Major Hurricane Helene

[Jtm12180]

37 minutes ago, jrips27 said:

The NHC intensity forecast now shows an intensity of 115 kt (Category 4) at
24 hours, which is mirrored by several of the regional hurricane
models and the SHIPS guidance.  It should be noted that additional
strengthening is possible beyond 24 hours before Helene makes
landfall Thursday evening.

And there's no way 130mph will be the ceiling IMO...NHC is so hesitant to forecast intensity even when all the proof is there that conditions are going to be ideal

[NeonPeon]

3 minutes ago, Jtm12180 said:

And there's no way 130mph will be the ceiling...NHC is so hesitant to forecast intensity when all the proof is there that conditions are going to be ideal

I don't know what you mean. Their prediction is on the upper envelope of the intensity guidance they have, and they reference that it could be higher. That's hardly hesitancy, it seems very reasonable.

Lastly, it's the spectators that care whether it hits this or that imaginary threshold. In terms of the impact this thing is being painted as the monster it is. A lot of the numbers are trivia. 

[LithiaWx]

26 minutes ago, NorthHillsWx said:

It’s probably been said on here but Atlanta to the upstate and Asheville need to prepare for extended outages and tree damage on top of historic flooding. This is going to be one those areas never forget, sadly. Seems pretty locked in at this point

I'm in my 40's and still remember Opal.  Smaller storm at different angle but that was memorable in Atlanta.

[TJW014]

3 minutes ago, Jtm12180 said:

And there's no way 130mph will be the ceiling IMO...NHC is so hesitant to forecast intensity even when all the proof is there that conditions are going to be ideal

Their intensity/position forecast is in 12 hour intervals. There's time in between the 24 hour fix/strength and when it makes landfall. That's why they note that further strengthening is possible up until landfall after 24 hours

[Allsnow]

 

[TPAwx]

27 minutes ago, Prospero said:

 

The Storm Surge prediction this time yesterday was almost all Greater than 9 feet above ground in our area so great news for Gulfport FL if this is more accurate. We are pretty used to 3 to 6 feet surges.

https://www.nhc.noaa.gov/refresh/graphics_at4+shtml/152934.shtml?inundation#contents

Guidance for TB remains at 5-8 feet.  

[SnowGoose69]

4 minutes ago, NeonPeon said:

I don't know what you mean. Their prediction is on the upper envelope of the intensity guidance they have, and they reference that it could be higher. That's hardly hesitancy, it seems very reasonable.

Lastly, it's the spectators that care whether it hits this or that imaginary threshold. In terms of the impact this thing is being painted as the monster it is. A lot of the numbers are trivia. 

I was surprised honestly they went that aggressive.  They rarely will go too nuts on intensity fcsts as its still hard to predict

[kvegas-wx]

Flying east over Pensacola now and then up the east side of the rain shield into Charlotte.  Pretty amazing, nothing but light chop.  I think the pilot said we were at 38k feet. 

Someone said earlier this will be Atlanta's Hugo.  Spot on.  Accelerating storm, intensifying storm will move far inland keeping ATL on the northeast quad.  Not much good news to be found with Helene.

[Hotair]

If Helene makes landfall as a Cat 4 as some anticipate it will be the 5th consecutive year we get a major cane striking the US 

[dwagner88]

10 minutes ago, Hotair said:

From an impact perspective would a more Easterly track away from Tally cause less storm surge issues for folks there?  As the wind field would be predominantly pushing out to sea?  

I don't think storm surge is a concern for Tallahassee. It's at like 200' ASL.

[OSUmetstud]

10 minutes ago, beanskip said:

Would love clarification on this -- I'm looking at 12z GFS/12z Euro/12z UK/12z ICon all showing landfall in Taylor County which is now outside or just on the eastern border of the cone. Are they all being discounted? 

I dont believe the icon is used whatsoever in the tropical model suite that nhc uses. And that 18z early cycle models shown here are being adjusted for current position which might pushing the tracks farther west than the raw 12z models. 

[CTWeatherFreak]

1 minute ago, Hotair said:

If Helene makes landfall as a Cat 4 as some anticipate it will be the 5th consecutive year we get a major cane striking the US 

It can landfall as a cat 3 and still satisfy that statement.

[beanskip]

1 minute ago, OSUmetstud said:

I dont believe the icon is used whatsoever in the tropical model suite that nhc uses. And that 18z early cycle models shown here are being adjusted for current position which might pushing the tracks farther west than the raw 12z models. 

