ATL: ISAAC - Post-Tropical - Discussion

[Aric Dunn]

center getting very close to Guadalupe should pass over northern portion in the next couple hours.

http://flhurricane.com/imageanimator.php?137

[Frank2]

On the WV loop there appears to be a TUTT-like feature across the Bahamas, Cuba and NW Caribbean:

http://www.goes.noaa.gov/HURRLOOPS/huwvloop.html

if that remains in place that will certainly affect the outcome of Isaac's intensity...

Frank

[Weatherfreak000]

Yep Isaac looks quite poor indeed ATM. Might even weaken even further like EURO predicted...

[otowntiger]

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

LLC?

Wow! He looks pretty pitiful. I'm starting to agree with wxman57's assessment on this storm. I think Isaac may just turn out to be pretty wimpy. Not to say he won't bring some awful and potentially catastrophic flooding to Haiti and DR and other islands but the chances if it becoming a significant hurricane or even a hurricane at all seem to be getting slimmer by the hour. Let's hope that stays the case.

Disclaimer: I don't know what I'm talking about and am not a professional meteorologist. Refer to the people who know what they are talking about to make plans accordingly.

[KWT]

center getting very close to Guadalupe should pass over northern portion in the next couple hours.

http://flhurricane.com/imageanimator.php?137

Yep looks like its heading right into the island, good job we have some convection rotating around so we can see it.

That nicely shows the way the convection has gone down the pan in the last 3-6hrs or so.

Worth noting, weak systems often survive the trek over Hispaniola, I've seen some strengthen infact, such as Fay.

[KWT]

This system really need to hope that ULL stops dropping WSW like it is, its heading right for the system, if it keeps up shear could spike up yet further which won't help this system.

[fci]

Satellite imagery and recon indicate that Isaac is really struggling with ENE wind shear and dry air into the core. There are no squalls within 50nm of the center. Soundings from the islands indicate a good bit of mid-level dry air that's likely being driven into Isaac's core by the persistent ENE wind shear. Good news for the Lesser Antilles is that any 45 mph sustained winds probably cover only a small area, and significant strengthening is unlikely before Isaac crosses into the eastern Caribbean.

I'm not really so sure Isaac will become a hurricane in the NE Caribbean. All other systems have struggled there this year, and I don't think the conditions there are so different than when Ernesto or Seven/Helene passed through. Down the road, I'm still not sure if the center will pass west, over, or east of the FL Peninsula. However, I am starting to doubt whether it will be a hurricane Monday morning.

Excellent news!

I'm not sure that is good news for the western and northern gulf coast

The poster is from "O Town"; Orlando and it is good news for him.
I live in Palm Beach County and it is good news to me.
It's all relative to where you live!

[Gustywind]

Guadeloupe always in orange vigilance should pass soon in red vigilance this afternoon given the latest weather forecast of Meteo-France Guadeloupe.

http://www.meteo.fr/temps/domtom/antill ... ameter=new Date().getTime()

Guadeloupe weather vigilance LEVEL ORANGE for the CYCLONE "ISAAC.



Phenomenon (type, name): TROPICAL STORM ISAAC.

Current position(distance): At 11AM, the center was located by 15 ° 9 N and 59 ° 3 West, about 230 km East-South-East of Guadeloupe.


Characteristics/current intensity of the cyclone: Tropical storm.

Estimated average maximum wind: 75 km/h wind gusts: 95 km/h.

Radius of winds force storm: up to 95 km around the center.

Minimum pressure: 1006 hectoPascals


Current direction (cap): West (270 °)

Speed: 33 km/h

Forecasts (path and intensity): Tropical storm ISAAC will cross this evening the Caribbean arc, the centre being planned to spend on Guadeloupe to 8 pm, which means that our archipelago will experience the worse conditions associated with this storm.This afternoon, the wind strengthens gradually sector northeast with average winds between 45 to 65 km/h and with gusts of 70 to 90 km/h under the highest thundery showers. Near 8PM, it switches to the South-East sector and blows in storm between 65 and 85 km/h sustained winds, 100-120 km/h in wind gusts. It decreases then by the end of the next night averaging 60 km/H Thursday, gusting to 80 km/h.
Rain, sometimes sustained and stormy, are more frequent this afternoon.They intensified in evening and next night and persisted the day of Thursday. Accumulations of rainfall may exceed 100 to 150 mm in 24 hours in many places, and more than 200 mm on the episode. The sea becomes strong and dangerous this afternoon in the Atlantic in a swell of sector East with average low of 2 m 50-3 m, and 3 m to4 m on the night by waves cross of Northeast and Southeast, waves maximum reaching 6 m. In Caribbean, she became agitated high in the night by Southeast swell, average lows of 2 m to 2 m 50.

