ATL: DORIAN - Post-Tropical - Discussion

[psyclone]

I'd suggest it's definitely exceeding expectations the past few hours. It may still be ultimately decimated by shear in the Caribbean but at the very least it's getting less fragile.

[SouthDadeFish]

Yes, the convective structure is improving, but I think one should be very careful when assessing the inner-core structure using only IR imagery. These bursts can be very misleading at times. It's quite possible another dry air intrusion collapses this convective burst in a few hours. Sustained, organized convection is key.

I will say that these small systems can experience rapid intensity changes fairly easily though. It's possible this is the start of an intensification period.

[NDG]

If the convection maintains that will make the LLC stay closer to it and not speed off to the west like the GFS and Euro show, it can also make it gain more latitude, gaining more latitude will help it maintain or gain more strength after passing the Lesser Antilles.

[NDG]

Convection has sustained but I think it’s diurnal energy.

Actually is past the diurnal maximum which happens in the early mornings. If convection maintains through the evening then we will know that it is strengthening.

We’ll see, I still think it won’t further develop. I’ve been very pessimistic about this storm, I’m starting to question if it might shut me up.

Is in a very fragile environment, it will be one of those storms that it will not surprise me if it becomes a hurricane because is in a low shear environment and will not surprise me as well if dry air keeps it on tap from becoming a hurricane if if digests some of it from time to time.

[Highteeld]

05L DORIAN 190825 1800 11.4N 53.5W ATL 40 1006

[Kazmit]

Up to 40kts officially, but it could very well be more than that by now.

[CrazyC83]

Up to 40kts officially, but it could very well be more than that by now.

Without an ASCAT pass or Recon, it will be hard to get higher. I'd probably go 45 kt but even that may be conservative?

[gatorcane]

The stronger Dorian gets the more on the right side of the track Dorian should go. Best shot it has long-term is for it to move north of Hispaniola and get into the Bahamas which should put it inbetween two upper-level lows with a window for further development. A distinct possibility exists it goes to the right of Hispaniola as noted by NHC in their last discussion.

[Highteeld]

Latest SHIPS RI indices got very aggressive, especially the 72 hour prog... yikes

[abajan]

05L DORIAN 190825 1800 11.4N 53.5W ATL 40 1006

Oh dear. It's happening.

[NDG]

The stronger Dorian gets the more on the right side of the track Dorian should go. Best shot it has long-term is for it to move north of Hispaniola and get into the Bahamas which should put it inbetween two upper-level lows with a window for further development. A distinct possibility exists it goes to the right of Hispaniola as noted by NHC in their last discussion.

That is correct, even if it was to miss Hispaniola to the south, such a small system will open up into a wave from the low level jet across the Caribbean and where shear is forecasted to pick up again next week.

[Weatherboy1]

This is going to be very tricky. A path shift 50/75 miles to the north could make a huge difference in terms of Dorian's ultimate strength/potential impact on the U.S./Florida. If he misses the shredder/worst of the mountains in Hispanola, then ...

[tgenius]

While anything is possible I am hoping that the dry air penetrates and breaks up the core. The storm is front page on miami herald already too.

[jconsor]

The stronger Dorian gets the more on the right side of the track Dorian should go. Best shot it has long-term is for it to move north of Hispaniola and get into the Bahamas which should put it inbetween two upper-level lows with a window for further development. A distinct possibility exists it goes to the right of Hispaniola as noted by NHC in their last discussion.

Two of the past three ECMWF runs (including today's 12z) have shown a strong TUTT upper low to Dorian's west and weakened the ridge to its north, enough to allow Dorian to turn NW in the E Caribbean across Hispaniola and toward the Bahamas. Both runs showed a weak system in the E Carib and tonight's run is likely initializing Dorian too weak. A stronger and more vertically deep system would be carried even further north, likely north of Hispaniola.

[Kingarabian]

Yes, the convective structure is improving, but I think one should be very careful when assessing the inner-core structure using only IR imagery. These bursts can be very misleading at times. It's quite possible another dry air intrusion collapses this convective burst in a few hours. Sustained, organized convection is key.

I will say that these small systems can experience rapid intensity changes fairly easily though. It's possible this is the start of an intensification period.

Although this recent SSMIS missed half the system, it does look like there's a lot of dry air is present near the center.

[wxman57]

Nothing unexpected today. Some slow strengthening, as expected. I notice that the new HWRF caps its peak intensity at 44 kts, vs. nearly 100 kts yesterday. GFS, Euro, and Canadian all indicate dissipation in the east Caribbean on Wednesday. NHC intensity forecast is higher than any dynamic guidance. I think they may drop it down below hurricane intensity next advisory.

[1900hurricane]

The sucky thing about small systems is that you need a really clean microwave pass to get a good picture of storm structure.

[SFLcane]

The stronger Dorian gets the more on the right side of the track Dorian should go. Best shot it has long-term is for it to move north of Hispaniola and get into the Bahamas which should put it inbetween two upper-level lows with a window for further development. A distinct possibility exists it goes to the right of Hispaniola as noted by NHC in their last discussion.

Two of the past three ECMWF runs (including today's 12z) have shown a strong TUTT upper low to Dorian's west and weakened the ridge to its north, enough to allow Dorian to turn NW in the E Caribbean across Hispaniola and toward the Bahamas. Both runs showed a weak system in the E Carib and tonight's run is likely initializing Dorian too weak. A stronger and more vertically deep system would be carried even further north, likely north of Hispaniola.

The Euro dissipates it it has for the last few runs.

[Aric Dunn]

models will continue to struggle until we get more data. the synoptic flights and recon tomorrow will help a lot.

the convection is doing its classic waning after the initial core build. it thrusts vorticity into the mid and upper levels and during the pulse down energy is conserved and we get a vertically stacked core .. then the convection builds into this column and you know the rest..

[Hypercane_Kyle]

Looks pretty restricted on the SE quad. Might be some residual easterly shear.