ATL: ARTHUR - Post-Tropical - Discussion

[NDG]

The lowest pressure measured by aircraft was 982.8mb yet the vortex says 988...that seems like an awfully large discrepancy doesn't it. It also looks like the dropsonde missed slightly.

I believe the 982.8 was an extrapolation and 988mb is what was actually measured.

NOAA's planes mslp extraps for some reason are always or most times lower than actual so I always wait for their Vortex message for an accurate reading.

[Alyono]

its NOT dry air. There was some shear this evening.

Dry air is so overused here. Yes, it is a major factor, but not to the extent as stated on these forums

[tolakram]

Live IR loop: http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=31&lon=-79&info=ir&zoom=1&width=1000&height=800&quality=95&type=Animation&palette=ir1.pal&numframes=10

In color: http://wwwghcc.msfc.nasa.gov/cgi-bin/get-goes?satellite=GOES-E%20CONUS&lat=31&lon=-79&info=ir&zoom=1&width=1000&height=800&quality=95&type=Animation&palette=ir2.pal&numframes=10

[TheStormExpert]

its NOT dry air. There was some shear this evening.

Dry air is so overused here. Yes, it is a major factor, but not to the extent as stated on these forums

Yeah I recently checked the shear maps and noticed it has slightly increased just to the east of the circulation. Looks like shear is the least along the western side of Arthur so that should help limit the dry air intrusions.

[UpTheCreek]

No upgrade as per TWC.

[TheStormExpert]

11pm advisory keeps it at 70mph, with pressure of 988mb now, and movement to the North @ 8mph.

[tolakram]

saved radar loop

[Hammy]

as per NHC advisory

Coastal radar data shows that Arthur is having trouble maintaining a
closed eyewall, which is likely due to continued entrainment of dry
air.

[ConvergenceZone]

11pm advisory keeps it at 70mph, with pressure of 988mb now, and movement to the North @ 8mph.

Wow, so much for the rapid intensification that I believed would happen based on how good it looked this morning...Perhaps the NHC is right about topping it off as a CAT 1 storm...

[txwatcher91]

Wow radar showing some 60k plus cloud tops on the eastern side of the center... And IR shows some hot towers. Usually means shear has relaxed and a strengthening phase is about to commence. Much research has been done on hot towers and how they typically precede an aggressive strengthening phase. Tomorrow morning may see a different system, much stronger IMO.

[Alyono]

11pm advisory keeps it at 70mph, with pressure of 988mb now, and movement to the North @ 8mph.

Wow, so much for the rapid intensification that I believed would happen based on how good it looked this morning...Perhaps the NHC is right about topping it off as a CAT 1 storm...

They will likely bust on the low side. Tomorrow is when the intensification has ALWAYS been expected.

[tolakram]

It's still intensifying more rapidly than some of the models predicted. The 12Z euro had Arthur at 983mb in 24 hours, or 12 hours from now, and it's already at 988mb.

[NDG]

I don't know if I agree with the coordinates of 79.1W, it looks more like 79.3W, IMO.

[Aric Dunn]

mid level dry still having a big roll in the convective pattern today.. should eventually become more conducive over night..

[NDG]

It's still intensifying more rapidly than some of the models predicted. The 12Z euro had Arthur at 983mb in 24 hours, or 12 hours from now, and it's already at 988mb.

Good point.

[hurricanehunter69]

Imagine that, Arthur is currently the strongest cyclone on the planet. And could possibly cause significant destruction to the United States. So much for season cancel...?

[hurricanes1234]

Is Arthur trying to see or is this similar to the "dry eye" which we saw last night?

[weathernerdguy]

Is Arthur trying to see or is this similar to the "dry eye" which we saw last night?

Starting to look like last night...

[ozonepete]

Right - and I'd bet that the 11 TCD will mentiom SST's if they haven't aleady...

Crossing isotherms is one major factor in strenthening or weakening systems...

Well they didn't Frank, old friend, because it's not an issue.

[hurricanes1234]

This same 'eye' isn't really that distinct on IR imagery.