Comments/Consequences: Probable passage in red vigilance during the afternoon. The bad weather conditions expected are likely to generate high troubles: flooding, overflow of streams and gullies, landslides, problems of transport, falls from branches, riskfrom welter to the coast.

Summary: Strong risk of occurrence of the phenomenon.

The expected impact is important

Validity - periodof the phenomenon: Effects cyclonic from 5 pm and Thursday 02AM. End of the episode scheduled Friday 24/08/2012.

Next newsletter: today Wednesday 22/08/2012 to 530PM.

[KWT]

Looks like the center might go right over you Gustywind in a few hours time, probably won't be anything too interesting, but still worth watching!

[tanguy97]

center getting very close to Guadalupe should pass over northern portion in the next couple hours.

http://flhurricane.com/imageanimator.php?137

No Aric the center will pass over guadeloupe at 7 p.m; Our air port is closing at 5 p.m and the code red at 3 p;m

[ConvergenceZone]

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

LLC?

Wow! He looks pretty pitiful. I'm starting to agree with wxman57's assessment on this storm. I think Isaac may just turn out to be pretty wimpy. Not to say he won't bring some awful and potentially catastrophic flooding to Haiti and DR and other islands but the chances if it becoming a significant hurricane or even a hurricane at all seem to be getting slimmer by the hour. Let's hope that stays the case.

Disclaimer: I don't know what I'm talking about and am not a professional meteorologist. Refer to the people who know what they are talking about to make plans accordingly.

I agree. WXMAN has been pretty damn accurate lately with his tropical predictions.
I know it might sound like he's bearish on every storm, but he's only this way because
the condtions this season just haven't been bullish for development, and I bet you
he's going to be right again on this one...This storm looks pathetic.

[KWT]

center getting very close to Guadalupe should pass over northern portion in the next couple hours.

http://flhurricane.com/imageanimator.php?137

No Aric the center will pass over guadeloupe at 7 p.m; Our air port is closing at 5 p.m and the code red at 3 p;m

Radar does suggest that the center is closer than it looked earlier, I'd agree with Aric, probably 3-4hrs tops before it reaches the island.

[BatzVI]

Just remember, it doesn't take a huge storm to have some really bad effects on the islands...

[KWT]

Just remember, it doesn't take a huge storm to have some really bad effects on the islands...

That is very true indeed, if it does go a touch further south than expected there is going to be a decent amount of rainfall over Haiti which doesn't really need a TS at all...

[Aric Dunn]

The latest frame you can see the center exposed but with some convection beginning to fire in all but the nw quad. just east of Guadalupe.

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


the red arrow is a little light sorry.

[Blown Away]

Radar: http://www.meteo.fr/temps/domtom/antill ... SAIC2.html
Visible Floater: http://www.ssd.noaa.gov/PS/TROP/floater ... short.html

For the first time it looks like the big band east of the circulation center is finally starting to wrap towards the NE quadrant, this area has been dry since the beginning. Also, based on the radar looks like our circulation center has moved above 16N.

[ConvergenceZone]

Just remember, it doesn't take a huge storm to have some really bad effects on the islands...

That is very true indeed, if it does go a touch further south than expected there is going to be a decent amount of rainfall over Haiti which doesn't really need a TS at all...

I agree KWT. This is going to be one heck of a rainstorm with lots of flooding no matter where it goes.....

[adam0983]

The storm was supposed to be weak until it passed the islands. The shear is supposed to let up tonight and Isaac is going to be in an environment with no shear. Once Isaac gets passed the Islands it will get going. All the models except for the Euro take this storm towards Florida's direction. The Euro has been wrong with this storm from day 1 and if the Euro was so mighty as everyone claims why hasn't the NHC gone with the Euro. The Euro has been horrible all season why trust it now.

[KWT]

There certainly looks like there is some sort of rotation to the SW on the LLC we are watching, that area is now into the 1km zone. Hard to tell whether its a MLC or whether its another LLC circulating round.

[Gustywind]

Given the latest infos from the authorities... Guadeloupe should pass in RED level at 3PM.