Tropical Wave East of Lesser Antilles

[Hurricaneman]

I have to think this recurves at 60W or west of that based on the Euro and not 40W like the GFS as the GFS is usually too strong with waves off of Africa but where it ultimately turns north will be key and how are the trough ridge positions going to be past 50W. This is one of those times where I would wait until the weekend before making a forecast

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[meriland23]

I understand the trough is steering currently west and then will change in a few days to all this to completely recurve, but, my curiosity is..if it is slower to strengthen than GFS assumes, how long until the trough shifts to drive it back westward? Or is this system destined to curve somewhere even if not by the anticipated trough. I am just curious whether this could potentially be dangerous for the US or not.

[cycloneye]

A tropical wave is forecast to move off the west coast of Africa
on Friday. Conditions appear to be favorable for some development
thereafter while the system moves westward at 10 to 15 mph across
the eastern Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent.

[alienstorm]

Wouldn't be surprise to have this classified as a Depression once it moves off the African coast.
Here is an excellent loop showing the circulation east of the main activity. http://rammb.cira.colostate.edu/ramsdis ... display=24

[mrbagyo]

Based on current imagery, I suspect the center to be very near 8.8N 6.0W - between Seguela and Korhogo, Cote d Ivoire





Here's another excellent tool where you can view images of the global weather, you can mix different kind of imagery and make a loop of it in an instant... and it has a cursor/pointer that shows the coordinates.

SSEC REAL EARTH

[cycloneye]

The latest analysis by the pouch folks.

ECMWF: Analysis continues to start at a low latitude and then track to the northwest on Day 1. After emerging from Africa, P23L intensifies, and except for a brief dip at 108 hours, OW values remain elevated.

GFS: GFS forecasts a westward-tracking tropical storm in the eastern Atlantic in about four days.

UKMET: Continues to forecast moderate OW values that remain fairly steady throughout the five days.

NAVGEM: Large, distinct pouch all five days, but OW peaks at 84 hours at only 3x10-9 s-2.

[Hurricaneman]

Based on current imagery, I suspect the center to be very near 8.8N 6.0E - between Seguela and Korhogo, Cote d Ivoire





Here's another excellent tool where you can view images of the global weather, you can mix different kind of imagery and make a loop of it in an instant... and it has a cursor/pointer that shows the coordinates.

SSEC REAL EARTH

I think you meant 6W

[mrbagyo]

I think you meant 6W

yeah 6W, made a mistake there. thanks for the correction.

[cycloneye]

From DR Jeff Masters blog about this pouch/wave.

STRONG DISTURBANCE STILL WESTBOUND OVER AFRICA

One of the season's strongest ‘Cape Verde’ disturbances is emerging off the West African coast, with virtually all global models forecasting the system to gradually intensify over the weekend as it heads West/Northwest. This strong wave with a cyclonic circulation field has a long history since it developed in the highlands of east-central Africa last weekend and has maintained a low-mid level circulation and significant convection as it crossed north Africa. The most reliable models (especially the GFS) have consistently shown this system developing into a strong cyclone this weekend and early next week – but also shows the system turning Northwestward and eventually northward as it approaches the central Atlantic. The latest (12Z GFS) model run has shown this recurvature occurring a bit further west than earlier runs - but the ‘theme’ of ultimately turning this system out to sea before it can impact the CARIB or US remains unchanged.

[cycloneye]

A tropical wave is forecast to move off the west coast of Africa
on Friday. Conditions appear to be favorable for some development
thereafter while the system moves westward at 10 to 15 mph across
the eastern Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent

[alienstorm]

Seems to be picking up latitude if this is the case it will be a re-curve early.

http://rammb.cira.colostate.edu/ramsdis ... display=12

[gatorcane]

The 12Z ECMWF position 168 hours from now:

[meriland23]

Seems to be picking up latitude if this is the case it will be a re-curve early.

http://rammb.cira.colostate.edu/ramsdis ... display=12

Erm.. I stared at that loop and I didn't see any gain in latitude... are my eyes broken? Or do you guys see the same thing?

[gatorcane]

No I don't see it gaining latitude in that loop.

[abajan]

:uarrow: No I don't see it gaining latitude in that loop.

With the transition from daytime to nighttime imagery in that loop, it's kinda hard to tell.

[Hammy]

I see the GFS has delayed development somewhat as it gets closer to exiting, is this because it has a better handle now that there's a physical wave, or is it starting the same stunt from last year?

[cycloneye]

A tropical wave is forecast to move off the west coast of Africa
on Friday. Conditions appear to be favorable for some development
thereafter while the system moves westward at 10 to 15 mph across
the eastern Atlantic.
* Formation chance through 48 hours...low...near 0 percent.
* Formation chance through 5 days...medium...40 percent

[abajan]

Just to keep things in perspective, 40% means that it is not expected to become a tropical depression within the next five days.

[Hammy]

Just to keep things in perspective, 40% means that it is not expected to become a tropical depression within the next five days.

Actually if something is flat-out not expected to develop they would give a 0% chance. The farther out things go the lower the % chances are, and this has more to do with the level of confidence more than black and white expectations that it either will or won't develop. I have yet to see anything a >50% for the five day that did not have at least 40% for the 48 hour period, even on the storms that have developed.

[meriland23]

It is only 0% cause it can't be any higher than that till it gets off of land. It is so strong that it expects to already be at 40% as soon as it hits the water.