ATL: DANNY - Remnants - Discussion

[NCSTORMMAN]

This thing is looking good so far and in the right spot to develop in my opinion. I am no met and never will be though. If by some miracle this thing passes through the Caribbean what is the steering looking like after that?

[gatorcane]

I agree wxman. It looks like the Euro keeps it just far enough south to stay out of the dry air. However, on visible satellite imagery it already looks like dry, stable air is already being entrained into the circulation, as the recent convective burst is now weakening. The GFS forecasts a very sharp moisture gradient and doesn't develop the disturbance. We'll see.

http://i.imgur.com/EsWn5ra.png

There may be some dry stable air but if you look at it's life since moving off Africa overall the trend is that convection and moisture are building around this wave. Also there seems to be some new convection building right over the LLC looking at the latest imagery from RAMMB. We could be looking at the typical "pulsing" up and down of convection that you see early on with development.

With both the ECMWF and UKMET on board with development (arguably our best models), the time of year, and where it is headed, it has my attention!

[gigabite]

This is the location of the moon at 15:15 utc 08/16/15.
Historically a New Moon pass under the an invest within 10 degrees of latitude is generally followed by some tropical development.
Tomorrows pass will fit this criteria also.
Tomorrow is the last day of the New Moon phase & the last day of this data set for this month.

____________________

This is not a forecast, just a note on previous observations.

[beoumont]

gigabite"
This is the location of the moon at 15:15 utc 08/16/15.
Historically a New Moon pass under the an invest within 10 degrees of latitude is generally followed by some tropical development.
Tomorrows pass will fit this criteria also.
Tomorrow is the last day of the New Moon phase & the last day of this data set for this month.

The following URL leads to the only moon phase vs tropical cyclone genesis study I have ever seen (and it shows a tendency for development on new and full moon.) Please, Gigabite, enclose a link to the other study you are referring to; and do explain your statement " New Moon pass under the an invest within 10 degrees of latitude" . How does one assign an earth latitude relative to the moon?

Observed Relations hips Bet ween 1 u nar Tidal Cycles
and Formation of Hurricanes and Tropical Storms’

http://docs.lib.noaa.gov/rescue/mwr/100/mwr-100-06-0451.pdf

[gatorcane]

96L showing up now in the Atlantic wide image....far bottom-right corner:

[BobHarlem]

96L showing up now in the Atlantic wide image....far bottom-right corner:

Gulf disturbance, wave north of Hispaniola, 96L has the light switch gone on finally?

[gatorcane]

The system appears to be growing in size when I loop the vis loop, plus the cyclonic turning is looking better as time goes on. Certainly looks like it has that "look" of something in the early stages of becoming a named system...

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

[cycloneye]

Up to 50%-60%

TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT SUN AUG 16 2015

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

A tropical wave and a surface low pressure system located several
hundred miles southwest of the Cape Verde Islands are producing a
concentrated area of showers and thunderstorms, which are beginning
to show signs of organization. Environmental conditions are expected
to be conducive for further development, and a tropical depression
could form by midweek as the disturbance moves westward at around 15
mph.
* Formation chance through 48 hours...medium...50 percent
* Formation chance through 5 days...medium...60 percent

$$
Forecaster Stewart

[gatorcane]

[Yellow Evan]

Wow, it looks great for an ATL system.

[northjaxpro]

I can understand NHC raising the percentages for development at this time. Latest satellite imagery shows the structure overall is looking rather healthy and 96L has grown in size as the day has progressed as well. If the current trends continue, it may get designated a TD within the next 24 hours or so.

[MGC]

96L looks to be embedded in a fairly moist envelope so I doubt dry air is currently an issue. If
The current burst of convection persists and shear remains low, I think 96L could develope...Mgc

[cycloneye]

Still hugging the 10.0N latitude.

96L INVEST 150816 1800 10.0N 28.2W ATL 20 1011

[LarryWx]

Related to the chance for 96L to form as a TC in the E MDR, here are the furthest east of some past TC's for seasons heading for strong+ El Nino:

1877 (superNino), 1888 (superNino), 1896: none in the E MDR but some could have been missed
1899: 31W
1902: 31W
1905, 1918, 1925, 1930, 1940; none but some could have been missed; 1930 had a TD form at 44W
1957: 22W (Carrie)
1965: 20W (Carol)
1972: (superNino): 5 TD's formed E of 35W though no TS's
1982: (superNino): 22W (Beryl)
1987: 3 eventual TS's had geneses E of 32W
1991: 26W (Danny) and 2 TD's E of 31W
1997: (superNino):nothing in the E MDR; Erika's genesis was at 44W

[Gustywind]

First mention as a special feature...

TROPICAL WEATHER DISCUSSION
NWS NATIONAL HURRICANE CENTER MIAMI FL
205 PM EDT SUN AUG 16 2015


...SPECIAL FEATURES...

