ATL: INVEST 95L - Discussion

[AutoPenalti]

Shear is starting to get into it. Dry air as well. This won’t last I feel.

[Nimbus]

Potential flash flood threat for southern facing shores of the big islands?
High cirrus clouds are expanding so ridging is evident over the low surface pressure.

Usually there is shear from off SA that keeps these low riders from spinning up till the western Carib.

[msbee]

Météo des Ouragans (Guadeloupe) FB post with a bad google translation
12 mins ·
The #invest95l brings a very bad weather to the little antilles:

Storms are spreading this sunday on the extreme east of the Caribbean, in parallel with a strong tropical wave called invest #95 l. This wave managed to fight the influence of wind shear and dry air of #Sahara, maintaining its integrity throughout the course to the west through the tropical Atlantic Ocean. The Tropical Wave 21 #ot21 probably took advantage of the rising movement at altitude provided by a large-scale feature called the Kelvin-coupled wave (#Ckw) moving in the region, as Friday #philippepapin has noticed on its Twitter account @pppapin (Naval Research Laboratory).

The expansion of thunderstorms on Sunday above and close to the small antilles, as well as the associated upper rising flow, indicate the force of 95 l. A strong difference at the next level was obvious above 95 l Sunday morning, a sign of the rising flow. The data from the scatterometer #ascat this sunday noon showed northern winds from 45 to 55 km / h on the west side of the wave, with the south winds being well south. No closed traffic was obvious. It wouldn't take much more organization for 95 l to close a surface center and become a tropical depression, but an interaction with the islands will probably cancel this potential.

[msbee]

another FB post from Meteo des Ouragens
Guadeloupe is getting a lot of rain.

Météo des Ouragans
Orange vigilance for heavy rains and thunderstorms in guadeloupe

The afternoon storms brought high quantities of water especially in the grands-backgrounds, on the region of pointoise, Petit-Bourg, guava and capesterre.

Heavy showers may affect these same areas at the beginning of the evening, increasing the risk of flooding.
A relative lull is then expected after 20 hours. The vigilance should then be brought back to the yellow level. Showers sometimes supported and stormy are still possible tomorrow, in a less general way.

The final improvement is expected on Tuesday.

Data Observed:

Rain totals measured in 1 Hours:

64 mm in #capesterre (#Neufchâteau)
36 mm in #petitbourg (#Montebello)

Rain totals measured in 3 Hours:

48 mm at the #commitments.
50 mm in #baiemahault (#convenience)
59 mm in small town (Montebello).
88 mm in capesterre (Neufchâteau)

[SFLcane]

Not much surface forcing so not surprised if this is a batch of clouds by later tonight.

[NDG]

Not much surface forcing so not surprised if this is a batch of clouds by later tonight.

There's actually pretty good surface convergence on the northern edge of the TW compared to 24 hours ago along with the good UL divergence, surface pressures are also 2-3 mb lower than 24 hrs ago.

[cycloneye]

Tropical Weather Outlook
NWS National Hurricane Center Miami FL
800 PM EDT Sun Jul 28 2019

For the North Atlantic...Caribbean Sea and the Gulf of Mexico:

A persistent area of cloudiness and thunderstorms located over the
eastern Caribbean Sea is associated with a tropical wave. This
disturbance is expected to move west-northwestward to northwestward
across the north-central Caribbean Sea during the next few days,
producing locally heavy rainfall and possibly some flooding across
portions of the Lesser Antilles, Puerto Rico and Hispaniola. Little
development of the disturbance, however, is likely during this time
as upper-level winds are becoming less conducive. The system is
forecast to move near or over the Straits of Florida or the Bahamas
by the end of the week where environmental conditions could be a
little more conducive for development.
* Formation chance through 48 hours...low...10 percent.
* Formation chance through 5 days...low...20 percent.

$$
Forecaster Beven

[abajan]

would this stronger and td3 was? looking like going same area as td3 but look will be
stronger before get to bahamas

Insofar as it's winds are concerned, it may not end up as anything noteworthy. However, latest satellite imagery suggests it's already producing copious amounts of rainfall. Praying for Hispaniola - especially Haiti. They've had way more than their fair share of flooding over the last several years.

Way back in 1970, when I was but a lad, there was a weak, slow moving tropical depression which wreaked havoc across a good portion of the Eastern Caribbean, due to prolonged torrential rainfall. Certain parts of Barbados recorded more than 23 inches of rain in just a few hours' time. People generally focus on winds (mostly due to the news media, I think), forgetting that there's also rainfall to consider.

[abajan]

Not much surface forcing so not surprised if this is a batch of clouds by later tonight.

There's actually pretty good surface convergence on the northern edge of the TW compared to 24 hours ago along with the good UL divergence, surface pressures are also 2-3 mb lower than 24 hrs ago.

https://i.imgur.com/kK42EXC.gif

Perhaps Storm2K should change the "Like" button to Agree. Because while I certainly agree with your post, I'm not liking the prospects for countries in the path of this high-rainfall producing system at all!

[wxman57]

Looks like TD Three, part two...

[TheStormExpert]

Model support for 95L and the wave that just emerged Africa has dwindled.

[TheStormExpert]

Looks like TD Three, part two...

Only this time hopefully they don’t classify it.

[SFLcane]

Convection steadily weakening over the graveyard tonight.

[cycloneye]

Location: 14.5°N 63.3°W
Maximum Winds: 25 kt Gusts: nan kt
Minimum Central Pressure: 1011 mb
Environmental Pressure: 1013 mb
Radius of Circulation: 120 NM
Radius of Maximum Wind: 90 NM

[CyclonicFury]

Model support for 95L and the wave that just emerged Africa has dwindled.

That's largely because of the track the ECMWF takes with it. It gets too stretched out due to land interaction with FL.

GFS has never really been bullish on this system to begin with, but GFS Legacy has been.

[Hurrilurker]

St Maarten is right on the northern edge of this. I wonder how much rain we will get from it. We need the rain but we don't need flooding.
we are getting some light rain now.

Yeah, I’m in Anguilla right now. Strong winds the last couple of days, tonight some light rain and some lightning, a bit scary because we were walking back from a restaurant to our hotel on the beach in the dark and the waves were getting a bit ornery too. They’re projecting rain for the next 2 days but it’ll probably be scattered. Honestly I don’t mind the cloud cover because it takes the edge off the hellacious heat during the day.

[msbee]

St Maarten is right on the northern edge of this. I wonder how much rain we will get from it. We need the rain but we don't need flooding.
we are getting some light rain now.

Yeah, I’m in Anguilla right now. Strong winds the last couple of days, tonight some light rain and some lightning, a bit scary because we were walking back from a restaurant to our hotel on the beach in the dark and the waves were getting a bit ornery too. They’re projecting rain for the next 2 days but it’ll probably be scattered. Honestly I don’t mind the cloud cover because it takes the edge off the hellacious heat during the day.

We are having the same weather. Quiet now. I am happy for the rain just as long as its not too much in a short period. Then we get flooding.

[SFLcane]

Upper diffluence was at work this evening now not much left.

[plasticup]

Convection returning near 15 N, 65 W and there looks like a little circulation underneath. Not dead yet, but nothing near as healthy as it was 24 hours ago though.

[tropicwatch]

Good thing 95L doesn't have much convection. Obvious anti-cyclone above it and a circulation below.