ATL HANNA: Extratropical - Discussion

[storms in NC]

here you go
AL, 08, 2008090100, , BEST, 0, 237N, 719W, 40, 997, TS,

[captain east]

Indeed. She's finally trying to consolidate convection over the center.

Where is the center though???

Pretty hard to pinpoint it on sat. imagery, but continuity would put it just to the north of the recent blowup, consistent with the shear blowing the convection off to the south.

Are you sure that isn't the center? Is there any spin going on in there? It just looks exactly like the center...

[cpdaman]

Indeed. She's finally trying to consolidate convection over the center.

Where is the center though???

Pretty hard to pinpoint it on sat. imagery, but continuity would put it just to the north of the recent blowup, consistent with the shear blowing the convection off to the south.

Are you sure that isn't the center? Is there any spin going on in there? It just looks exactly like the center...[/quote]

it could be , the "best track #'s" are not recon, and AJC3 said these things like to get tucked under convection, so who knows

[masaji79]

From the last visible images of the day it looks like the LLC is just under the northern extent of the large convection burst. Almost appears as if the burst sucked the LLC under it. But then again could just be my eyes playing tricks on me.

http://www.ssd.noaa.gov/goes/flt/t2/loop-vis.html

[cpdaman]

also it would appear to me the bouy to the east at 23.85 / 70.85 has winds (SE) that match up with a position of the LLC to the SW. AJC3 does this make any sense.

the best track of 23.7/ 71.9 would be due west of that bouy and i would expect at least south winds or SSW if that was actually true.

[umguy]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

[MetroMike]

Given the models spreads on her, its pretty hard to define any reasonable trends.

[AJC3]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml

[jlauderdal]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

be happy, they have an excellent shot of being right..

[ExBailbonds]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml

Well this cone is 250 miles wide at 12 hrs and 650 miles wide a t 72 hrs. That is cetainly not a normal cone.

[cpdaman]

bouy to the east or Ne is rising , yet has sustained tropical storm winds now

http://www.ndbc.noaa.gov/station_page.php?station=41046

[captain east]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml

Well this cone is 250 miles wide at 12 hrs and 650 miles wide a t 72 hrs. That is cetainly not a normal cone.

What are you talking about thats totally normal... *sarcasm*
Anyways, it's starting to look a little better after every new frame.

[jlauderdal]

Just looking at the NHC's forecast track that I'm a bit let down. The forecast cone is from SFL to VA? I mean most anyone can say that.

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml

Well this cone is 250 miles wide at 12 hrs and 650 miles wide a t 72 hrs. That is cetainly not a normal cone.

since you didn't believe ajc3 maybe you will believe what i took right off the nhc site, he tried to make it easy but instead you can digest this:

fyi, here is the link: http://www.nhc.noaa.gov/aboutcone.shtml

Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2008 for the Atlantic and eastern North Pacific basins are given in the table below.

One can also examine historical tracks to determine how often the entire 5-day path of a cyclone remains completely within the area of the cone. This is a different perspective that ignores most timing errors. For example, a storm moving very slowly but in the expected direction would still be within the area of the cone, even though the track forecast error could be very large. Based on forecasts over the previous 5 years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60-70% of the time.

Radii of NHC forecast cone circles for 2008, based on error statistics from 2003-2007:

Forecast Period
(hours)


2/3 Probability Circle,
Atlantic Basin
(nautical miles)


2/3 Probability Circle,
Eastern North Pacific Basin
(nautical miles)
12 39 36
24 67 66
36 92 92
48 118 115
72 170 161
96 233 210
120 305 256

Example Graphic of 5-Day Track Forecast Cone:

[masaji79]

Hanna certainly looks must better than she did yesterday and this morning. This morning it looked like Hanna was going to open up into a wave! Just goes to show that tropical cyclones can really be unpredictable sometimes.

