Tropical Wave in Central Atlantic (Is Invest 97L)

[Hurricaneman]

Its looking good, and looks to come off at a really low latitude of about 10N

The GFS develops this after day9 and has a decent tropical storm in the fantasy land of 384hrs in the Bahamas
The Canadian develops this and sends it north of the islands at day 10
The NAVGEM develops this and is at 19N 52W at 180hrs
The Euro doesn't develop it

so this may be one that needs to be kept an eye on but it could also fizzle like previous waves

[cycloneye]

This is new pouch 25L.



http://www.met.nps.edu/~mtmontgo/storms2013/P25L.html

[ouragans]

The African train is definitely in action. This is the third interesting wave, and a 4th one is over central Sudan. I wonder if this one will not be the first wave to cross the Atlantic and reach 60W in good shape

[Gustywind]

Pouch group analysis.

http://www.met.nps.edu/~mtmontgo/synops ... 082200.txt

SYNOPSIS 2013082200

P25L
12N, 7E
700 hPa


ECMWF: Typical African pouch with some uncertain positions. On Day 3, shows signs of splitting into two pouches, east and west. I end up tracking the western one because by Day 5, it is stronger.

GFS: Much smaller than P24L to the west. Eventually, once over the Atlantic, OW values near the center rise a little, but it is so tiny that it hardly registers on the time series.

UKMET: Relatively easy pouch to track while over west Africa. However, this circular pouch is forecast to weaken and become elongated zonally and by 120 hours, it is depicted with the typical SW-NE monsoonal elongation just off the African coast.

NAVGEM: (Not part of early consensus) Track is a bit erratic while over Africa, but otherwise, P25L is easy to track for a pouch over west Africa. Leaves Africa at a higher latitude than ECMWF, GFS, and UKMET. OW stays fairly low, with only a minuscule rise when P25L hits the Atlantic on Day 5.

[Gustywind]

The African train is definitely in action. This is the third interesting wave, and a 4th one is over central Sudan. I wonder if this one will not be the first wave to cross the Atlantic and reach 60W in good shape

Yeah you may be right about that , we wonder a lot concerning these twaves and their shape status As we've entering the peak now numerous twaves could be suspicious especially this one?! We will see more during the next couple of days.

[blp]

Also the 18z FIM picked up on it as well and carries in the same area as GFS just a little faster.

[Hurricaneman]

The 0zGFS doesnt develop it this run, but thats because it stalls it out at 38W and get absorbed into another low pressure at 10 days, that doesn't seem too likely that this stalls for like 96hrs so this might be some kind of feedback issues

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[cycloneye]

The latest analysis by the pouch group.

P25L
12N, 1W
700 hPa


ECMWF: Large, fairly distinct pouch all five days. Only the position near the African coast in uncertain with multiple OW maxima, but that is common there.

GFS: Similar temporary uncertainty near the African coast as in ECMWF, otherwise, P25L is a distinct, easily-tracked pouch.

UKMET: OW gradually increases for this westward-moving pouch.

[Hurricaneman]

The 6zGFS shows this developing around late next week, something to monitor is nothing else

[cycloneye]

Here is the discussion of this wave/pouch from the San Juan NWS.

TROPICAL WAVE IS CURRENTLY OVER WRN AFRICA AND IS
ASSOCIATED WITH AN MCS. GLOBAL MODELS HAVE BEEN VERY CONSISTENT
IN DEVELOPING THIS WAVE EVENTUALLY INTO A TROPICAL CYCLONE IN THE
DY5-7 TIME FRAME (THU AUG 29-SAT AUG 31) ALTHOUGH THEY ARE SHOWING
SIGNIFICANT SPEED DIFFERENCES. BASED ON OFFICIAL NHC/WPC MEDIUM
RANGE GUIDANCE THIS WAVE MAY HAVE A LOW PRES AREA ASSOCIATED WITH
IT OR MAY BECOME A TROPICAL CYCLONE NEXT FRI AND BE IN THE
VICINITY OF 14N AND 47W NEXT SAT AUG 31.

[jinftl]

NOAA is bullish - high confidence of tropical cyclone formation in eastern atlantic in Aug 28 - Sept 3 timeframe

[lester]

18z GFS fantasyland has a 967(!) mb system recurving

[AtlanticWind]

http://www.ssd.noaa.gov/eumet/eatl/rb-l.jpg

[jinftl]

From Dr. Jeff Masters blog on Friday, his thoughts on the changes that may be about to take place in the next week or so:

A tropical wave that emerged form the coast of Africa on Thursday night could develop by Wednesday the 28th midway between Africa and the Lesser Antilles Islands, according to this morning's 00Z run of the Navy's NAVGEM model. However, this forecast is dubious, as none of the other models is calling for tropical cyclone formation in the Atlantic during the coming week. The tropical Atlantic is dominated by dry, stable air, and a new outbreak of dust and dry air is exiting the coast of Africa this weekend, which will keeping the Tropical Atlantic dry though at least Thursday, August 29. Another tropical wave will come off the coast of Africa on Monday August 26, and these two tropical waves may be able to prime the tropical Atlantic for higher chances of development by leaving a moister environment for a vigorous tropical wave predicted to move off the coast of Africa on Thursday, August 29.

[Hurricaneman]

The 0ZGFS is a little concerning for the islands and the pattern on it coincides with the Euro nicely except for the GFS is a little faster at 240 than the Euro

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[HurricaneMaster_PR]

GFS 00Z in 252 hrs

[HurricaneMaster_PR]

[HurricaneMaster_PR]

This is how it ends. Wow!!!

[Hurricaneman]

This has a potential to be interesting if the models are right, but doesn't really get going until after day 5 so we have many days to watch whether or not this heads out to sea or make a landfall on either the island and or the US mainland

The posts in this forum are NOT official forecast and should not be used as such. They are just the opinion of the poster and may or may not be backed by sound meteorological data. They are NOT endorsed by any professional institution or storm2k.org. For official information, please refer to the NHC and NWS products

[hurricaneCW]

One of the most aggressive runs I've seen from the gfs regarding that system. Granted it's way, way out there but you can follow that wave/storm several days back