Model Runs & Discussions of GOM-Bahamas

This is the general tropical discussion area. Anyone can take their shot at predicting a storms path.

Moderator: S2k Moderators

Forum rules

The posts in this forum are NOT official forecasts and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or STORM2K. For official information, please refer to products from the National Hurricane Center and National Weather Service.

Help Support Storm2K
Message
Author
Stratosphere747
Category 5
Category 5
Posts: 3772
Joined: Thu Sep 11, 2003 8:34 pm
Location: Surfside Beach/Freeport Tx
Contact:

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#901 Postby Stratosphere747 » Mon Sep 17, 2007 10:33 pm

0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#902 Postby cycloneye » Mon Sep 17, 2007 10:37 pm

00z GFS 200mb at 24 hours

Strong upper winds in gulf.
0 likes   

MiamiensisWx

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#903 Postby MiamiensisWx » Mon Sep 17, 2007 10:38 pm

If you look at this loop, you can see conditions are quite hostile in the W Bahamas. Note the outflow boundaries: this is an indication of upper-level shear. The shear actually appears to be a partial contributor to the low-level convergence in the area. The divergence is too strong for consolidation, so any potential LLC would lose its associated convection and/or remain broad and weak. Personally, I don't see a developing sfc low near Andros Island, Bahamas. I do see a possible broad rotation over the islands, but it's the league of shear. Finally, the convection near the Turks and Caicos (E of the Bahamas) isn't situated an an ideal environment: it is over an area of weaker low-level convergence and 850 mbar vorticity. Additionally, it is susceptible to competition from adjacent thunderstorms. I don't see any low-level circulation there. I will need to see further persistence before I think it has a shot, in spite of the fact that it's situated in an environment of lower shear. The possible larger circulation is situated over the W Bahamas beneath strong shear.

http://www.ssd.noaa.gov/goes/east/gmex/loop-vis.html

http://www.ssd.noaa.gov/goes/east/tatl/loop-ir2.html

Can a professional meteorologist chime in here on my thoughts?
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#904 Postby cycloneye » Mon Sep 17, 2007 10:43 pm

00z GFS 200mb at 42 hours

Upper Winds still screaming.
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#905 Postby cycloneye » Mon Sep 17, 2007 10:48 pm

00z GFS 200mb at 54 hours

50 kt upper winds.
0 likes   

User avatar
Extremeweatherguy
Category 5
Category 5
Posts: 11095
Joined: Mon Oct 10, 2005 8:13 pm
Location: Florida

#906 Postby Extremeweatherguy » Mon Sep 17, 2007 10:49 pm

low forms in eastern GOM (54 hrs) = http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_054s.gif
0 likes   

User avatar
ROCK
Category 5
Category 5
Posts: 9485
Age: 54
Joined: Tue Aug 17, 2004 7:30 am
Location: Kemah, Texas

Re:

#907 Postby ROCK » Mon Sep 17, 2007 10:50 pm

Extremeweatherguy wrote:low forms in eastern GOM (54 hrs) = http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_054s.gif



but how can it? is it seeing the ULL as the low itself?
0 likes   

User avatar
Steve
S2K Supporter
S2K Supporter
Posts: 9623
Joined: Sat Apr 05, 2003 11:41 pm
Location: Not a state-caster

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#908 Postby Steve » Mon Sep 17, 2007 10:52 pm

>>I buy the first part but not the last. I don't see the upper low backing away. I think it will be the kicker to get the sfc low started, but I think the sfc low will have to contend with it...and may have to work thru it. I don't see the upper low backing away anytime soon. If it can sink south and whatever develops can work west of the low...then the upper environment will be really good...but that won't happen till later...like the weekend...and once it is in the central GOM...

At least since August, there have been no static upper troughs across the Gulf whenever there were surges or tropical waves coming in from the east. I'm going to have to disagree with you and AFM about the early game, though I think we get on the same page toward the weekend. We also disagree on potential intensity. You guys are WAY underplaying the threat (should a system materialize). I need to go to bed, and I'm only on Page 41 of 48. Ugh.

Steve
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#909 Postby cycloneye » Mon Sep 17, 2007 10:53 pm

00z GFS 200mb at 66 hours

Still fierce upper winds in parts of GOM.
0 likes   

User avatar
Ptarmigan
Category 5
Category 5
Posts: 5316
Joined: Wed Aug 16, 2006 9:06 pm

Re: Model runs & Discussion for GOM - Bahamas (Threads merged)

#910 Postby Ptarmigan » Mon Sep 17, 2007 10:56 pm

wxman57 wrote:Interesting discussions, AFM/Derek. I agree, AFM, that the upper low could be the spark that gets some kind of low going, possibly near Florida on one side or the other. But the question I have is how the global models would handle the upper-level features (i.e., the low) given that they don't really forecast tropical systems well. 5-day forecasts are often pretty bad as far as upper wind predictions, particularly if the model "thinks" the low its developing isn't tropical in nature. So maybe the shear you're seeing isn't really going to be there by Friday?

