ATL: ALBERTO - Post-Tropical

[Aric Dunn]

well fine..

here.. I know you all will see it.

The "current" main circ is about to be in the eastern BOC. not to be long winded right now. soooo

image below of a little bit ago show 3 vorts the southernmost one is the largest and most defined. if you toggle the slider back and forth you will see all 3 vorts. The northern one ( which is what I though earlier was a likely candidate) is rotating around this southern. the vort offshore os dropping south and previously passed by the station along the coast and you can see the change in wind direction as it went by. it also explains the current wind direction.

that same station is about to see another wind switch as the larger circ approaches.

SO it appears the ICON has pretty much nailed the idea of the wave/circ and the ridging being strong enough to push the energy into the BOC.. will be an interesting next 24 hours from a science point of view.
will likely see convection build with this circ as it approaches the boc ..

make sure toggle this loop and you will see.
http://weather.cod.edu/satrad/exper/?pa ... colorbars=

[Alyono]

since the model thread somehow was locked

WTNT82 EGRR 240403

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 0000UTC 24.05.2018

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 78 HOURS
FORECAST POSITION AT T+ 78 : 23.6N 83.3W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 27.05.2018 84 24.8N 83.6W 998 37
0000UTC 28.05.2018 96 27.2N 84.3W 992 40
1200UTC 28.05.2018 108 28.6N 84.5W 988 48
0000UTC 29.05.2018 120 30.2N 83.7W 989 33
1200UTC 29.05.2018 132 31.4N 84.2W 993 27
0000UTC 30.05.2018 144 32.0N 85.0W 996 23

[Alyono]

WTNT82 EGRR 240403

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 0000UTC 24.05.2018

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 78 HOURS
FORECAST POSITION AT T+ 78 : 23.6N 83.3W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 27.05.2018 84 24.8N 83.6W 998 37
0000UTC 28.05.2018 96 27.2N 84.3W 992 40
1200UTC 28.05.2018 108 28.6N 84.5W 988 48
0000UTC 29.05.2018 120 30.2N 83.7W 989 33
1200UTC 29.05.2018 132 31.4N 84.2W 993 27
0000UTC 30.05.2018 144 32.0N 85.0W 996 23

[AJC3]

Please keep the criticism of model output a little less pointed. The mods and admins here are already tired of tone of several of the "model war" posts that we've seen on here. And please keep the tone of your posts respectful toward each other. Thanks.

[Twisted-core]

ICON 144 hours.. landfall Brownsville lol ..

Ircon model as fsr as i know is nonhydrostatic cored.model and a v/handy mesoscale for snow forecasting with micro-climates. Topical use ?:sun:

[Sciencerocks]

[CyclonicFury]

00z Euro stronger through 72 hours, appears to have a tropical storm northeast of the Yucatan Peninsula by that time.

[Aric Dunn]

96 hours.. the euro is about 60mph.. hmm..

[chaser1]

Hmmm. ok.. well I have looked a little closer and have done some more analysis. .. I have found a well defined circ with some vorts rotating around it.

will take some fresh eye's on it if anyone wants to toggle this loop (while I draw up an image) and see if they see what I noticed is going on? it is actually impressive the new goes16 imagery can make out at night.. I love it..

hint look just to the south of where I drew that circle earlier.. use the slider to go back and forth .. you will see it eventually.

also pay attention to the station on the western yucatan.. who can tell me why the wind direction changed ?
https://www.sailwx.info/tmp/5b063ae1_1c46_547.png


http://weather.cod.edu/satrad/exper/?pa ... colorbars=

So, on one hand we clearly see what appears to be a weak and broad but well defined low level turning over West Central Yucatan. Meanwhile, all models (okay, not the ICON perhaps) seem to latch on to a system that wont evolve for another 48 hours or more and seemingly come from the N.W. Caribbean or just north of Yucatan. Models may all be out to lunch especially in light of the seemingly well defined low level swirl that seems to be barreling west...... without convection. Hence, I believe this feature might well continue to move westward in a relative high shear environment and with limited capacity to maintain its own integrity beyond a day or two. Plan B? Yet another feature borne of the existing trough extending south into the far N.W. Caribbean. Thats my take on the present scenario

[Twisted-core]

WTNT82 EGRR 240403

MET OFFICE TROPICAL CYCLONE GUIDANCE FOR NORTH-EAST PACIFIC AND ATLANTIC

GLOBAL MODEL DATA TIME 0000UTC 24.05.2018

NEW TROPICAL CYCLONE FORECAST TO DEVELOP AFTER 78 HOURS
FORECAST POSITION AT T+ 78 : 23.6N 83.3W

LEAD CENTRAL MAXIMUM WIND
VERIFYING TIME TIME POSITION PRESSURE (MB) SPEED (KNOTS)
-------------- ---- -------- ------------- -------------
1200UTC 27.05.2018 84 24.8N 83.6W 998 37
0000UTC 28.05.2018 96 27.2N 84.3W 992 40
1200UTC 28.05.2018 108 28.6N 84.5W 988 48
0000UTC 29.05.2018 120 30.2N 83.7W 989 33
1200UTC 29.05.2018 132 31.4N 84.2W 993 27
0000UTC 30.05.2018 144 32.0N 85.0W 996 23

