Tropical Storm Erika

[SN_Lover]

Also, for everyone trashing Florida for declaring a state of emergency, it was due to the expected threat of new and continued flooding, because in case you've been too fixated on Erika, Florida has been pretty wet the past few days... And more rain from a tropical system would definitely cause significant problems, especially if the NAM were to verify. 

Justification of QPF using the NAM LOL 

[jojo762]

Justification of QPF using the NAM LOL 

GFS isn't that different either. Feel like the NAM could easily verify in this situation. This will be still at the very least a tropical remnant, if not a tropical depression/storm.  Main difference between the GFS/NAM is track. Also, feel free to check out the WPC official QPF forecast if you don't believe it.

[ncforecaster89]

Also, for everyone trashing Florida for declaring a state of emergency, it was due to the expected threat of new and continued flooding, because in case you've been too fixated on Erika, Florida has been pretty wet the past few days... And more rain from a tropical system would definitely cause significant problems, especially if the NAM were to verify.

I can only speak for myself, and emphasize that the "state of emergency" was 100% warranted when it was declared. With the threat of a TC induced heavy flooding event (with or without the accompanying strong winds). I'd respectfully argue it would've been both irresponsible and negligent, not to do so, for it's a prerequisite to free up the resources necessary to adequately respond to a prospective significant event (in this case, the forecast was suggesting an intensifying hurricane impact to portions of the Florida peninsula).

[jojo762]

I can only speak for myself, and emphasize that the "state of emergency" was 100% warranted when it was declared. With the threat of a TC induced heavy flooding event (with or without the accompanying strong winds), I'd respectfully argue it would've been both irresponsible and negligent, not to do so, for it's a prerequisite to free up the resources necessary to adequately respond to a prospective significant event (in this case, the forecast was suggesting an intensifying hurricane impact to portions of the Florida peninsula).

Believe that the main issue with people was pure ignorance as to what a declaration actually does. It creates mobility, essentially, like you said.

[SN_Lover]

I can only speak for myself, and emphasize that the "state of emergency" was 100% warranted when it was declared. With the threat of a TC induced heavy flooding event (with or without the accompanying strong winds). I'd respectfully argue it would've been both irresponsible and negligent, not to do so, for it's a prerequisite to free up the resources necessary to adequately respond to a prospective significant event (in this case, the forecast was suggesting an intensifying hurricane impact to portions of the Florida peninsula).

If a state cant normally support themselves during a weak tropical storm or depression, then that state needs new leadership. Hurricane Katrina was state of emergency worthy, this weak system is not. 

[jojo762]

If a state cant normally support themselves during a weak tropical storm or depression, then that state needs new leadership. Hurricane Katrina was state of emergency worthy, this weak system is not. 

Guess every state in the United States needs new leadership when they declare a state of emergency. Except when it kills 1000+ and causes $108 Billion dollars in damage. Most states do not have the man power, resources, or money to handle these type of events, that is why they declare "state's of emergency's." I can see what you're saying though, relatively speaking, it seems pathetic that a hurricane-hardened state like florida can't handle a TD/TS by itself. Comes down to money and resources that they can't access w/o the declaration.

[PSUBlizzicane2007]

Justification of QPF using the NAM LOL 

 

GFS and Euro have both had solutions involving a stalling TC or TW over the Florida area.

 

...and stalling for 5+ days too.

[SN_Lover]

GFS and Euro have both had solutions involving a stalling TC or TW over the Florida area.

 

...and stalling for 5+ days too.

Yea, they did. not anymore though. 

[KeysCurteese]

Isn't it sad that I have to search for weather news on here rather than it being readily available via local news sources or The "Weather" Channel? Although, I'm grateful that I stumbled upon this forum for some actual scientific discussion related to hurricane season.

 

Also, I'd like to add that flooding is our major concern in the Keys right now. The concern wasn't about the potential of a Cat 1 or Tropical Storm, but simply the sheer amount of water that could be dumped on us. Also, it just so happens that August 30th/31st are our "king tide" days. The high tides already put my area under knee deep water at times. It's entertaining, but a bit ridiculous. I've observed a significant change just over the last few years. 

