ATL: CHANTAL - Post-Tropical

[Gustywind]

Hurricane Season

Tropical Update

Dr. Greg Postel, Hurricane/Storm Specialist, The Weather Channel

http://www.weather.com/newscenter/tropical/

Jul 6, 2013 5:45 am ET

REST OF ATLANTIC

NHC has given an eastern-Atlantic tropical wave a 10% chance of developing in the next 2 days. Though this system exhibits a well-defined rotation in the satellite animations, nearby weather data (including model guidance) suggests it probably has little future. The destructive forces of the dry and dusty Saharan Air Layer are lurking just around the corner.

[cycloneye]

Circulation looks solid at this loop.

http://rammb.cira.colostate.edu/ramsdis ... height=480

[gatorcane]

Not looking too bad this morning. Looks like shear will remain low for the next several days at least and SSTs are high since it is at such a low lattitude. If it can deal with the SAL, it may just have a chance though I continue to think SAL will get to this system. Still only the GFS shows some kind of low-level vorticity reaching the NE Leewards 4 days from now. So model support is just not there for this to develop into a named system at this time probably because they see the SAL layer.

[jinftl]

couldn't match the date, location any better...let's see what happens...very interesting. i remember bertha being an outlier 'what in the heck' cape verde storm back in '96 so early in the season that not only developed too early in the eastern atlantic but actually made it to the u.s. as a hurricane.

Climatology may not favor this system to develop but sometimes mother nature throws out the window that. One example was Bertha of 1996 that formed on July 5. So let's watch and see what occurs with 95L down the road.

http://weather.unisys.com/hurricane/atl ... /track.gif

[RL3AO]

The end of that visible loop was very impressive. I'm sure its in the mid level but that was a very very noticeable circulation on the loop.

[jinftl]

Dr. Masters blog this morning:

"As we approach mid-July, it's time to begin turning our attention to tropical waves coming off the coast of Africa. We have our first such system worthy of attention today, a tropical wave designated 95L over the Eastern Atlantic near 8°N 33°W, about 800 miles southwest of the Cape Verde Islands. Satellite loops show a modest area of heavy thunderstorms that is showing a moderate amount of spin. Wind shear is moderate, 10 - 20 knots, and ocean temperatures are warm, 28°C. The 8 am EDT Saturday forecast from the SHIPS model predicted that 95L would encounter cooler waters of 27.5°C over the weekend as it headed west to west-northwest at 15 - 20 mph. Wind shear is expected to remain moderate though Monday, which may allow for some additional organization. However, 95L is embedded in a very large area of dry air associated with the Saharan Air Layer (SAL), and July African waves typically have considerable trouble getting organized in the very dry air of the SAL.

The disturbance could arrive in the Lesser Antilles Islands as early as Tuesday. A band a strong upper-level winds associated with the subtropical jet stream is expected to be over the northern islands at that time, and if 95L has penetrated as far north as 15°N latitude by that time, it will have to face very high wind shear of 30+ knots. But if 95L stays farther to the south, wind shear should be lower, giving the storm a better chance of development. None of the reliable forecast models predict that 95L will develop. In their 8 am EDT July 6 Tropical Weather Outlook, NHC gave the disturbance a 20% chance of developing into a tropical depression or tropical storm by Monday."

[WilmingtonSandbar]

I remember this storm being so early in the season that we weren't even paying attention in Wilmington. I was on my way to Raleigh for a concert, and my buddy started asking why all the news vans were headed in the other direction. We turned the CD player to a radio station, and in about 5 minutes turned the car around to go board up homes and a couple businesses. Sorry, for it being off-topic, but this just brought back a memory I felt I needed to share.

Climatology may not favor this system to develop but sometimes mother nature throws out the window that. One example was Bertha of 1996 that formed on July 5. So let's watch and see what occurs with 95L down the road.

http://weather.unisys.com/hurricane/atl ... /track.gif

[cycloneye]

One word IMPRESSIVE!

[RL3AO]

Maybe its an illusion, but that really looks like banding in the SE quad.

[Hurricanehink]

I'm definitely getting a Bertha 96/08 vibe. Needs to gain some latitude though so it doesn't crash into South America.

[CrazyC83]

That looks like a lot more than 20%! I'd be willing to call it a depression if it lasts much longer!

[cycloneye]

Maybe its an illusion, but that really looks like banding in the SE quad.

Yes,banding to the SE. Closeup loop.

[cycloneye]

Does anyone has an archieve of how the Saharan Air Layer was at the time Bertha formed in early July of 1996?

[Hurricaneman]

I think the models are underestimating this, its staying below the SAL, has a deep moisture source with the Monsoon trough, there seems to be little to no shear to disrupt it and it clearly has banding so this is IMO is a Depression, but we really cant tell because there are no ground observations, so my thought is 40% chance at development before the islands

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

[Aric Dunn]

It was well on its yesterday and now have had persistent convection and clear signs of a circ. given the structure of it atm it is very likely a TD. its quite impressive. hehe though it took them less than 24 hr to become a invest... i figured them since what happened with 92l they would not even mention it,. lol

[cycloneye]

I think the models are underestimating this, its staying below the SAL, has a deep moisture source with the Monsoon trough, there seems to be little to no shear to disrupt it and it clearly has banding so this is IMO is a Depression, but we really cant tell because there are no ground observations, so my thought is 40% chance at development before the islands

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

If a ship would be in the area to gather observatons it would be fantastic.

[Hurricane Andrew]

Looks really nice.

[Hurricane Andrew]

SHIPS/DSHIPS keep it on a slow strengthening pace.

[SouthDadeFish]

Definitely a very impressive wave. While OSCAT missed the center on its pass last night, it did show winds of TS force on the west side of the circulation:



Currently, the wave is embedded in the ITCZ, which is helping it fight off the SAL by providing a moisture source. If it develops and detaches from the ITCZ, its circulation will probably entrain some of that dry air. I think it's best bet for survival is to either stay really far south, or develop a strong enough circulation quickly, so it can somewhat fight off the shear and dry air in its path. Personally, I would put the odds higher than 20% of this thing becoming a TC in the next 48 hours. More like 50%. The Lesser Antilles should keep an eye on this thing.

Again, this is all just my opinion.

[rockyman]

This 5 day SAL loop shows just how impressive this system has been, with clear spinning since it left the African coast:

http://tropic.ssec.wisc.edu/real-time/s ... litE5.html