[jlauderdal]

Hanna certainly looks must better than she did yesterday and this morning. This morning it looked like Hanna was going to open up into a wave! Just goes to show that tropical cyclones can really be unpredictable sometimes.

looks decent enough on IR but what is happening at the surface is what we really want to know, RECON

[ExBailbonds]

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml[/quote]


Well this cone is 250 miles wide at 12 hrs and 650 miles wide a t 72 hrs. That is cetainly not a normal cone.[/quote]

since you didn't believe ajc3 maybe you will believe what i took right off the nhc site, he tried to make it easy but instead you can digest this:

fyi, here is the link: http://www.nhc.noaa.gov/aboutcone.shtml

Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2008 for the Atlantic and eastern North Pacific basins are given in the table below.

One can also examine historical tracks to determine how often the entire 5-day path of a cyclone remains completely within the area of the cone. This is a different perspective that ignores most timing errors. For example, a storm moving very slowly but in the expected direction would still be within the area of the cone, even though the track forecast error could be very large. Based on forecasts over the previous 5 years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60-70% of the time.

Radii of NHC forecast cone circles for 2008, based on error statistics from 2003-2007:

Forecast Period
(hours)


2/3 Probability Circle,
Atlantic Basin
(nautical miles)


2/3 Probability Circle,
Eastern North Pacific Basin
(nautical miles)
12 39 36
24 67 66
36 92 92
48 118 115
72 170 161
96 233 210
120 305 256

Example Graphic of 5-Day Track Forecast Cone:[/quote]

Ya I can read and I and what I read says the cone should be 39 miles at 12 hrs and 305 miles at 120

[captain east]

Hanna certainly looks must better than she did yesterday and this morning. This morning it looked like Hanna was going to open up into a wave! Just goes to show that tropical cyclones can really be unpredictable sometimes.

looks decent enough on IR but what is happening at the surface is what we really want to know, RECON

When is recon going in again? I really wanna see how she's doing...

[cpdaman]

Hanna certainly looks must better than she did yesterday and this morning. This morning it looked like Hanna was going to open up into a wave! Just goes to show that tropical cyclones can really be unpredictable sometimes.

looks decent enough on IR but what is happening at the surface is what we really want to know, RECON

ya , one thing i am pleased with though is that the bouy on her eastern side has been rising quicker over the past few hours so , she is probably sliding away, even though on IR 2 the convection is closer now (pivoted to her south)

[jlauderdal]

The cone is simply represents 2/3 of the average statistical error in the forecast track. Nothing more, nothing less.

http://www.nhc.noaa.gov/aboutcone.shtml

Well this cone is 250 miles wide at 12 hrs and 650 miles wide a t 72 hrs. That is cetainly not a normal cone.[/quote]

since you didn't believe ajc3 maybe you will believe what i took right off the nhc site, he tried to make it easy but instead you can digest this:

fyi, here is the link: http://www.nhc.noaa.gov/aboutcone.shtml

Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle. The circle radii defining the cones in 2008 for the Atlantic and eastern North Pacific basins are given in the table below.

One can also examine historical tracks to determine how often the entire 5-day path of a cyclone remains completely within the area of the cone. This is a different perspective that ignores most timing errors. For example, a storm moving very slowly but in the expected direction would still be within the area of the cone, even though the track forecast error could be very large. Based on forecasts over the previous 5 years, the entire track of the tropical cyclone can be expected to remain within the cone roughly 60-70% of the time.

Radii of NHC forecast cone circles for 2008, based on error statistics from 2003-2007:

Forecast Period
(hours)


2/3 Probability Circle,
Atlantic Basin
(nautical miles)


2/3 Probability Circle,
Eastern North Pacific Basin
(nautical miles)
12 39 36
24 67 66
36 92 92
48 118 115
72 170 161
96 233 210
120 305 256

Example Graphic of 5-Day Track Forecast Cone:[/quote]

Ya I can read and I and what I read says the cone should be 39 miles at 12 hrs and 305 miles at 120[/quote]

not sure where you are seeing 250 miles at 12 hours also the error is on either side of the track

[ExBailbonds]

[quote="jlauderdal
not sure where you are seeing 250 miles at 12 hours also the error is on either side of the track[/quote]


There is a distance scale on the graphic. Get a ruler check it out.

EDIT: I not bashing the NHC here just pointing out that this cone is much wider than normal. This is one tricky forcast for sure.