Surface trough east of the Bahamas: (Is INVEST 94L)

[boca]

This area has been persistent over the last view days and it looks like an ULL but moving west towards the Bahamas.

[NDG]

Not an ULL, this is actually a piece of northern energy from a tropical wave that has been traveling across the Atlantic that is interacting with an ULL/trough further north & west.
Models show its weak low level vorticity and moisture envelope really well. They forecast it to continue moving west towards the Bahamas but may not reach FL because of the incoming cold front for the eastern US early next week. GFS is the only model showing the vorticity to become more defined when it reaches the Bahamas.

[NDG]

[AJC3]

Not an ULL, this is actually a piece of northern energy from a tropical wave that has been traveling across the Atlantic that is interacting with an ULL/trough further north & west.
Models show its weak low level vorticity and moisture envelope really well. They forecast it to continue moving west towards the Bahamas but may not reach FL because of the incoming cold front for the eastern US early next week. GFS is the only model showing the vorticity to become more defined when it reaches the Bahamas.

The early afternoon TWD shows this analysis to be spot on...

Tropical Weather Discussion
NWS National Hurricane Center Miami FL
127 PM EDT Fri Jul 19 2019

...TROPICAL WAVES...

A Caribbean tropical wave axis is near 63W from 21N southward,
moving west around 15 kt. Scattered moderate convection extends
from 15N-18N between 63W-67W. The wave has a surface trough as
seen in this morning's scatterometer pass. At 700 mb, the wave is
well-defined from the San Juan and Guadeloupe rawindsondes and the
total precipitable water imagery.

ATLANTIC OCEAN...

Refer to the Tropical Waves section above for details on the three
waves traversing the basin.

A surface trough - broken off from an easterly wave - extends from
23N63W to 26N62W - has scattered moderate and isolated strong
convection from 23N-26N between 60W-65W.

[NDG]

Nice vorticity this morning with this tropical wave now north of P.R. & Hispaniola. Still no model support for development. But I will not be surprised if it flares up really nice as it approaches the Bahamas & SE FL as UL winds become better and reaches even warmer waters, will catch people's attention by then. IMO.
Latest GFS shows it reaching FL but gets absorbed really quick by the unusual July cold front across the eastern US.

[Aric Dunn]

Well that happened fast.. the mid level vort from yesterday working down to the low levels. Very clear there is a llc trying to develop. Deep convection building. No reason we couldnt get a sheared system out of this even with no models support. It has happened before.

[toad strangler]

Very anomalous cold front for mid July.

[NDG]

[Aric Dunn]

I mean shear looks good at all levels from what data we have. but I find it a little suspect with that large upper trough moving west over florida. Very likely we will have some shear. but I dont think it will be enough to stop development. If convection can maintain for the next 24hrs.... at least pulsing this thing has a decent shot as it nears the bahamas.

[cycloneye]

Something to watch.

 https://twitter.com/AndyHazelton/status/1152603190849933319

[Aric Dunn]

Something to watch.

https://twitter.com/AndyHazelton/status/1152603190849933319

most of the dry air appears in the upper levels. but as it approaches the bahamas things to moisten up a lot.

it needs to be watched for sure.

[Aric Dunn]

12z GFS is showing more vorticity and organization. TD or weak TS is possible.

[NDG]

Closer look at the ASCAT pass earlier this morning.

[Aric Dunn]

Vorticity of course is increasing ..

[Tampa Bay Hurricane]

Could this be a quick spin up tropical storm for south Florida like last year’s Gordon?

[Aric Dunn]

Could this be a quick spin up tropical storm for south Florida like last year’s Gordon?

It is not out of the question..

[floridasun78]

i think unlily will be invest because of dry air already kill it as see early afternoon sat pic look already weaking so let see how look by late afternoon

[Aric Dunn]

i think unlily will be invest because of dry air already kill it as see early afternoon sat pic look already weaking so let see how look by late afternoon

the morning will be key for convection.

[sunnyday]

Assuming a depression or trop storm does develop and head toward S Fl, what time frame might be involved? Thank you for your thoughts/ideas.

[Kingarabian]

12Z UKMET weakly develops this once it reaches 35N.