Major Hurricane Florence: STORM MODE THREAD

[mappy]

8 minutes ago, NJwx85 said:

Didn't realize that, however the point is still the same.

check next time that you are posting the right information. 

[navvet8992]

Wilmington to Savannah to Atlanta. Hmmm

[jbenedet]

8 minutes ago, 40/70 Benchmark said:

Likely means a weaker LF, so there's that.

Def. no more than a cat 3.

Possibly. But in my view that positive is reduced in every respect—including the wind— by the increased duration. 

[WhiteoutWX]

2 minutes ago, 40/70 Benchmark said:

Trend is going to being to be towards less impact should this trend continue....main threat being fresh water flooding.

Tell that to Wilmington... I think the Euro shows lots of possibilities still on the table. This would spare inland area for the most part but could be devastating for coastal locations with prolonged impacts from wind, surf, rain.

[bdgwx]

Yep. COAMPS does the same thing. It just makes the turn south further north after stalling longer. Either way the message is loud and clear. The steering flow is going to breakdown as Florence approaches the coast. Various models have been showing it off and on in a variety of different forms.

[40/70 Benchmark]

Just now, jbenedet said:

Possibly. But in my view that positive is reduced in every respect—including the wind— by the increased duration. 

Duration...sure, assuming it comes in quickly enough.

But I'm not sure how a case could be made against a reduced intensity at LF.

[40/70 Benchmark]

Just now, WhiteoutWX said:

Tell that to Wilmington... I think the Euro shows lots of possibilities still on the table. This would spare inland area for the most part but could be devastating for coastal locations with prolonged impacts from wind, surf, rain.

"Should this trend continue"-

[Stebo]

This is going to be dangerously to the coast if it doesn't come ashore, that is a much bigger disaster if the eye wall takes down the coast to Savannah.

[40/70 Benchmark]

2 minutes ago, Stebo said:

This is going to be dangerously to the coast if it doesn't come ashore, that is a much bigger disaster if the eye wall takes down the coast to Savannah.

Yea, if it slides down the coast, that it probably worst case for most.

[bdgwx]

This kind of goes without saying, but I'll say it anyway. Because the steering flow breaks down and Florence stalls/turns so close to the shore the consequences are magnified a lot. Sure, it injects an element of chance in determining landfall, but it also effects intensity at landfall, precipitation, etc. It would likely weaken under the stall scenario, but it'd also be over water longer so it would likely retain strong tropical characteristics longer as well. There's a lot of give and take with that scenario.

[OUGrad05]

11 minutes ago, 40/70 Benchmark said:

Trend is going to being to be towards less impact should this trend continue....main threat being fresh water flooding.

Wilmington basically gets Nuked as does the the NC coast for hours and hours....but yeah ok.

[GreensboroWx]

The Euro run is a worse case scenario for the SE coast of NC down through SC....the duration of the winds/rains would be catastrophic. 

[jbenedet]

6 minutes ago, 40/70 Benchmark said:

Duration...sure, assuming it comes in quickly enough.

But I'm not sure how a case could be made against a reduced intensity at LF.

Not making a case, simply underscoring the unknowns regarding the slowdown and stall—how quickly does he decelerate and where exactly does the stall occur? 

[Gravity Wave]

Could Florence's SW drift combined with the NE flow of the Gulf Stream mitigate the impacts of upwelling in this scenario?

[40/70 Benchmark]

1 minute ago, OUGrad05 said:

Wilmington basically gets Nuked as does the the NC coast for hours and hours....but yeah ok.

You have to read the entire post...I wasn't speaking on that exact solution, but was speculating as to implications of a continues trend towards faster stalling further from shore.

People read what they want to-

[MarkSC]

NHC has its work cut out for it at 5 PM.  Maybe a path from Wilmington to just onshore and then a slow drift SW through interior SC as a compromise between Euro and FV3?  Ensembles will be interesting.  

[40/70 Benchmark]

1 minute ago, jbenedet said:

Not making a case, simply underscoring the unknowns regarding the slowdown and stall—how quickly does he decelerate and where exactly does the stall occur? 

Yea, I Know....brings in alot of uncertainty...no doubt.

[KoalaBeer]

3 minutes ago, 40/70 Benchmark said:

Yea, if it slides down the coast, that it probably worst case for most.

