ATL: DORIAN - Post-Tropical - Discussion

[meriland23]

Do you guys think it will be a GOMer, ECer, or a fish... IYO

[Gustywind]

Latest SSD numbers...


DATE/TIME LAT LON CLASSIFICATION STORM
24/0545 UTC 13.5N 27.1W T1.5/1.5 98L
23/2345 UTC 13.4N 25.5W T1.0/1.0 98L

[ronjon]

[quote="meriland23"]Do you guys think it will be a GOMer, ECer, or a fish... IYO[/quote

Strong Atlantic ridging forecast to remain over the next week by the global models. Too early to say but at least for now doesn't look likely to recurve into the open Atlantic.

[Gustywind]

Hello TD 4


BULLETIN
TROPICAL DEPRESSION FOUR ADVISORY NUMBER 1
NWS NATIONAL HURRICANE CENTER MIAMI FL AL042013
500 AM EDT WED JUL 24 2013

...TROPICAL DEPRESSION FORMS OVER THE EASTERN ATLANTIC...


SUMMARY OF 500 AM EDT...0900 UTC...INFORMATION
----------------------------------------------
LOCATION...13.9N 28.1W
ABOUT 310 MI...500 KM WSW OF THE CAPE VERDE ISLANDS
MAXIMUM SUSTAINED WINDS...35 MPH...55 KM/H
PRESENT MOVEMENT...WNW OR 285 DEGREES AT 20 MPH...32 KM/H
MINIMUM CENTRAL PRESSURE...1008 MB...29.77 INCHES

[cycloneye]

What I can say about the formation of TD 4 is that is a harbinger of what is likely to be a much more dangerous August and September for much of the basin and we have to be prepared for what mother nature will bring during those months.

[Gustywind]

8AM discussion.



...SPECIAL FEATURE...
TROPICAL DEPRESSION FOUR HAS FORMED FROM THE TRPCL WAVE-LOW
SYSTEM AND ITS CENTER IS LOCATED NEAR 13.9N 28.1W ABOUT 269 NM
WSW OF THE CAPE VERDE ISLANDS. ITS PRESENT MOVEMENT IS WNW AT 17
KT WITH MAXIMUM SUSTAINED WINDS OF 30 KT AND A MINIMUM CENTRAL
PRESSURE OF 1008 MB. THIS GENERAL MOTION IS EXPECTED TO CONTINUE
DURING THE NEXT COUPLE OF DAYS. SOME SLIGHT STRENGTHENING IS
EXPECTED DURING THE NEXT 48 HOURS...AND THE DEPRESSION IS
FORECAST TO BECOME A TROPICAL STORM LATER TODAY OR TONIGHT.

[jlauderdal]

Do you guys think it will be a GOMer, ECer, or a fish... IYO[/quote

Strong Atlantic ridging forecast to remain over the next week by the global models. Too early to say but at least for now doesn't look likely to recurve into the open Atlantic.

long runner looks probable, been awhile since we had a long runner make it all the way across, its rather uncommon

[Gustywind]

Tropical Depression Four Forms

Published: Jul 24, 2013, 6:33 AM EDT weather.com

http://www.weather.com/news/weather-hur ... c-20130723

Tropical Depression Four has formed over the far eastern Atlantic Ocean, southwest of the Cape Verde Islands, finally producing enough persistent convection to be classified as a tropical cyclone. At any time, T.D. Four may intensify into Tropical Storm Dorian.

The depression will track toward the west-northwest over the next several days on the south side of an intensifying Bermuda-Azores high, and will remain over open waters through the weekend.

It may approach the Leeward Islands late Sunday night or early Monday morning, though it's not clear whether the system will track to the north of the islands at this early timeframe.

This all assumes this system will survive the voyage. Some dry air lurks ahead of the system, and wind shear may increase over the system in three days. These ingredients are both hostile to tropical cyclones.

Interests in the Leeward Islands, including Puerto Rico and the U.S. Virgin Islands, should monitor the progress of this system.

[KBBOCA]

A commenter named SLU has some really interesting research posted this morning on Dr. Jeff Masters' blog comments.

