ATL: KIRK - Remnants - Discussion

[Aric Dunn]

We must be looking at two different storms, Aric. I pieced together an ASCAT from 4 separate images (11Z and 12Z). There's not even good support for an LLC, much lest a strengthening TS. Winds 30 kts at most. NHC will keep it at 35 kts because they don't like to go back and forth between TD/TS.

[url]http://wxman57.com/images/12ZKirkASCAT.JPG[/rl]

Fair enough. though we all know scatt data with fast moving systems is suspect.

since this morning it has now shot out a large outflow boundary ( convection building along it, not the convective pattern from last night and not typical for a TS) which of course means the SAL/dry air has found its way in.

[Hurricaneman]

This doesn’t look like a healthy tropical storm, the SAL is wreaking havoc with it

[1900hurricane]

Oh cool, a NAtl tropical cyclone below 10ºN.

[emeraldislenc]

Does not look heathy at all

[LarryWx]

The model consensus is telling me that as long as Kirk doesn’t move W to WNW just N of the Greater Antilles, the CONUS will likely not be affected by Kirk directly as the Caribbean would likely keep him weak and well north of the Antilles would likely recurve well east of the CONUS.

The 12Z CDN ensemble members illustrate the above idea well about the highest risk to the CONUS being within the corridor just N of the Greater Antilles.

[TropicalAnalystwx13]

Kirk is a lesson in the effects of kelvin waves on tropical cyclones. Shear according to the 18z SHIPS is 5kt--that's actually up from the 0kt it recorded at 12z. Ocean temperatures are 27C and climbing, while mid-level RH values are hovering around 70 percent. Despite this, the storm is struggling. That doesn't make sense until you discover that the bulk of a convectively-suppressed kelvin wave is passing overhead. Thanks to this and increasing shear in 3 days or so, dissipation still looks likely before or as Kirk enters the Caribbean.

If it were to make it farther west into the NW Caribbean, there's a convectively-coupled wave that could make things interesting. I find it difficult to believe there will be enough left of Kirk by then though.

[LarryWx]

Oh cool, a NAtl tropical cyclone below 10ºN.

Kirk is tied for 4th furthest south Atlantic TC on record at 8.3N.


Furthest south Atlantic TCs on record (all 5 were 33.0W or further east):

1. 7.2N Isidore 9/4/1990

2. 7.7N #3 of 9/16/1902

3. 8.0N Flora of 9/26/1963

4. 8.3N tied are Pablo of 10/4/1995 & Kirk of 9/22/2018

[chaser1]

Kirk is a lesson in the effects of kelvin waves on tropical cyclones. Shear according to the 18z SHIPS is 5kt--that's actually up from the 0kt it recorded at 12z. Ocean temperatures are 27C and climbing, while mid-level RH values are hovering around 70 percent. Despite this, the storm is struggling. That doesn't make sense until you discover that the bulk of a convectively-suppressed kelvin wave is passing overhead.

Kelvin Wave??? So wait. At the current rate, Kirk's westernmost outflow boundary might reach um....California LOL, before it's own LLC crosses 40W as a result of the anomalous deep layer flow ultimately causing Kirk to whisk off to the west at a warp-speed of 25 mph (in addition to 5 kt's of shear). Are you suggesting that these unusually strong late season deep layer easterlies are "inconsequential"....... or that they in fact are a direct result of Kirk's nemesis - Kahn.... oops, I mean Kelvin?

[cycloneye]

Down to TD.

AL, 12, 2018092400, , BEST, 0, 94N, 343W, 30, 1007, TD

[TropicalAnalystwx13]

Kirk is a lesson in the effects of kelvin waves on tropical cyclones. Shear according to the 18z SHIPS is 5kt--that's actually up from the 0kt it recorded at 12z. Ocean temperatures are 27C and climbing, while mid-level RH values are hovering around 70 percent. Despite this, the storm is struggling. That doesn't make sense until you discover that the bulk of a convectively-suppressed kelvin wave is passing overhead.

Kelvin Wave??? So wait. At the current rate, Kirk's westernmost outflow boundary might reach um....California LOL, before it's own LLC crosses 40W as a result of the anomalous deep layer flow ultimately causing Kirk to whisk off to the west at a warp-speed of 25 mph (in addition to 5 kt's of shear). Are you suggesting that these unusually strong late season deep layer easterlies are "inconsequential"....... or that they in fact are a direct result of Kirk's nemesis - Kahn.... oops, I mean Kelvin?

Nope, what I'm saying is the kelvin wave isn't helping matters. The fast forward speed is an issue too with regard to the ability to maintain a vigorous low-level circulation, but we have precedent for systems moving at this speed without looking like a collection of upper-level outflow and outflow boundaries.

[wxman57]

Possibly down to a TW (tropical wave). Might be an LLC left, though. It still has a tough road ahead.

[Hurricaneman]

Looks like we have convection going off over or near the center

[Hurricaneman]

By the way the convective suppressed kelvin wave was well predicted by models, the models don’t predict much strengthening until Tuesday and that’s when this will have a chance to gain strength until between 60 and 65w and 30 to 35kts of shear become a problem for Kirk after

[galaxy401]

What is it with tropical storms in the MDR and not understanding that you have to slow down if you want to organize further?

There's been what 10 storms in the last 5 years that have struggled partially because of its fast speed.

[brohavwx]

Okay, make like I know nothing ... could you explain how this computes ... PLEASE ... maybe I'm smoking something that I don't now that I am or someone else is.

Tropical Depression Kirk Discussion Number 7
NWS National Hurricane Center Miami FL AL122018
1100 PM AST Sun Sep 23 2018

... A pair of ASCAT passes between 2300 and 0000 UTC indicated that Kirk has likely opened up into a trough of low pressure and no longer has a closed surface circulation.
... The ASCAT data showed almost no sign of the previous surface center of Kirk, so the initial position was shifted significantly to the west, closer to the wave axis.

And both ASCAT passes look like this ...



and

[brohavwx]

Granted winds speeds are low around the CoC ... but its not open.

[brohavwx]

And convective bursts occurring all around, especially on the South, East and North where they were absent a few hours ago.

[Aric Dunn]

[Sciencerocks]

It's closed but very weak!

Probably 5-10 knt westerly winds tops.

[chaser1]

It's closed but very weak!

Probably 5-10 knt westerly winds tops.

Yep, that's about it in a nutshell. Sporadic convection might/should be enough to maintain some level of inflow but it's kinda on life-support at the moment