ATL: TROPICAL STORM BILL (03L)

[KWT]

Hard to tell, I'm not really all that sure the models have a good grip on the strength of the upper high, I think this simply because the models seem to be too slow. Now a slower system is generally going to be because the steering currents not as strong and that occurs in weaker pressure system generally. When it slows down thats going to be a good idea when the system will start to gain latitude.

[MGC]

The Gulfstream is tasked to fly on Monday. So, we will know then the strength of the ridge. Until then the model can only guess....MGC

[KWT]

Yep thats going to be very telling, thats when we will know a lot more about Bill's future track I suspect.

However till then all we can really do is compare where Bill is and where the models suggested it will be.

Also I suspect we will have hurricane Bill by this time tomorrow...

[Bocadude85]

Yep thats going to be very telling, thats when we will know a lot more about Bill's future track I suspect.

However till then all we can really do is compare where Bill is and where the models suggested it will be.

Also I suspect we will have hurricane Bill by this time tomorrow...

Yes I wouldnot be surprised to see Hurricane Bill by tomorrow

[attallaman]

I had a TS Bill make landfall just west of here back in late June 2003 and as I remember that system was nothing to sneeze at because it brought two very tall pine trees down on top of my neighbor's house but it had a different track than the current TS Bill. So would I be correct in saying that right now TS Ana poses more of a threat to the GOM than the current TS Bill? That right now according to the latest computer models and what I have read in this thread that TS Bill poses more of a threat to the east coast of the USA than the GOM?

[thetruesms]

I had a TS Bill make landfall just west of here back in late June 2003 and as I remember that system was nothing to sneeze at because it brought two very tall pine trees down on top of my neighbor's house but it had a different track than the current TS Bill. So would I be correct in saying that right now TS Ana poses more of a threat to the GOM than the current TS Bill? That right now according to the latest computer models and what I have read in this thread that TS Bill poses more of a threat to the east coast of the USA than the GOM?

Currently, yes. However, both are still far out enough from any potential US impact that you should keep watching carefully.

[KWT]

Also here is a heights currently of the high:

http://laps.fsl.noaa.gov/cgi/laps/domai ... latest.cgi

You can see where the weakness is progged to form, for now though its holding on as ridging. Should see some WNW motion by 50W latest if it carries on to weaken through the middle of the two cells like expected.

[clfenwi]

15/2345 UTC 11.4N 35.2W T2.5/2.5 BILL -- Atlantic

[KWT]

Center maybe a touch too far north on that given the NHC position is 11.3N. The convection on its south side is very interesting though I have to admit, the upper high is still surpressing the convection to the south it seems.

[Bocadude85]

Also here is a heights currently of the high:

http://laps.fsl.noaa.gov/cgi/laps/domai ... latest.cgi

You can see where the weakness is progged to form, for now though its holding on as ridging. Should see some WNW motion by 50W latest if it carries on to weaken through the middle of the two cells like expected.

Wonder how much of a weakness will really develop.

[clfenwi]

AL, 03, 2009081600, , BEST, 0, 112N, 359W, 35, 1004, TS, 34, NEQ, 25, 25, 0, 25, 1011, 200, 25, 0, 0, L, 0, , 0, 0, BILL, M,

TAFB's estimate must have been a bit south of SAB's.

EDIT: And well to the west!

[cycloneye]

WHXX01 KWBC 160015
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
0015 UTC SUN AUG 16 2009

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 BILL (AL032009) 20090816 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...
090816 0000 090816 1200 090817 0000 090817 1200

LAT LON LAT LON LAT LON LAT LON
BAMS 11.2N 35.9W 11.6N 38.3W 12.6N 41.0W 13.4N 43.8W
BAMD 11.2N 35.9W 11.5N 38.5W 12.1N 41.1W 12.8N 43.8W
BAMM 11.2N 35.9W 11.6N 38.4W 12.3N 41.1W 13.1N 43.9W
LBAR 11.2N 35.9W 11.3N 39.1W 11.7N 42.6W 12.2N 46.3W
SHIP 35KTS 42KTS 50KTS 58KTS
DSHP 35KTS 42KTS 50KTS 58KTS

...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...
090818 0000 090819 0000 090820 0000 090821 0000

LAT LON LAT LON LAT LON LAT LON
BAMS 14.4N 46.6W 16.1N 52.8W 19.1N 59.4W 21.5N 66.2W
BAMD 13.8N 46.4W 16.2N 51.3W 19.7N 56.5W 24.1N 61.1W
BAMM 14.1N 46.7W 16.4N 52.3W 19.5N 58.5W 22.4N 64.3W
LBAR 12.8N 50.0W 13.6N 56.5W 17.8N 59.2W .0N .0W
SHIP 66KTS 83KTS 88KTS 90KTS
DSHP 66KTS 83KTS 88KTS 90KTS

...INITIAL CONDITIONS...
LATCUR = 11.2N LONCUR = 35.9W DIRCUR = 265DEG SPDCUR = 14KT
LATM12 = 11.5N LONM12 = 33.3W DIRM12 = 259DEG SPDM12 = 12KT
LATM24 = 11.8N LONM24 = 30.7W
WNDCUR = 35KT RMAXWD = 25NM WNDM12 = 30KT
CENPRS = 1004MB OUTPRS = 1011MB OUTRAD = 200NM SDEPTH = M
RD34NE = 25NM RD34SE = 25NM RD34SW = 0NM RD34NW = 25NM

$$



UKMET is the outlier.

