ATL: Tropical Depression Fay

[Javlin]

From HPC this afternoon:

FINAL...

THE 12Z GFS BACKED OFF ON THE DEPTH OF THE TROUGH COMING INTO THE PACIFIC NORTHWEST LATE IN THE PERIOD...IN LINE WITH THE BLEND CHOSEN FOR THE UPDATE PACKAGE...SO MADE NO CHANGES FOR THE FINAL ISSUANCE OF THE FRONTS AND PRESSURES OVER MOST OF THE NATION FOR DAYS 3 THROUGH 7. COORDINATION WITH TPC RESULTED IN DIRECTING THE POSSIBLE TROPICAL SYSTEM NORTHWARD EAST OF FLORIDA...BUT AGREED WITH THE SPECIALIST THERE THAT CONFIDENCE IN EITHER THE STRENGTH OR TRACK OF THIS LOW IS QUITE LOW. THE 12Z GEM GLOBAL TAKES THE SYSTEM SOUTH OF CUBA...THEN LIFTS IT INTO THE EASTERN GULF OF MEXICO...WHILE THE GFS TRACKS IT NORTHWARD WELL SHORT OF THE FLORIDA COAST IN A HEAVILY SHEARED ENVIRONMENT.

Very interesting Ron I brought this up in the models thread in the sense if GFS data was being injested by the GFDL and HWRF and skewing there outputs possibilily.Still days out and as others have noted look at the trends.Kevin

[Frank2]

From what I was once told (by a meteorologist) the bursting seen in the current IR can indicate weakening, since the [heat] energy is being transported from the surface and released at high levels, much like a balloon, so, that's not conducive to strengthening...

If Derek or one of the other meteorologists here wants to comment, I'd appreciate it...

[Aquawind]

So weird..while the overall envelop has improved greatly from the SW-NE stretched blob to a more symetrical shaped system today. We still have 2 obvious circulations still in very close proximity..and they are like polorized or something to keep them from stacking..lol ohh thats right..this is weather..

[cpdaman]

frank your last two posts appear to me to be well past the border of wishful thinking

[cheezyWXguy]

From what I was once told (by a meteorologist) the bursting seen in the current IR can indicate weakening, since the energy is being transported from the surface and released at high levels, much like a balloon...

Yeah thats true, but more likely associated with stronger storms and major hurricanes. But with invests, where consistent convection is less likely, I dont believe it indicates weakening.

[gatorcane]

Guys in the models thread you will see that the Euro has joined the GFDL and HWRF on a very close SE/E coast of FL approach.

comments, thoughts are welcome.

[Frank2]

frank your last two posts appear to me to be well past the verge of wishful thinking

No, just an observation made under similar circumstances by one of the NHC meteorologists that I worked for...

Again, any professional comments on what I mentioned in the previous post would be appreciated (not to step on gatorcane's claws, er, toes)...

LOL

[txag2005]

Is recon done? If so, I imagine there isn't much of a chance of an upgrade before tomorrow unless another flight is scheduled.

[Derek Ortt]

no Frank... the burst warms the core... if a burst collapses, that causes weakening as there are large scale downdrafts

[RL3AO]

Is recon done? If so, I imagine there isn't much of a chance of an upgrade before tomorrow unless another flight is scheduled.

Recon is there for another 5 hours with a new flight arriving at 1am ET.

[txag2005]

Is recon done? If so, I imagine there isn't much of a chance of an upgrade before tomorrow unless another flight is scheduled.

Recon is there for another 5 hours with a new flight arriving at 1am ET.

Sorry I'm new to all this. Recon will be flying in the system for another 5 hours?

[NEXRAD]

Guys in the models thread you will see that the Euro has joined the GFDL and HWRF on a very close SE/E coast of FL approach.

comments, thoughts are welcome.

Models tend to "windshield-wiper" around in the medium-range when it comes to tropical cyclones. My suspicion for the current jump in the models is that some additional data from the NOAA high altitude jets was incorporated into the 12Z runs but not as much in the 00 or 06Z runs. It also seems that the 12Z models are all better initialized for 92L's position. If I'm recalling right, the 00Z and 06Z runs were initialized with a couple of different starting points for 92L.

