ATL: ISAAC - Post-Tropical - Discussion

[crimi481]

May be worth mentioning
This WV Loop shows a Tropical Sytem below Mexico ( bottom left screen)
Looks like energy/moisture from it - being drawn into Isaac's S.W. side. Strange

http://www.ssec.wisc.edu/data/geo/index ... thod=flash

[CronkPSU]

It's about as good as it's looked right now...

With respect sir/ma'am. They eye is coming appart. The most recent radar shows the eyewall breaking away and expanding. My opinion this thing is coming apart.

this radar???

http://radar.weather.gov/radar.php?prod ... X&loop=yes

looks as symmetrical as it ever has

[Texashawk]

Eye is becoming very nicely defined:



Uploaded with ImageShack.us

[stormreader]

May be worth mentioning
This WV Loop shows a Tropical Sytem below Mexico ( bottom left screen)
Looks like energy/moisture from it - being drawn into Isaac's S.W. side. Strange

http://www.ssec.wisc.edu/data/geo/index ... thod=flash

Really nice looking upper air environment for Isaac. Don't see any weakening any time too soon.

[nautical wheeler]

OK, plesae help me here. Perhaps I'm stupid and can't properly read a radar. Anybody's welcome to answer: What does this loop suggest to you?

http://radar.weather.gov/radar.php?product=N0Z&rid=LIX&loop=yes

Thanks in advance - this is for another board.

I could be way off here. I'm in no way qualified to answer your question so TFWIW. I think the "eye" is actually not closed but is open on the west side. It just appears closed because the dry west side appears circular. I think that dry air is rotating within the core to the SW which give the illusion that the center is moving SW. Look closely at the far eastern side of the "eye" and you'll see a notch that I believe might be the "true" eye. It is essentially motionless right now but has been drifting ever so slightly WNW. You have to look close to see it.

As I said, I could be completely wrong but as I type that large circle appears to be coming apart..

[WxGuy1]

It doesn't look like any standard-height surface observation site (the ASOS and AWOS sites) has yet to sample actual Cat 1 wind speeds. Latest analysis from HRD: http://img825.imageshack.us/img825/7518 ... ontour.png

From the surface observations I've seen, this looks pretty good. The only hurricane-force winds I've seen have been with the oil platforms above the water. I know KBVE was close to hurricane force winds, and I'm sure there were some peaks in there.

Note that the SS scale (and the NHC's estimate of 80 mph winds) is based on sustained winds, not peak wind gusts. Has anyone seen actual Cat 1 winds over land in the past few hours? The HRD analyses suggest that's not occurring, and that supports what I've seen in the surface observations. Of course, it's not uncommon for the surface observations to record considerably lower-than-max-winds observations, since the highest winds typically occur over a very small part of the storm near the eyewall and typically only near the coast on the onshore / right side of the circulation. The NHC site notes that the winds typically decrease one entire SS category if one is more than ~1/2 mile from the coast.

The latest KGAO ob is 50 kts sustained with gusts to 65 kts, which is still tropical storm condition.

It's always tough to find ASOS/AWOS measurements that match NHC advisory values. A couple possible reasons:
-ASOS/AWOS sites are relatively sparse may not fully sample the strongest winds
-ASOS/AWOS typically report sustained winds as a 2-minute average, which will be lower than the 1-minute average used by NHC.
-The NHC advisory winds are supposed to be the highest winds possible for a marine exposure...so by definition they will be isolated.
-Of course, it's always possible the advisory winds are too high.

You've highlighted the primary reasons why we don't tend to see corroborating surface observations, though I didn't know that the ASOS/AWOS sustained wind speed was a 2-minute average. I can only think of a couple of US landfalls in the past 5-7 years for which I've seen METARs with sustained winds matching the advisory wind. I tend to think this is primary the result of (a) the relative dearth of AWOS/ASOS sites on the coast and (b) the relatively porous nature of the ASOS and AWOS systems. It'd be great to have access to Texas Tech's UHRT StickNet data in real-time... I know they've deployed at least 20 StickNet sites across far southeastern LA, and data from the system is being disseminated to the NWS and is being used in the HRD analyses.

Note that I wasn't intending to say that the advisory speed is too high. The advisory wind speed looks very much justified based upon the SFMR data and flight-level winds,

[boomstyk]

It's about as good as it's looked right now...

With respect sir/ma'am. They eye is coming appart. The most recent radar shows the eyewall breaking away and expanding. My opinion this thing is coming apart.

this radar???

http://radar.weather.gov/radar.php?prod ... X&loop=yes

looks as symmetrical as it ever has

Correct but Larger. Now I'm not a met so I really don't know. But a larger eye is usually a sign of a weaker storm. That exact radar shows the eyewall coming away and making that inner band the new wall. Unless somehow that represents RI I think it is breaking down.

