ATL: HELENE - Post-Tropical - Discussion

[Nimbus]

992.9 now

With winds from 330 so its moving NW on track

Glad you agree it did did not tracked south of the buoy as you initially thought it was going to do

NHC used this buoy in the 5PM update they have access to the data real time not 20 minutes delayed.
They said the system meandered WNW for a bit and expected the turn to the NW.
Recon plane is in now so they will center it better with radar for the drops and confirm.

[weeniepatrol]

[NDG]

Wow, and the pressure continues to drop.

Atmospheric Pressure (PRES): 992.0 mb

[TallyTracker]

With a storm the size of Helene, the wind/pressure relationship is likely going to support much lower pressures for certain wind speeds. For instance, Helene may already have a pressure in the 980s. While impressive, the winds may still only be 50-60 mph. It may take pressure in the 970s to get a minimal hurricane at this size.

Some of the model depictions of a Cat 2 storm with pressure in the 950s may be accurate. See Ike for instance of a low pressure with huge wind field but Cat 2 winds.

[Zonacane]

With a storm the size of Helene, the wind/pressure relationship is likely going to support much lower pressures for certain wind speeds. For instance, Helene may already have a pressure in the 980s. While impressive, the winds may still only be 50-60 mph. It may take pressure in the 970s to get a minimal hurricane at this size.

Some of the model depictions of a Cat 2 storm with pressure in the 950s may be accurate. See Ike for instance of a low pressure with huge wind field but Cat 2 winds.

Depends on the pressure gradient and the size of the core

[TampaCE]

No Hurricane Warning for Pinellas County. Phew. Looks like we're in good shape here. Even Denis Phillips said it's looking much better for Tampa Bay. *Crossing fingers*

It is. Hopefully we just get our party squalls and some fun weather. It's going to remain miserably hot and humid in the wake of this system (unlike Ian) so anything that reduces power outages is a good thing. I am most pleased with today's developments

I’ve been at work most of the day. Can y’all tell what happened that’s good for Pinellas? Is it the storm taking longer to get organized or something else?

[weeniepatrol]

[StPeteMike]

With a storm the size of Helene, the wind/pressure relationship is likely going to support much lower pressures for certain wind speeds. For instance, Helene may already have a pressure in the 980s. While impressive, the winds may still only be 50-60 mph. It may take pressure in the 970s to get a minimal hurricane at this size.

Some of the model depictions of a Cat 2 storm with pressure in the 950s may be accurate. See Ike for instance of a low pressure with huge wind field but Cat 2 winds.

Ike was running into a high pressure to the west, inside Texas, before landfall. I would imagine the interaction would cause the lower pressure.

[NDG]

Pressure at the buoy continues to drop.

Atmospheric Pressure (PRES): 991.8 mb

[Nimbus]

Pressure at the buoy continues to drop.

Atmospheric Pressure (PRES): 991.8 mb

We got the flip to southwest ( 220 deg true ) passed directly over.

[MJGarrison]

With a storm the size of Helene, the wind/pressure relationship is likely going to support much lower pressures for certain wind speeds. For instance, Helene may already have a pressure in the 980s. While impressive, the winds may still only be 50-60 mph. It may take pressure in the 970s to get a minimal hurricane at this size.

Some of the model depictions of a Cat 2 storm with pressure in the 950s may be accurate. See Ike for instance of a low pressure with huge wind field but Cat 2 winds.

Depends on the pressure gradient and the size of the core

Agree—it’s all about pressure gradient. A larger storm means a greater distance over which the pressure decreases toward the center of the storm, and so a smaller pressure gradient.

Certainly a tighter core will create higher wind speeds, but the background pressure in which that tight core exists is already lower than if it were a smaller storm.


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[weeniepatrol]

[aspen]

Starting to get “that look” now. Convection is gradually building over the center, pressure is dropping, outflow has greatly expanded to almost all quadrants of the storm…could be getting ready for some significant intensification tomorrow.

990.6mb extrap from NOAA is probably 993-992mb in reality, since they usually run a little low.

[Ubuntwo]

Starting to get “that look” now. Convection is gradually building over the center, pressure is dropping, outflow has greatly expanded to almost all quadrants of the storm…could be getting ready for some significant intensification tomorrow.

990.6mb extrap from NOAA is probably 993-992mb in reality, since they usually run a little low.

It is at maximum 991.8 as that is the current buoy observation.

[derpbynature]

https://imgur.com/zgHHiVh

Starting to get "The Look" just as the lights are going out

[NDG]

NOAA recon found lowest pressure near 19.8N and 85.1W but I think it missed the center because of near by deep convection.

221530 1948N 08506W 6958 03096 9905 +146 +113 355013 016 /// /// 03

[zzzh]

Latest convection burst covered the LLC.

[Travorum]

And buoy pressure starts to go back up, overall minimum was 991.8

[cheezyWXguy]

NOAA recon found lowest pressure near 19.8N and 85.1W but I think it missed the center because of near by deep convection.

221530 1948N 08506W 6958 03096 9905 +146 +113 355013 016 /// /// 03

Yep pretty sure they missed the center to the south by a bit. Regardless, that’s like a 10mb drop from the last flight, and ahead of schedule compared to a good number of the models iirc.

[LandoWill]

Does anyone know whatever happened to the swfmd radar that used to have the forecast line of a storm? I remember watching one last year and you could see the wobbles or when it would start to deviate slightly off the forecasted line. they used to have it on their radar, but i remember the one earlier this season it was gone. any other websites with radars with forecast lines?

Edit, they must have fixed it, i found it now

https://www.sfwmd.gov/weather-radar/cur ... conditions