[USCAPEWEATHERAF]

I find that models do not take into account possible reformation of the low level center of a tropical storm or depression while going over the islands.  Given this, we should keep a watchful eye on Erika as she can still pull north of Cuba as low level circulation reformation can occur at any time.  Also the shear maps from PSU ewall suggests that shear will continue to drop over Cuba, FL straits and the Bahamas in the 24-60 hour window perhaps longer depending on how long her remnants stay over water and could possibly regenerate.  Given the amount of uncertainty its foolish not to pay attention to such a volatile situation.

[jojo762]

To someone who did not care about a system having a LLC, or looked at the models whatsoever, they might be pretty impressed by Erika right now given the amount of and strength of DMC. Most of it is likely orographically enhanced, but still impressive. Of course most of it is pretty well sheared, and there is next to no outflow to speak of, but i'm talking purely about DMC. Also... Looks to be moving west still/again.

[Minnesota Meso]

GFS and Euro have both had solutions involving a stalling TC or TW over the Florida area.

 

...and stalling for 5+ days too.

 

As a matter of fact the 28/12z Euro run drops 10-15" of rain along the western coast of Florida and 8-10 inland about 10 miles deep.  The State of Emergency was well warranted as the Gov can activate the National Guard now and deploy rapidly as needed. That kind of rainfall will cause massive flooding in low lying areas where concrete has replaced mothers natures way of dealing with large amounts of water.

[negative-nao]

We better hope this thing does not stall. or else there well be massive flooding

 

 

[ncforecaster89]

Up early and getting ready for work. At the current time, latest satellite presentation suggests a possible reformation of the LLCOC much farther to the N of the one I suspect no longer exists (used for continuity in the latest NHC advisory).

RECON is currently investigating the aforementioned "spin" on satellite to see if there is a definitive LLCOC in that location. Interestingly, they've already noted an uncontaminated SFMR reading of 37 kt. (Minimal TS-force) very nearby. This possible COC is situated just N of the NE coast of Cuba.

We'll just have to see what else they find...if anything.

[jbenedet]

Consistently too high with regards to intensity and this is the result....Open wave/TD as it was, and still is, and it's going west due to low level wind steering, which predominates. This is going to hit the south coast of Hisapaniola, and possibly graze northern Jamaica, before re-curving in the extreme Northwestern Caribbean.

If you're off with the forecast intensity, you are incorrect with the forecast track.

A persistence forecast takes it right between Jamaica and Cuba..

Bump. Persistence ftw.

[ncforecaster89]

ERIKA APPEARS TO BE DISSIPATING... ...HURRICANE HUNTER AIRCRAFT CURRENTLY INVESTIGATING THE SYSTEM...

SUMMARY OF 800 AM EDT...1200 UTC...INFORMATION...

LOCATION...21.0N 75.5W ABOUT 55 MI. ENE OF HOLGUIN CUBA

MAXIMUM SUSTAINED WINDS...40 MPH

PRESENT MOVEMENT...WNW OR 290 DEGREES AT 20 MPH

MINIMUM CENTRAL PRESSURE...1010 MB...29.82 INCHES

At 800 AM EDT (1200 UTC), the center of Tropical Storm Erika was

relocated near latitude 21.0 North and longitude 75.5 West.

EDIT: They note that Erika is likely degenerating into an open trough and advisories may be discontinued, very soon.

[turtlehurricane]

Agreed. Seems like a pretty reasonable description to me.

A normal person reading that CNN headline would think an unpredictable monster storm was heading towards Florida.

[turtlehurricane]

Also, for everyone trashing Florida for declaring a state of emergency, it was due to the expected threat of new and continued flooding, because in case you've been too fixated on Erika, Florida has been pretty wet the past few days... And more rain from a tropical system would definitely cause significant problems, especially if the NAM were to verify. 