Yeah, lol, almost didn't include ICON in my list, but it's a carbon copy of the other three. I guess I need to learn more about those spaghetti plots. They have all been consistently west of their operational brothers and sisters. 

[Hotair]

1 minute ago, dwagner88 said:

I don't think storm surge is a concern for Tallahassee. It's at like 200' ASL.

Wow I looked it up. 7 to 200 ft ASL. Learn something new everyday. Thought all of Florida was pretty much at sea level.  

[Hotair]

2 minutes ago, CTWeatherFreak said:

It can landfall as a cat 3 and still satisfy that statement.

True

[LithiaWx]

1 minute ago, beanskip said:

Yeah, lol, almost didn't include ICON in my list, but it's a carbon copy of the other three. I guess I need to learn more about those spaghetti plots. They have all been consistently west of their operational brothers and sisters. 

If you think about it models specifically designed for the tropics should be more accurate than globals.  Why have them if not?

[SnowGoose69]

1 minute ago, LithiaWx said:

If you think about it models specifically designed for the tropics should be more accurate than globals.  Why have them if not?

I've found storms where they are not though.  We've seen tropicals where NHC is using the Euro dead on and basically ignoring those hurricane models

[wncsnow]

4 minutes ago, SnowGoose69 said:

I've found storms where they are not though.  We've seen tropicals where NHC is using the Euro dead on and basically ignoring those hurricane models

That's usually their modus operandi 

[Normandy]

This is an absolutely generational hurricane heading towards Florida.  The surge from this will be outrageous, and the inland wind will be astonishing due to fast movement.  Incredible satellite presentation

 

[OSUmetstud]

2 minutes ago, wncsnow said:

That's usually their modus operandi 

It's not really. The tropical concensus type models which are typically the best blend in a good deal of euro and euro ensemble already and adjust for known biases 

[Hotair]

Tampa and neighboring areas have a real strong chance of breaking all-time storm surge records during this storm.  Forecasts are +/- 2 ft 

 

 

[wxeyeNH]

I'm just reading this thread as a non met, but here's my thought. Although everyone is honking at RI including the NHC I'm  surprised at how much dry air is still wrapping in this giant gyro. Ss of yet there is not a solid large CDO around the apparent center.  I will probably be wrong but maybe we will be lucky and only see a steady modest intensification instead of a 35 or 40mb drop over the next 24 hours.  

[Wannabehippie]

From Dr. Levi Cowan

 

 

 

[OSUmetstud]

These are last years atlantic homogeneous track errors at 12, 24, and 36 hours which might have some relevance. Best are nhc, tropical concensus, and ecmwf

 

[Hotair]

First I hear of this term “Prandtl number amplification”   Is this founded on solid science? If so, is it already baked In into the mainstream models ?  
 

 

[WxWatcher007]

Very impressive look. 

[NeffsvilleWx]

23 minutes ago, Hotair said:

Wow I looked it up. 7 to 200 ft ASL. Learn something new everyday. Thought all of Florida was pretty much at sea level.  

No, it'll be well over a century until the entire state is underwater due to climate change.

[beanskip]

9 minutes ago, OSUmetstud said:

These are last years atlantic homogeneous track errors at 12, 24, and 36 hours which might have some relevance. Best are nhc, tropical concensus, and ecmwf

 

Well, somebody in the top 3 is about to take a beating because the 12z Euro is so far east it's literally out of the NHC cone.

 

[OSUmetstud]

2 minutes ago, beanskip said:

Well, somebody in the top 3 is about to take a beating because the 12z Euro is so far east it's literally out of the NHC cone.

 

The 18z early cycle ecmwf was adjusted westward already. It's one of the blue models on the right edge of this map. That's the forecast that the error calculations would be using. 

 

[beanskip]

2 minutes ago, OSUmetstud said:

The 18z early cycle ecmwf was adjusted westward already. It's one of the blue models on the right edge of this map. That's the forecast that the error calculations would be using. 

 

Which brings me back to my now three-day old observation that the spaghetti models have almost always been well west of the original run. Which could be because the original runs have consistently been too far east. I know I sound argumentative -- not trying to be at all, just want to understand. I don't recall there being such consistent widepread adjustments between the operational runs and these early cycle runs. And esp. in one consistent direction. I guess we will find out!