Major Hurricane Helene

[Hotair]

Tide around Tampa beginning to show effects of storm 

 

[WxWatcher007]

One more. Tail Doppler is extremely helpful.

 

[40/70 Benchmark]

1 minute ago, SnoSki14 said:

It's ramping up now. Large CDO structure developing and wrapping around 

Right......the implication is that we aren't behind schedule much.....if it reamined stagnant today, then its time to adjust. The envt. never looked optimal yeseterday and last night.

[CoastalWx]

That water will get high in Tampa with this a little further east. As soon as the wind goes from SE-SW-WSW..it will pile in. 

[RamblinRed]

Happy to see the overnight developments. Sort of gone from potentially horrible to just very bad.

TLH and ATL being on the west side of the storms a big deal. 

It's current track through GA takes through alot more of the least populated areas.

Still planning to sleep in the basement Thursday night given all the trees around us.

Doesn't look like it is going to blow up to quite as huge as monster as was being modeled last night.

[CoastalWx]

The doppler velocity image is telling. Those areas well east of center will get whacked real good.

[jm1220]

2 minutes ago, RamblinRed said:

Happy to see the overnight developments. Sort of gone from potentially horrible to just very bad.

TLH and ATL being on the west side of the storms a big deal. 

It's current track through GA takes through alot more of the least populated areas.

Still planning to sleep in the basement Thursday night given all the trees around us.

Doesn't look like it is going to blow up to quite as huge as monster as was being modeled last night.

It’s good that it seems to be targeting the least populated area it can but hopefully it stays far enough away from Tampa to not make that situation worse. The flooding impacts inland though are baked in no matter what it does at this point. 

[WxWatcher007]

9 minutes ago, 40/70 Benchmark said:

Right......the implication is that we aren't behind schedule much.....if it reamined stagnant today, then its time to adjust. The envt. never looked optimal yeseterday and last night.

 

7 minutes ago, CoastalWx said:

The doppler velocity image is telling. Those areas well east of center will get whacked real good.

One of the main differences from a few days ago is that the hurricane intensity models really peak this as it’s making landfall. That has its own implications if correct with regard to mixing winds down, but those models really crank the east side while only making the wind field more symmetrical this afternoon and evening. 
 

HWRF as an example, even if a bit overdone, I’m looking at structure here. 

 

[CoastalWx]

3 minutes ago, WxWatcher007 said:

 

One of the main differences from a few days ago is that the hurricane intensity models really peak this as it’s making landfall. That has its own implications if correct with regard to mixing winds down, but those models really crank the east side while only making the wind field more symmetrical this afternoon and evening. 
 

HWRF as an example, even if a bit overdone, I’m looking at structure here. 

 

It's also why I am more concerned with interior SC and NC. This is going to be a good hit there wind wise. CLT may gust higher than ATL to be honest.

[Hotair]

Graphic from NYT showing probabilities of damaging winds for different regions.  Concerned this will downplay dangers as you often have damaging tornado events well outside the forecast track 

[purduewx80]

All the gravity waves radiating out on first vis are indicative of intensification picking up now too. 

[purduewx80]

One of the main reasons ATL should be calmer is due to the cold air damming and stabilization at the surface. Need that southerly component to maximize gust potential. That matters less in the expose ridges farther north. 

[SomeguyfromTakomaPark]

Looking at the visible GOES it looks like it's starting to get that look, wouldn't be surprised to see RI shortly. 

[CoastalWx]

It needs to wrap deep convection further around the center, but yeah eye is starting to clear out a bit. 

[40/70 Benchmark]

9 hours ago, 40/70 Benchmark said:

I don't think the timing of the cycle of internal processes bodes well for FL....they need to pray this never quite gets its act together. I said when it interacted with Yucatan that any chance of a prelandfall EWRC was out the window.

Yes, that is some thing I have been noting...maybe not in terms of maxamizing surge, but otherwise the system will probably be more impactful than had it pulled a Katrina out over the loop current. Sure, there would be an internet-ogling-orgy from all of us weather dorks, but this is the more precarious scenario in terms of maxamizing the wind threat IMO.

11 minutes ago, WxWatcher007 said:

 

One of the main differences from a few days ago is that the hurricane intensity models really peak this as it’s making landfall. That has its own implications if correct with regard to mixing winds down, but those models really crank the east side while only making the wind field more symmetrical this afternoon and evening. 
 

HWRF as an example, even if a bit overdone, I’m looking at structure here. 

 

 

[olafminesaw]

4 minutes ago, purduewx80 said:

All the gravity waves radiating out on first vis are indicative of intensification picking up now too. 

Solar min doing it's work. I wonder if the storm will maintain some level of asymmetry through landfall. Large systems have a hard time mixing out dry air entirely sometimes. 

[Hotair]

Starting to cook now 

 

[Interstate]

Still a good bit of dry air on the west side though.

[OSUmetstud]

It's gradually strengthening but it's not going to really take off until it has a better inner core and a smaller rmw.

[WxWatcher007]

Speaking to the asymmetrical wind field. Seeing 114kt at that height is interesting. 
 

 

[beanskip]

So maybe not now, but at some point we're going to have to talk about these spaghetti models and their "corrected" tracks.

