Tropical Storm Helene,Analysis,Sat Pics,Models Thread #3

[MiamiensisWx]

The ULL developing off the Outer Banks may also additionally help to weaken the lingering mid-level western Atlantic ridging and further open up the slight mid-level weakness left by Gordon, additionally allowing the surface front behind Gordon and east-central U.S. mddle to upper-level trough and low in the Great Lakes/Illinois vicinity to further penetrate the mid-level ridging and weaken the existing ridging influence in the west-central Atlantic. This also could, along with the ULL off North Carolina, allow Helene to potentially slow or stall briefly beyond 48 to 56 hours in the vicinity just east of Bermuda (ala Erin of 2001, both in terms of track and a potential slowing/stalling of movement in a similar timeframe) before being ultimately recurved quicker by the ULT moving off the Eastern Seaboard.

The ULL influence developing off North Carolina, besides helping in opening up a slight addition weakness for Helene, could potentially begin to shear Helene at the middle levels in the 36 to 56 hours timeframe for a period.

[Thunder44]

I just seen the ECMWF, and still recurves out to sea and is much faster than last run.

[wxman57]

I just saw the ECMWF, and still recurves out to sea and is much faster than last run.

Yep, it's about a day ahead of the NHC track, recurving Helene around 58-59W.

[cycloneye]

This is a real consensus now from the global models.

[MiamiensisWx]

This is a real consensus now from the global models.

Sorry, but the image won't show up.

[cycloneye]

I see it posted CVW,but anyway here is the link.Go to frame 1.

http://euler.atmos.colostate.edu/~vigh/guidance/

[gatorcane]

I see it posted CVW,but anyway here is the link.Go to frame 2.

http://euler.atmos.colostate.edu/~vigh/guidance/

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[MiamiensisWx]

I see it posted CVW,but anyway here is the link.Go to frame 2.

http://euler.atmos.colostate.edu/~vigh/guidance/

I see it as well, but the dreaded red error X shows up. Thanks for linking it, though.

[Stratosphere747]

Frame 2 is for Gordon..

You need 1 for Helene.

[cycloneye]

http://euler.atmos.colostate.edu/~vigh/guidance/

At link go to Late-Cycle-Track Guidance at frame 1.

[wxman57]

Here's an 18Z model plot I just made, minus BAM, LBAR, XTRAP, and CLIMO models. Note that they have all shifted east. NHC track from 15Z is left of all guidance. Look for an eastward adjustment by NHC at 21Z, possibly 2 degrees longitude farther east, recurving between 58-59W. Also note that the NHC track is MUCH slower than the 18Z model guidance, by as much as 1 1/2 days, maybe more.

NHC generally has been following the CONU track. But look how far apart they are now!

[MiamiensisWx]

http://euler.atmos.colostate.edu/~vigh/guidance/

At link go to Late-Cycle-Track Guidance at frame 1.

Yep, I know, and the link works. I was referring to it posted as an image.

[MWatkins]

A dramatic shift north and east is assured...in fact the new 120H verify point could be as much as 600NM from the 12Z 120H verify position.

MW

[wxman57]

A dramatic shift north and east is assured...in fact the new 120H verify point could be as much as 600NM from the 12Z 120H verify position.

MW

Yep, the NHC's new 120hr position is 40N/50W, very near the last point on the CONU track. Big, big shift east and faster on this advisory.

[Lowpressure]

A dramatic shift north and east is assured...in fact the new 120H verify point could be as much as 600NM from the 12Z 120H verify position.

MW

Mike, why are the models doing so porely this year. They all had this right the first time, then some wanted to bend west (split camps). They seem to really be having a hard time with synoptic patterns. I am not suggesting they are all wrong, just that it seems they are really struggling this year moreso than usual. Is this year really that awkward?

[cycloneye]

Mike look at the 5 PM trrack.You are correct.

[Stratosphere747]

The models are just being scrutinized more this year, and too many folks are trying to decipher them the wrong way instead of being patient.

It's amazing how much better some of them become once the NOAA info is fully ingested.

[wxman57]

A dramatic shift north and east is assured...in fact the new 120H verify point could be as much as 600NM from the 12Z 120H verify position.

MW

Mike, why are the models doing so porely this year. They all had this right the first time, then some wanted to bend west (split camps). They seem to really be having a hard time with synoptic patterns. I am not suggesting they are all wrong, just that it seems they are really struggling this year moreso than usual. Is this year really that awkward?

I don't know if the models have had "holes" in them. The "split camps" you're seeing are due to the differences between dynamic and staticistical/climo models. You just cannot use the BAM models, LBAR, and Climo models north of about 15N. Weaker storms, too, are very difficult for the models to get a handle on. But the main dynamic models did VERY well with Florence, Gordon, and Helene so far.

[P.K.]

This would be a significant system if the model is anywhere near correct. It is of course a fair way out though.

[wxman57]

Here's a modification of my previous graphic to show the new NHC 21Z 120-hr position: