ATL: FAY - Post-Tropical - Discussion

[Aric Dunn]

The vort about to go inland is not at surface.

look at the surface obs to the SW of it.. all still out of the NE.

something will almost certainly come out of the convection and vorticity to the south as it rotates north overnight.

[wxman57]

I would think that the NHC should be starting PTC Six advisories, as it has a "high" chance of development and will be impacting land within 48 hrs (NJ coast). Those are their criteria. The NHC doesn't like starting advisories at 11pm, so perhaps they will initiate PTC advisories at 5am. It's still too disorganized to qualify for a depression. Maybe by tomorrow night...

[sma10]

Normally I would laugh at this Invest with great gusto. However, the propensity for these weak sauce systems so far in 2020 that WANT to develop regardless of negative immediate influences combined with much larger indicators abroad has me too concerned about peak season to laugh.

Yes, feeling the same.

Obviously not a scientific obs, but this kind of has a similar feeling to 2005 (when seemingly every swirl developed). Mind you, not outright predicting we reach the Greek alphabet this season, but at this point it seems like a possibility

[Ubuntwo]

The small circ near Wilmington has started diving SW, maybe even SSW the past few frames on radar. Seems likely to pull a loop and turn back east, considering the generally westerly flow.

If it starts moving east, once diurnal maximum sets in ramping up is inevitable. Of course it could weaken and another center could prop up nearer to the heavy convection.

[Aric Dunn]

The small circ near Wilmington has started diving SW, maybe even SSW the past few frames on radar. Seems likely to pull a loop and turn back east, considering the generally westerly flow.

If it starts moving east, once diurnal maximum sets in ramping up is inevitable. Of course it could weaken and another center could prop up nearer to the heavy convection.

It is dropping that way because of the circ to the south.. you could see just befire sunset on visible. And now on shortwave.

There is even the convergence line between the two vorts.

The southern one will swing north and likely take over by morning. Convection should begin to really fire over it.

If convection does not build with then.of.course the north one will wobble around and eventually take over

[AnnularCane]

Normally I would laugh at this Invest with great gusto. However, the propensity for these weak sauce systems so far in 2020 that WANT to develop regardless of negative immediate influences combined with much larger indicators abroad has me too concerned about peak season to laugh.

Yes, feeling the same.

Obviously not a scientific obs, but this kind of has a similar feeling to 2005 (when seemingly every swirl developed). Mind you, not outright predicting we reach the Greek alphabet this season, but at this point it seems like a possibility

I'm not ready to predict something like that either, but if Klotzbach raises his numbers much more that could take us into Greek alphabet territory.

[Ubuntwo]

Normally I would laugh at this Invest with great gusto. However, the propensity for these weak sauce systems so far in 2020 that WANT to develop regardless of negative immediate influences combined with much larger indicators abroad has me too concerned about peak season to laugh.

Yes, feeling the same.

Obviously not a scientific obs, but this kind of has a similar feeling to 2005 (when seemingly every swirl developed). Mind you, not outright predicting we reach the Greek alphabet this season, but at this point it seems like a possibility

I'm not ready to predict something like that either, but if Klotzbach raises his numbers much more that could take us into Greek alphabet territory.

Think about it this way, if we just follow 2019's pace from here on out, we'll reach Greek letters.

[NXStumpy_Robothing]

The small circ near Wilmington has started diving SW, maybe even SSW the past few frames on radar. Seems likely to pull a loop and turn back east, considering the generally westerly flow.

If it starts moving east, once diurnal maximum sets in ramping up is inevitable. Of course it could weaken and another center could prop up nearer to the heavy convection.

It is dropping that way because of the circ to the south.. you could see just befire sunset on visible. And now on shortwave.

There is even the convergence line between the two vorts.

The southern one will swing north and likely take over by morning. Convection should begin to really fire over it.

If convection does not build with then.of.course the north one will wobble around and eventually take over

It's less of the effect of the southern vort and more due to the general broad rotation that 98L is. While the vort near Wilmington is impressive in its definition and structure, it still is not the definite center of 98L, though the lowest pressures can be found there. The shear in the area seems poised to prevent the broad rotation from finding a vort to consolidate around (due to the removal of convection from over the area of spin), which is what appears to be simulated on the GFS (+ reformation near the Outer Banks). We'll just have to see though.

[Steve]

Blow-up right now seems to be mostly off the NC Coast on IR. It almost looks shear induced, but that could be the eastern side of one of the circulations rotating around the low pressure area. IDK.
https://cdn.star.nesdis.noaa.gov//GOES1 ... 0x1000.gif

There are still differences in the models. GFS pretty much hits Delaware and goes up sort of through Philly/New Jersey into New York. It doesn't get strong - 1004, but it shows some weather rotating through it here and there. GFS doesn't really get it much off the coast, and it initializes off the NC Coast. ICON still mostly stays offshore and hits Long Island a couple mb deeper than the GFS gets. NAM 3km takes it to south Jersey Friday around noon in the 998/997mb range. 12km is about 1003mb at Long Island; 32km is about the same as the 12km but faster.

