Tropical Storm Helene,Analysis,Sat Pics,Models Thread #3

[fci]

Oh I suspect a few "un-named" members who consistently predict an EC or Fl landfall for most every storm; will pop up with their usual "it's going more west than expected" or " The 17 troughs may STILL miss her" or something like that!

You can also tell by the historic storm tracks that are mentioned, e.g. "Didn't Andrew/Katrina/Hugo etc......do this, too?"

Oh, that's a great one to add to the quote list!!!

[Derek Ortt]

it could be that helene was not a cat 3. Remember, the first recon this afternoon found 966 and the second one had a lower pressure.

The SFMR is usually fine when there is no land interferences and at these wind speeds. It could be that the Dvorak technique simply failed this time and Helene was weaker than the sat signature suggested

There have been big descrepencies the other way. Wilma had T numbers at 6.0, yet it was the most intense hurricane ever

[Jim Hughes]

There was also a considerable solar wind increase today above the 500 km/sec level. The solar wind speed is currently in the 630 km/sec range. Must I redundantly point out to everybody that ATL tropical systems become somewhat disorganized during these times. A pressure rise makes sense and this is not post analysis since I have written about this endless times.

Didn't the pressure fall since yesterday? I seem to remember a 970mb pressure on the 17th, and 964mb today. Helene looked stronger today than yesterday, and recon measured a lower pressure. Keep in mind we're comparing partial recon with satellite estimates to create a trend. Bad satellite wind estimates previously may have to be discarded. Helene could heave strengthened in the past 24 hours, meaning it was weaker than estimated earlier.

There was a 954 mb reading given in the 11am advisory today. Now I realize that some people could say that this system was not as strong as earlier indications and this would explain the pressure rise and the slightly slower winds.

Well where were these intensity questions before the 5pm discussion?

I have been continually pointing out this year (And last) that storms are always given the higher status on most occassions in regards to the data. When in doubt bump it up or keep it the same.

Now this all has a meaning because of all the GW/stronger storm talks.

Today's perception is what is important here and not the reanalysis later. The public only hears about these storms now. They will not care, nor even know, whether systems like Ernesto end up being downgraded.

There needs to be a better system in place in regards to forecasting strength by means of satellite data. One day it's Dvorak the next day it's something else.

There is only one consistent thing here. They always seem to choose the data that supports a stronger system. Even when it goes against recon.

[Pebbles]

Personally I would rather see storms over estimated then under estimated.

The only people I can think of that would be disappointed that a storm is not as strong as predicted are some (not all) us 'weather freaks'. 99.9 percent of the rest of the population would rather prepare for the worst and be relieved that it wasn't a less severe situation.

Specially as we as a society should realize there is still a long road ahead learning how to become better at hurricane forecasting. People seem to forgotten just how short a time we have been able to forecast such complex systems. There is so much MORE to learn.

Unfortunately you always get those that complain if they get effected by a less strong storm then predicted. Honestly I know it's a PITA to deal with these things but wish they would keep in mind to be RELIEVED that things were better then expected.

Sometimes I have to remember you just can't make everyone happy no matter how hard one tries.

[Jim Hughes]

Personally I would rather see storms over estimated then under estimated.

The only people I can think of that would be disappointed that a storm is not as strong as predicted are some (not all) us 'weather freaks'. 99.9 percent of the rest of the population would rather prepare for the worst and be relieved that it wasn't a less severe situation.

Specially as we as a society should realize there is still a long road ahead learning how to become better at hurricane forecasting. People seem to forgotten just how short a time we have been able to forecast such complex systems. There is so much MORE to learn.

Unfortunately you always get those that complain if they get effected by a less strong storm then predicted. Honestly I know it's a PITA to deal with these things but wish they would keep in mind to be RELIEVED that things were better then expected.

Sometimes I have to remember you just can't make everyone happy no matter how hard one tries.

I would agree with your point Pebbles in regards to what you are talking about . But you also have to consider everything as whole. Public perception are brougt into most matters. Especially when it pertains to global warming.

Some people within the scientifc community are trying to link global warming with the tropical intensity level rise (Some are questioning even if there has been a rise)

So this does have some relevance here even if some think that it is meaningless.

[cycloneye]

18/2345 UTC 24.0N 50.9W T5.5/5.5 HELENE -- Atlantic Ocean

The SSD dvorak sat estimates remain unchanged from this afternoon data.

