ATL: DORIAN - Post-Tropical - Discussion

[Blown Away]

Interesting to see where Dorian crosses PR, it’s a timing issue between GFS/Euro, faster to get to CONUS the more likely the landfall. So if Dorian goes over E tip of PR, that extra time will favor GFS, if over Central or West it favors Euro...

[abajan]

Definition of the NHC Track Forecast Cone

Definition:

The cone represents the probable track of the center of a tropical cyclone, and is formed by enclosing the area swept out by a set of circles (not shown) along the forecast track (at 12, 24, 36 hours, etc). The size of each circle is set so that two-thirds of historical official forecast errors over a 5-year sample fall within the circle.

So if it’s done properly, the storm center falls within the cone only 66% of the time. A full 33% of the time, one should expect the track of Dorian, for example, to fall outside the cone.

Absolutely. I wonder how many people realize that. This NHC video needs to be shared and re-shared as much as possible.

[USTropics]

Interesting to see where Dorian crosses PR, it’s a timing issue between GFS/Euro, faster to get to CONUS the more likely the landfall. So if Dorian goes over E tip of PR, that extra time will favor GFS, if over Central or West it favors Euro...

Actually, both models hit PR within miles of each other (easier to see on high-res and zoomed in):

00z GFS


00z ECMWF


Biggest difference is really the extent of ridging, even at 72 hours (ECMWF extends all the way into Arkansas):

[Kingarabian]

The goodness is that Dorian is still struggling with dry air and some shear. Cloud tops remain warm and the strongest winds are likely sparse and near the center.

[abajan]

Despite Homestead and the keys being out of the cone, there’s still a chance of TS Force Winds.

And there's still a chance they'll get the full impact!
https://www.youtube.com/watch?v=04QRN5gUe08

[GCANE]

 https://twitter.com/pppapin/status/1166588454018457600

[LarryWx]

The goodness is that Dorian is still struggling with dry air and some shear. Cloud tops remain warm and the strongest winds are likely sparse and near the center.
https://i.imgur.com/oqBiKam.png

The problem is that Dorian is more like a powerful engine in idle rather than an engine that is sputtering.

[HDGator]

The goodness is that Dorian is still struggling with dry air and some shear. Cloud tops remain warm and the strongest winds are likely sparse and near the center.
https://i.imgur.com/oqBiKam.png

The problem is that Dorian is more like a powerful engine in idle rather than an engine that is sputtering.

Best analogy I have read in three days.

[GCANE]

[GCANE]

Last Vortex Message from Recon indicated an elliptical eye open in the SW.
2C warm core measured at 850mb

[Kingarabian]

The goodness is that Dorian is still struggling with dry air and some shear. Cloud tops remain warm and the strongest winds are likely sparse and near the center.
https://i.imgur.com/oqBiKam.png

The problem is that Dorian is more like a powerful engine in idle rather than an engine that is sputtering.

Unfortunately there does not look like there's enough shear to keep it at bay after it passes PR.

[Bocadude85]

COC starting to come into San Juan radar view

https://radar.weather.gov/ridge/radar.php?rid=JUA&product=N0R&overlay=11101111&loop=yes

[GCANE]

Poleward outflow channel has kicked in.
Outflow is actually better than I expected yesterday with the eastern half improving.
Getting the ring of 200mb PV at about the optimal distance from the CoC.

[GCANE]

COC starting to come into San Juan radar view

https://radar.weather.gov/ridge/radar.php?rid=JUA&product=N0R&overlay=11101111&loop=yes

Long range shows the eye

https://radar.weather.gov/ridge/radar.p ... A&loop=yes

[Nancy Smar]

