Tropical Wave over the SE Bahamas (Is INVEST 91L)

[SoupBone]

Current shear maps do not = a forecast. The GFS has been showing anticyclonic follow developing over this system on approach to Florida as the PV streamer splits with an upper level low backing to the west. The problem seems to be the movement speed is way too fast, and there isn’t enough time to organize after crossing Florida.

Thank you. I'm tired of people using shear analysis maps to "forecast" what a potential tropical cyclone will run into in 5 days as if it's some static thing that never changes

Not quite sure why you're attacking the shear maps. People post everything from current weather conditions to forecasted conditions 10 days in the future. Everyone on this board knows that all of that is subject to change. Every single last piece of it. With that said, you'd have to be going after everyone for posting 10-day forecasts.

[Ian2401]

Anyone have the EPS probability map? Would like to see if the odds have gone back up.

To piggyback off this post... anyone know where to get those graphics? I see them all the time on wxtwitter and can never seem to find it.

[SFLcane]

They can be found here ---> https://lab.weathermodels.com/

[ronjon]

Vorticity is certainly more robust on the 12z GFS and Euro. Have to watch as any potential development is still 4-5 days away. The fast motion of this system riding the ridge will likely prohibit any major development,

[stormlover2013]

wouldn't surprise me if this goes more west of new orleans with that stout ridge

[Siker]

12z EPS is actually much less enthusiastic than the 00z. Only like 10 members develop a depression out of this.

[Aric Dunn]

Another thing... the models keep the vorticity very close or overland all the way to essentially the florida straights. But from the what we currently have the vorticity is well north of DR so lets see if the models start showing more next few runs.

[NDG]

Around 14 to be exact, down from 25 or so last night.

[cajungal]

Wonder how long all this rain will last before we see the sun again. I know many are saying 7-10 days. Cancelled my trip to Grand Isle for tomorrow that I was looking forward to. Because it looks like a complete washout. Trying to reschedule for next Saturday the 8th. Praying rain chances will be a lot lower.

[stormlover2013]

Another thing... the models keep the vorticity very close or overland all the way to essentially the florida straights. But from the what we currently have the vorticity is well north of DR so lets see if the models start showing more next few runs.

So ur saying the models haven’t picked up yet with it going through the straits ?

[Aric Dunn]

Another thing... the models keep the vorticity very close or overland all the way to essentially the florida straights. But from the what we currently have the vorticity is well north of DR so lets see if the models start showing more next few runs.

So ur saying the models haven’t picked up yet with it going through the straits ?

just saying the models have the vorticites all over the place. partially over land fast or slower. north or south, some with little to no vorticity at all. except for the Euro..

[Cpv17]

Another thing... the models keep the vorticity very close or overland all the way to essentially the florida straights. But from the what we currently have the vorticity is well north of DR so lets see if the models start showing more next few runs.

So ur saying the models haven’t picked up yet with it going through the straits ?

The further north it develops, the better chance it has at staying east of us here in Texas and we’d be on the dry side of the storm so we probably wouldn’t get much out of it unless it’s a sheared sloppy mess then maybe.

[Aric Dunn]

18z GFS now showing development much more vorticity and concentrated.

[cycloneye]

8 PM TWO: Up to 20% in 5 days.

Disorganized showers and thunderstorms extending from Hispaniola
northward for a few hundred miles over the adjacent Atlantic
waters are associated with a tropical wave interacting with an
upper-level trough. This activity is forecast to spread westward or
west-northwestward enhancing the rainfall across portions of
Hispaniola, the Turks and Caicos Islands, the Bahamas, and Florida
into early next week. Strong upper-level winds are expected to
prevent any development of this system during the next 2 to 3 days,
but environmental conditions could become less hostile when the
system reaches the eastern Gulf of Mexico during the early to middle
part of next week.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...low...20 percent.

[jlauderdal]

Sofla on the dirty side of this thing..

18z GFS now showing development much more vorticity and concentrated.

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[Steve]

18Z GFS is now mostly in line with the 12Z EC. Both cross the southern tip of Florida mostly not closed and both then cross SELA closed. The difference comes after landfall. Both approach from the ESE, but gfs moves northwest through the middle of LA and ends up in SE OK before turning up and out. Going out, a front picks it up and it rolls north of the blocking conus high which in turn drives the next wave near day 14 into Deep South Texas and northern Mexico.

18Z GFs
https://www.tropicaltidbits.com/analysi ... 3118&fh=72

The European is more west moving after landfall, crosses Louisiana around or south of Alexandria in central LA, bends across the Piney Woods of East Texas, crosses Hill Country intact and dips wsw and sw into Mexico as the Conus ridge builds south and pushes it down. That ridge is farther west and extends through the 4 corners and into the Pacific (if you run at 500mb)

Ecmwf
https://www.tropicaltidbits.com/analysi ... 3112&fh=54

Timelines:

GFS
1) Crossing SFL Monday morning
2) Hits SELA Tuesday evening
3) Crossing the borders and near borders of LA/TX/AR/OK Thursday morning

The GFS has it booking. Storms that take a couple days to get from south Florida to the NCGC like Betsy or Katrina can get a lot stronger. This won’t have time to get very strong at all on the GFS.

ECMWF
1) Crossing SFL Monday morning
2) Hits SELA later Tuesday night or Wednesday early am
3) in SETX Wednesday night
4) Crosses Austin/New Braunfels/San Antonio late Thursday night and into Friday day.

Euro is slightly slower than gfs and presumably why it has it slightly better organized. It’s been known to overdo ridges just as gfs sometimes erodes them too fast. We are in the 5 day window on both models, so they should be getting better in successive runs.

[cycloneye]

@DrRickKnabb
Water vapor loop shows upper-level trough over Bahamas imparting strong wind shear to the tropical wave, preventing development through holiday weekend on approach to Florida. Once in Gulf next week, shear weakens, but will it have enough time over water to form? Don’t tune out!

 https://twitter.com/DrRickKnabb/status/1035684788412329985

[sunnyday]

How much rain is So Fl supposed to get?

[Steve]

How much rain is So Fl supposed to get?

Looks like almost the entire peninsula gets 1.5”+ over the next week. Obviously any feeder training bands for the current gulf system or the one to come could give you that much in less than an hour. I think the HPC is underdoing and that there will be way more localized heavier rains than what’s depicted. JMO. Caveat is that the system itself will probably pass by fairly quickly.
https://www.wpc.ncep.noaa.gov/qpf/p168i.gif?1535769413

[Steve]

Not too much change track wise so far on the GFS to 72 hours. It’s cruising wnw across the Gulf from south Florida toward Louisiana. Turning gets increasingly evident over time but that’s what it won’t have. Unless the next few plots end up taking this farther south than a landfall on sela, I can’t see it getting more than 35-40 knots.