Hurricane Florence Catch all Thread

[Santa Claus]

Southwesterly shear definitely starting to make its presence felt.  If the storms entrains any of that dry air it might have significant effects.  The mid and low levels show some erosion of the CDO.

[LongBeachSurfFreak]

Allot of model hugging just like during the winter.

the gfs is way over doing intensity once it gets close into the coast. We saw exactly that with Irene and allot of people got burned with the doomsday predictions. The same thing happened with Gloria In 85. It takes a near perfect evolution to get anything more then a low end cat 1 into our region. (See hurricane of 38) Sandy had the aide of baroclynicity, which wouldn’t be much of a factor here with a more pure tropical storm. Anything that gets close to the coast north of the Gulf Stream mixes up cold shelf waters rapidly. So any talk about our waters being above normal is pretty mute. You really need to see a storm get sling shot in and through (again see 38)

Right now I want to focus on what’s going on with the WAR. There is still a good chance this thing finds a weakness and escapes. The one good thing for those wanting mayhem is the tendency for the strength of the WAR to be stronger then modeled in the long term.

 

[NJwx85]

 

[MJO812]

NHC has acknowledged that the storm will likely miss the trough in their 11 PM discussion

[Rtd208]

 

[jrodd321]

00z Euro into NC. 

 

 

[CIK62]

GFS seems to be pushing 30 foot seas into the NY Bight next Thurs. AM.    Would this mean another Sandy setup?     High tide is at 11:17AM that day.

[Sportybx]

1 hour ago, CIK62 said:

GFS seems to be pushing 30 foot seas into the NY Bight next Thurs. AM.    Would this mean another Sandy setup?     High tide is at 11:17AM that day.

Wasn’t sandy 12 feet above normal ? 

[NJwx85]

We'll get a few days of some big waves regardless of the exact track of Florence, but I think it's in poor taste and border line irresponsible to compare this system to Sandy right now.

As has been discussed in noisome, Sandy was undergoing rapid extratropical transition on approach. Because of the transition, Sandy wasn't as susceptible to decreasing sea surface temperatures and shear as it would have been if the system had remained purely warm core. The transition also caused the wind field to expand dramatically. None of this appears to be on the table with Florence, therefore the system should be steadily weakening on closest approach.

That's not to say that we cannot get whacked by one hell of a storm. I just believe that the Sandy comparisons are over the top. 

[LibertyBell]

If you want a comparison to a storm coming from the east, this reminds me of Felix in 1995.  That season we had a lot of storms recurve around 70W but Felix caused a lot of mayhem for forecasters.  It was a Cat 4 135 mph hurricane at one point but weakened as it got closer to the NC shoreline from the east and the closest it got was around 200 miles from Cape Hatteras.  Some of the models had it coming up the coast to around Montauk as a strong TS or weak hurricane but that never happened, it stalled out under the really strong WAR of August 1995 (which also gave us a rainless month until the final day and widespread wildfires throughout the area), did a little loop off Cape Hatteras and went back east and all it did for our region was cause a lot of riptides and very high surf.

[LongBeachSurfFreak]

40 minutes ago, NJwx85 said:

We'll get a few days of some big waves regardless of the exact track of Florence, but I think it's in poor taste and border line irresponsible to compare this system to Sandy right now.

As has been discussed in noisome, Sandy was undergoing rapid extratropical transition on approach. Because of the transition, Sandy wasn't as susceptible to decreasing sea surface temperatures and shear as it would have been if the system had remained purely warm core. The transition also caused the wind field to expand dramatically. None of this appears to be on the table with Florence, therefore the system should be steadily weakening on closest approach.

That's not to say that we cannot get whacked by one hell of a storm. I just believe that the Sandy comparisons are over the top. 

I don’t know why anyone would compare this scenario to Sandy. Apples and oranges. 

NHC is really struggling with the intensity forecasts. I doubt Florence is much more then a cat 1 right now and on it’s way down to a trop storm. This really goes to show how much we still have to learn collectively. Smaller storms are really subject to intensity swings. Once Florence gets into that area with some good OHC if shear drops it could easily bounce back to a major. 

One thing these weakening periods do tend to do is increase the size of the storm after restrengthening resumes. That’s where you start increasing the danger for the east coast. A larger storm with a bigger wind field is much better at imparting it’s energy into the ocean through a larger fetch. So if Florence ends up being a very large storm down the road it would obviously have much greater coastal impacts. 

[LibertyBell]

5 minutes ago, LongBeachSurfFreak said:

I don’t know why anyone would compare this scenario to Sandy. Apples and oranges. 

NHC is really struggling with the intensity forecasts. I doubt Florence is much more then a cat 1 right now and on it’s way down to a trop storm. This really goes to show how much we still have to learn collectively. Smaller storms are really subject to intensity swings. Once Florence gets into that area with some good OHC if shear drops it could easily bounce back to a major. 