Strongy disagree, even if that rain forecast verified it would be nothing out of the usual. State of emergency was declared for possible tropical storm conditions.

[turtlehurricane]

Up early and getting ready for work. At the current time, latest satellite presentation suggests a possible reformation of the LLCOC much farther to the N of the one I suspect no longer exists (used for continuity in the latest NHC advisory).

RECON is currently investigating the aforementioned "spin" on satellite to see if there is a definitive LLCOC in that location. Interestingly, they've already noted an uncontaminated SFMR reading of 37 kt. (Minimal TS-force) very nearby. This possible COC is situated just N of the NE coast of Cuba.

We'll just have to see what else they find...if anything.

Good call, the only thing resembling a circulation center is that swirl north of Cuba, and NHC put the official center there.

 

It's extremely unlikely it will strengthen into anything before reaching florida, its a tiny naked swirl. The tropical cyclone structure has been completely destroyed.

 

[Ground Scouring]

The Donald (Apprentice) to Erika: "You're fired!"

[MGorse]

Strongy disagree, even if that rain forecast verified it would be nothing out of the usual. State of emergency was declared for possible tropical storm conditions.

 

Which is interesting as the NHC never issued watches for Florida.

[audioguy3107]

Well, that's that.  Finally put of of her misery.

 

Special Message from NHC Issued 29 Aug 2015 12:54 UTC   

Erika has dissipated as a tropical cyclone. NHC will issue a Special Advisory shortly. Tropical storm watches/warnings being discontinued.

 

- Buck

[turtlehurricane]

Which is interesting as the NHC never issued watches for Florida.

The state of emergency was declared at the time watches would usually go up. Maybe it was a miscommunication, perhaps they had a previous conference with nhc but nhc changed their mind right before the advisory.

Literally any nhc watch or warning in Florida prompts a state of emergency.

I wonder how much insurance raised their rates on new applicants this week?

Sent from my iPhone

[MGorse]

The state of emergency was declared at the time watches would usually go up. Maybe it was a miscommunication, perhaps they had a previous conference with nhc but nhc changed their mind right before the advisory.

Literally any nhc watch or warning in Florida prompts a state of emergency.

I wonder how much insurance raised their rates on new applicants this week?

Sent from my iPhone

 

Not sure and I would not speculate, but again watches were never issued for Florida.

[sfenn1117]

The state of emergency was declared at the time watches would usually go up. Maybe it was a miscommunication, perhaps they had a previous conference with nhc but nhc changed their mind right before the advisory.

Literally any nhc watch or warning in Florida prompts a state of emergency.

I wonder how much insurance raised their rates on new applicants this week?

Sent from my iPhone

Insurance rates must be filed and approved by the state insurance commissioner months in advance. The one thing an insurance company can do is place a hold on new insurance applications until the storm is over.

I think the governor bought into the hype as opposed to reason, but at the same time, would be blasted if Erika strengthened and the state of emergency wasn't declared. I don't have a problem with it, but the media is begging for this to be a big deal and won't give it up.

[LovingGulfLows]

The Atlantic has been sucking the last few years when it comes to tropical development, meanwhile the Pacific has been on fire for years now.

[hazwoper]

The Atlantic has been sucking the last few years when it comes to tropical development, meanwhile the Pacific has been on fire for years now.

 

Property owners along thre Atlantic coast would say the Atlantic has been wonderful. 

[phil882]

I will be stocking up on supplies tomorrow if this current NHC scenario holds.

 

 

 

It did hold, which is why FL issued a state of emergency to allow for the flow of supplies and manpower in the event of a substantial storm. A decision that you are now bashing unnecessarily. 

 

 

The fact that none of the ECM and GFS ensembles have Erika doing much of anything is pretty telling...

 

 

But turtlehurricane said that these models were useless. I don't understand how they could be getting the intensity and track nearly correct when they don't have the sufficient resolution. Is this a fluke?

