ATL: ISAIAS - Post-Tropical - Discussion

[tiger_deF]

The lowest pressure at 4PM seems to be the east end of the island at 29.45" (997.3mb)

Not sure if its closed off though.

https://i.imgur.com/2yxWjT9.png

https://i.imgur.com/P8xddlR.png

'
I think it would be more impressive if a broad elongated low pressure area had such a relative pressure drop than if it was closed

[aspen]

When will the next recon flight take off? Or would it be postponed if Isaias remains too close to Hispaniola for too long?

[curtadams]

The lowest pressure at 4PM seems to be the east end of the island at 29.45" (997.3mb)
Santo Domingo (South Shore) at 29.62"
Puerto Plata (North Shore) at 29.55"

The real point would be that the entire DR is in a low-pressure area with fairly similar pressures. Definitely will be at least a tropical low after moving off Hispaniola but perhaps too large to re-organize before it reaches the Bahamas and even the US mainlands (assuming it even does get here.)

[Highteeld]

https://weather.cod.edu/satrad/?parms=m ... =undefined

[jlauderdal]

Isaias seems to be 'ignoring' Hispaniola.

inflow could be choked as it moves away, something to watch for the next 12 hours

[Ubuntwo]

Any guesses for the NHC's upcoming intensity and track? I'll go with 60 kt max, just as they have it now and they move the cone east a good ways.

Depends if Stewart is doing the forecast or not

65kt, because that's in ATCF

[jlauderdal]

Any guesses for the NHC's upcoming intensity and track? I'll go with 60 kt max, just as they have it now and they move the cone east a good ways.

65nts max, nudge to the east because of the intensity increase..they wont go to a hurricane yet but if this intensification continues at 11 pm they will

[craptacular]

When will the next recon flight take off? Or would it be postponed if Isaias remains too close to Hispaniola for too long?

There is one scheduled to take off in about 40 minutes (5:30 EDT), per the Plan of the Day posted yesterday.

[GCANE]

The lowest pressure at 4PM seems to be the east end of the island at 29.45" (997.3mb)
Santo Domingo (South Shore) at 29.62"
Puerto Plata (North Shore) at 29.55"

Obvious where the surface low is especially with the strong convection firing from winds piling up against the mountains.
Not sure if its closed off though.

https://i.imgur.com/2yxWjT9.png

https://i.imgur.com/P8xddlR.png

There were some west winds around Puerto Plata but they just shifted to the east.
Could be outflow from that strong convection.
No other west winds I can see around the island.

[Evil Jeremy]

I can feel S2k collectively holding in it's breath while the NHC takes every second they have to put together this advisory package.

[AutoPenalti]

I can feel S2k collectively holding in it's breath while the NHC takes every second they have to put together this advisory package.

You could literally cut the tension with a knife.

[Evil Jeremy]

A Tropical Storm Watch has been issued for the east coast of
Florida from Ocean Reef northward to Sebastian Inlet.

Discussion highlights:

"There is currently a significant
concentration of convection near the mid-level center that is
located along the northern coast of the island, and recent
surface observations suggest that a new center may be forming
near the area of mid-level rotation seen in satellite imagery. The
advisory position has been placed between the previous estimated
center location and the mid-level center until it becomes more clear
that reformation has occurred."

"The 1200 UTC dynamical model guidance has shifted eastward and now
that Isaias is expected to become a stronger and deeper cyclone,
that also favors a more eastward track. The updated official
forecast is a blend of the various consensus aids. Since the new
center is still in its formative stage some additional shifts in
the track may occur."

"It still needs to be stressed that that there is a higher
than usual amount of uncertainty in the intensity forecast."

No mention of possible future Hurricane Watches for Florida, although Storm Surge Watches are possible down the line.

75MPH Hurricane forecast from 36hrs-96hrs.

[HurricaneFrances04]

Forecast to become a hurricane in the Bahamas but no Hurricane Warning for the Bahamas????

[nativefloridian]

From NHC 5pm Discussion:
CHANGES WITH THIS ADVISORY:

The government of the Bahamas has issued a Tropical Storm Warning
for the northwest Bahamas.

A Tropical Storm Watch has been issued for the east coast of
Florida from Ocean Reef northward to Sebastian Inlet.

[chaser1]

I can feel S2k collectively holding in it's breath while the NHC takes every second they have to put together this advisory package.

Lol, true. I'm thinking no eastward track adjustment and sustained winds at 70 mph

[Jr0d]

only needs to be a few hours of faster motion to push every model into florida before the ridge breaks down.

Lets say the average speed until landfall is 15 mph(assuming it slows down big time before Florida) and is currently 10 hours ahead of the EURO's forecast point, that would mean it would make an extra 150miles before turning north. That is a major difference!

As always with potentially landfalling systems(well any system really), there are so many variables that have huge consequences down the road.

Amateur opinion, NOT to be taken as a professional forecast!

[Evil Jeremy]

The lack of a Hurricane Watch in the Central/Northern Bahamas is odd. I wouldn't be surprised if the Bahamas issues those within the next half hour.

[EquusStorm]

Looks good to me. I'm by far the most curious about what happens with the midlevel center on the north coast... definitely will be up late watching that

[chaser1]

I can feel S2k collectively holding in it's breath while the NHC takes every second they have to put together this advisory package.

Lol, true. I'm thinking no eastward track adjustment and sustained winds at 70 mph

Oops, just saw the 5:00 pm had just come out. Guess I'm wrong on track change though. Sounds like they've adjusted it slightly to the east again

[jlauderdal]

The lack of a Hurricane Watch in the Central/Northern Bahamas is odd. I wouldn't be surprised if the Bahamas issues those within the next half hour.

Brown is the new Stewart, sounds like they want to intensify it more, lets see where that LLC finally forms than we can make a landfall prediction, maybe it neve hits land, runs the gulf stream off the coast and OTS before NC..regardless, we will have to prepare for a high end TS/CAT 1 and don't forget hanna was an over achiever so beware, it can happen...a few hours of motion not in the forecast and you get hit