ATL: ISAAC - Post-Tropical - Discussion

[SapphireSea]

Recon comments if true indicate that the circulation flow is not very deep-layered. There is significant east wind at 4km-5km, this is probably the persistent shear and inhibiting factor to the storm. I think the general rule of thumb at this point for S. FL is whether or not by tomorrow this becomes a hurricane. If it stays a mess, the westerly models will probably verify, if it begins to steer with deeper layers I would probably say it may end up following the east envelope. It's too hard to call with any certainty because of all the factors it is throwing out at us (we dont even know where there is a real center right now).

[CrazyC83]

20120822 2345 15.6 62.0 T3.0/3.0 09L ISAAC

[ozonepete]

Yeah, but as I just posted, the surface obs aren't so complicated. Latest obs from Dominca (not shown) have winds at 2 to 3 mph over the last hour. The surface center is going over it now. So combined with the ENE winds at Antigua and WSW winds at Martinique, the center can't be southwest of St. Lucia. One thing that RECON can't do better than land stations is measure surface winds. The center is passing over or just passed Dominica now.

Personal Forecast Disclaimer:
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.

[wxman76]

Using the NHC satellite page and overlaying the forecast plots from the NHC. If one assumes "D" as the true center the storm iwas definitely south of its 18z/22 position and if the motion continues will be south of it's 06z/23 position.

Personal Forecast Disclaimer:
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.

[CrazyC83]

Yeah, but as I just posted, the surface obs aren't so complicated. Latest obs from Dominca (not shown) have winds at 2 to 3 mph over the last hour. The surface center is going over it now. So combined with the ENE winds at Antigua and WSW winds at Martinique, the center can't be southwest of St. Lucia. One thing that RECON can't do better than land stations is measure surface winds. The center is passing over or just passed Dominica now.

Personal Forecast Disclaimer:
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.

That seems to agree with my thinking - it probably made landfall near 0000Z. That agrees with the NOAA plane and is just SE of the AF plane center.

[ROCK]

20120822 2345 15.6 62.0 T3.0/3.0 09L ISAAC

is that raw T numbers? just curious on how this is 3.0 when you have a mess of an internal structure...

[Blown Away]

20120822 2345 15.6 62.0 T3.0/3.0 09L ISAAC

Is that 3.0 number right??

Looking at the satellite I think its go time now for Isaac!! JMHO

[RL3AO]

20120822 2345 15.6 62.0 T3.0/3.0 09L ISAAC

is that raw T numbers? just curious on how this is 3.0 when you have a mess of an internal structure...

Because dvorak is sat estimate only. When you look it actually is developing some good banding.

[ozonepete]

20120822 2345 15.6 62.0 T3.0/3.0 09L ISAAC

Is that 3.0 number right??

That's why they call it an "objective" analysis. The ADT program compares this structure to thousands of others in its database and makes a call. Fortunately for all of us it doesn't read storm2k.

[wxman76]

New low pressure extrapolated 1003.0mb at 15.933N 62.817W by recon.

[CronkPSU]

HRD/AOML/NOAA ‏@HRD_AOML_NOAA

@AustinLouis5 intensifying storm circulations should extend through whole troposphere. Shallow storm suggests it is not strengthening.

HRD/AOML/NOAA ‏@HRD_AOML_NOAA

#N42: Most recent radar analysis shows broad, weak circulation at 2 km and possible circulation displaced at least 100 km to south at 7 km.

[CourierPR]

Isaac has a huge circulation. I have this feeling that we'd better not downplay this because I suspect it's going to wreak havoc in a few days.

[stormhunter7]

#N42: Most recent radar analysis shows broad, weak circulation at 2 km and possible circulation displaced at least 100 km to south at 7 km. Per NOAA HRD on NOAA52

sounds like Iassc has a way to go to be built vertically..... surface low is moving to fast to build a good structure vertically... until it slows down, this large system should stay a moderate TS

[Portastorm]

Here is an interesting graphic from over in Weather Underground:



Uploaded with ImageShack.us

[SeminoleWind]

New low pressure extrapolated 1003.0mb at 15.933N 62.817W by recon.

If Thats true then wouldnt that put it toward the northern side of Isaac?

[Blown Away]

I'm no pro met, but Isaac is looking much better on the IR.
http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

[SouthDadeFish]

Convection continues to increase:

[Ikester]

Isaac's circulation is massive. It'll be hard for Isaac to 'bomb'. I suspect a slow but gradual strengthening trend. Keep in mind that a pressure of 1003 mb is HIGH for a storm so large. It's probably why we haven't seen the winds increase all that much. I still suspect 45 mph sustained winds is generous. As an example, Ike was a huge hurricane. It's pressure at landfall was 950 mb yet it was 'only' a category 2 storm. Size does matter.

[CourierPR]

New low pressure extrapolated 1003.0mb at 15.933N 62.817W by recon.

If Thats true then wouldnt that put it toward the northern side of Isaac?

Which would seemingly confirm what Jim Cantore was stating earlier concerning the northern part of the storm becoming dominant.

[KBBOCA]

Here is an interesting graphic from over in Weather Underground:



Uploaded with ImageShack.us

That historical track graphic seems to suggest if Isaac heads west into the Gulf, "WATCH OUT!" (which I know many have been saying here.) Some of the storms that hit Texas were very strong. I hope and pray we do not have any kind of repeat scenario.

I'm just an amateur. Refer to NHC for official info!