[cycloneye]

HURRICANE HELENE (AL082006) ON 20060919 0000 UTC

...00 HRS... ...12 HRS... ...24 HRS... ...36 HRS...
060919 0000 060919 1200 060920 0000 060920 1200

LAT LON LAT LON LAT LON LAT LON
BAMD 24.1N 51.1W 24.6N 52.3W 25.0N 54.0W 26.1N 55.8W
BAMM 24.1N 51.1W 24.6N 52.6W 25.1N 54.4W 25.9N 56.3W
A98E 24.1N 51.1W 25.0N 52.6W 26.4N 54.0W 28.0N 55.3W
LBAR 24.1N 51.1W 24.9N 52.5W 25.6N 54.4W 26.3N 56.4W
SHIP 100KTS 99KTS 103KTS 102KTS
DSHP 100KTS 99KTS 103KTS 102KTS

...48 HRS... ...72 HRS... ...96 HRS... ..120 HRS...
060921 0000 060922 0000 060923 0000 060924 0000

LAT LON LAT LON LAT LON LAT LON
BAMD 27.6N 57.5W 31.8N 58.8W 35.2N 57.0W 36.6N 51.1W
BAMM 27.1N 58.1W 30.7N 59.0W 32.8N 56.6W 34.0N 50.3W
A98E 30.2N 56.7W 37.9N 55.8W 45.6N 43.7W 43.2N 24.3W
LBAR 27.7N 57.9W 32.6N 57.8W 39.8N 51.0W 43.3N 33.1W
SHIP 103KTS 97KTS 90KTS 74KTS
DSHP 103KTS 97KTS 90KTS 74KTS

...INITIAL CONDITIONS...
LATCUR = 24.1N LONCUR = 51.1W DIRCUR = 310DEG SPDCUR = 8KT
LATM12 = 22.9N LONM12 = 49.8W DIRM12 = 329DEG SPDM12 = 10KT
LATM24 = 21.3N LONM24 = 49.2W
WNDCUR = 100KT RMAXWD = 20NM WNDM12 = 110KT
CENPRS = 960MB OUTPRS = 1015MB OUTRAD = 200NM SDEPTH = D
RD34NE = 200NM RD34SE = 150NM RD34SW = 125NM RD34NW = 150NM

Unchanged intensity (100kts) from the 00:00z models.

[ronjon]

A dramatic shift north and east is assured...in fact the new 120H verify point could be as much as 600NM from the 12Z 120H verify position.MW

Mike, why are the models doing so porely this year. They all had this right the first time, then some wanted to bend west (split camps). They seem to really be having a hard time with synoptic patterns. I am not suggesting they are all wrong, just that it seems they are really struggling this year moreso than usual. Is this year really that awkward?

I think they're doing just fine. From very early on, we had some models predicting more or less the current consensus - the first two fronts miss and the 3rd gets her. Short-term the model have been close and accurate throughout. The disagreement has been over the intensity and location of fronts generally 5 or more days out - and that's just not something models are very exact on, nor have they been in the past. The difference is a) the fronts have started a bit early, b) we're looking at front-subject storms in the mid Atlantic that would normally get ignored and c) models aren't as good over ocean because there's little data. Until recently, there just wouldn't be much discussion of the exact track of a very-likely-fish at least a week from the EC in the unlikely event she came there. Even with Ernesto the differences arose mostly from that front digging in - it's just unusual to have a strong front in FL then.

I gotta give it up for the GFDL - I bow to the almighty one. It is probably the best model for tropical cyclone tracking currently available. I thought, as a few others, that Helene would track more west ala GFS and UKMET - boy was I wrong. My take on this years models is that they're having a hard time with nearby upper level lows (in addition to the fronts). It seems the models did alot better job in 2004 & 2005 when these ULLs were not as prominent and we had a lower shear environment.

[curtadams]

I'm surprised at the difference between air recon speeds and the Dvorak estimates. 30 knots is a lot, and this is exactly the scenario Dvorak is supposed to be best at. Is the NOAA flight attempting to measure max winds?

[wxman57]

There was a 954 mb reading given in the 11am advisory today. Now I realize that some people could say that this system was not as strong as earlier indications and this would explain the pressure rise and the slightly slower winds.

Well where were these intensity questions before the 5pm discussion?

I have been continually pointing out this year (And last) that storms are always given the higher status on most occassions in regards to the data. When in doubt bump it up or keep it the same.

