairly far north because of the NOGAPS going through the Yucatan Channel and the GFS farther north (than it is now). But now the NOGAPS is shifting south, GFS is way south, and GFDL is way south. As you can see by the images below, neither the ECMWF nor the GFS brings Felix into the BoC.

The CONU, as a result, has shifted way south to the southern Bay of Campeche. We decided to adjust our track about 60 miles farther south (half way down to CONU) until we're sure the trend will continue. Though I think it’s quite possible that Felix hits Nicaragua and dies in Central America without emerging into the BoC, Good news for Tampico northward, bad news for Nicaragua/Honduras.

I analyzed the charts below down to 0.5 mb for better resolution of Felix and 500mb heights to 10 meters.

12Z THU ECMWF:


12Z THU GFS:


12Z FRI ECMWF:


12Z FRI GFS:

[Recurve]

Thanks '57, excellent analysis as always.


Unless something goes pop to send Felix north now, it won't later. The consensus isn't blind. I don't see this getting anywhere near the Gulf and any due North motion is about impossible, so less worries for US Gulfcoasters but very bad for Central America.

The ABOVE post is NOT an official forecast and should not be used as such. It is just the opinion of the poster and may or may not be backed by sound meteorological data. It is NOT endorsed by any professional institution including storm2k.org For Official Information please refer to the NHC and NWS products.

[Extremeweatherguy]

Thanks for the update wxman..but I am still in a "I will believe it, when I see it" mode. I just have a hard time believing the GFS right now given the fact that it doesn't even develop the system right and shows it making landfall in Belize as a weak >1010mb low that doesn't even look to be closed at the time. Also, just because the European did well with Dean doesn't mean that it will do well with Felix too..and I am definitely not going to be putting all my eggs in that basket. For the moment, I will stick with the NHC and if they decide to shift southward to your idea, then I will be more inclined to buy into it. I just feel that there are still too many uncertanties with the trough placement, strength and timing, and I also do not want to write off possible impacts by Henriette or that low east of FL just yet. Thanks again though for updating us on your thoughts! It is always nice to hear all the meteorological opinions out there for the storm.

[Ptarmigan]

Thanks for the update wxman..but I am still in a "I will believe it, when I see it" mode. I just have a hard time believing the GFS right now given the fact that it doesn't even develop the system right and shows it making landfall in Belize as a weak >1010mb low that doesn't even look to be closed at the time. Also, just because the European did well with Dean doesn't mean that it will do well with Felix too..and I am definitely not going to be putting all my eggs in that basket. For the moment, I will stick with the NHC and if they decide to shift southward to your idea, then I will be more inclined to buy into it. I just feel that there are still too many uncertanties with the trough placement, strength and timing, and I also do not want to write off possible impacts by Henriette or that low east of FL just yet. Thanks again though for updating us on your thoughts! It is always nice to hear all the meteorological opinions out there for the storm.

Same here. Sure the models have a consensus, they are meaningless because it is too early to tell.

[Normandy]

I think it hitting Nicaragua is a stretch....almost as much of a stretch has it hitting Brownsville....it would have to head pretty much 275 from this point on to strike Nicaragua and die in CA. I'd say a track similar to Dean at this point is more likely....maybe a brush with Honduras.

Just my opinion though.

[Ptarmigan]

Computer models were conservative when it came to fast it would strengthened. They were off with it.

[Stratosphere747]

Computer models were conservative when it came to fast it would strengthened. They were off with it.

??

What does this have to do with the track?

[Ptarmigan]

??

What does this have to do with the track?

Computer models predict how much the storm will strengthened. It got the track right though. We have a long way to go when it comes to strengthening.

[ronjon]

I'd just like to add that just because the GFS doesn't develop the low off GA/FL doesn't mean it won't happen. Heck, tell me which global model (or any model) which forecast Felix. Currently, there is a 1015 mb low off the GA/FL coast with warm SSTs and low shear. It is currently attached to a frontal system. I see a slow transition toward tropical characteristics. It is progged to drift slowly south and then SW. This feature may be the ultimate wild card on Felix's track - I raised this issue earlier in the other thread and was basically dismissed by a bunch of amateurs. If it developed, it would create a weakness over the eastern side of the 500 mb ridge rather than the western side with the Tx trough. This could pull Felix more NW in the NW caribbean.

[Tampa Bay Hurricane]

I'd just like to add that just because the GFS doesn't develop the low off GA/FL doesn't mean it won't happen. Heck, tell me which global model (or any model) which forecast Felix. Currently, there is a 1015 mb low off the GA/FL coast with warm SSTs and low shear. It is currently attached to a frontal system. I see a slow transition toward tropical characteristics. It is progged to drift slowly south and then SW. This feature may be the ultimate wild card on Felix's track - I raised this issue earlier in the other thread and was basically dismissed by a bunch of amateurs. If it developed, it would create a weakness over the eastern side of the 500 mb ridge rather than the western side with the Tx trough. This could pull Felix more NW in the NW caribbean.

I think that it could happen...the system may develop and cause an issue with the ridge...

[vaffie]

I'd just like to add that just because the GFS doesn't develop the low off GA/FL doesn't mean it won't happen. Heck, tell me which global model (or any model) which forecast Felix. Currently, there is a 1015 mb low off the GA/FL coast with warm SSTs and low shear. It is currently attached to a frontal system. I see a slow transition toward tropical characteristics. It is progged to drift slowly south and then SW. This feature may be the ultimate wild card on Felix's track - I raised this issue earlier in the other thread and was basically dismissed by a bunch of amateurs. If it developed, it would create a weakness over the eastern side of the 500 mb ridge rather than the western side with the Tx trough. This could pull Felix more NW in the NW caribbean.

I just looked at a loop of the area that you're talking about and a convective blob has appeared over the last couple hours with a weak rotation as it drifts south. Wow, what a fly in the ointment this might end up being. If there were rapid development of it tomorrow, Felix could become a much bigger headache than it is now.