ATL: Ex-DANIELLE - Models

[KWT]

Thats what could happen if this one decides to die enroute in the Atlantic Ivanhater like the 12z ECM suggests.

I don't see any real reason for that to happen unless the TUTT still plays a big part, it just seems to be an off run to me.

Well if a high is indeed there ...

[gatorcane]

12z Euro strengthening in the Bahamas with a high to the north..

gotta love the tropics

Nice, what a flip in Euro....is the GFS trending this way as well you wonder...especially after looking at the last run with ridging building in over the CONUS.

[Ivanhater]

228 hours could be headed for S. Florida

[KWT]

Yah but Gatorcane it weakens to a barely closed low on this run...which is a massive flip from every other model and also its on previous operational runs.

However its the Euro so lets not totally dismiss it for showing something different...its the nightmare set-up though, a bit like Andrew where it nearly dies in the Atlantic and by the time it strengthens the set-up aloft suddenly is more condusive to send it westwards.

[Ivanhater]

Notice the high

BIG change

[gatorcane]

Yah but Gatorcane it weakens to a barely closed low on this run...which is a massive flip from every other model and also its on previous operational runs.

However its the Euro so lets not totally dismiss it for showing something different...its the nightmare set-up though, a bit like Andrew where it nearly dies in the Atlantic and by the time it strengthens the set-up aloft suddenly is more condusive to send it westwards.

Euro at 240 hours...strong ridge to the north, headed west towards the Bahamas but weak, however, there would be plenty of time for it to strengthen if it were to head towards Florida:

http://www.ecmwf.int/products/forecasts ... 0082012!!/

[Ivanhater]

Restrengthening as it heads west under a high.

[KWT]

Euro at 240 hours...strong ridge to the north, headed west towards the Bahamas but weak, however, there would be plenty of time for it to strengthen if it were to head towards Florida:

http://www.ecmwf.int/products/forecasts ... 0082012!!/

Its quite interesting though note the ECM still only suggests at worse a moderate TS there...and the eCM now has the resolution to go well into the mid 900s if it wants to, the fact it only goes to say 1008mbs can be taken at face value nowdays.

Still its a pattern that needs watching...odds on a recurve will go down IF we get more model runs like that!

FWIW, GFS has been weakening the system steadily in the first 96hrs, maybe conditions aren't as condusive as expected!

[SouthFloridawx]

Restrengthening as it heads west under a high.

When did the Euro start backing off on development?

[wxman57]

The Euro usually doesn't forecast systems to be too strong, and it's not backing off on development by any means. It's not so good with intensity.

[cycloneye]

18z Tropical Models

Code: Select all

WHXX01 KWBC 201840
CHGHUR
TROPICAL CYCLONE GUIDANCE MESSAGE
NWS TPC/NATIONAL HURRICANE CENTER MIAMI FL
1840 UTC FRI AUG 20 2010
 
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
 
DISTURBANCE INVEST (AL952010) 20100820 1800 UTC
 
        ...00 HRS...   ...12 HRS...   ...24 HRS. ..   ...36 HRS...
        100820  1800   100821  0600   100821  1800   100822  0600
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    11.0N  27.0W   11.4N  28.3W   11.7N  29.8W   12.2N  31.4W
BAMD    11.0N  27.0W   11.4N  28.5W   11.9N  30.3W   12.4N  32.4W
BAMM    11.0N  27.0W   11.4N  28.4W   11.9N  30.0W   12.4N  31.8W
LBAR    11.0N  27.0W   11.4N  29.0W   12.4N  31.8W   13.3N  35.1W
SHIP        25KTS          30KTS          39KTS          51KTS
DSHP        25KTS          30KTS          39KTS          51KTS
 
        ...48 HRS...   ...72 HRS...   ...96 HRS. ..   ..120 HRS...
        100822  1800   100823  1800   100824  1800   100825  1800
 
         LAT    LON     LAT    LON     LAT    LON     LAT    LON
BAMS    13.1N  33.3W   15.8N  39.3W   18.7N  47.0W   20.6N  53.0W
BAMD    12.9N  34.8W   14.3N  39.7W   17.6N  44.8W   22.5N  49.4W
BAMM    13.1N  33.9W   15.3N  39.5W   18.1N  46.2W   20.9N  51.6W
LBAR    14.1N  38.6W   15.0N  45.9W   15.1N  51.0W   21.8N  52.0W
SHIP        65KTS          86KTS          91KTS          92KTS
DSHP        65KTS          86KTS          91KTS          92KTS
 
         ...INITIAL CONDITIONS...
LATCUR =  11.0N LONCUR =  27.0W DIRCUR = 270DEG SPDCUR =   8KT
LATM12 =  11.0N LONM12 =  25.3W DIRM12 = 270DEG SPDM12 =   6KT
LATM24 =  11.0N LONM24 =  24.1W
WNDCUR =   25KT RMAXWD =  100NM WNDM12 =   25KT
CENPRS = 1009MB OUTPRS = 1012MB OUTRAD =  200NM SDEPTH =   S
RD34NE =    0NM RD34SE =    0NM RD34SW =    0NM RD34NW =   0NM
 
$$


[dwsqos2]

The 0Z run was rather anemic through day 7 as well.

[SouthFloridawx]

Wx Warrior... this is the whole 30L & 31L mess.

[SouthFloridawx]

The Euro usually doesn't forecast systems to be too strong, and it's not backing off on development by any means. It's not so good with intensity.

Okay, I see it now... Thanks.

[KWT]

Yeah the ECM looks a good deal too weak IMO, the TUTT isn't strong on that run either so no real reason why it should stay weak like it does on 12z ECM...

BUT...there is some upper ridging...its not expansive or anything but its enough to need watching in case it trends more that way.

[ronjon]

Major pattern change in the works as ridging builds over the western Atlantic - that's why you can never be real sure on these long range tracks that are 6 to 10 days out even with model consistency. I'm certainly not going to say this storm is a threat to anyone yet, but its looking more and more uncertain that the system will re-curve harmlessly into the open Atlantic. The tropics are always surprising. KWT, as one who has tasted crow, the bones are hard on the teeth and feathers sometimes get stuck in your throat.

[KWT]

I'm looking forward to it with BBQ source if it comes to that!

Alas we do have to remember this is only one run from the ECM and we stil have probably 95% model agreement on a recurve all at the same longitude as the image cycloneye said.

However a little alarm bell has rung with the 12z ECM...not just because of the weakness of the system BUT the fact it does have a very slight upper high present near 60W...thats totally different to all other models!

Simply put, if this one becomes a hurricane east of 60W, it recurves...if it doesn't...then anything could happen!

[ronjon]

Here's the 12Z Euro at 240 hrs - it actually has 95L moving W-SW from days 8-10. GOM anyone?

[gatorcane]

I'm looking forward to it with BBQ source if it comes to that!

Alas we do have to remember this is only one run from the ECM and we stil have probably 95% model agreement on a recurve all at the same longitude as the image cycloneye said.

However a little alarm bell has rung with the 12z ECM...not just because of the weakness of the system BUT the fact it does have a very slight upper high present near 60W...thats totally different to all other models!

Simply put, if this one becomes a hurricane east of 60W, it recurves...if it doesn't...then anything could happen!

If I see a few runs of the ECMWF in a row like this one, alarm bells will really be sounding. ECMWF usually gets the upper-air pattern correct in the long-range more than other models in my opinion.

Based on the last couple of runs, the ECMWF is sniffing out a ridge building in the long-range off the Eastern CONUS.

[ronjon]

500 mb pattern at 240 hrs from the 12Z Euro. Strong Ridging - no sign of trofs.