ATL: ISAAC - Post-Tropical - Discussion

[caneman]

11 AM advisory has it slowed to 17 mph now

[MJS1]

Not sure if its just an optical illusion due to the expanding convection or not but Isaas appears he could miss the next NHC point to the right

http://www.ssd.noaa.gov/PS/TROP/floaters/09L/flash-vis-short.html

I guess it has to do where the center of circulation is...Vis satellite pics at night are not the ideal medium to determine that, I believe...

[SouthDadeFish]

Here is a microwave pass from about the time that radar pic was posted:



Keep in mind the 91GHz shows primarily ice scattering, so there still may be warm rain in the SW part of that possible eyewall.

Here is the 37 GHz, which would normally be able to show if we had a closed ring or not, but the resolution isn't so great:

[Mildlysane]

All of the local mets (pbc) keep stressing the tornado threats. We live in a mobile home.

Me too, but in Englewood (Charlotte County, on the Gulf, between Sarasota and Ft Myers). Hope it wasn't a mistake staying here! It is hard going anywhere with 2 cats and 2 dogs, though.

[jinftl]

In terms of potential intensity in the near and long-term, this graphic shows the NHC's thinking at 11pm. As of now, there is a low % chance of Isaac intensifying to Cat 3 or higher intensity (11% chance of Cat 3, 3% chance of Cat 4). Could this change? Absolutely. But right now, he is most likely to be a Cat 1 (43%), a Cat 2 (21%) or a TS (20%) in 48 hours and most likely yo be a TS (34%), Cat 1 (25%), or Cat 2 (13%) in 72 hours. Let's watch the trend for future releases of this.

[Ixolib]

Per the NHC:

...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST...

Hoping someone can translate what is meant by "continuity with the previous forecast"???

[cycloneye]

Saved loop of Cuban Radar.

[Meteorcane]

Per the NHC:

...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST...

Hoping someone can translate what is meant by "continuity with the previous forecast"???

Basically means they don't want drastic shifts from forecast advisory to advisory period (ie wind-shield wipering) and they will wait for more data and then gradually move it closer to the solution they believe is most plausible (usually around the dynamical model consensus)

[jes]

I'm sure we are all so tired of this (although I live for it daily). Anyway, I am beginning to care less where it goes --- I want to know the intensity. I can live through 100 mph winds with not that much preparation, but if it increases to a cat 3 I really need to know. I don't hear much about intensity except that it can get stronger. Well, how likely is this --- Getting stronger is my biggest concern. Any idea's how likely this may be?

[Ixolib]

Per the NHC:

...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST...

Hoping someone can translate what is meant by "continuity with the previous forecast"???

Basically means they don't want drastic shifts from forecast advisory to advisory period (ie wind-shield wipering) and they will wait for more data and then gradually move it closer to the solution they believe is most plausible (usually around the dynamical model consensus)

Thanks!!

[smw1981]

Per the NHC:

...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST...

Hoping someone can translate what is meant by "continuity with the previous forecast"???

Just means they don't want to drastically shift the cone because the previous forecast was in one place and the current forecast is in a different place.. Instead, they will just do it slowly. (Which IMO is definitely best for them because people would lose confidence in them if they shifted them with every model run!!)

[Chris_in_Tampa]

Saved loop of Cuban Radar.

Do you happen to have the link for that? I can't find an updating image anywhere.

[cycloneye]

Saved loop of Cuban Radar.

Do you happen to have the link for that? I can't find an updating image anywhere.

I found that loop at WeatherUnderground forum.

[Chris_in_Tampa]

I found that loop at WeatherUnderground forum.

I know the NHC has access to it, so I guess someone else just happens to know where as well.

[tolakram]

Per the NHC:

...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST...

Hoping someone can translate what is meant by "continuity with the previous forecast"???

The NHC can't go flipping their track around every time a model moves around. Right now the GFS and some models based off the GFS have moved west, but they really want confirmation this is a trend and not a model goof before making a shift. So they move slowly at first, and continue moving if the trend appears real. It's really the best way to forecast when all you have is models that, at this time frame, are only so reliable.

IMO if GFS 0Z and Euro shift then it's a real west trend.

[cycloneye]

A tweet from Jim Cantore:

Jim Cantore ‏@JimCantore

Westward model shift is worrisome & not totally reflected in latest cone 4 continuity. Big day in Isaacs life tomorrow.

[jeff]

I'm sure we are all so tired of this (although I live for it daily). Anyway, I am beginning to care less where it goes --- I want to know the intensity. I can live through 100 mph winds with not that much preparation, but if it increases to a cat 3 I really need to know. I don't hear much about intensity except that it can get stronger. Well, how likely is this --- Getting stronger is my biggest concern. Any idea's how likely this may be?

The potential is there for a strong storm in the Gulf with both the GFS and ECMWF showing good 200mb anticyclone over Isaac and potential for dual outflow channels. Negative may remain the larger than average wind field...may see low pressures, but the winds spread out and weaker...similar to Ike. Potential is there and it would not take much to make this a major hurricane at landfall on the US Gulf coast.

[ballred]

Wouldn't a more rapid intensification tend to pull the storm north at least in the short term?

[Blinhart]

...THE NHC FORECAST IS LIES BETWEEN THEM. THE UPDATED TRACK IS VERY CLOSE TO THE PREVIOUS ADVISORY THROUGH 36 HOURS. AFTER THAT TIME...THE TRACK HAS BEEN ADJUSTED WESTWARD...BUT IT REMAINS EAST OF THE DYNAMICAL MODEL CONSENSUS TO RETAIN SOME CONTINUITY WITH THE PREVIOUS FORECAST.

Stated in the latest Disco, sounds like they are keen on moving it West, looks like they moved the cone about 50 miles this time, so if that continues, wouldn't be shocked to see this move about 20 to 40 miles each time they update the cone until they are actually certain on where he will make final landfall.

[Meteorcane]

Just curious is that strong convective band to the east of Isaac, being caused primarily by orographic uplift of the flow over the mountains of Eastern Cuba?