Now this all has a meaning because of all the GW/stronger storm talks.

Today's perception is what is important here and not the reanalysis later. The public only hears about these storms now. They will not care, nor even know, whether systems like Ernesto end up being downgraded.

There needs to be a better system in place in regards to forecasting strength by means of satellite data. One day it's Dvorak the next day it's something else.

There is only one consistent thing here. They always seem to choose the data that supports a stronger system. Even when it goes against recon.

The 954mb in the 11am EDT advisory was based purely on satellite estimates. There were no such measurements. The only previous pressure measurement was 970mb the day before. Today's measured pressure was nearly 10mb lower than yesterday's, so Helene was most likely weaker yesterday.

Recon did not reach Helene until prior to the 5pm EDT advisory. That data appeared to confirm that Helene was weaker than had been estimated by satellite data, but not weaker than the day before.

Of course, recon in Helene was only a partial recon. It's difficult to sample an area the size of Helene with a single plane. Satellite Dvorak technique does have its problems, but there's no other method that's better at present. And satellite is all we have out in the middle of the ocean. For some reason, ships tend to avoid hurricanes.

The NHC did make a good point in that the recon plane most likely missed the stronger winds, as Helene certainly had the look of a strong Cat 3 on satellite.

Jim, I've seen your previous posts about the Sun's possible effects on tropical cyclone activity. My first impression would be that I'm skeptical of such a relationship, as I haven't seen/heard any talk of this in the hurricane forecasting community. Have you presented any papers at the AMS conferences on tropical meteorology? Is anything available online? I'm not saying I don't believe that such a direct relationship could be possible, just that I've not seen any evidence presented at any conferences that would support such conclusions.

[Jim Cantore]

Do we have an ERC going here? The eye has shrunk quite a bit it looks like.

[trugunz]

Do we have an ERC going here? The eye has shrunk quite a bit it looks like.

It is getting smaller

[JonathanBelles]

big things come in small packages?

[Evil Jeremy]

and big smells come in younger sisters! just had to say that lol..

[Weatherfreak14]

Do we have an ERC going here? The eye has shrunk quite a bit it looks like.

It is getting smaller

I wonder can this mean we might see the winds go up and the pressure go down by 11pm.

[Jim Hughes]

There was a 954 mb reading given in the 11am advisory today. Now I realize that some people could say that this system was not as strong as earlier indications and this would explain the pressure rise and the slightly slower winds.

Well where were these intensity questions before the 5pm discussion?

I have been continually pointing out this year (And last) that storms are always given the higher status on most occassions in regards to the data. When in doubt bump it up or keep it the same.

Now this all has a meaning because of all the GW/stronger storm talks.

Today's perception is what is important here and not the reanalysis later. The public only hears about these storms now. They will not care, nor even know, whether systems like Ernesto end up being downgraded.

There needs to be a better system in place in regards to forecasting strength by means of satellite data. One day it's Dvorak the next day it's something else.

There is only one consistent thing here. They always seem to choose the data that supports a stronger system. Even when it goes against recon.

The 954mb in the 11am EDT advisory was based purely on satellite estimates. There were no such measurements. The only previous pressure measurement was 970mb the day before. Today's measured pressure was nearly 10mb lower than yesterday's, so Helene was most likely weaker yesterday.

Recon did not reach Helene until prior to the 5pm EDT advisory. That data appeared to confirm that Helene was weaker than had been estimated by satellite data, but not weaker than the day before.

Of course, recon in Helene was only a partial recon. It's difficult to sample an area the size of Helene with a single plane. Satellite Dvorak technique does have its problems, but there's no other method that's better at present. And satellite is all we have out in the middle of the ocean. For some reason, ships tend to avoid hurricanes.

The NHC did make a good point in that the recon plane most likely missed the stronger winds, as Helene certainly had the look of a strong Cat 3 on satellite.

Jim, I've seen your previous posts about the Sun's possible effects on tropical cyclone activity. My first impression would be that I'm skeptical of such a relationship, as I haven't seen/heard any talk of this in the hurricane forecasting community. Have you presented any papers at the AMS conferences on tropical meteorology? Is anything available online? I'm not saying I don't believe that such a direct relationship could be possible, just that I've not seen any evidence presented at any conferences that would support such conclusions.

