Jeanne 11PM Probabilties - hmmm...

[staggy]

Miami and West Palm Beach have been added to the 11PM probabilities for Jeanne. They both have 2% for 8PM Wed to 8PM Thu. Are they starting to see something?

[yoda]

Probably not. They are probably just covering their bases.

http://www.wunderground.com/tropical/tr ... _5day.html

[Derecho]

People seem to convince themselves there's some sort of hidden "real" NHC forecast and that the actual forecast put out is some sort of front. Why, I don't know.

It seems the probability tables are part of this belief. They're MASSIVELY overanalyzed and picked apart.

The problem is people don't understand how they are made, what they represent.

The probability tables are NOT produced by a committee at NHC sitting around and debating whether to give city X this percentage, city Y that percentage and then typing the numbers in by hand; however, for years, it's been clear a lot of board posters are under this mis-impression.

They basically are simply a text representation of the familar cone of probabilty, which is centered around the official forecast track.

The 11PM forecast slowed down the forecast movement of Jeanne a lot, with the last points on the forecast track further W than the previous forecast (but still not showing it heading in any determined way towards the US.)

Hence, the 72 hour probabilities mean the edge of the probability cone catch Florida and give some points there a few % points of probabilty.

If you actually asked people at NHC they'd possibly belive Jeanne has LESS or the same probabilty of hitting the US now than earlier today; this is no grand hint of anything.

[staggy]

I'm well aware of how the probabilty tables work. I was just making an observation.

[ColdFront77]

People seem to convince themselves there's some sort of hidden "real" NHC forecast and that the actual forecast put out is some sort of front. Why, I don't know.

It seems the probability tables are part of this belief. They're MASSIVELY overanalyzed and picked apart.

The problem is people don't understand how they are made, what they represent.

The probability tables are NOT produced by a committee at NHC sitting around and debating whether to give city X this percentage, city Y that percentage and then typing the numbers in by hand; however, for years, it's been clear a lot of board posters are under this mis-impression.

There is no way to truly know what a weather board member feels about specific issues dealing with a tropical system when the discussion isn't going any further than a broad statement like this one.

[canecaster]

I have to disagree that probabilities always eflect the forecast track. Probabilities are computer generated, based more on NHC guidance. The forecast track may be drawn left or right of the guidance and actually be somewhat at odds with the forecast track, as we saw with Ivan at times. So actaully, probabilities can reveal a trend that may have not yet been expressed in the official forecast.

[canecaster]

I have to disagree that probabilities always eflect the forecast track. Probabilities are computer generated, based more on NHC guidance. The forecast track may be drawn left or right of the guidance and actually be somewhat at odds with the probabilities, as we saw with Ivan at times. So actaully, probabilities can reveal a trend that may have not yet been expressed in the official forecast.

[TSmith274]

The probabilities were interesting with Ivan. One way you could tell that they are computer generated was that the mouth of the Mississippi river had the highest probability for a day or so. This was simply because the Mississippi delta sticks out into the gulf and was closest to the center of Ivan. It wasn't that Ivan was really going to make lanfall there. The Mobile area was always a pretty good bet for landfall. It was just that the computers had picked up on it because it sticks out into the gulf some 90 miles. At least this is how it was explained to me, and it makes sense. Any opinions on this?

[snowflake]

One the mets here who is also the states climatalogist said that the chances of Jeanne moving westward and making a land fall is slim.

[Doc Seminole]

Good to see a post from you Derecho.

[mobilebay]

Good to see a post from you Derecho.

Yea I remember a quote when Ivan was in the Caribbean and the Canadian was predicting an Alabama/Florida line Landfall. "Western Outliers rarely verify". This just in Derocho... It did.

[bahamaswx]

Good to see a post from you Derecho.

Yea I remember a quote when Ivan was in the Caribbean and the Canadian was predicting an Alabama/Florida line Landfall. "Western Outliers rarely verify". This just in Derocho... It did.

Hence "rarely," not "never."

[mobilebay]

Good to see a post from you Derecho.

Yea I remember a quote when Ivan was in the Caribbean and the Canadian was predicting an Alabama/Florida line Landfall. "Western Outliers rarely verify". This just in Derocho... It did.

Hence "rarely," not "never."

Point is . he jumped on someone for posting that model, like he always does.