ATL: ISAAC - Post-Tropical - Discussion

[SouthDadeFish]

The following is solely my opinion and not a professional forecast:

If, and I mean if, Isaac can mix out the dry air tonight, then the stage is set for some decent intensification. Microwave imagery has been showing Isaac has consistently tried building up a inner core only for it to succumb to dry air and fall apart. Tomorrow, the ULL to the SW of Isaac should continue to move away from the storm, and an upper level anticyclone should balloon over the storm. This process will generate a much more favorable upper level environment for the storm. Also, assuming the dry air is no longer being entrained into the center of the storm, Isaac will become much more symmetrical, with good outflow channels. As a result, it would not surprise me to see Isaac strengthen from a 65-70 knot hurricane tomorrow at 12Z to a 90-95 knot hurricane by landfall around 6Z Wednesday. For Isaac to become a major hurricane we would have to see some serious rapid intensification (30+ knots in 18 hours starting 12Z tomorrow), which I find extremely unlikely at this time.

As a result, the thing I would keep an eye on is the dry air circling around the storm from the SW, then SE, to NE sides of the storm. If the convection becomes more symmetrical, then that would be a good sign the storm is about to really intensify. Until that happens, we will most likely see the same process we have been witnessing the last two or three days.

Again, this is only my opinion.

[Tom8]

The center coming into view

[ConvergenceZone]

Those microwave scans are a bit dated. Satellite imagery over the past 2 hours indicates a significant drop-off in convection. Squalls had been wrapping around the east and northeast side earlier but those died out. Even the convection to the southwest of the center is now diminishing. Oh, and I don't see any west movement to Texas. Even the GFDL now says SE LA. Of course, that may mean it can't possibly go there...

Any chance this storm is done? No more strengthening before landfall?

Truthfully, I don't think anyone here will be able to accurately answer that question. It could strengthen a little bit more or it could level off at 70 mph, or even go down in strength if the convection collapses and pulls in more dry air.

[windnrain]

Isaac seems to like strengthening at night so lets see.

[GCRain]

if isaac can slow even more it can deepen.

Every post you make you want this thing to be bad.Why? Have you ever experienced a major hurricane and it's aftermath?

[PTPatrick]

Exact landfal at this point is probably moot. Model consensus is between NOlA and Gulfport. Unfortunately the most heavily damaged county in Katrina , Hancock, appears to be the bearer of the brunt of another inundating surge. This is arguably the most surge prone count in the county in the us and this a perfect track to build it up. Regardless of the strength whether cat 1-2 or even ts... With a large wind field and angle approach, and long duration through 2 tides, Hancock is going to get soggy. Mid teens feet of surge is not out of the question in those areas west of bay st Louis...fortunately most of what was rebuilt was rebuilt very high(this will be impressive but probably still half of Katrina's surge for those places) . Could rival 1947 surge in that areas though. Depending on structure worst weather could ultimately end up we east toward mobile and biloxi. But that's difficult to predict at this point as its still got some growing to do.

[rockyman]

If (big if) the dark spot on this satellite loop is the eye, Isaac is well north of its NHC forecast track (click the Fsct Pts box):

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

[bella_may]

Rainstorm has been the biggest pessimist with the storm. She didn't even think it would be a hurricane yesterday. I wouldn't say she "wants"
it to be bad. She's just stating the facts.

[Dean4Storms]

Isaac has strengthened all day. This morning Recon was doing good to find flight level winds over 50kts and pressure was around 992mb and now 12 hours later he's down to 982mb and flight level winds in the 60's and some 70's. I see no reason with him still 36 hours out that he won't strengthen, he's getting better organized, UL winds are favorable and the SST's are plenty warm enough.

So yes, he's likely to strengthen folks and the million dollar question remains...How Much?

36 hours in favorable conditions and mid 80sst's can do a bunch for a 70mph TS!

[alienstorm]

Eye is now visible on infrared say Hello to Hurricane Isaac.

[rainstorm]

if isaac can slow even more it can deepen.

Every post you make you want this thing to be bad.Why? Have you ever experienced a major hurricane and it's aftermath?

ugh. i think this has been hashed over 1000 times. nothing i want or dont want has anything to do with what isaac will do. if the weather did what i wanted it would never rain a drop in virginia and that sure aint happenin. back to isaac, if it slows to a crawl it will have time to get organized.

[Smurfwicked]

Is it just me or is the start of the eye becoming more visible and defined at the end of this loop? http://radar.weather.gov/ridge/radar.ph ... 1&loop=yes



Uploaded with ImageShack.us

[SouthDadeFish]

Isaac has strengthened all day. This morning Recon was doing good to find flight level winds over 50kts and pressure was around 992mb and now 12 hours later he's down to 982mb and flight level winds in the 60's and some 70's. I see no reason with him still 36 hours out that he won't strengthen, he's getting better organized, UL winds are favorable and the SST's are plenty warm enough.

So yes, he's likely to strengthen folks and the million dollar question remains...How Much?

36 hours in favorable conditions and mid 80sst's can do a bunch for a 70mph TS!

All of the dry air to the NE of the center suggests conditions are not too favorable.

[stormreader]

[imghttp://www.ssd.noaa.gov/PS/TROP/floaters/09L/flash-vis-long.html][/img]

Looks like a tiny pinhole eye. Can that be real???

[Buckeye05]

Eye is now visible on infrared say Hello to Hurricane Isaac.

Except for the part where it continues to gulp dry air and doesn't have hurricane force winds...

[SouthDadeFish]

[imghttp://www.ssd.noaa.gov/PS/TROP/floaters/09L/flash-vis-long.html][/img]

Looks like a tiny pinhole eye. Can that be real???

This is what I said on another message board, and again is only my opinion:

I hate to be a party pooper, but I think infrared imagery is playing tricks on your eyes. I believe what you are seeing, which does remsemble an eye, is convection firing over the center, with the remnants of the previous convective burst laying around at much a lower level in the atmosphere. From the current satellite frames the recent convective burst that is superimposed over the older burst makes it appear that an eye is forming. However, when you consider the fact that recon is no longer saying there is an eye, as well as the fact that cloud tops have been warming prior to the burst, as well as all the dry air, it makes sense that this is not an eye forming. We will see in the following recon reports and satellite frames though.

[mesoclone]

Ok, so I have been a member for 10 years with probably less than 20 posts cause most of my questions are answered by other members. But I forgot my username and such so I'll start over not a big deal. Anyways I was wondering how the diurnal cycle will effect this storm. Will the decrease in atmospheric temps. but stable oceanic temps. cause Isaac to gain strength? How does this work? Mind you I am a novice at this.

[stormreader]

http://www.ssd.noaa.gov/PS/TROP/floater ... -long.html

Pinhole eye....

[stormreader]

Ok, so I have been a member for 10 years with probably less than 20 posts cause most of my questions are answered by other members. But I forgot my username and such so I'll start over not a big deal. Anyways I was wondering how the diurnal cycle will effect this storm. Will the decrease in atmospheric temps. but stable oceanic temps. cause Isaac to gain strength? How does this work? Mind you I am a novice at this.

I don't know, I checked "visible" (at night). Its right where the center appears to be.... Don't know what to think.

[SapphireSea]

I don't think that's an eye at all. It looks like just dry air entraining near the center. We will have to wait a good 2-3 good frames before we can conclude what it is. But it does not look like an eye whatsoever.