Well I am just bringing up a relationship that seem to show up almost all the time. As for whether it was weaker before. I go back to my prior point about why the somewhat continual overestimation by the forecasters then?

Why can't we get these satellite estimates close to being right?

As for beliefs and my research. I recently wrote up a research discussion that I may try and submit somehow. Or at least try and submit it at some type of conference. It deals with the space weather forcing upon the cyclical nature of the Polar Eurasia Teleconnection, ozone lelels, and some other things.

It seems to have quieted down a good deal of the GW talks at certain places during the past five weeks.

And even TWC seems to have quieted down somewhat about GW.

Dr. Heidi Cullen was always posting about it almost on a weekly basis on their blog in one way or another up until I talked about it last month.
( She has gotten things from me before.) I also sent it on to two others at TWC.

Many people know that I am on to something here and some knowledgeable people (climate an atmospheric experts) are dodging any discussion about it. I have challenged many to discuss it but they pass.

Lets just say this paper intimidates the hell out of certain people and their prior perceptions. I think I have shocked all the serious doubters who thought that I was just an Internet forecaster.

[brunota2003]

NOT OFFICIAL JUST OPINION OF THIS POSTER:
it appears to this ametuer that Helene now has a complete eyewall, no opening so the SW anymore, which may go along with the reports of it looking like it has contracted some as it has finally closed off...the sat images I was using where these two:
85H Sat Image
Color
As you can see in those two shots, the eyewall is completely closed off now and Helene may possibly strengthen...

[wxman57]

Well I am just bringing up a relationship that seem to show up almost all the time. As for whether it was weaker before. I go back to my prior point about why the somewhat continual overestimation by the forecasters then?

Why can't we get these satellite estimates close to being right?
..... snip

My point was that we don't know that we overestimated the intensity before. We don't really know what the intensity is now. Let's assume that the core of stronger winds has a radius of 100 nm. That's over 31,000 square miles for a single plane to investigate over a couple of hours. What are the odds that the plane found the pockets of highest winds with such a short observation period? Not very good. Even with 2 or 3 planes in a hurricane, the peak wind could be missed. Hurricane wind fields are not at all symmetric, and the 3-dimentional aspect of the wind fields doesn't make estimating or measuring surface winds any easier.

I'm not sure that there is any quick answer to your 2nd question about getting satellite estimates closer to being right. In fact, I'm not sure the satellite estimates were wrong. Without extensive direct observations of each hurricane, it's hard to improve on the Dvorak technique. Maybe future generations of satellites with greater remote sounding capabilities will help not only estimate current intensity but provide the needed data for better intensity forecasts.

[Jim Hughes]

Well I am just bringing up a relationship that seem to show up almost all the time. As for whether it was weaker before. I go back to my prior point about why the somewhat continual overestimation by the forecasters then?

Why can't we get these satellite estimates close to being right?
..... snip

My point was that we don't know that we overestimated the intensity before. We don't really know what the intensity is now. Let's assume that the core of stronger winds has a radius of 100 nm. That's over 31,000 square miles for a single plane to investigate over a couple of hours. What are the odds that the plane found the pockets of highest winds with such a short observation period? Not very good. Even with 2 or 3 planes in a hurricane, the peak wind could be missed. Hurricane wind fields are not at all symmetric, and the 3-dimentional aspect of the wind fields doesn't make estimating or measuring surface winds any easier.

I'm not sure that there is any quick answer to your 2nd question about getting satellite estimates closer to being right. In fact, I'm not sure the satellite estimates were wrong. Without extensive direct observations of each hurricane, it's hard to improve on the Dvorak technique. Maybe future generations of satellites with greater remote sounding capabilities will help not only estimate current intensity but provide the needed data for better intensity forecasts.

Well you are going both ways in regards to what we do or do not know about the true strength of Helene. So nobody can actually say if it did or did not have an effect. If the relationship is true.

I can not make up the actual solar wind speed, it is a fact, and I have written about the possible importance here (> 500 km/sec) and I also can only go by what the NHC puts out in regards to estimated strength with these advisories.

So I feel like if there was to be a tilt it would have to go my way. Once again.... if the relationship is true blue.

[Thunder44]

Helene might of weakened early this morning when it turned NNW overnight. I remembered the storm seemed to have flattened a bit on the west side, on satellite imagery,which was also mentioned in the morning TPC discussion by Franklin. He mentioned a small upper-low to the west of the storm. This may also happened during the satellite eclispe as well.