[KWT]

I think thats probably the more likely one to be honest given the convection placement, though it does seem maybe a touch too far west?

Also Derek is right about the models...the GFS is lifting out Bill for a *totaly different* reason as the ECM/CMC combo. The ECM/CMC have the ULL cause a weakness in the high as it pulls away leaving a nice hole for Bill...whilst the GFS digs a upper trough down off the east coast far enough to lift Bill somewhat NW.

Also the ECM was a shocking 4 degrees too far east within just 24hrs!!!

[attallaman]

I had a TS Bill make landfall just west of here back in late June 2003 and as I remember that system was nothing to sneeze at because it brought two very tall pine trees down on top of my neighbor's house but it had a different track than the current TS Bill. So would I be correct in saying that right now TS Ana poses more of a threat to the GOM than the current TS Bill? That right now according to the latest computer models and what I have read in this thread that TS Bill poses more of a threat to the east coast of the USA than the GOM?

Currently, yes. However, both are still far out enough from any potential US impact that you should keep watching carefully.

Thanks for the input.

[KWT]

Still pulling just south of west I see!

I put another post in the other thread. ECM has been awful with the forward speed so far as Derek suspected it would, 0z run yesterday had Bill at 32/12 in 24hrs, its actual placement is 35.9/11.2, which is actually nearly 4 degrees out, or over 200 miles out in 24hrs...

[Emmett_Brown]

I think thats probably the more likely one to be honest given the convection placement, though it does seem maybe a touch too far west?

Also Derek is right about the models...the GFS is lifting out Bill for a *totaly different* reason as the ECM/CMC combo. The ECM/CMC have the ULL cause a weakness in the high as it pulls away leaving a nice hole for Bill...whilst the GFS digs a upper trough down off the east coast far enough to lift Bill somewhat NW.

Also the ECM was a shocking 4 degrees too far east within just 24hrs!!!

KWT, just to make sure that I understand, do you mean that Bill is 4 degrees further W than the ECM forecasted for this time? If so, which run ECM run? Thanks

[KWT]

Saturdays 0z ECM run, I saved an image of it then estimated its about 32W (though even if I'm slightly out by 1 degree, thats still 3 degrees!) then compared it to the best track thats just come out.

Derek has been saying for so long the models don't handle easterly surges at all well and the ECM certainly isn't doing too great.

The next checkpoint is tomorrow 0z at roughly 40W, which is already looking a bit of a long shot...

[Emmett_Brown]

Saturdays 0z ECM run, I saved an image of it then estimated its about 32W (though even if I'm slightly out by 1 degree, thats still 3 degrees!) then compared it to the best track thats just come out.

Derek has been saying for so long the models don't handle easterly surges at all well and the ECM certainly isn't doing too great.

The next checkpoint is tomorrow 0z at roughly 40W, which is already looking a bit of a long shot...

Ok, thanks KWT That kind of error certainly could be significant if it accumulated over several days, could mean the difference in hitting or missing a weakness. Amazing that the models can be this far off in such a short period of time. I remember the original forecasts for Ana for example, crossing 20N at 40W... that certainly didn't pan out!

[KWT]

Exactly Emmett thats why the Derek has been so dismissive of certain models. The best thus far in that respect has been the UKMO/GFS.

It almost certainly will have at least some impact. The way the ECM has it heading NW I'd assume is through the hole in the upper high left by the ULL as it pulls away to the NE. Firstly we know how tough they are to forecast. Secondly if its quite a bit quicker then progged then it'll be closer to the weakness, which is about 50W. A slow system won't get through quickly enough...think of it a bit like baseball in some respects for you Americans

By the way I've saved a couple of 12z ECM runs as well...the 12z ECM is ever so slightly quicker but not by much really...the benchmark is 38W for the 0z ECM and 39W for the 12z run by 0z Monday.

[Bocadude85]

Exactly Emmett thats why the Derek has been so dismissive of certain models. The best thus far in that respect has been the UKMO/GFS.

It almost certainly will have at least some impact. The way the ECM has it heading NW I'd assume is through the hole in the upper high left by the ULL as it pulls away to the NE. Firstly we know how tough they are to forecast. Secondly if its quite a bit quicker then progged then it'll be closer to the weakness, which is about 50W. A slow system won't get through quickly enough...think of it a bit like baseball in some respects for you Americans

By the way I've saved a couple of 12z ECM runs as well...the 12z ECM is ever so slightly quicker but not by much really...the benchmark is 38W for the 0z ECM and 39W for the 12z run by 0z Monday.

I wonder if we could see Bill move NW towards the weakness and then turn back towards the west as the high builds in? Perhaps similar to Andrew?