Major Hurricane Florence: STORM MODE THREAD

[NJwx85]

Just now, DCTeacherman said:

https://weather.cod.edu/satrad/exper/?parms=meso-meso1-14-48-0-100-1&checked=map&colorbar=undefined

It looks remarkably symmetrical here.

Yeah looks like that loop I posted is low quality and should probably be taken down.

[friedmators]

Microwave has multiple EWesque features.

[CoastalWx]

It's an old timer kind of rule, but the stretched out ESE-WNW look sort of shows you where the corridor for that thing to go is in the mean time. 

[CTWeatherFreak]

Maybe someone can clarify this for me.  Ive always read/heard of two explanations of Storm Surge.. One is that it is the phenomena where exceedingly low pressure in the eye 'sucks' up the water like straw and carries it inland.. The other is that the winds piling up the water on the north/east  side of the storm (depending on trajectory) deposit it inland.  Which one is correct?

 

[Derecho!]

2 minutes ago, CTWeatherFreak said:

Maybe someone can clarify this for me.  Ive always read/heard of two explanations of Storm Surge.. One is that it is the phenomena where exceedingly low pressure in the eye 'sucks' up the water like straw and carries it inland.. The other is that the winds piling up the water on the north/east  side of the storm deposit it inland.  Which one is correct?

 

It's overwhelmingly wind pile up; in an extremely strong hurricane the low pressure is perhaps a foot. 

https://www.nhc.noaa.gov/surge/surge_intro.pdf

 

[Baroclinic Zone]

12 minutes ago, Snow88 said:

The saving grace will be if the storm stalls just offshore and weakens as it moves southwest.

Saving grace from what?  What a stupid comment.

[Kelathos]

2 minutes ago, Baroclinic Zone said:

Saving grace from what?  What a stupid comment.

Would a stall by the coast mitigate some of the inland flooding potential? Heaviest rains might not make it far enough up river. Prior model runs were catastrophic in that regard.

[Baroclinic Zone]

Just now, Kelathos said:

Would a stall by the coast mitigate some of the inland flooding potential? Heaviest rains might not make it far enough up river. Prior model runs were catastrophic in that regard.

Define inland?  A stalled/meandering TC is going to be pumping moisture over broader area where a storm that is progressive won't have the same impact.  This storm looks like a Harvey redux. 

[f2tornado]

26 minutes ago, Snow88 said:

The saving grace will be if the storm stalls just offshore and weakens as it moves southwest.

Negative, aside from sparing locations further inland more wind/flood damage. The stall will allow for persistent surge through multiple tide cycles combined with feet of rain with nowhere to escape. The potential exists for a large swath of coast to be more or less obliterated. This is what Hazel 1954 did: "All traces of civilization on the immediate waterfront between the state line and Cape Fear were practically annihilated... every pier in a distance of 170 miles of coastline was demolished". 

[audioguy3107]

Satellite presentation looks the best that Florence has looked in a couple of days,  Convection is very symmetrical and the eye is not ragged in the least.  I wouldn’t be surprised if recon found pressures in the upper 930’s at some point today.

[40/70 Benchmark]

22 minutes ago, Baroclinic Zone said:

Saving grace from what?  What a stupid comment.

The wind would be less severe, but more cane force over a larger area and the flooding just as bad.

[NJwx85]

This is the 06z HWRF, it shows about 18 hours of sustained hurricane force winds pounding the NC coast. The wind field is humungous and the storm surge will be severe in some areas.

[OSUmetstud]

Storm is very NE quad heavy. Flight level winds are barely hitting 100kts in the other quads. Not true surprising with solid forward motion currently. Looks pretty steady-state despite the improved appearance form last night. 

[hawkeye_wx]

Second recon pass found the pressure back up a few mb to about 947 mb.

[NJwx85]

2 minutes ago, hawkeye_wx said:

Second recon pass found the pressure back up a few mb to about 947 mb.

They probably just missed the center

[stormtracker]

1 hour ago, Snow88 said:

The saving grace will be if the storm stalls just offshore and weakens as it moves southwest.

This is a serious post?

[OSUmetstud]

Just now, NJwx85 said:

They probably just missed the center

It was a 948mb dropsonde. The winds were around 10 kt. 

[SACRUS]

Fuel for Florence is most favorable prior to the coast

 

[Baroclinic Zone]

10 minutes ago, 40/70 Benchmark said:

The wind would be less severe, but more cane force over a larger area and the flooding just as bad.

Winds generating the majority of the damage diminished over the last 48hrs when this stall/meandering solution became predominant.  It's shifted to a catastrophic surge/flooding storm.  And by no means should the winds be ignored.  A Cat 3 storm will cause severe damage.  Places in NC/SC will see 12-24"+ of rain with no where for that to drain for a several days.  Not good.