This system really does have me concerned. With a ridge building to the north and a slow west movement beneath it, it would seem like quite a favorable environment for TC development/intensification. The "fly in the ointment" is that upper low. What if the models are wrong with its strength and/or location (or even its existence) by Friday? My gut is telling me that this system could be a real problem. Or maybe it's all the Corn Chex I just ate.


I am just an amateur and I too have this gut feeling that the tropics is up to no good. Even all the local mets on the news say something could brew in the tropics. At best, it will just mean more rain. Hopefully, this is wrong. I do like Corn Chex, preferable the Chex Mix with the worchester sauce. 8-)
Last edited by Ptarmigan on Mon Sep 17, 2007 10:57 pm, edited 1 time in total.
0 likes   

jhamps10

#911 Postby jhamps10 » Mon Sep 17, 2007 10:56 pm

and GFS does not move the surface low at all between 54 and 66, but it DOES intensify it. different than 18z, where it stalls it and kills it.
0 likes   

User avatar
Extremeweatherguy
Category 5
Category 5
Posts: 11095
Joined: Mon Oct 10, 2005 8:13 pm
Location: Florida

#912 Postby Extremeweatherguy » Mon Sep 17, 2007 10:57 pm

78 hrs..

low in central GOM = http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_078s.gif

upper level winds lightening considerably = http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_078s.gif
0 likes   

Stormcenter
S2K Supporter
S2K Supporter
Posts: 6684
Joined: Wed Sep 03, 2003 11:27 am
Location: Houston, TX

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#913 Postby Stormcenter » Mon Sep 17, 2007 10:58 pm

cycloneye wrote:00z GFS 200mb at 66 hours

Still fierce upper winds in parts of GOM.



If these upper winds pan out this possible develop has zero chance
of becoming anything significant at the surface in the GOM. IMO
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#914 Postby cycloneye » Mon Sep 17, 2007 10:59 pm

00z GFS 200mb at 78 hours

Less shear in general,but still some South upper winds a little strong.
0 likes   

User avatar
ROCK
Category 5
Category 5
Posts: 9485
Age: 54
Joined: Tue Aug 17, 2004 7:30 am
Location: Kemah, Texas

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#915 Postby ROCK » Mon Sep 17, 2007 11:00 pm

Am I wrong in saying how does this low EVEN form in such hostile conditions?
0 likes   

User avatar
Extremeweatherguy
Category 5
Category 5
Posts: 11095
Joined: Mon Oct 10, 2005 8:13 pm
Location: Florida

#916 Postby Extremeweatherguy » Mon Sep 17, 2007 11:00 pm

By 78 hours the upper level winds are lightening up a lot.

Compare:

48 hrs - http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_048s.gif

78 hrs - http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_078s.gif

As the mets have said, the best chance for significant development will be in the central GOM as these upper level winds die down.
Last edited by Extremeweatherguy on Mon Sep 17, 2007 11:04 pm, edited 1 time in total.
0 likes   

User avatar
Extremeweatherguy
Category 5
Category 5
Posts: 11095
Joined: Mon Oct 10, 2005 8:13 pm
Location: Florida

#917 Postby Extremeweatherguy » Mon Sep 17, 2007 11:02 pm

90 hrs..

low heading west in the GOM = http://www.nco.ncep.noaa.gov/pmb/nwprod ... n_090s.gif

Light upper level winds over the low = http://www.nco.ncep.noaa.gov/pmb/nwprod ... 0_090s.gif
0 likes   

User avatar
wxmann_91
Category 5
Category 5
Posts: 8013
Age: 34
Joined: Fri Jul 15, 2005 2:49 pm
Location: Southern California
Contact:

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#918 Postby wxmann_91 » Mon Sep 17, 2007 11:02 pm

ROCK wrote:Am I wrong in saying how does this low EVEN form in such hostile conditions?

The low is progged to work from the upper levels down to the SFC.

The Euro actually backs off the upper low to the SE while an upper anticyclone develops over the future system... as does the GFS in later periods. That is an extremely favorable upper air pattern, as we've seen with STY Wipha.
0 likes   

User avatar
cycloneye
Admin
Admin
Posts: 145870
Age: 69
Joined: Thu Oct 10, 2002 10:54 am
Location: San Juan, Puerto Rico

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#919 Postby cycloneye » Mon Sep 17, 2007 11:03 pm

00z GFS 200mb at 90 hours

Less shear in West GOM than in EGOM.
0 likes   

User avatar
ROCK
Category 5
Category 5
Posts: 9485
Age: 54
Joined: Tue Aug 17, 2004 7:30 am
Location: Kemah, Texas

Re: Second Depression to form in the GOM?? 00z GFS Rolling in

#920 Postby ROCK » Mon Sep 17, 2007 11:04 pm

wxmann_91 wrote:
ROCK wrote:Am I wrong in saying how does this low EVEN form in such hostile conditions?

The low is progged to work from the upper levels down to the SFC.

The Euro actually backs off the upper low to the SE while an upper anticyclone develops over the future system... as does the GFS in later periods. That is an extremely favorable upper air pattern, as we've seen with STY Wipha.



Ahhhh......now I see the light..... :D
0 likes   


Return to “Talkin' Tropics”

Who is online

Users browsing this forum: HurricaneBelle, riapal, Sunnydays, texsn95 and 39 guests