ATL: DORIAN - Post-Tropical - Discussion

[sponger]

Ryan Maue
@RyanMaue
Note, this pretty much verified.
HWRF did remarkable for short term rapid intensification.
NHC 950 mb at 00Z.

Such a doom run 2 days ago and it nailed it!

[Blinhart]

Its deepening rapidly but please control the sensationalism

I'm not sensationalizing this at all, I was asking a question that I know many people were thinking.

I'm going to go ahead and cast my vote for sensationalism. Everyone waits around for the new updates wondering "how strong did he get" and almost immediately we get "is this going to be the strongest Ever". That's almost the definition of sensationalism. It's like watching your favorite team make a basket and then immediately thinking "what if they never miss another shot". It's just too much too soon. It's sensational.

I was asking a question of what others thought of were the chances of it happening? I was not stating that it was going to happen. I even stated that I don't think it will happen.

[Hammy]

Waiting to see what this next sonde brings... NE eyewall. Wonder if it hits Cat 4 if they will issue a separate update or wait for 2300 regular one?

They might have a position update with the increased speed, I've seen them do it a few times for hurricane upgrades without doing an actual advisory.

[drezee]

114kts unflagged

9583 +164 +155 132091 111 114 017 00

[Yellow Evan]

Cloud tops seem to be warming. No more full B ring on BD, with the ring being broken on the west side.

[Michele B]

Well we can all feel a little less guilty marveling over this intensifying storm now that a US landfall looks unlikely. However, the Bahamas are still UTG so don't completely forget about them.

You really need to stop this, sounding the all clear and saying a US threat is unlikely is way off from one set of model runs when many of those runs/ensembles still show it over FL.

Sounds to me like TWC mets are also now "hedging" and saying - or showing - that several models are now keeping it near the shoreline, both onshore and off shore.....rather than right across the state, or up the "spine" - like they thought Irma would do for a long time last year.

I'm NOT calling an "all clear" but it looks like we really might see a storm that turns north sooner rather than later. It would be a good thing, or course, and it's not just "wishful thinking" on my part, but it looks like this thing doesn't WANT to meet up with the Bermuda high....which seems poised to pull away before Dorian gets in position.

[supercane4867]

HWRF has Dorian going through another two ERCs before landfall. The first one could begin tonight

[1900hurricane]

Whenever a system like this becomes intense like this with recon coverage, I always play the mental game of

At 00Z, DT is 6.0 for a WMG eye in LG and surrounded by B, which about matches what recon has found *so far*. That should be the basis for the FT. It's close to constraints coming into play considering an FT increase of 0.5 in 6 hr, 1.0 in 12 hr, and 1.5 in 24 hr, but that should still fall under the rapid development curve of a 1.5 T increase per day. Additionally, SATCON has spiked up recently. Microwave estimates haven't been available for a few hours, but they did match well with the 18Z intensity of 100 kt. ADT is at about 110 kt right now, although hamstrung by its own constrains some. Using this data, I'd probably go 115 kt, although a more conservative forecaster might use 110 kt.

[Yellow Evan]

HWRF has Dorian going through another two ERCs before landfall. The first one could begin tonight

HWRF has the ability to predict ERC's now?

[Highteeld]

125 kt FL, 114 SFMR unflagged twice. Needs an upgrade

[Yellow Evan]

Whenever a system like this becomes intense like this with recon coverage, I always play the mental game of

At 00Z, DT is 6.0 for a WMG eye in LG and surrounded by B, which about matches what recon has found *so far*. That should be the basis for the FT. It's close to constraints coming into play considering an FT increase of 0.5 in 6 hr, 1.0 in 12 hr, and 1.5 in 24 hr, but that should still fall under the rapid development curve of a 1.5 T increase per day. Additionally, SATCON has spiked up recently. Microwave estimates haven't been available for a few hours, but they did match well with the 18Z intensity of 100 kt. ADT is at about 110 kt right now, although hamstrung by its own constrains some. Using this data, I'd probably go 115 kt, although a more conservative forecaster might use 110 kt.

http://rammb.cira.colostate.edu/products/tc_realtime/products/storms/2019AL05/4KMSRBDC/2019AL05_4KMSRBDC_201908302330.jpg

This was T5.5 six hours ago, T5.0 12 hours ago IIRC, so not sure how constraints are a problem in this case.

[MetroMike]

Nice 96 frame with Fl and Dorian showing general w/nw motion near the end?

https://weather.cod.edu/satrad/?parms=s ... orbar=data

[supercane4867]

HWRF has Dorian going through another two ERCs before landfall. The first one could begin tonight

HWRF has the ability to predict ERC's now?

I'm not sure how accurate it is but the sudden expansion of the eye can be clearly seen on simulated IR, likely indicates an ERC

[1900hurricane]

Whenever a system like this becomes intense like this with recon coverage, I always play the mental game of

At 00Z, DT is 6.0 for a WMG eye in LG and surrounded by B, which about matches what recon has found *so far*. That should be the basis for the FT. It's close to constraints coming into play considering an FT increase of 0.5 in 6 hr, 1.0 in 12 hr, and 1.5 in 24 hr, but that should still fall under the rapid development curve of a 1.5 T increase per day. Additionally, SATCON has spiked up recently. Microwave estimates haven't been available for a few hours, but they did match well with the 18Z intensity of 100 kt. ADT is at about 110 kt right now, although hamstrung by its own constrains some. Using this data, I'd probably go 115 kt, although a more conservative forecaster might use 110 kt.

http://rammb.cira.colostate.edu/products/tc_realtime/products/storms/2019AL05/4KMSRBDC/2019AL05_4KMSRBDC_201908302330.jpg

This was T5.5 six hours ago, T5.0 12 hours ago IIRC, so not sure how constraints are a problem in this case.

Exactly, I even explicitly mentioned that. Although, I was wrong about ADT's constraints. It has no limit right now.

[ScottNAtlanta]

Recon got a reading of 114kt or about 130mph in this pass through the center.

[Nancy Smar]

Center Temp : +19.5C Cloud Region Temp : -62.0C

[StruThiO]

[johngaltfla]

Current, not future. The steering currents will have to be substantially stronger than currently indicated, in my opinion, to divert or steer a major hurricane like this once it becomes a strong Cat 4 or stronger.

Thats not how steering currents work, but sure thats your opinion.

I'll quote the paper from the US Naval Observatory, Section One, Influences on Tropical Cyclone Motion:

1.3 Tropical Cyclone Winds Affecting Steering

Large TC s have strong winds out to 5-7 miles radially that could affect steering flow computations. Super Typhoon Abby (1983) was large enough (a 30 knot wind radius of over 350 nm or 650 km) that TC winds were included in steering flow computations (Chan, 1986). There is evidence that the steering flow concept may not be as applicable in large size TCs as it is for small size TCs.

The debate at the academic level continues to this day, but I've always referenced the papers which tend to support deviations in storm paths away from steering currents once storms approach what would be considered "Super Typhoon" type status, which this storm might well peak at before it settles down. Everything is about the timing but I will not dismiss out of hand your theory about the steering currents, nor the scientific research about storms creating their own "paths" or environments ahead of impacts on land.

https://www.usno.navy.mil/NOOC/nmfc-ph/ ... /se100.htm

[ScottNAtlanta]

Nice 96 frame with Fl and Dorian showing general w/nw motion near the end?

https://weather.cod.edu/satrad/?parms=s ... orbar=data

I bet there was one hell of a stadium effect for the recon to see before the sun went down

[Kingarabian]

114kts unflagged

9583 +164 +155 132091 111 114 017 00

948-950mb and 115kts is reasonable.