Ya it's kind of crazy that a run like that could be almost worse case but if the stall trends even further offshore it could be an improvement. 

[Quincy]

It's really hard to put this into context since there hasn't been a storm that has evolved anywhere near what's expected with Florence. You can look at Emily in 1993, as that was a category 3 hurricane that slowly curved out to sea, but came close to an Outer Banks landfall. Flooding would be even worse this time around and over a more populated area, while rainfall amounts would be substantially greater. You can't really make the comparisons to Hugo and Isabel, since those storms tracked steadily northwest after making landfall. Storms like Floyd and Irene were relatively fast movers as well, so it's safe to say that the area hasn't really experienced anything like what's about to come, even in the "best case scenario" of a weakening storm staying just offshore.

Even without a direct landfall, most of the Outer Banks are going to be heavily inundated, if not completely underwater due to a prolonged easterly fetch and increasing size of the storm. A stall and/or a drift to the W/SW would cause major to catastrophic impacts to larger population centers, like Wilmington and Jacksonville, and quite possibly Myrtle Beach as well.

[ROOSTA]

5 minutes ago, 40/70 Benchmark said:

Duration...sure, assuming it comes in quickly enough.

But I'm not sure how a case could be made against a reduced intensity at LF.

Disagree Ray. Combine hvy rainfall with steady TS force with even a few gusts to hurricane force will still cause widespread power outages. Once one gets beyond D3 without power is becomes life-threatening. It's not going to be an Andrew (flatten countryside) at least not modeled presently so in that regard I agree.  QPF is going to be historic if the drift comes to pass.

[TriPol]

Has there ever been a storm that's stalled right before making landfall in the Carolinas?

[40/70 Benchmark]

Just now, KoalaBeer said:

Ya it's kind of crazy that a run like that could be almost worse case but if the stall trends even further offshore it could be an improvement. 

Yea, all I said.

Wasn't a forecast.

 

[40/70 Benchmark]

2 minutes ago, ROOSTA said:

Disagree Ray. Combine hvy rainfall with steady TS force with even a few gusts to hurricane force will still cause widespread power outages. Once one gets beyond D3 without power is becomes life-threatening. It's not going to be an Andrew (flatten countryside) at least not modeled presently so in that regard I agree.  QPF is going to be historic if the drift comes to pass.

You disagree that the stall would result in a weaker LF?

Possibly just as devastating, but weaker.

[csnavywx]

This is the nightmare scenario I was afraid of. That trend from 3 days ago never did stop and now with the midwest ridge helping out, we've got ourselves a coastal staller. An earlier stall isn't necessarily good either, because while there will be some extra time for wind shear to weaken it, I don't expect the shear to stay indefinitely and the Gulf Stream will abate some of the weakening associated with upwelling, especially if there actually is some slight southwest motion.

[Dunkman]

2 minutes ago, TriPol said:

Has there ever been a storm that's stalled right before making landfall in the Carolinas?

Yes, but I only ever remember it happening with tropical storms and a category 1 (I think it was Dennis maybe?) Even then it was devastating as water steadily backed up into rivers and sounds. It's hard to imagine what that looks like if it's a category 3-4 stalled off the coast.

[jacindc]

I'm usually all for mocking people who post about every wobble or "it looks like it's slowing down" or "it might be changing direction" but man, this is going to be excruciating to watch if it happens like this.

[MUWX]

When is recon headed back out?

[ag3]

Just remember the old version GFS has had a stall off OBX and then drift south for many days (before today's 12z run).

Several other models have shown this type of scenario one way or another as well.

This is the 1st time the Euro has shown it. Definitely could be a trend starting.

[mappy]

1 minute ago, ag3 said:

Just remember the old version GFS has had a stall off OBX and then drift south for many days (before today's 12z run).

Several other models have shown this type of scenario one way or another as well.

This is the 1st time the Euro has shown it. Definitely could be a trend starting.

one run outcome is not a trend, nor can one say its a the start of a trend. 

[ROOSTA]

2 minutes ago, 40/70 Benchmark said:

You disagree that the stall would result in a weaker LF?

Possibly just as devastating, but weaker.

Intensity you know is the last feature, parameter to be forecast correctly.  Gulf stream waters around 90F are pretty deep and close to the coast. It's an unknown so leave at that.