Luckily it won't be a vicious hit. You don't ever want to see a major take the likely track toward Delaware or southern NJ through Philly, NY, Long Island and all points east and above. That's a lot of impact. Hopefully everyone up that way gets to enjoy a day or two of squalls and feeder bands without any damage or losing power.

[Steve]

Also, that tail is juiced. Many of the depictions show it as a small storm with a long tail. We'll see.

[NXStumpy_Robothing]

Courtesy of the lovely people behind http://tropic.ssec.wisc.edu/tropic.php, some factors are pointing towards the center finding a spot to consolidate around well east of Myrtle Beach/Wilmington and south of Cape Hatteras. Both lower-level convergence and upper-level divergence are at their strongest here; 700mb vorticity max occurs in this area, with the 850mb and 925mb vorticities also having high values here (though maxed out in areas slightly more west and more diffuse overall); the 500mb vorticity level and spin appears to be strongest just northeast of the area; a pocket of negative shear tendency and lower shear has opened near and over the area; and, convection south of Cape Hatteras has really picked up over the past several hours (albeit potentially shear-induced).

Not to mention the previous eddy near Wilmington has lost some definition and appearance on radar as well. Station plots along the coastline have seen a shift in winds, indicating a weakening of this eddy and a return to the larger rotation, as well as a minor twist to now include this new convective mass. I would not be surprised to see something develop in this area in the coming hours.

[CrazyC83]

I would think that the NHC should be starting PTC Six advisories, as it has a "high" chance of development and will be impacting land within 48 hrs (NJ coast). Those are their criteria. The NHC doesn't like starting advisories at 11pm, so perhaps they will initiate PTC advisories at 5am. It's still too disorganized to qualify for a depression. Maybe by tomorrow night...

If the winds will remain offshore and TS watches or warnings are not required, then such advisories would not be necessary.

[CrazyC83]

Normally I would laugh at this Invest with great gusto. However, the propensity for these weak sauce systems so far in 2020 that WANT to develop regardless of negative immediate influences combined with much larger indicators abroad has me too concerned about peak season to laugh.

Yes, feeling the same.

Obviously not a scientific obs, but this kind of has a similar feeling to 2005 (when seemingly every swirl developed). Mind you, not outright predicting we reach the Greek alphabet this season, but at this point it seems like a possibility

I'm not ready to predict something like that either, but if Klotzbach raises his numbers much more that could take us into Greek alphabet territory.

This feels somewhat more like 2011 right now...getting a lot of low-quality early season activity.

[GCANE]

Latest multi IR satellite analysis
Wind field looks better than yesterday

[GCANE]

Latest AMSU core analysis.
It's tightened up and increased in temperature but a strong boundary-layer inversion has set in which is inhibiting convection near the CoC.

[GCANE]

The shear caused by the mid-level jet is beginning to dissipate.
It is now phased with an UL negative-tilt trough and in between two mid-level vorts.
Watching to see if it breaks that boundary-layer inversion.

[GCANE]

A good chunk of that wave just cutoff and is heading for the CoC.
Could get a blowup later today as it starts to entrain.
Stay tuned.

[Aric Dunn]

I see that vort off willmington took over... but has not moved. and another convective burst is being blown off. good news for New England.

Looking more like it may end up being sub-tropical at this point as well. it will pass the gulf stream into cooler waters at about the same time it starts seeing some baroclinic forcing.

[GCANE]

A naked swirl in the morning.
What could be better?

Looking for convection to fire to the west.
May happen.
2500 CAPE to the NE.
Convective inhibition has lifted along the coast with some moderate shear.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 AM EDT Thu Jul 9 2020

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

1. Shower and thunderstorm activity has increased overnight in
association with an area of low pressure located about 60 miles east
of Wilmington, North Carolina. The thunderstorm activity is
currently located well east and northeast of the low's center, but
only a small increase in organization or a reformation of the
center closer to the thunderstorm activity could result in the
formation of a tropical or subtropical cyclone later today or
tonight. The low is expected to move northeastward or
north-northeastward near or just offshore of the North Carolina
Outer Banks later today and then along the mid-Atlantic coast
tonight through Friday night.

Regardless of development, the system is expected to produce
locally heavy rainfall that could cause some flash flooding across
portions of eastern North Carolina, the coastal mid-Atlantic, and
southern New England during the next few days. Gusty winds are also
possible along the North Carolina Outer Banks today, and along
the mid-Atlantic and southern New England coasts Friday and
Saturday. Interests in these areas should monitor the progress of
this system and refer to products from your local National Weather
Service office. An Air Force Reserve Hurricane Hunter aircraft is
scheduled to investigate this system later today.
* Formation chance through 48 hours...high...80 percent.
* Formation chance through 5 days...high...80 percent.

Forecaster Brown