ATL: DORIAN - Post-Tropical - Discussion

[Blown Away]

still looking good

I agree. Some new convection still popping up http://www.ssd.noaa.gov/PS/TROP/floater ... imated.gif

Based on the latest NHC position, 91L should be near 20.5N/63.5W, which is @150 W of the popping convection and rotation around a possible MLC...Not sure how good 91L is...
http://www.ssd.noaa.gov/PS/TROP/floater ... imated.gif

[Alyono]

91L has a beautiful upper-level environment w/ a well-defined anticyclone. It's no wonder its outflow looks so nice.

If the environment was as beautiful as you are saying, the MLC would not be 120 NM east of the LLC

[artist]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Interesting. He states now that he actually spoke to the NHC. He is the met for CBS local Miami

[TropicalAnalystwx13]

91L has a beautiful upper-level environment w/ a well-defined anticyclone. It's no wonder its outflow looks so nice.

If the environment was as beautiful as you are saying, the MLC would not be 120 NM east of the LLC

We don't know if that is a mid-level center or low-level center. Recon didn't investigate it. The feature the plane found earlier could've just been a random vorticy. We won't know until the next mission.

It's not hard to tell based on satellite imagery Dorian is not being affected by shear. Outflow is impressive in all four quadrants. But if you need anymore proof, check 100-250mb winds.

[MGC]

IMO, 91L is not a TC. Needs more convection near the MCL to kickoff a LLC there. Still loads of dry air and the southerly shear near PR will cause it to decouple even more. That ULL looks to be anchored in place so I doubt the shear relaxes until 91L moves towards the western Bahamas......MGC

The above is the opinion of MGC and not an official forecast.

[SapphireSea]

91L has a beautiful upper-level environment w/ a well-defined anticyclone. It's no wonder its outflow looks so nice.

If the environment was as beautiful as you are saying, the MLC would not be 120 NM east of the LLC

We don't know if that is a mid-level center or low-level center. Recon didn't investigate it. The feature the plane found earlier could've just been a random vorticy. We won't know until the next mission.

It's not hard to tell based on satellite imagery Dorian is not being affected by shear. Outflow is impressive in all four quadrants. But if you need anymore proof, check 100-250mb winds.

Shear can happen between any layers of the atmosphere. Just because the winds are nice and light between 500mb-200mb in the same direction does not mean shear is 0. If sea level winds are from E at 20kt and mid level are at E or ESE at 10kt thats 10kt of shear, you will have a an MLC that is 100s of miles east of any LLC.

[SFLcane]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Interesting. He states now that he actually spoke to the NHC. He is the met for CBS local Miami

A very good one at that

[SFLcane]

Stacy is on tonight so well what he has to say next TWO

[gatorcane]

Well DMAX is coming up tonight, and there is some popping convection near the MLC already. If we see convection increase around there tonight, that would indicate an LLC is forming there and this certainly can become a Tropical Storm again quite quickly.

[chaser1]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Really??? Thats interesting, but makes sense. In many forming systems it is not uncommon for a low level center to form, only to get "spit out" because there was no traction (meaning it was transitory almost like an eddie and simply not yet structurally connected to the MLC yet). Until a dominant and distinct low level center has formed, than it simply remains a wave unless or until the mid level vorticity eventually works its way down to the center. To assume that the westward surface wind shift noted by recon "was the center", would have practically meant that Dorian had established a low level center and thus we'd likely be already calling it a depression. Furthermore, the fact that there's no persistance of low level feature yet is confirmation enough that it simply is not yet a depression again. I could'nt agree more that if a LLC were to develop, than it would seem most likely under a bursting convection and likely in line with the MLC.

[TropicalAnalystwx13]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Makes perfect sense and goes along perfectly with what I've been thinking all afternoon.

[Blown Away]

TAFB has our low as "Possible Cyclone" over next 72 hours...This is a change

[boca]

TAFB has our low as "Possible Cyclone" over next 72 hours...This is a change

What was the TAFB showing before I was at work so Im trying to catch up with everyone else.

[chaser1]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Makes perfect sense and goes along perfectly with what I've been thinking all afternoon.

Though this makes senseto me (and perhaps to most), am not to sure of the significance. Ultimately a LLC will have to form "somewhere" prior to Dorian being upgraded and that is not going to happen immediately (given lack of present convection and verified low level circulation center). So is this solely relevant with regards to where models initialize the system center?

[Blown Away]

18z...The initial point was based off the postion that is farther W than where the suspect LLC may be...Guessing there will be some adjustment to these tracks

[Blown Away]

[mg]http://img27.imageshack.us/img27/280/e6kb.jpg[/img]
TAFB has our low as "Possible Cyclone" over next 72 hours...This is a change

What was the TAFB showing before I was at work so Im trying to catch up with everyone else.

Wave w/o a low...

[chaser1]

Which local Miami station is "zoom radar" affiliated with again?

[boca]

[mg]http://img27.imageshack.us/img27/280/e6kb.jpg[/img]
TAFB has our low as "Possible Cyclone" over next 72 hours...This is a change

What was the TAFB showing before I was at work so Im trying to catch up with everyone else.

Wave w/o a low...

Thanks and very interesting

[TropicalAnalystwx13]

ZoomRadar twitter..
Some news... NHC is relocating the center of Dorian ENE of where the current fix is. As of the last fix from NHC the plane flew on only the west side of the system and thus the surface center was placed there. But there is the realization that another center is likely ENE of there. It will need to be investigated by microwave data this evening and the next hurricane hunter flight. - Jeff Berardelli

Makes perfect sense and goes along perfectly with what I've been thinking all afternoon.

Though this makes senseto me (and perhaps to most), am not to sure of the significance. Ultimately a LLC will have to form "somewhere" prior to Dorian being upgraded and that is not going to happen immediately (given lack of present convection and verified low level circulation center). So is this solely relevant with regards to where models initialize the system center?

If the feature on satellite is indeed the center, then 91L is well on its way to becoming Dorian again...much closer than others thought it was. The fact that thunderstorms have constantly developed over this feature today makes me believe we have a well-defined low-level center there.

[Blown Away]

AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MIAMI FL
148 PM EDT SUN JUL 28 2013

...THE TROPICAL WAVE WHICH IS FORMER T.S. DORIAN WILL ACROSS THE
BAHAMAS AT MID WEEK AND APPROACH SOUTH FLORIDA AROUND THURSDAY AND
FRIDAY TIME FRAME. BOTH THE GFS AND ECMWF AGREE WITH THIS
SOLUTION. THE NAM REDEVELOPS DORIAN INTO A TROPICAL SYSTEM NORTH
OF THE BAHAMAS ON WEDNESDAY BUT THE GOOD NEWS IS THAT THE NAM HAS
A HORRIBLE TRACK RECORD WITH TROPICAL SYSTEMS AND SO NOT MUCH
FAITH IS PLACED WITH THAT SOLUTION. AT ANY RATE, THERE COULD BE AN
INCREASE IN SHOWER ACTIVITY AGAIN BY LATE IN THE WEEK AND GOING
INTO NEXT WEEKEND WITH THE MOISTURE INCREASE...