See this thread:
http://www.wunderground.com/blog/JeffMa ... commenttop

(comment #2140)

The commenter writes:

The formation of 2 tropical storms this month east of the Caribbean is bad, bad news for anyone who was hoping for a quite Cape Verde season. Every single season since 1950 which featured such development east of 60 west all featured very hectic Cape Verde seasons and most of them had at least one extremely deadly hurricane. This year with the stronger than normal ridge you can expect that if we get a deadly Cape Verde hurricane we can expect it to threaten land.

He then goes on to show the storm tracks for the various seasons in question.

TD4 has definitely got my attention... perhaps it won't become a major hurricane as it's still early, but I think it forebodes a very serious CV season!

[Gustywind]

Tropical Depression Four Forms in the Eastern Atlantic
By Alex Sosnowski, Expert Senior Meteorologist
July 24, 2013; 6:35 AM

http://www.accuweather.com/en/weather-n ... r/15641010

The large tropical wave of low pressure that moved off Africa on Sunday strengthened into Tropical Depression Four on Wednesday morning.

Further development into a tropical storm is possible over the next 24 hours. If this happens it will be the fourth named storm of the Atlantic season and the name will be Dorian.

However, much of the tropical Atlantic was being influenced by dry air and dust this week. Dry air tends to work against tropical development.

As we have seen in the past, sometimes these systems, especially the larger ones, can overcome the surrounding dry air. However, the system would have a better chance of development through the middle of the week, rather than late in the week.

"As the feature continues to drift on a slightly north of west course, it is likely to encounter a zone of increasingly disruptive winds at midlevels of the atmosphere this week," Kottlowski said.

At present course and speed, the system would be near the Leeward Islands this weekend and could brush some of the northern islands of the Caribbean next week as a tropical wave of low pressure or perhaps something stronger and more organized. Even if it does not develop fully, the system could bring a period of showers and thunderstorms to these islands.

If sustained winds of 39 mph or higher are found, then the system is upgraded to a tropical storm and given a name.

Next, if sustained winds reach 74 mph or higher, the system is upgraded to a hurricane.

Occasionally, a system can go right from a tropical disturbance to a tropical storm. This happens during rapid development and can occur when aircraft cannot investigate the system often enough or sufficient high-resolution satellite data is not available.

[GCANE]

Do you guys think it will be a GOMer, ECer, or a fish... IYO[/quote

Strong Atlantic ridging forecast to remain over the next week by the global models. Too early to say but at least for now doesn't look likely to recurve into the open Atlantic.

IMHO, this may wobble a little to the SW next day or two. Gut is saying right now, could run through the Carib.

[meriland23]

TD4 might become a dud, but it's existence is symbolic of something much more dire.

[senorpepr]

In my Worldwide Tropical Outlook, I highlight some of the challenges with TD Four's forecast. The last couple minutes also touch on the other two invests, 98W and 98E.

[youtube]http://www.youtube.com/watch?v=9LxH_C9acuQ[/youtube]

[blp]

00z Euro abandons the early recurve sceanario and now favors a recuvre right off of the Florida coast. That is a significant change from the 12z package. It is still on the nothern half of the models.

http://moe.met.fsu.edu/cgi-bin/ecmwf-opertc2.cgi?time=2013072400&field=850mb+Vorticity&hour=Animation

[Blown Away]

06z

Intensity models killing it off late in the forecast...

[Blown Away]

00z Euro abandons the early recurve sceanario and now favors a recuvre right off of the Florida coast. That is a significant change from the 12z package. It is still on the nothern half of the models.

http://moe.met.fsu.edu/cgi-bin/ecmwf-opertc2.cgi?time=2013072400&field=850mb+Vorticity&hour=Animation

May not matter, not much left once it reaches @60W

[jlauderdal]

TD4 might become a dud, but it's existence is symbolic of something much more dire.

current performance is a predictor of future results?

[Aric Dunn]

call me crazy that a eye feature trying to form? just woke up lol


http://www.ssd.noaa.gov/goes/east/tatl/loop-rgb.html

[tolakram]

Latest off the FTP site



ftp://goes.gsfc.nasa.gov/pub/goeseast/overview2/vis/

[meriland23]

TD4 might become a dud, but it's existence is symbolic of something much more dire.

current performance is a predictor of future results?

It was in reference to the post above about storms forming near cape verde with a strong ridge this early in the year. Can't be a good sign for the upcoming months..