ATL: INVEST 92L - Discussion

[Blown Away]

The NW Carib looks more impressive than the EPAC area which has an 80% chance of development and more model support. Saved loop:

You would think an area of persistent disturbed weather in the NW Caribbean this time of year would get a mention...

[supercane]

You would think an area of persistent disturbed weather in the NW Caribbean this time of year would get a mention...

NHC did mention it in the 8 AM EDT TWO:

000
ABNT20 KNHC 191142
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON OCT 19 2015

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

Showers and thunderstorms over the northwestern Caribbean Sea and
portions of the Yucatan Peninsula are associated with a weak area
of low pressure. Only marginally conducive upper-level winds and
the potential for this system to interact with land should preclude
significant development as this disturbance moves westward to west-
northwestward into the Bay of Campeche during the next few days.
Regardless of tropical cyclone formation, locally heavy rains in
association with this system should spread from the Yucatan
peninsula into southeastern Mexico through at least mid-week.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...10 percent

$$
Forecaster Kimberlain

[LarryWx]

You would think an area of persistent disturbed weather in the NW Caribbean this time of year would get a mention...

NHC did mention it in the 8 AM EDT TWO:

000
ABNT20 KNHC 191142
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
800 AM EDT MON OCT 19 2015

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

Showers and thunderstorms over the northwestern Caribbean Sea and
portions of the Yucatan Peninsula are associated with a weak area
of low pressure. Only marginally conducive upper-level winds and
the potential for this system to interact with land should preclude
significant development as this disturbance moves westward to west-
northwestward into the Bay of Campeche during the next few days.
Regardless of tropical cyclone formation, locally heavy rains in
association with this system should spread from the Yucatan
peninsula into southeastern Mexico through at least mid-week.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...10 percent

$$
Forecaster Kimberlain

What I don't agree with is putting the chance of development within 48 hours at 0%. Also, that is deep and somewhat organized convection likely associated with a very slow moving weak surface low that appears to be offshore to me. Furthermore, shear looks light/favorable rather than just marginally favorable per models to me. In addition, model consensus keeps this offshore another 24 hours. So, for all of these reasons, I'd have the chance within 48 hours up at 10% or maybe even 20%. I don't get the 0% at all.

Edit: After looking at the sat (vis and color IR) loops going through 13:45 Z, I'd raise it to 30% within 48 hours.

[Blown Away]

Weird El Nino Year...

[LarryWx]

Geneses for 10/11-20:

http://www.nhc.noaa.gov/climo/images/10_11_20_nhc.png

[Sanibel]

There might be a second Low forming over Yucatan.

I saw this yesterday.

[LarryWx]

There might be a second Low forming over Yucatan.

I saw this yesterday.

Kudos! Nice call.
Latest vis loop at least suggests a rather tight LLC about 100 miles E of N Belize (I'd love to see buoy reports to confirm this is actually occurring) with little movement, persistent/organized convection, and light shear. So, land interaction shouldn't be interfering much. About the only thing I can think of that would prevent this from becoming at least a TD by tomorrow assuming it stays out over water for nearly another 24 hours per model progs would be the EPAC competing blob, which isn't doing a whole heck of a lot at the moment.
I'd go 30% chance for development in the WC within 48 hours (in reality within 24 hours).

[Weatherwatcher98]

I am watching it. It is the only Game in town.

[supercane]

ABNT20 KNHC 191738
TWOAT

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT MON OCT 19 2015

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

Showers and thunderstorms over the northwestern Caribbean Sea and
portions of the Yucatan Peninsula are associated with a weak area of
low pressure. Only marginally conducive upper-level winds and the
potential for this system to interact with land should preclude
significant development as this disturbance moves westward to west-
northwestward into the Bay of Campeche and the extreme southwestern
Gulf of Mexico during the next few days. Regardless of tropical
cyclone formation, locally heavy rains associated with this system
should spread from the Yucatan Peninsula across southeastern Mexico
during the next few days.
* Formation chance through 48 hours...low...near 0 percent
* Formation chance through 5 days...low...10 percent

$$
Forecaster Kimberlain

[LarryWx]

^For the next 48 hours, the NHC is still following model guidance, which shows a persistent very slow moving weak low that doesn't become a TC, and going with near 0% for that period. I think this is in reality likely at least 10-20% and quite possibly near 30%, which would still mean 70% chance of no development. Perhaps this will be added in the postseason as a TD+ in the WC IF it actually does strengthen into one by tomorrow. It still looks pretty good to me.
Other opinions?

[NDG]

There's still no indication that there's anything developing at the surface in the western Caribbean, broad surface low is still inland over norther Guatemala/southern MX.
Vorticity near the deep convection east of the Yucatan is still above the surface. There is zero model support for development for 92L while all models show development for 97E.
GFS still paints a very wet pattern for coastal TX and parts of LA for later this week.

[gatorcane]

The NW Caribbean convection sure is persistent and it seems to be deepening further with little movement.

[Weatherwatcher98]

Yep something to watch.

[Blown Away]

The NW Caribbean convection sure is persistent and it seems to be deepening further with little movement.

Persistent convection ball with slight rotation in NW Caribbean... NHC seems confident it will move westward over land... Likely the case, but late season can spring up surprises...

[Stormcenter]

Now that does look impressive I must say.

The NW Caribbean convection sure is persistent and it seems to be deepening further with little movement.

Persistent convection ball with slight rotation in NW Caribbean... NHC seems confident it will move westward over land... Likely the case, but late season can spring up surprises...

[LarryWx]

It looks like the battle of the twin blobs.

Does anyone know if there are any buoys nearby? I'm guessing the answer is no because their readings would likely have been posted by now.

This ASCAT looks old (10:44 PM EDT last night I think, before last night's move offshore and today's development):

http://manati.star.nesdis.noaa.gov/asca ... MBas76.png

[stormlover2013]

that will emerge with 92l in the BOC, just good ole moisture babyyy hopefully coming to texas lol

[xironman]

The low right of Belize looks pretty good.

[LarryWx]

The low right of Belize looks pretty good.

Indeed, it does. However, it is running out of time per the models as they have it near its current location over open water til around late morning tomorrow....so maybe another 18 hours or so at most. Afterward, it is progged to move westward into land.

[gatorcane]

there definitely seems to be some kind of spin starting east of Northern Belize and it is stationary still. Latest SAT imagery even shows a high tower developing well out over water. Steering higher up in the atmosphere is not the same as the low-level steering. Should it decided to really deepen overnight, not sure it would just move inland into the Yucatan. All of the models do agree on it getting steered by low-level steering and are showing it inland by tomorrow. Given this good consensus, that is the most likely outcome.