Again, open to different opinion.

[MHurricanes]

Recent Joe Bastardi Tweets:

Joe Bastardi ‏@BigJoeBastardi
Grande Isle Mayor says All Hell is breaking loose ( his words) 966 closed wall, could hit 960 as dynamics improving to counter marshes

Joe Bastardi ‏@BigJoeBastardi
I believe evidence will show this does cat 2-3 wind damage in the parishes south of New Orleans.Wind comes down to sfc in tightening storms

Joe Bastardi ‏@BigJoeBastardi
The parishes south of New Orleans may be witnessing an attempt by the gulf to over-run them as this storm will pound away next 24 hrs

[crimi481]

Hope I am wrong - but the enlarging eye not sign weakening -and may be Isaac bulking up - another surge in effort to center to catch up to its overall size. Looks Typhoon-ish

[boomstyk]

Recent Joe Bastardi Tweets:

Joe Bastardi ‏@BigJoeBastardi
Grande Isle Mayor says All Hell is breaking loose ( his words) 966 closed wall, could hit 960 as dynamics improving to counter marshes

Joe Bastardi ‏@BigJoeBastardi
I believe evidence will show this does cat 2-3 wind damage in the parishes south of New Orleans.Wind comes down to sfc in tightening storms

Joe Bastardi ‏@BigJoeBastardi
The parishes south of New Orleans may be witnessing an attempt by the gulf to over-run them as this storm will pound away next 24 hrs

Loves the Drama doesn't he? LOL

[Texashawk]

As I recall, Ike had a huge eye too as its pressure dropped.

I can tell you from personal experience that we were not cheated by the experience.

[catskillfire51]

the weather channel is saying that the pressure is still dropping, when they get off commercial break they will be talking about it

[Meteorcane]

Looks like Galliano and Grand isle stations are down, they were our best hopes to see near sustained hurricane force winds (although that concern is a distant second to the concern for lives and property, in that region which has been getting pounded for the last several hours.

[Hurricaneman]

Recent Joe Bastardi Tweets:

Joe Bastardi ‏@BigJoeBastardi
Grande Isle Mayor says All Hell is breaking loose ( his words) 966 closed wall, could hit 960 as dynamics improving to counter marshes

Joe Bastardi ‏@BigJoeBastardi
I believe evidence will show this does cat 2-3 wind damage in the parishes south of New Orleans.Wind comes down to sfc in tightening storms

Joe Bastardi ‏@BigJoeBastardi
The parishes south of New Orleans may be witnessing an attempt by the gulf to over-run them as this storm will pound away next 24 hrs

Loves the Drama doesn't he? LOL

Yep, Joe is known to pimp up storms, 100+mph gust does not make a cat 2 or 3, its just a gust its probably 80mph with that just like the NHC says

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products.

[monicaei]

Recent Joe Bastardi Tweets:

Joe Bastardi ‏@BigJoeBastardi
Grande Isle Mayor says All Hell is breaking loose ( his words) 966 closed wall, could hit 960 as dynamics improving to counter marshes

Joe Bastardi ‏@BigJoeBastardi
I believe evidence will show this does cat 2-3 wind damage in the parishes south of New Orleans.Wind comes down to sfc in tightening storms

Joe Bastardi ‏@BigJoeBastardi
The parishes south of New Orleans may be witnessing an attempt by the gulf to over-run them as this storm will pound away next 24 hrs

I know this guy is a pro met, and a well respected one I'm sure, but he sure seems to have a catastrophe fetish? Yes, the GOM is going to swallow us all!?

I don't know where you are, or he is,but that's not as lip licking fantastic as you think...

[CronkPSU]

wgno crew are all saying it has to be going west (and maybe even WSW) and wondering what the hell NHC is talking about

[boomstyk]

As I recall, Ike had a huge eye too as its pressure dropped.

I can tell you from personal experience that we were not cheated by the experience.

But is a larger eye different that an enlarging eye? Again I will say I don't know. My thoughts and experience following this board tells me that an enlarging eye is a bad thing for a storm. In addition the tops are coming off the storm. Although as i say this I realize that all of those symptoms are sometimes signs of RI. Interesting.

I still think she's coming appart. Although over water not far from 30c sst is extremely interesting.

[wxwatcher1999]

wgno crew are all saying it has to be going west (and maybe even WSW) and wondering what the hell NHC is talking about

NHC finally mentioned the possibility of moving further west and maybe taking the models into consideration

[Meteorcane]

An oil platform is reporting a 968 mb pressure with 20 mph winds, I don't know the height which could have a minor influence on pressure.

[ROCK]

I dont know....I though the NHC would have seen these models and made adjustments.....no choice now IMO....