It's worth noting that other 12Z models (e.g. the CMC) have also shifted west and some still are farther east. The overall envelope for the model handling of 92L goes from south of Cuba and the East Central Gulf of Mexico all the way to east of the Bahamas. That's a really big window.

- Jay

[Frank2]

Derek,

Ah - thanks - I had a feeling that it wasn't quite right (over the ballpark fence, perhaps, but, it's still a foul ball)...

LOL

[Derek Ortt]

Guys in the models thread you will see that the Euro has joined the GFDL and HWRF on a very close SE/E coast of FL approach.

comments, thoughts are welcome.

Models tend to "windshield-wiper" around in the medium-range when it comes to tropical cyclones. My suspicion for the current jump in the models is that some additional data from the NOAA high altitude jets was incorporated into the 12Z runs but not as much in the 00 or 06Z runs. It also seems that the 12Z models are all better initialized for 92L's position. If I'm recalling right, the 00Z and 06Z runs were initialized with a couple of different starting points for 92L.

It's worth noting that other 12Z models (e.g. the CMC) have also shifted west and some still are farther east. The overall envelope for the model handling of 92L goes from south of Cuba and the East Central Gulf of Mexico all the way to east of the Bahamas. That's a really big window.

- Jay

There was no G-IV flight last night

[RL3AO]

Is recon done? If so, I imagine there isn't much of a chance of an upgrade before tomorrow unless another flight is scheduled.

Recon is there for another 5 hours with a new flight arriving at 1am ET.

Sorry I'm new to all this. Recon will be flying in the system for another 5 hours?

E. 14/1700Z TO 15/0000Z

Mission goes from 17z to 0z (1pm ET to 8pm ET).

[Aquawind]

Is recon done? If so, I imagine there isn't much of a chance of an upgrade before tomorrow unless another flight is scheduled.

There might be enough obs/facts in addition to visable data yet to make a descision..but clearly nothing pertaining to the core of this wave has done anything quickly..so no hurries imo. This stacking issue is what they call critical..lol

[Wthrman13]

From what I was once told (by a meteorologist) the bursting seen in the current IR can indicate weakening, since the [heat] energy is being transported from the surface and released at high levels, much like a balloon, so, that's not conducive to strengthening...

If Derek or one of the other meteorologists here wants to comment, I'd appreciate it...

Nope. The stronger the convection, the more intense the TC, or at least it signals intensification. Strong convection indicates a warming core, which leads to falling pressures at the surface. Once a TC gets established, and particularly if it has a clear eye, the warm core is maintained more by subsidence warming in the eye, which in turn is forced by convection in the eyewall. So, you can have situations where the convection levels off in intensity, but structural changes in the eye and eyewall can still maintain a strong warm core and intense cyclone. Bottom line is, in developing TC's, the more convection near the center, the better.

[Stormcenter]

Guys in the models thread you will see that the Euro has joined the GFDL and HWRF on a very close SE/E coast of FL approach.

comments, thoughts are welcome.

Models tend to "windshield-wiper" around in the medium-range when it comes to tropical cyclones. My suspicion for the current jump in the models is that some additional data from the NOAA high altitude jets was incorporated into the 12Z runs but not as much in the 00 or 06Z runs. It also seems that the 12Z models are all better initialized for 92L's position. If I'm recalling right, the 00Z and 06Z runs were initialized with a couple of different starting points for 92L.

It's worth noting that other 12Z models (e.g. the CMC) have also shifted west and some still are farther east. The overall envelope for the model handling of 92L goes from south of Cuba and the East Central Gulf of Mexico all the way to east of the Bahamas. That's a really big window.

- Jay

Yeah but the "money" models are the ones the NHC pays the most attention to and
those are the one that have it along the Florida east coast.

[Just Joshing You]

No one commented on Dvorak T-Numbers up to 2.0?

[RL3AO]

No one commented on Dvorak T-Numbers up to 2.0?

Whats there to comment about? It could be a T2.5 it looks so good, but without a closed LLC...