This is yesterday's 18z map -- just 30-36 hours from landfall.

Half of these solutions are outside of the 8 a.m. cone!

All except one are west of the current trackline.

Questions:

Why were the spaghetti plots so much farther west than the operational runs and even the ensembles?

Why did the NHC defer so strongly to the spaghetti maps?

What am I missing?

[OSUmetstud]

4 minutes ago, beanskip said:

So maybe not now, but at some point we're going to have to talk about these spaghetti models and their "corrected" tracks.

This is yesterday's 18z map -- just 30-36 hours from landfall.

Half of these solutions are outside of the 8 a.m. cone!

All except one are west of the current trackline.

Questions:

Why were the spaghetti plots so much farther west than the operational runs and even the ensembles?

Why did the NHC defer so strongly to the spaghetti maps?

What am I missing?

This was all explained yesterday. Hasn't the track only moved like 20 miles east? 

The nhc uses the corrected models because it's the best tools we have. What else do you want them to use? 

 

[beanskip]

8 minutes ago, OSUmetstud said:

This was all explained yesterday. Hasn't the track only moved like 20 miles east? 

The nhc uses the corrected models because it's the best tools we have. What else do you want them to use? 

 

I've been tracking storms for 30 years. The operational Euro has always ruled the roost, not these spaghetti plots.

When did that change?

Why are the spaghetti plots so out of line with all the operational runs?

You said before the tropical models were driving this, but they are also now on the far eastern edge of the cone and have trended east a lot more than 20 miles. 

The NHC track is surely going to keep moving east at 11 and when it does, ALL of the 18z spaghetti tracks will either be west of the center track and/or completely out of the cone.

The above points haven't been explained AT ALL. 

[CoastalWx]

1 minute ago, beanskip said:

I've been tracking storms for 30 years. The operational Euro has always ruled the roost, not these spaghetti plots.

When did that change?

Why are the spaghetti plots so out of line with all the operational runs?

You said before the tropical models were driving this, but they are also now on the far eastern edge of the cone and have trended east a lot more than 20 miles. 

The NHC track is surely going to keep moving east at 11 and when it does, ALL of the 18z spaghetti tracks will either be west of the center track and/or completely out of the cone.

The above point haven't been explained AT ALL. 

Those tropical models usually are closer to being correct. The globals like the gfs and euro (euro has been shit lately) are good..but I believe what Osumetstud posted, showed higher position errors vs the tropical models. 

 

However, when the globals and tropical models differ this close to landfall, usually one set sort of caves closer to the other. Indeed the early cycle 12z stuff ticked east again. Sometimes this stuff happens. That's why we as humans hopefully can add value and not let the machines take over.

[beanskip]

11 minutes ago, OSUmetstud said:

This was all explained yesterday. Hasn't the track only moved like 20 miles east? 

The nhc uses the corrected models because it's the best tools we have. What else do you want them to use? 

 

I mean, show me a storm where less than 24 hours from landfall, the most recent run of the operational Euro shows a landfall OUTSIDE THE NHC CONE!

Like, what is happening? 

[OSUmetstud]

5 minutes ago, beanskip said:

I've been tracking storms for 30 years. The operational Euro has always ruled the roost, not these spaghetti plots.

When did that change?

Why are the spaghetti plots so out of line with all the operational runs?

You said before the tropical models were driving this, but they are also now on the far eastern edge of the cone and have trended east a lot more than 20 miles. 

The NHC track is surely going to keep moving east at 11 and when it does, ALL of the 18z spaghetti tracks will either be west of the center track and/or completely out of the cone.

The above point haven't been explained AT ALL. 

The spaghetti plots there is just the operational models corrected for current position to get the best forecast possible. The euro gfs and the tropical models are all there getting the same adjustments. Its been done for years and it improves forecast error. 

These are yesterday's 5 day track and today's. It's barely moved. 

[SnowGoose69]

14 minutes ago, OSUmetstud said:

This was all explained yesterday. Hasn't the track only moved like 20 miles east? 

The nhc uses the corrected models because it's the best tools we have. What else do you want them to use? 

 

I think the current NHC track is 40 miles or so E of the 5pm yesterday   Its east of ATL by a nose

[beanskip]

Just now, SnowGoose69 said:

I think the current NHC track is 40 miles or so E of the 5pm yesterday   Its east of ATL by a nose

And it's going to keep moving east. 

[OSUmetstud]

1 minute ago, SnowGoose69 said:

I think the current NHC track is 40 miles or so E of the 5pm yesterday   Its east of ATL by a nose

I'm talking about the landfall location. It's barely moved

 

[bdgwx]

It was posted here a couple of years ago from someone with inside information that the NHC relies heavily on TVCN and IVCN for track and intensity forecasts respectively. For those that don't know these are the so called consensus ensemble suites. At least up through 2023 TVCN was comprised of GFS, ECMWF, UKMET, COAMPS, and HWRF while IVCN was comprised of SHIP, LGEM, COAMPS, HWRF, and HMON. I'm not sure if this has been updated for the 2024 season. Does anyone know if TVCN/IVCN have changed for the 2024 season?