2020 Global Model Runs Discussion (Out thru day 16)

[wxman57]

Don't worry, Floridians, my Gulf of Mexico hurricane barrier is now in place. 00Z and 06Z GFS runs have confirmed this.

[SFLcane]

Don't worry, Floridians, my Gulf of Mexico hurricane barrier is now in place. 00Z and 06Z GFS runs have confirmed this.

Lol, there was never nothing there to break your barrier just the crazy loonie gfs model.

[DestinHurricane]

Looks like GFS still develops it but on Epac side.

[TheStormExpert]

Are we really going to buy the fact that the models show development on the East Pacific side in October during a La Niña?

I mean the MJO is moving from west to east so it lends some credit, but I’m not buying any models showing a major hurricane striking Mexico giving the fact that this basin has seriously underperformed this year.

[SFLcane]

GFS ENS
CAN ENS
EURO ENS

All still hinting at something in the W Carib.

This is true. It just looks like the EPAC will be more favored at least at first.

[tolakram]

Every year we get the cold front talk, I never understand it. The October bump in activity seems directly related to the first strong cold front coming down and dissipating, which is a catalyst for development. Opal 1995 is a good example. It weakened on approach but was still a formidable hurricane when it struck.

Pensacola temperature archive from Weather Underground.


Weather map archive: https://library.noaa.gov/Collections/Digital-Collections/US-Daily-Weather-Maps

Sept 23rd 1995


Without these fronts October would probably be a lot slower. Oh, and fall arrives every year, some are colder than others. Has anyone found any correlation between fall land temperatures and hurricane activity?

[CourierPR]

Joe Bastardi
@BigJoeBastardi
okay. so it was 5 days ago I tweeted this. Last of the impact storms likely coming from W Caribbean origin, Combination of Pattern response/suppressed african wave train. Quite concerned about another major. not for another 10 days or more tho.

[cheezyWXguy]

Don't worry, Floridians, my Gulf of Mexico hurricane barrier is now in place. 00Z and 06Z GFS runs have confirmed this.

Lol, there was never nothing there to break your barrier just the crazy loonie gfs model.

The only thing that may be “loonie” about the gfs at this point is its tendency to overproduce in the epac. The ingredients of the setup are the same as on previous runs, but as I said yesterday, if the front does not make it far enough south in the Caribbean, development may not occur at all due to a lack of interaction between the front and the wave. This is exactly what it’s depicting, and is why the system doesn’t get going until the epac. This is still just as much up in the air as it was yesterday, because the variation of the setup is still pretty significant. This isn’t a climo bias or convective feedback (things i would actually consider loonie), and if any of this is, it’s the strength of the system on the epac side, which I’m not even confident is purely a bias at this point either.

[SFLcane]

Don't worry, Floridians, my Gulf of Mexico hurricane barrier is now in place. 00Z and 06Z GFS runs have confirmed this.

Lol, there was never nothing there to break your barrier just the crazy loonie gfs model.

The only thing that may be “loonie” about the gfs at this point is its tendency to overproduce in the epac. The ingredients of the setup are the same as on previous runs, but as I said yesterday, if the front does not make it far enough south in the Caribbean, development may not occur at all due to a lack of interaction between the front and the wave. This is exactly what it’s depicting, and is why the system doesn’t get going until the epac. This is still just as much up in the air as it was yesterday, because the variation of the setup is still pretty significant. This isn’t a climo bias or convective feedback (things i would actually consider loonie), and if any of this is, it’s the strength of the system on the epac side, which I’m not even confident is purely a bias at this point either.

Well it’s got support from the European ensembles which Is why I just think the initial surge favors the EPAC. Potentially mid month for the Caribbean. Honestly The big thing is to not trust a model signal more than like a week out in the Caribbean for a specific system. These early-season cold fronts are gonna cool off most of the Gulf too.

[SoupBone]

The GFS does this EVERY year.

[cheezyWXguy]

Lol, there was never nothing there to break your barrier just the crazy loonie gfs model.

The only thing that may be “loonie” about the gfs at this point is its tendency to overproduce in the epac. The ingredients of the setup are the same as on previous runs, but as I said yesterday, if the front does not make it far enough south in the Caribbean, development may not occur at all due to a lack of interaction between the front and the wave. This is exactly what it’s depicting, and is why the system doesn’t get going until the epac. This is still just as much up in the air as it was yesterday, because the variation of the setup is still pretty significant. This isn’t a climo bias or convective feedback (things i would actually consider loonie), and if any of this is, it’s the strength of the system on the epac side, which I’m not even confident is purely a bias at this point either.