Here's a visual plot of the 00Z run.


https://imgur.com/7bn1K6u

[Aric Dunn]

Hmmm. ok.. well I have looked a little closer and have done some more analysis. .. I have found a well defined circ with some vorts rotating around it.

will take some fresh eye's on it if anyone wants to toggle this loop (while I draw up an image) and see if they see what I noticed is going on? it is actually impressive the new goes16 imagery can make out at night.. I love it..

hint look just to the south of where I drew that circle earlier.. use the slider to go back and forth .. you will see it eventually.

also pay attention to the station on the western yucatan.. who can tell me why the wind direction changed ?
https://www.sailwx.info/tmp/5b063ae1_1c46_547.png


http://weather.cod.edu/satrad/exper/?pa ... colorbars=

So, on one hand we clearly see what appears to be a weak and broad but well defined low level turning over West Central Yucatan. Meanwhile, all models (okay, not the ICON perhaps) seem to latch on to a system that wont evolve for another 48 hours or more and seemingly come from the N.W. Caribbean or just north of Yucatan. Models may all be out to lunch especially in light of the seemingly well defined low level swirl that seems to be barreling west...... without convection. Hence, I believe this feature might well continue to move westward in a relative high shear environment and with limited capacity to maintain its own integrity beyond a day or two. Plan B? Yet another feature borne of the existing trough extending south into the far N.W. Caribbean. Thats my take on the present scenario

yep that is pretty much it..

only thing is the ICON. it does not keep this well defined circ heading w/wnw. it slows to a stop tomorrow. then turns north keeping it in the divergent shear zone.. given the present status .. a blend between the EURO CMC and ICON sounds about right. and considering the past 3 days the system has done nothing akin to the GFS. we can disregard the GFS for the time being. Tomorrow 12z and for sure by 00z we will know for sure which camp is going to win. GFS ... or every other model lol. after the first 2 days we still wont have a clue given the upper trough set up.. have to wait until it is in place.

[chaser1]

As I just posted in the models thread, present satellite presentation of what appears to be a broad LLC hitch-hiking westward through W. Central Yucatan, just doesn't seem to jive with nearly every model output; Not unless the present apparent LLC were to suddenly hit the breaks and meander northward by 48 or so hours from now. Not sure I buy this feature maintaining itself without adequate convection to at least help induce continued inflow. I think the feature we're all seeing will spin out and an altogether new feature will evolve in time.

[AtlanticWind]

Euro CMC west and GFS Ukmet to the east. Time will tell

[chaser1]

Will no doubt be an interesting evolution (or a big broad rainy comma lol)

[AtlanticWind]

Hwrf shows a hurricane hitting just west of NO


https://www.tropicaltidbits.com/analysi ... 2400&fh=90

https://www.tropicaltidbits.com/analysi ... 2400&fh=90

[AtlanticWind]

Hwrf shows a hurricane in the gulf

https://www.tropicaltidbits.com/analysi ... 2400&fh=90

[AtlanticWind]

HMON

https://www.tropicaltidbits.com/analysi ... 400&fh=108

[Aric Dunn]

Hwrf shows a hurricane in the gulf

https://www.tropicaltidbits.com/analysi ... 2400&fh=90

the max I see is 54 kts... you cant look at eh 850 mb level for weak systems like this. those winds will not translate to the surface. 60 mph is what the HWRF is at and the Euro .

[USTropics]

I've been following the different levels of vorticity for the past 3-4 days. 850mb level (closest to the surface) has definitely increased this evening in the NW Caribbean/Yucatan, but remains quite elongated currently. Continuing up into the atmosphere (700mb), you can start to see the decoupling; there has been an increase over the 850mb vort signature, but also this stagnant area near western Cuba. It seems the area near western Cuba is currently being propped up by it's vort signature at the 500mb levels (this has been moving generally NNW, and seems to be the area the GFS had favored working its way down to the surface ~850mb level in previous runs).

Quick animated image:

[AtlanticWind]

Hwrf shows a hurricane in the gulf

https://www.tropicaltidbits.com/analysi ... 2400&fh=90

the max I see is 54 kts... you cant look at eh 850 mb level for weak systems like this. those winds will not translate to the surface. 60 mph is what the HWRF is at and the Euro .

Pretty low pressure for a tropical storm tho, but I know many cases that pressure is not a definite indicator.