ATL: CHANTAL - Post-Tropical

[AtlanticWind]

It gets pretty complex once Chantal gets north of the islands, it may get blocked at some point . Intensity is also a big question.

[Jevo]

0z GFS +162 850mb

[SapphireSea]

Building ridge brings into northern florida.

I had a feeling that steering would probably collapse. The trough does feel a bit sharp for July though, to the point where it cuts off a low center. I have my doubts, but all synoptics do point to something like N.FL and N threat. Makes me wonder what shear they see under the collapsing and rebuilding ridge though.

[meriland23]

It gets pretty complex once Chantal gets north of the islands, it may get blocked at some point . Intensity is also a big question.

All models agree it will just peter out whether a ridge builds or not. That it cause it will either crawl over DR or the Cuban mountains.. either way, causing it to diminish.

[Jevo]

0z GFS +171 Landfall Prediction.. N.FL/GA

[TexasF6]

My opinion says yes? Due to upper air dynamics & other factors unseen until Recon takes those crucial 1st analysis, especially with the new technology available. But I would defer technical aspects like this to AirForceMet & or Wxman57 or any promets with tropical Recon expert knowledge.

[Evil Jeremy]

It gets pretty complex once Chantal gets north of the islands, it may get blocked at some point . Intensity is also a big question.

All models agree it will just peter out whether a ridge builds or not. That it cause it will either crawl over DR or the Cuban mountains.. either way, causing it to diminish.

Not all models see death before the ridge may or may not build back in. NHC is speculating on possible dissipation (which is valid). However, many models suggest survival, including the 00z GFS.

[BigB0882]

If the ridge does build back in then timing is everything. It could end up in the Gulf if that ridge builds in a little earlier or if the storm moves a little more slowly.

[SapphireSea]

Recon helps really establish how well stacked a storm is, and knowing it's true depth will tell you what steering layer to use. 850mb for something like this 750mb for something bit stronger through 500mb. 500mb to 300mb for something really deep. Can make a big difference. Look at the strange W to SW hook BAMD has been throwing out, while not accurate, it does use different calculations for the appropriate steering layer which can very a bit.

GIV samples true higher resolution initial values using data out at sea with soundings from the mainland to feed into the GFS and other models. Usually if this was a RI storm we would probably have seen a GIV scheduled as soon as the storm could've been within advisory ranges for US mainland given its speed. A ridge may be weaker or stronger than what it is initialized with and can make a good difference.

[AtlanticWind]

We may still see some model variation due to her fast speed , 2 or 3 mph faster or slower forward speed could make a big difference on the model outputs.

[Jevo]

0z NAVGEM (Formerly NOGAPS) +24



0z NAVGEM (Formerly NOGAPS) +48

[Rgv20]

18zGFDL Ensemble Members surprisingly tightly clustered thru 90hrs..




Looks like Hispaniola kills Chantal off..

[Jevo]

0z NAVGEM (Formerly NOGAPS) +72

[SapphireSea]

It gets pretty complex once Chantal gets north of the islands, it may get blocked at some point . Intensity is also a big question.

All models agree it will just peter out whether a ridge builds or not. That it cause it will either crawl over DR or the Cuban mountains.. either way, causing it to diminish.

Not all models see death before the ridge may or may not build back in. NHC is speculating on possible dissipation (which is valid). However, many models suggest survival, including the 00z GFS.

I can see harsh shear near a trough or too powerful of a ridge. I would figure a collapsing and rebuilding deep layer ridge would setup a low shear environment, given that no other features show up near the storm. That may too much on the border of speculation though. The land interaction and when the steering layer collapses is going to have a big impact on where it goes and how strong, IMO.

[SouthDadeFish]

Looking better on this recent TRMM pass than earlier today:

[cycloneye]

Looking better on this recent TRMM pass than earlier today:

http://img5.imageshack.us/img5/3855/ptl7.jpg

http://img27.imageshack.us/img27/5092/3b56.jpg

Wow,much better yes.

[AtlanticWind]

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

Looking healthy on the floater.

[meriland23]

http://www.ssd.noaa.gov/PS/TROP/floaters/03L/flash-rb-long.html

Looking healthy on the floater.

Bit of a blow up towards the last few frames..

[Jevo]

From the Navy

[NDG]

IMO, chances that Chantel will be a fish after tracking through the Lesser Antilles are very small.
Both the GFS and ECMWF including their ensemble means show that after a trough digs down across the eastern US, the Bermuda ridge will claim it space once again. The models show the ridge move back west towards the eastern US push the trough westward towards the MS River valley, very similar to the sypnotic set up this past week.
At this point I would put Chantal making landfall anywhere between S FL and the Carolinas on some degree of a westerly track after the Bermuda ridge starts building westward, unless models change.
But I tell you what, both the GFS and ECMWF have being doing a fairly good job with their sypnotic forecasts in their medium to long range.

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