One thing these weakening periods do tend to do is increase the size of the storm after restrengthening resumes. That’s where you start increasing the danger for the east coast. A larger storm with a bigger wind field is much better at imparting it’s energy into the ocean through a larger fetch. So if Florence ends up being a very large storm down the road it would obviously have much greater coastal impacts. 

What do you think of my Felix 1995 comparison?  Just based on the approach from the east, not the final outcome for our area of course.

[LongBeachSurfFreak]

15 minutes ago, LibertyBell said:

What do you think of my Felix 1995 comparison?  Just based on the approach from the east, not the final outcome for our area of course.

It’s good for surf impacts as that storm closed beaches for more then a week. That’s the one thing that’s a certainty. 

[NJwx85]

28 minutes ago, LongBeachSurfFreak said:

I don’t know why anyone would compare this scenario to Sandy. Apples and oranges. 

NHC is really struggling with the intensity forecasts. I doubt Florence is much more then a cat 1 right now and on it’s way down to a trop storm. This really goes to show how much we still have to learn collectively. Smaller storms are really subject to intensity swings. Once Florence gets into that area with some good OHC if shear drops it could easily bounce back to a major. 

One thing these weakening periods do tend to do is increase the size of the storm after restrengthening resumes. That’s where you start increasing the danger for the east coast. A larger storm with a bigger wind field is much better at imparting it’s energy into the ocean through a larger fetch. So if Florence ends up being a very large storm down the road it would obviously have much greater coastal impacts. 

I agree that Florence isn't looking her best right now, but this is probably the most hostile environment it's going to face, and things start improving as early as late tonight. Shear will be decreasing and SST will be increasing. I'm sure that once the system reaches the more favorable conditions we will see gradual improvements and beyond 60 hours conditions look nearly ideal for intensification. 

The short term weakening obviously increases the odds that Florence is going to miss the weakness in the ridge in about 96 hours, and then after that it would just come down to how close it can get to the coast.

[Monmouth_County_Jacpot]

Well that was an interesting 12z GFS run

[Gravity Wave]

Yikes.

[Gravity Wave]

Right now it's GGEM, Euro, and UKIE vs GFS, although the Euro brings an organized Florence up north after NC landfall while the GGEM has it stalling and dying out down there.

[Stormlover74]

21 minutes ago, Gravity Wave said:

Yikes.

And basically takes 48 hours to go from Delaware to cape cod

[NJwx85]

That's not something you see everyday lol

[Sportybx]

1 hour ago, Gravity Wave said:

Yikes.

Yeah that don’t look so good ....

[SnoSki14]

The Upper Level environment must be superb on the gfs, it's really slow to weaken. 

[Santa Claus]

It'll depend on the strength of the ridge and any kickers that might come along but all else being equal I think there's a fairly significant model bias to slowing storms down too much as they get caught in the westerlies.  Seems like extratropical and tropical systems tend to clear a good deal faster than they get modelled.  How many times on this board do you hear that such-and-such model shows snow starting on Friday night and it's still snowing at hour 72, and then that doesn't happen, lol.

[Santa Claus]

5 minutes ago, SnoSki14 said:

The Upper Level environment must be superb on the gfs, it's really slow to weaken. 

Don't forget, the GFS had major issues last year with predicting storm strengths.  Really abysmal.

Also I'm guessing part of the reason it's slow to weaken is baroclinic enhancement trading off against increasing shear and decreasing SSTs.

[MJO812]

Just now, bluewave said:

4th run in a row for the Euro with a Florence landfall and slowdown near NC to the Delmarva. The WAR is so strong that Florence gets cut off from the westerlies.

 

It shifted slightly north

[NJwx85]

43 minutes ago, SnoSki14 said:

The Upper Level environment must be superb on the gfs, it's really slow to weaken. 

Virtually no wind shear until near the BM and even that is modest. Biggest weakening factor appears to be upwelling which would be a slow death given time of year and track near the gulf stream.

[Gravity Wave]

19 minutes ago, NJwx85 said:

Virtually no wind shear until near the BM and even that is modest. Biggest weakening factor appears to be upwelling which would be a slow death given time of year and track near the gulf stream.

Yeah, i think people are being a little cavalier in saying it won't be more than a 1 by the time it gets up to the Delmarva (assuming no significant land interaction over NC, of course).

 

E: Another issue if it really hugs the coast and stalls is that upwelling impacts could be mitigated by the relative shallowness of the continental shelf.

[MJO812]

Eps?

[purduewx80]

3 minutes ago, Snow88 said:

Eps?

maue is posting them on his twitter. click his link to see live updates.

 

[snow1]

The good thing is this storm looks to stay south of us And go OTS after

[MJO812]

19 minutes ago, snow1 said:

The good thing is this storm looks to stay south of us And go OTS after

Uh?