 

 

The GFS literally can't resolve a tropical cyclone. It is a classic mid-latitude forecaster mistake to use global models for tropical cyclone forecasting. They are useful for determining larger scale steering currents, but not for actually projecting a tropical cyclone.

 

The GFS and euro do better than other global models, since the other ones aren't even useful (CMC? JMA?). It's like picking out the best piece of garbage. I'm actually amused at the ignorance displayed by a few of you, I am saying nothing ground breaking here.

 

I mean look at this comparison. Does this look anything close to a tropical cyclone? If the GFS totally can't resolve a tropical cyclone, can it resolve other features approximately 1000 km in diameter with grid points every 12-13 km? That allows > 500 grid points for such a feature on a 2 dimensional plane... which I'd say is more than enough to "resolve" a feature. 

 

 

 

 

I already said the facts.... global models can barely resolve tropical cyclones, and there's not enough data to initialize with anyways. The equations aren't particularly optmal for tropical forecasting either, they are designed for mid-latitue weather. Higher resolution models with equations that are tuned for hurricanes are a much better option, although we still got a long way to go even with those.

 

This is all well known, at least for real tropical cyclone modelers and forecasters. I am just re-iterating what the experts already know.

 

The same general equations that govern the atmosphere in the mid-latitudes also govern the tropics. There aren't new equations we apply in the tropics only. The differences come in how you handle convection and microphysics and some parameterizations are better at handling these processes in the mid-latitudes versus the tropics. Those aren't real equations that actually govern the atmosphere, but rather empirical equations that represent our best guess in how those processes work. 

 

If you want a real discussion then present your arguments, so far your only argument is globals can forecast QPF without microphysics.... which is a terrible example since globals are very inaccurate for qpf due to lack of microphysics.

 

I simply repeated your insult back to you, I was calling the GFS garbage for tropical cyclone forecasting and you took it personally. If you don't like being insulted then maybe you shouldn't insult others.

 

I presented my brief arguments: "global models can barely resolve tropical cyclones, and there's not enough data to initialize with anyways. The equations aren't particularly optmal for tropical forecasting either, they are designed for mid-latitue weather. Higher resolution models with equations that are tuned for hurricanes are a much better option, although we still got a long way to go even with those." Prove that any of those statements are wrong instead of throwing red herrings. I could go deeper into it, there are dozens of things in global models that are detrimental to tropical cyclone forecasting, which is the reason hurricane models are being produced.

 

A major problem with the atmospheric science field is people that act like you massively slow down scientific progress by nitpicking ideas and derailing them, while presenting none of their own. There is almost zero progress in government laboratories and even UW-Madison since scientists from other institutions torpedo ideas, so it takes years to publish and then other people have already published it, which is quite inefficient since it wastes money to have many institutions working on the same thing.

 

There is almost always a confrontational stance between meteorologists, where if someone disagrees with something they take it personally and then it becomes a pride thing. And then scientists complain when all their funding gets cut.... that's what happens when you produce nothing and spend all your time ruining other people's projects.

 

This is mostly unrelated to you, this is not a serious scientific debate obviously. What I'm saying is the last thing we need is people demanding hard empirical evidence on a casual discussion board, when the subject being discussed is not fully understood.

 

AMS journals are already in ruins due to similar behavior, no reason to ruin AmericanWX too.

 

Sounds like you need some met-ed help: http://www.meted.ucar.edu/nwp/model_precipandclouds/print.htm#page_2.0.0(its free to log in and read)

 

Alternatively:

http://www.dtcenter.org/events/workshops15/moist_phys/presentations/08_Ferrier_moist_proc.pdf

 

GFS has a microphysics scheme, but it's pretty crude and doesn't explicitly represent many fundamental processes in order to increase computational time. However, without microphysics there would be no way to simulate clouds, and it would be impossible to simulate tropical cyclones which depends on the latent heat tendencies produced from tropospheric condensation.  

