ATL: GONZALO - Remnants - Discussion

[CyclonicFury]

Any guesses on NHC intensity at 5pm? I'm thinking 65kts, but it's the NHC so I wouldn't be surprised if it's lower.

45kt/1000mb. The advisory is out.

[Hurricane Mike]

The Hurricane Center doesn't seem too optimistic about Gonzalo's chances.

[chaser1]

Or he could be transitioning to a CDO dominant form

That's my guess. 5:00 pm will probably bring this to near hurricane intensity. Probably see an eye tonight

[BYG Jacob]

Or he could be transitioning to a CDO dominant form

That's my guess. 5:00 pm will probably bring this to near hurricane intensity. Probably see an eye tonight

Yeah it's a sign he's still improving his organization and maturing as a hurricane (don't @ me on that).

[chaser1]

Ha?! Just posted my thought that Gonzalo is really deepening when I just read that NHC is less then impressed. We'll see..... I'm sticking with an eye popping event tonight.

[wx98]

No change in wind speed:

5:00 PM AST Wed Jul 22
Location: 9.9°N 45.0°W
Moving: W at 14 mph
Min pressure: 1000 mb
Max sustained: 50 mph

[ConvergenceZone]

The Hurricane Center doesn't seem too optimistic about Gonzalo's chances.

Yea, they think it will dissipate in the Carib due to extreme shear, and they are probably right

[MarioProtVI]

I see no reason why this was kept at 50 mph. Apparently it’s CDO is “ragged” which I don’t see really. Would’ve gone 60 mph. NHC really being nitpicky with these storms today....

[Aric Dunn]

Too funny..

[aspen]

Looking a little puffy. Might’ve swallowed a bit of dry air and could be trying to mix it out.

[SouthDadeFish]

I am extremely puzzled. The NHC is great at what they do, but in my opinion, the NHC has been playing catch-up throughout the last 48 h. I don't see how you get an intensity estimate of only 45 kt for a system that has an eye poking out off and on throughout the day and a closed eyewall on MW imagery.

I also don't trust the global models for intensity forecasts with this one, as they have clearly missed something up until this point. They never forecast genesis in the first place. I don't think the HWRF solution is unreasonable. Maybe I'm the one missing something, but we'll see....

[Aric Dunn]

I am extremely puzzled. The NHC is great at what they do, but in my opinion, the NHC has been playing catch-up throughout the last 48 h. I don't see how you get an intensity estimate of only 45 kt for a system that has an eye poking out off and on throughout the day and a closed eyewall on MW imagery.

I also don't trust the global models for intensity forecasts with this one, as they have clearly missed something up until this point. They never forecast genesis in the first place. I don't think the HWRF solution is unreasonable. Maybe I'm the one missing something, but we'll see....

Pretty sure we are all right there with you... lol

[EquusStorm]

Wish we had recon going in sooner so we can know for sure. Seems like a system they're going to conservatively hold then have to bump up 20+ kts in special advisories when/if structure keeps improving, buuuut that of course assuming it doesn't run into the wall of dry air. I don't trust the global models at all on this one, it's going to be a smaller scale game of watching very local conditons, but this could either start falling apart completely in a couple days or rapidly deepen into a significant hurricane and not too much in between. Hard to compromise the forecast between those two extremes

[supercane4867]

It could be undergoing some structural changes. Needs next microwave to confirm.

[AutoPenalti]

Just throwing it out there, what may look great on the outside may not look that way on the inside, some may think NHC have been conservative but if anything they are right on track on intensity.

hint: microwave

[EquusStorm]

Just gonna be obsessively watching that CDO all evening and night to see what changes, dMax should be interesting

[SouthDadeFish]

Fresh microwave within the past hour and my thoughts below:

 https://twitter.com/MikeFischerWx/status/1286046955982987266

[Highteeld]

Tropical Storm Gonzalo Discussion Number 5
NWS National Hurricane Center Miami FL AL072020
500 PM AST Wed Jul 22 2020

Satellite imagery suggests that Gonzalo's intensification has
paused since the last advisory. The cyclone continues to show a
central dense overcast, and microwave imagery indicates a small
convective ring present under the overcast. However, the CDO has
become a bit ragged, and the other banding seen earlier has
dissipated. Subjective and objective satellite intensity estimates
are in the 45-55 kt range, the the initial intensity remains a
possibly conservative45 kt.

The initial motion is now 270/12. There is no change to the
track forecast philosophy. Gonzalo is on the south side of a low-
to mid-level subtropical ridge, and this feature should steer the
storm generally westward at a faster forward speed for the next 60
h or so. After that time, a motion toward the west-northwest is
expected. The new NHC forecast track is again little changed from
the previous track, and it lies very close to the consensus models.

The intensity forecast remains very problematic and of low
confidence. On one side, the cyclone structure, light shear
environment,and warm sea surface temperatures suggest strengthening,
possibly even rapidly, should occur. In addition, the SHIPS-based
guidance and the HWRF still make the system a hurricane. On the
other side, the GFS, UKMET, and ECMWF models continue to forecast
the system to weaken to an open wave by 120 h, possibly due to dry
air entrainment and large-scale subsidence, and microwave imagery
suggests that a tongue of drier air is present west and southwest
of the cyclone. The NHC intensity forecast again compromises
between these extremes, showing Gonzalo peaking as a hurricane in
36-48 h, followed by weakening in deference to the GFS/UKMET/ECMWF.
The new intensity forecast is unchanged from the previous forecast.
As noted before, the small size of this system makes it
susceptible to significant fluctuations in intensity, both upward
and downward

[Frank2]

I wouldn't get too frustrated - the NHC has time and will make needed adjustments. Perhaps it'll be based on what you mentioned, but they've been burned too many times when it comes to upgrading solely on satellite measurements. Nothing like surface or aircraft observations. Outside of an undeniable eye, they might wait for recon to verify it's strength.

Also, the ongoing split between models as they continue to state is a low-confidence forecast and probably why they are hesitant.

Frank

[Kazmit]

Hm. The NHC doesn't seem to mind classifying storms but is much more selective with increasing their intensity.