Well it’s got support from the European ensembles which Is why I just think the initial surge favors the EPAC. Potentially mid month for the Caribbean. Honestly The big thing is to not trust a model signal more than like a week out in the Caribbean for a specific system. These early-season cold fronts are gonna cool off most of the Gulf too.

I agree, which is why my last sentence is in there. My point is, we are still seeing the same setup, but with varying results due to pattern variability. If an argument can be made that, historically, setups like this tend to play out in a way that more likely favors epac development, I would go along with that. But aside from that, a model showing epac development at 10 days out should be taken with as little of a grain of salt as a model showing Caribbean development 10 days out.

[CyclonicFury]

 https://twitter.com/CyclonicFury/status/1309166463970938880

[aspen]

GFS is showing what looks like a CAG setup going into the first days of October, but it’s stuck pumping out TCs in the EPac.

[CyclonicFury]

Climo would suggest the modeled MDR TC may not develop right away, but potentially wait until near the Lesser Antilles, which makes it something to watch if it does not develop quickly.

[cheezyWXguy]

GFS is showing what looks like a CAG setup going into the first days of October, but it’s stuck pumping out TCs in the EPac.

Agreed. 3 epac systems between day 5 and day 10 on the 12z

[ElectricStorm]

GFS is showing what looks like a CAG setup going into the first days of October, but it’s stuck pumping out TCs in the EPac.

The way the EPAC has been lately I doubt anything gets strong over there any time soon

[chris_fit]

12 GFS stalls out the front over C. FL.
12 GFS ENS showing lots of W Carib activity starting in 8 Days (Next Friday)

[Spacecoast]

Weren't the new GEFS ensembles supposed to go out to 35 days? I remember Levi posted one 35day run a while back, but not since.
Is it available somewhere, or has NCEP given up on this feature?
I was looking forward to living in super fantasyland.

[jasons2k]

21 Hurricanes have crossed the Yucatan Channel during Oct / Nov(all recorded years).
The majority of these (12, or 57%) have hit Florida. Naples, Cape Coral, and Panama City seem to be climatologically popular.

2018 MICHAEL PANAMA CITY CAT5
2009 IDA PENSACOLA ET
2005 WILMA NAPLES CAT3
1964 ISBELL NAPLES CAT2
1948 UNNAMED KEYS / MIAMI CAT2
1946 UNNAMED TAMPA CAT1
1924 UNNAMED EVERGLADES / MIAMI CAT1
1921 UNNAMED TAMPA CAT3
1910 UNNAMED CAPE CORAL CAT2
1894 UNNAMED PANAMA CITY CAT3
1873 UNNAMED CAPE CORAL CAT3
1852 UNNAMED APALACHICOLA CAT2

https://i.ibb.co/THDLyQr/Capture6.jpg

Note that Ida (2009) was extratropical at landfall. If one excludes Ida and counts the remaining eleven cases, then eight (73%) of the remainder struck the FL peninsula from Tampa Bay southward. So if a hurricane were to pass through the Yucatán Channel during the months of October and/or November, it would be most likely to impact Central and/or South Florida (peninsular) as a hurricane. Based on historical data, Cat-3 status (105 knots) seems to be the uppermost boundary for these cases at landfall, given the influence of strong vertical wind shear related to incoming autumnal troughs, along with relatively cooler SSTs in the Gulf during October/November vs. August/September. So the fact that Central/South Florida has not been impacted by a major hurricane yet is potentially very good news, since most of the region’s Cat-4+ hits have been related to CV-type, MDR-related activity during the peak months of August and September. (The exception, Cat-4 King ‘50, originated in the W Caribbean in October 1950, but actually headed NNW into Miami: an extremely unusual trajectory and location for the month of October.) So if we get a W-Caribbean major hurricane that tracks through the Channel and impacts Central/South FL, it would almost certainly be no stronger than a Cat-3 at landfall, and would more likely be weakening and/or steady-state than a MH impacting the same region in August/September. Again, very good news. Another Wilma would not be pleasant, but certainly much better than a Cat-4+.

This is a fantastic post, and something that I have been explaining to my relatives in the Tampa Bay area for years.

Even in the summer, yes there is always a chance that a major, even a strong major could hit at the worst possible spot just north of the bay and send a massive surge into the Tampa Bay metro area. It could happen. They even made a fake movie about it called “Hurricane Phoenix.”

However, because of the shape of the coast, odds are that if a storm is moving at such an angle to make a landfall there in the first place, it’s going to be a storm that is getting sheared and picked-up by a trough, and therefore in a weakening phase. That’s why the stronger storms that take a more classic track either go up to the panhandle or they make a direct hit somewhere in South Florida first.

[chris_fit]

12 GFS ENS seems much more active than previous runs - time frame keeps coming in.