[olafminesaw]

There's no dry air to speak of that may be ingested on landfall, which is rather remarkable.

[mappy]

8 minutes ago, NJwx85 said:

They probably just missed the center

nope

[NJwx85]

1 minute ago, Baroclinic Zone said:

Winds generating the majority of the damage diminished over the last 48hrs when this stall/meandering solution became predominant.  It's shifted to a catastrophic surge/flooding storm.  And by no means should the winds be ignored.  A Cat 3 storm will cause severe damage.  Places in NC/SC will see 12-24"+ of rain with no where for that to drain for a several days.  Not good.

I think the duration of the onshore wind is also something that shouldn't be ignored or downplayed. A slow moving cane with a large wind field is going to push a lot of water towards the coast.

[JasonOH]

A larger wind field will also contribute to more upslope flow overall.  This extra lift will increase the flood threat inland.

[NJwx85]

Just now, olafminesaw said:

There's no dry air to speak of that may be ingested on landfall, which is rather remarkable.

Spoke of this yesterday. Typically when storms approach the Carolinas we have a trough digging southeast helping to wrap dry air in from the South. In this rare scenario we have no trough and thus very little dry air intrusion. The trajectory allows the flow into the system to remain out of the Caribbean. 

[Baroclinic Zone]

Just now, NJwx85 said:

I think the duration of the onshore wind is also something that shouldn't be ignored or downplayed. A slow moving cane with a large wind field is going to push a lot of water towards the coast.

Correct.  I tried to preface my post the best I could.

[NJwx85]

4 minutes ago, mappy said:

nope

Yes, someone else already posted this.

It looked to me like they had missed the center based on this graphic, but I realize it's not completely accurate. 

[WeatherfreakVA]

Well, Im in Central VA. Over the past 48 hours, my rainfall estimates went from 15 inches to 2 inches. People in my area wiped out the local walmarts and supply stores. Local media was saying brace yourself. Now it approaches and does a loop around my location staying atleast 250miles from my location during the duration. Most I can forsee is some gusty showers, and maybe an isolated tornado threat, and even then, we may be too far from the center to get upper support. But one small thing Id like to add. Anyone in the path of Florence needs to go now. With a stall over or just off the coast, won't really matter much.  The strength of Florence is not something the Carolinas have had to deal with and may make Hugo of 89 look like childs play. The upwelling that Florence will produce will weaken the storm regardless. So once stalled it will begin to loose strength over land or not. However, if it stalls and sits, I can foresee this system going hybrid which coukd drastically affect its size and possibly its eventual path. Now from that point, as the models begin its westward push into the Carolinas, Im seeing the potential that the western ridge being over modeled as the EURO, GFS, CMC, was initially doing with the atlantic ridge. Looking at larger picture, I can absolutely see how the models may trend more northward instead of northwestward toward Tennessee. Possibly bringing the system over the apps and eventually across PA and out, instead of Atlanta or Ohio. Yes the ridge will be buckling on both sides of Florence. But Im not sold on the huge loop around VA idea. Even with a 5 day post landfall hurricane, Ive witnessed some of the worst flooding in my life. With Florence being as large as she is, my area already being saturated couldnt handle another drop, especially from the remnants of a tropical system.  My overall feeling is the storm will stall and hook SW, West, and eventually North. The differnce of 150 miles closer to VA would be the difference between nothing and something major. Everyone has thrown in the towel on the possible impacts to my area. But the closest approach to my area is 5 days out still. As history has taught me with hurricane forecasting, if you believe the 5 day models are correct, then you will probably have sunny weather. I also believe the tornado threat may be abnormally elevated with Florence based on opposing flow surrounding the storm as its stalled. This will be my last post unless we have a flip flop in models. Ive only made a few posts as when I joined 2 days ago, we were well into the systems impact zone. You guys are awesome here and I will continue to use this platform in the future. May the lord be with the many who are being stubborn and riding out the storm. Im afraid if it stalls just off the coast, a 100 mile stretch of the coast may have around 72 hours of hurricane force conditions. History will be made and we will have to redraw the coast. 

[mappy]

Just now, NJwx85 said:

Yes, someone else already posted this.

It looked to me like they had missed the center based on this graphic.

 

recon flights will always have dropsondes into the eyewall and the eye, it is best to look for those readings when making definitive statements about pressure/wind. they can be found further down on the tropical tidbits recon page for Florence. 

[OSUmetstud]

1 minute ago, mappy said:

recon flights will always have dropsondes into the eyewall and the eye, it is best to look for those readings when making definitive statements about pressure/wind. they can be found further down on the tropical tidbits recon page for Florence. 

There's always a bit of parallax error on the SAT overlays. 

[mappy]

1 minute ago, OSUmetstud said:

There's always a bit of parallax error on the SAT overlays. 

yes, this too. good catch.