Invest 91L

[Scorpion]

Come on 91L! You can do it!

[senorpepr]

So...is it close to being a Tropical Depression?

I would still resist in thinking that. Although the low has slightly deepened, the overall conditions seem way too harsh. I don't believe the low level conditions are quite tropical cyclone material as well...

[senorpepr]

So...is it close to being a Tropical Depression?

I would still resist in thinking that. Although the low has slightly deepened, the overall conditions seem way too harsh. I don't believe the low level conditions are quite tropical cyclone material as well...

Yeah, after looking at some streamline analyses over the area, southerly winds are still missing on the western side of 91L. Even the westerly winds over northern Colombia are weak...

[HURAKAN]

Shear decreasing big time over the low pressure area, but farther north the story is the opposite.

[kevin]

Code: Select all

Shear to the north of the system increasing wouldn't be a problem right? It might actually help to flare convection. Also if an anticyclone develops over the low then when the low moves it will bring the decreased shear with it?

That's what my thinking goes like. Someone please correct it, I'm not sure that this is correct.

[x-y-no]

So...is it close to being a Tropical Depression?

I'd say not.

There is a rather oblong surface circulation which might be closed, hard to tell. There's basically nothing at the mid-level. a little dip in the flow is all. And while there is a high building at the upper level, it's centered over the coast of Costa Rica, a couple of hundred nautical miles southwest of where it would need to be to help enhance it.

Jan

[senorpepr]

Code: Select all

Shear to the north of the system increasing wouldn't be a problem right? It might actually help to flare convection. Also if an anticyclone develops over the low then when the low moves it will bring the decreased shear with it?

That's what my thinking goes like. Someone please correct it, I'm not sure that this is correct.

The problem in the situation is that the forecasts have the low moving toward the higher shear instead of just keeping it to the north. This will put the shear overhead within a few days.

[x-y-no]

Code: Select all

Shear to the north of the system increasing wouldn't be a problem right? It might actually help to flare convection. Also if an anticyclone develops over the low then when the low moves it will bring the decreased shear with it?

That's what my thinking goes like. Someone please correct it, I'm not sure that this is correct.

If the upper level high were building directly over the LLC, then indeed having a jet to the north could ventilate it and help enhance convection. But things just aren't stacking well enough for that in this case, IMHO.

Jan

[kevin]

Oh cool, I see what you're talking about. At least I got the idea right, which is a start. Where can I find model forecasts for shear?

[krysof]

this system needs a lot of help

[x-y-no]

Oh cool, I see what you're talking about. At least I got the idea right, which is a start. Where can I find model forecasts for shear?

The Penn State site offers that:

http://met.psu.edu/tropical/tcgengifs/

Pick "850-200mb shear" for the model and hour of your choice.

Jan

[MGC]

Sorry but there is just way too much shear in the Caribbean currently. A series of UL lows look to be the culprit as they are causing the subtropical jet to be very intense.....MGC

[kevin]

Oh cool, I see what you're talking about. At least I got the idea right, which is a start. Where can I find model forecasts for shear?

The Penn State site offers that:

http://met.psu.edu/tropical/tcgengifs/

Pick "850-200mb shear" for the model and hour of your choice.

Jan

Thanks I appreciate it, this year I hope to learn a lot about the weather.

[x-y-no]

Thanks I appreciate it, this year I hope to learn a lot about the weather.

Yep ... as far as I'm concerned, that's what this place is about. And a tremendous resource it is.

[HURAKAN]

Well, according to this map the only place where conditions are "favorable" for development right now, is where the disturbance is located!

[HURAKAN]

2:05 PM Atlantic Tropical Weather Discussion

A 1007 MB LOW
HAS FORMED OVER THE SW CARIBBEAN AT 14N79W. A SURFACE TROUGH
EXTENDS S FROM THE LOW TO PANAMA NEAR 9N80W...AND EXTENDS NE
FROM THE LOW TO E CUBA NEAR 20N74W. THIS SYSTEM IS PRESENTLY
WEAK AND IS FORECAST TO DRIFT NE. CONTINUED CONVECTION IN THE
AREA IS LIKELY. IN THE UPPER LEVELS...A NARROW E/W RIDGE IS
OVER THE CARIBBEAN WITH AXIS ALONG 12N BETWEEN 70W-90W ENHANCING
CONVECTION. UPPER LEVEL MOISTURE COVERS THE ENTIRE CARIBBEAN
SEA. THERE IS A STRONG POSSIBILITY OF CONTINUED FLOODING OVER
PARTS OF THE GREATER ANTILLES E OF CUBA INTO THE NE LEEWARD
ISLANDS WITH THE THREAT OF LIFE-THREATENING MUDSLIDES OVER HIGH
TERRAIN.

[Matt-hurricanewatcher]

It has now a broad LLC. Plus the upper ridge is building...If shear keeps going down there is a chance.

[cyclonaut]

This thing has no chance..It can bring very heavy rains too some areas & cause some serious problems but developing into any formidable tropical system is just not in the cards @ this time.

[Matt-hurricanewatcher]

It is not smart to say that something that has a upper level high building over it. With a surface low already formed has no chance. There almost, I can't say it or I will get banned, as bad as the people that say it might become a hurricane over the next 24 hours.

[wx247]

Even though it looks we won't get development out of 91L, it is good to see something to talk about in the Atlantic Basin.

Hopefully the flooding and mudslides caused by this system won't be too severe.