AL, 05, 2019082806, 03, OFCL, 0, 164N, 635W, 50, 0, TS, 34, NEQ, 50, 30, 0, 30, 0, 0, 0, 60, 0, , 0, JPC, 310, 10, , , 12, NEQ, 45, 30, 15, 45,
AL, 05, 2019082806, 03, OFCL, 0, 164N, 635W, 50, 0, TS, 50, NEQ, 20, 0, 0, 0, 0, 0, 0, 60, 0, , 0, JPC, 310, 10, , , 12, NEQ, 45, 30, 15, 45,
AL, 05, 2019082806, 03, OFCL, 3, 168N, 639W, 50, 1003, TS, 34, NEQ, 50, 30, 0, 30, 0, 0, 0, 60, 0, , 0, JPC, 310, 11, , , 12, NEQ, 45, 30, 15, 45,
AL, 05, 2019082806, 03, OFCL, 3, 168N, 639W, 50, 1003, TS, 50, NEQ, 20, 0, 0, 0, 0, 0, 0, 60, 0, , 0, JPC, 310, 11, , , 12, NEQ, 45, 30, 15, 45,
AL, 05, 2019082806, 03, OFCL, 12, 179N, 653W, 55, 0, TS, 34, NEQ, 50, 30, 0, 30, 0, 0, 0, 65, 0, , 0, JPC, 310, 12,
AL, 05, 2019082806, 03, OFCL, 12, 179N, 653W, 55, 0, TS, 50, NEQ, 20, 0, 0, 10, 0, 0, 0, 65, 0, , 0, JPC, 310, 12,
AL, 05, 2019082806, 03, OFCL, 24, 195N, 668W, 55, 0, TS, 34, NEQ, 60, 40, 20, 40, 0, 0, 0, 65, 0, , 0, JPC, 320, 11,
AL, 05, 2019082806, 03, OFCL, 24, 195N, 668W, 55, 0, TS, 50, NEQ, 30, 0, 0, 20, 0, 0, 0, 65, 0, , 0, JPC, 320, 11,
AL, 05, 2019082806, 03, OFCL, 36, 214N, 682W, 60, 0, TS, 34, NEQ, 70, 50, 20, 50, 0, 0, 0, 75, 0, , 0, JPC, 325, 12,
AL, 05, 2019082806, 03, OFCL, 36, 214N, 682W, 60, 0, TS, 50, NEQ, 30, 20, 0, 20, 0, 0, 0, 75, 0, , 0, JPC, 325, 12,
AL, 05, 2019082806, 03, OFCL, 48, 233N, 696W, 65, 0, HU, 34, NEQ, 70, 50, 30, 50, 0, 0, 0, 80, 0, , 0, JPC, 325, 11,
AL, 05, 2019082806, 03, OFCL, 48, 233N, 696W, 65, 0, HU, 50, NEQ, 30, 20, 10, 20, 0, 0, 0, 80, 0, , 0, JPC, 325, 11,
AL, 05, 2019082806, 03, OFCL, 48, 233N, 696W, 65, 0, HU, 64, NEQ, 15, 0, 0, 0, 0, 0, 0, 80, 0, , 0, JPC, 325, 11,
AL, 05, 2019082806, 03, OFCL, 72, 261N, 730W, 80, 0, HU, 34, NEQ, 80, 70, 40, 60, 0, 0, 0, 100, 0, , 0, JPC, 305, 10,
AL, 05, 2019082806, 03, OFCL, 72, 261N, 730W, 80, 0, HU, 50, NEQ, 40, 30, 20, 30, 0, 0, 0, 100, 0, , 0, JPC, 305, 10,
AL, 05, 2019082806, 03, OFCL, 72, 261N, 730W, 80, 0, HU, 64, NEQ, 15, 0, 0, 0, 0, 0, 0, 100, 0, , 0, JPC, 305, 10,
AL, 05, 2019082806, 03, OFCL, 96, 277N, 771W, 85, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 105, 0, , 0, JPC, 295, 10,
AL, 05, 2019082806, 03, OFCL, 120, 290N, 800W, 85, 0, HU, 34, NEQ, 0, 0, 0, 0, 0, 0, 0, 105, 0, , 0, JPC, 300, 7,

[GCANE]

Seems like the core is moist and protected from dry air.
Seeing no lightning around the eye.
All the lightning is occuring in the feeder band to the east.

[GCANE]

Drop 15
Can't get more moist and better lapse rate than this.

[USTropics]

SHIPS increasing RI values, some are nearly 9x normal climo:

Code: Select all

Matrix of RI probabilities
------------------------------------------------------------------------------
  RI (kt / h)  | 20/12 | 25/24 | 30/24 | 35/24 | 40/24 | 45/36 | 55/48  |65/72
------------------------------------------------------------------------------
   SHIPS-RII:    11.7%   40.1%   27.7%   15.0%    0.0%   32.7%   39.5%   33.9%
    Logistic:    11.9%   30.1%   24.3%   18.6%    8.5%   22.4%   23.4%   26.9%

 https://twitter.com/webberweather/status/1166616792929853446

[Aric Dunn]

I litterally just woke up after dreaming dorian was starting to deepen lol.

Radar is pretty impressive. Definitely deepening since recon left.

Might actually make a run at hurricane before likely passing on the east side of PR tonight.

[GCANE]

Mid Atlantic Ridge a bit weaker and more to the east than forecast in previous model runs.
IMHO about the same chance Dorian skirts PR as going over PR.