 

I've said multiple times in this thread that global models are very useful for determining large scale steering patterns, they are an essential tool no doubt. However the actual projection of a tropical cyclone in a global model is fairly dismal. I think the false alarm rate for RI is so high that the magnitude of the low in a global model projection shouldn't really be considered. Unfortunately the GFDL and HWRF have even worse false RI rates. 

 

The only time globals are quite useful is in the case of a large, mature hurricane. With something like Erika the results are abysmal.

 

So how do you rationalize that global models are useless for TC forecasting if the higher resolution TC dynamical guidance (GFDL and HWRF) have even worse false alarm rates. Are they all useless for TC. Are all models useless for TCs?

 

You mentioned before that global models can't resolve TCs. Than why would they be more useful in a mature TC if they can't be resolved. You are contradicting yourself. Are you saying all weak and small TCs can't be resolved. You have more of an argument there. But you certainly haven't been clear (to me at least) on what you are trying to describe. 

 

It's actually a testament to our lack of understanding that global models on average produce better track forecasts statistically. Zooming in on a hurricane's structure amplifies the number of unknowns the model has to deal with, more assumptions and estimates are made, and every single mistake versus reality can ruin the whole forecast. This is why when we zoom out to a crude representation of a hurricane in global models there are better results on average. We have been locked in a stalemate where more resolution and data degrades the forecast, because there are fundamental problems with our understanding of hurricane structure and the equations which drive it.

 

When it comes to Erika the only thing of real use of globals is the representation of large scale steering patterns, which is just about enough to make an accurate forecast when dealing with a weak TC, even if the projection in the model is inaccurate.

 

What's more useful: A projection that's more accurate for the wrong reasons, or a projection that's less accurate for the right reasons?

 

I actually agree with some of this... as models increase their degrees of freedom that the variables are allowed to be advected and modified (by increasing resolution), you will introduce more uncertainty and errors grow upscale as you run a simulation forward in time. Convection in tropical ocean basins is one of the leading sources of error growth that often leads to wildly different solutions to the synoptic flow pattern as you go beyond 5 days. More resolution does not equal a better solution if those additional grid point introduce additional errors. 

 

As for what equations drive hurricanes... they are the same ones that drive the remainder of our atmosphere. We introduce simplifications, and our initial conditions introduce errors that sometimes make it difficult or impossible to simulate these phenomena realistically. 

 

But all you need to simulate the atmosphere is:

 

-The Navier-Stokes equations which includes Newton's second law: real and apparent forces, and turbluence + mixing

-1st Law of thermodynamics

-Ideal gas law

-Continuity equation

-Clausius-Clapeyron equation

 

Now from these equations you can derive hundreds if not thousands of other equations that might explicitly describe the phenomena you want to look at (e.g., fronts, mid-latitude dynamics, tropical cyclones). However, the building blocks are all there. To say we don't know the right equations to run a model is silly. We do, its just these equations are complex and require simplification to run in a computational environment, introducing error that occurs even before you give the equations inaccurate base state conditions of the atmosphere. 

 

-------

 

And one last thing. Part of being a good scientist is being able to explain your thoughts clearly and coherently. Its why writing to journals is so hard, because you need to explain what you discovered in a way that your fellow scientists can understand as clearly as you do. Its why the peer review process exists. Just because somebody have a novel new idea does not necessarily mean that they are able to explain their new idea in a way that people would understand. Journals benefit from the peer review process because there is that screening process that allows other scientists in your field to see what you are working on and see if it makes sense to them. Without that, you don't have a scientific journal. You just have a message board like the one you see here, with people sharing whatever thoughts they deem appropriate. Perhaps there are a few useful comments here and there, but do you really think that is how scientific debate should be done?

[smokeybandit]

A state of emergency only means the state can put a framework in place to respond more quickly and efficiently to storm-related issues.  I don't see the big deal in Florida declaring for it when at the time forecasts shows Florida a direct hit.

[Mallow]

 

 

Beautiful post, phil. Thanks for taking the time.