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

[SFLcane]

Nothing on the GFS... euro will probably crack tonight showing nada.

[NDG]

Is looking like the GFS is back on development, by looking at the 18z run so far, more vorticity north of Hispaniola.

[Cpv17]

Definitely more vorticity on the 18z GFS compared to 12z.

[Bocadude85]

We saw the GFS and Euro do the same thing in 2016 with hurricane Hermine, Euro insisted on development in the Bahamas while the GFS showed no development.

[SFLcane]

Nothing to see on the GFS it looks like the weak wave is entwined into a upper level low over Florida. Rainy holiday weekend for Florida.

[NDG]

Nothing to see on the GFS it looks like the weak wave is entwined into a upper level low over Florida. Rainy holiday weekend for Florida.

Still looks like it will show development over the GOM.

[blp]

Much sharper on the 18z vs 12z. I think GFS is coming around.

[fendie]

Take a look at the TPW loop (below). There is little or no rotation associated with the wave, and TPW isn't extremely high - two strikes against development. In contrast, look a that the wave now emerging off the west coast of Africa. Significant rotation and higher TPW values.

http://tropic.ssec.wisc.edu/real-time/mtpw2/product.php?color_type=tpw_nrl_colors&prod=natl&timespan=72hrs&anim=html5

It's amazing what you can tell about the atmosphere from a Total Precipital Water loop. I see what you mean about a lack of spin associated with this tropical wave. It does look like moisture is streaming towards the persistent (albeit tiny) storms at the crest of the tropical wave (near 18N 57W).

Maybe this persistence will be enough to maintain vorticity as the wave passes north of Puerto Rico and into more a more favorable environment for cyclogenesis. I thInk it's safe to say each model run (ensembles and mesoscale included) will be heavily scrutinized over the coming days. This should come as no surprise given September is almost upon us.

[toad strangler]

GFS has been flip flopping around today. Still a week plus out. If nothing else it’s the 1st time this season to keep tabs on the full swath of models.

[cycloneye]

Texas bound.

[Cpv17]

Texas bound.

Maybe a depression?

[toad strangler]

18z NAVY moving through the Bahamas to the NW. Just a wave but juicy.

[Hurricaneman]

18z NAVY moving through the Bahamas to the NW. Just a wave but juicy.

Nope, closed low near Andros island

[cycloneye]

Detailed discussion from the San Juan NWS:

.SHORT TERM...Rest of today through Thursday...
The unstable conditions and a moist environment will continue
across the region due to the proximity of a TUTT low and associated
trough. The latter will linger north of the islands before it
eventually drifts west northwest and weakens. The tropical wave
is so far expected to cross the local area late Wednesday through
Thursday. The interaction of the Tutt low and the tropical wave
will increase instability and moisture transport across the region
through the end of the work week. Therefore, expect a gradual
increase in moisture transport overnight through early Wednesday
resulting in increased showers and possible thunderstorm activity
over the coastal waters and parts of the islands. During the rest
of the day on Wednesday, good available moisture and instability
will lead to quick development of afternoon showers and thunderstorms
across the interior and western portions of Puerto Rico, as well
as the streamer-like showers and isolated thunderstorms off El
Yunque and downwind of the local islands. Active weather is expected
each afternoon especially over portions of west and northwest Puerto
Rico due to the daytime heating and additional local forcing.

Model guidance continued to suggest Thursday afternoon through Friday
as the wettest period with layered precipitable water values exceeding
2.0 inches. Urban and small stream flooding, as well as quick rises
in water levels along rivers will be likely as well as mudslides in
areas of steep terrain.

[Javlin]

NavGem alittle further N closed above Orlando area Erin like.

http://moe.met.fsu.edu/cgi-bin/navgemtc ... =Animation

[stormlover2013]

Navy worse than cmc

[sphelps8681]

Navy worse than cmc

What are you seeing?

[Javlin]

Navy worse than cmc

I agree to a degree but at least she's in the same playground as the Euro and the GFS;consensus still a couple of days out though.

[gatorcane]

NavGem alittle further N closed above Orlando area Erin like.

http://moe.met.fsu.edu/cgi-bin/navgemtc ... =Animation

The NAVGEM has a really good upper environment conducive for development on its approach to Florida with a large upper anti-cyclone over the Bahamas:



The GFS is completely the opposite hence no development:

[cycloneye]

Saved Loop of wave still east of Leeward Islands. Some more convection than earlier.