A 1011 MB LOW IS CENTERED OVER THE EASTERN ATLC NEAR
10N27W...SEVERAL HUNDRED MILES SOUTHWEST OF THE CAPE VERDE
ISLANDS. CONVECTION ASSOCIATED WITH THIS LOW HAS REMAINED
PERSISTENT THROUGH MUCH OF THE DAY TODAY...WITH NUMEROUS
MODERATE CONVECTION FROM 06N TO 13N BETWEEN 24W AND 31W.
ENVIRONMENTAL CONDITIONS ARE EXPECTED TO BE CONDUCIVE FOR SOME
DEVELOPMENT OF THIS SYSTEM OVER THE NEXT SEVERAL DAYS AS IT
CONTINUES W AT 10 TO 15 KT. THE CHANCES OF THIS LOW DEVELOPING
INTO A TROPICAL CYCLONE OVER THE NEXT 48 HOURS IS MEDIUM. FOR
ADDITIONAL INFORMATION...PLEASE REFER TO THE ATLC TROPICAL
WEATHER OUTLOOK UNDER AWIPS/WMO HEADERS MIATWOAT/ABNT20 FOR MORE
DETAILS.

[Gustywind]

From the Weather Channel.
http://www.weather.com/storms/hurricane ... l-atlantic

Watching Tropical System in the Atlantic

The Atlantic has been very quiet this hurricane season, but that may be changing. We are watching Invest 96-L off the coast of Africa for possible development.

It's been a very a very quiet first half of August in the Atlantic basin of the tropics. No tropical depressions or named storms have formed yet this month, largely due to unfavorable upper-level winds and dry air.

August is the first month of a period that runs through September and into early October where we typically look farther east into the Atlantic for development. This is in addition to the typical formation areas that are closer to the United States.
Right now, we have our eyes on an area of interest in the far eastern Atlantic dubbed Invest 96-L. This is a naming convention used by the National Hurricane Center to identify features they are monitoring for potential future development into a tropical depression or a tropical storm.
The National Hurricane Center has given Invest 96-L a 60 percent chance (medium chance) of further development into a tropical depression or tropical storm over the next five days as it tracks west across the open Atlantic Ocean.

As of early Wednesday afternoon, satellite imagery showed clusters of showers and thunderstorms bubbling up in association with Invest 96-L to the southwest of the Cape Verde Islands. This is being driven by a tropical wave and an area of low pressure near the surface of the earth.

Is this a reason to be concerned? Since Invest 96-L is well away from any land areas at this time, we have plenty of time to monitor its progress. As mentioned before, dry air and unfavorable upper winds have dominated the Atlantic so far this month, so we'll see if Invest 96-L can survive the journey to a longitude near the Lesser Antilles over the next week or so.

At the moment, winds aloft in the area near Invest 96-L are not too strong and the environment is somewhat moist, according to hurricane specialist Dr. Greg Postel of The Weather Channel. This is why it's being given a medium chance of development at this time.

Stay tuned to The Weather Channel and check back with weather.com for updates in Invest 96-L.

[Hammy]

I'll throw my continuing doubful two cents in here: Convection is collapsing for the most part, and all indications based on cloud motion tells me that the actual low center has been left behind in the dry air around 22W. Given the decreasing model support (which was never strong to start with) and continuing dry air surround it, I'd personally put 20-30% chances of development.

[tolakram]

Live view: http://oiswww.eumetsat.org/IPPS/html/MSG/RGB/NATURALCOLOR/FULLRESOLUTION/index.htm

You can shift + drag to zoom in.

It doesn't look that bad and I don't see any evidence the LLC, if there is one, has been left behind.

Personal Forecast Disclaimer:
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.

[gigabite]

gigabite"
This is the location of the moon at 15:15 utc 08/16/15.
Historically a New Moon pass under the an invest within 10 degrees of latitude is generally followed by some tropical development.
Tomorrows pass will fit this criteria also.
Tomorrow is the last day of the New Moon phase & the last day of this data set for this month.

The following URL leads to the only moon phase vs tropical cyclone genesis study I have ever seen (and it shows a tendency for development on new and full moon.) Please, Gigabite, enclose a link to the other study you are referring to; and do explain your statement " New Moon pass under the an invest within 10 degrees of latitude" . How does one assign an earth latitude relative to the moon?

Observed Relations hips Bet ween 1 u nar Tidal Cycles
and Formation of Hurricanes and Tropical Storms’

http://docs.lib.noaa.gov/rescue/mwr/100/mwr-100-06-0451.pdf

* Thanks for the research paper.
* It is a nice searchable .pdf.
* You realize the paper predates the GOES weather satellite program, and no reference more recent than 1972.
* It is basically a frequency study of all tidal periods, and cyclone formation with out the aid of spread sheet analysis or study site selection capability.

This is personal research that I have pursued since I worked for the county storm drainage department in 1982. Back then the computers were DOS, and the programming language was basic. The idea of the line of thought is that gravity is associative. That is forces in the " x " direction add up to a force greater than a single lunar tidal force. I observe some tropical storms over the last 1.7 lunar epochs ( 33 years ) that occur coincidentally at the same time at the New Moon and have noticed some attributes that have some frequency during the New Moon phase.



The black dot is the New Moon. The left image is 13:00, the right image is 18:00, The pressure, and movement of the image has not changed, but the system has deformed as the rotation of the Earth brings the system past the shaft of gravity. Please note that the black dots are representations of the moon's location not the actual location at the time of the image.

[wxman57]

12Z Euro develops about a 1007mb low by mid week. Winds 25-30 kts. It dissipates the low as it nears the Caribbean NEXT Wednesday. Long way out. It has a tough road ahead with plenty of dry air followed by high wind shear in the Caribbean. That may not prevent it from becoming a TD or weak TS before it's torn apart near the Caribbean.

Here's a plot from my workstation (valid Thursday evening). I have the map analyzed to the 1/2 millibar. Winds are contoured starting at 20 kts.