ATL: HERMINE - Models

[Steve]

I'm looking at the trend, this could be nothing no doubt but the trend is west, euro today is 500 miles west than what it was last night...ridging is holding steady

Look at the map at 500. GFS has the ridge @ 500 embedded in that larger high pressure there which appears impenetrable from the south. It's centered a bit east of here farther up in the atmosphere at 200mb. So the ridge/high is pretty much in place from the surface up through at least 40,000 feet or so (roughly at jet height). Windflow at 200 is up around the larger high toward the TX/LA border. That level appears to have the greatest influence on its movement.

[Siker]

18z GFS ensembles significantly more enthusiastic.

18z:



12z:

[PTrackerLA]

Good catch Siker some strong TC's in the 18z ensembles. I would be surprised if the 00z operational did not come in stronger, we shall see.

[NDG]

18z HWRF has a naked swirl tracking through the central Bahamas, as if it there's strong westerly shear on top of it.

[Steve]

Agreed. It appears to me like the hwrf is over emphasizing or possibly outsizing Fiona's potential influence in the 18z run.

[NDG]

I went back to Earl's archives. Many people were laughing at the Euro when it was showing Earl becoming a very small tight Tropical Storm south of Jamaica/Haiti area while the GFS was not developing it into a weak tropical storm until it would get north of Honduras if not close to Belize. Yes before that the Euro was somewhat all over but once it locked in development over the central Caribbean it was very persistent. The CMC at this point was not developing Earl because it showed westerly shear over the Western Caribbean. The Euro was also the first Global model to show the strong ridging over the the southern US which kept it well south in the BOC while the GFS was showing it to track further north into Tampico

[Aric Dunn]

HWRF doing that same thing almost. very odd.

[jason1912]

 https://twitter.com/blizzardof96/status/768196804538138624

[Bocadude85]

HWRF has a strengthening tropical storm heading for SFla @ 120 hours

http://www.tropicaltidbits.com/analysis/models/hwrf/2016082318/hwrf_mslp_wind_99L_41.png

[TheAustinMan]

The 12Z HWRF parent domain develops nearby Fiona into a hurricane, which may be to blame for HWRF's weakened-development of 99L. Note that Fiona does not reintensify that much when using Fiona's HWRF domain.

[BobHarlem]

The 18Z HWRF parent domain develops nearby Fiona into a hurricane, which may be to blame for HWRF's weakened-development of 99L. Note that Fiona does not reintensify that much when using Fiona's HWRF domain.

This is one of the strangest things i've seen yet. Fiona really seems to be giving a lot of the models pure hell. Anyone have any idea what is going on here?

[SunnyThoughts]

Maybe its the fact that this system has not developed yet with a inner core that the models can latch on to, and the close proximity with Fiona at the same time?

[AutoPenalti]

I don't get it, Fiona is done, no model besides HWRF is intensifying it. What is it seeing??

[deltadog03]

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[BobHarlem]

The 18Z HWRF parent domain develops nearby Fiona into a hurricane, which may be to blame for HWRF's weakened-development of 99L. Note that Fiona does not reintensify that much when using Fiona's HWRF domain.

i looked at this closer, this was from the 12z run, the 18z run doesn't show it.

[TheAustinMan]

The 18Z HWRF parent domain develops nearby Fiona into a hurricane, which may be to blame for HWRF's weakened-development of 99L. Note that Fiona does not reintensify that much when using Fiona's HWRF domain.

i looked at this closer, this was from the 12z run, the 18z run doesn't show it.

Thanks for pointing that out! I've corrected my initial post.

______
18z GFDL. TropicalTidbits has the frame flying off into the Caribbean, but 99L here is depicted emerging into the Gulf of Mexico after a brief trip over South Florida. It does not ramp up the intensity of 99L, but looking at the isobars it appears to suggest some sort of tropical depression.

[gatorcane]

Something doesn't seem right with the GFS. How does it not deepen this with an upper-anticyclone over it with SSTs in the mid to upper 80sF? I noticed the ULL over Florida it once had is much weaker and displaced more to the west than previous runs:

[floridasun78]

models need input from gulf stream plane all models are having error with 99l

[chaser1]

Not only do I think that the 18Z initialized 99L about 50 miles too far the North (about 1 degree), but the HWRF 18Z - 6hr. forecast had 99L at about 17.5N & 60W. Ironically, only the GFDL appears to show a track into the NE Caribbean and south of P.R. Not saying this will occur but just saying that changes things up some if it were to.

[gatorcane]

00Z Guidance, some intensity models have ramped up: