Invest 99L E of Lesser Antilles,Comments,Sat Pics,Etc #3

[Extremeweatherguy]

ok folks. ken01 has given us some false information. Jeff Masters NEVER said this. I just checked and that comment came from someone reading his forum and not Jeff himself. For proof of this, click this link and check below his post where it says "reader's comments":

http://www.weatherunderground.com/blog/ ... amp=200607

BTW, for those who do not want to look back a page, here is Ken's post:

New comment just out about 99L, for whatever it's worth, from Jeff Masters Blog:


Wind shear has increased to 25knots around 99L. 99L has done well in the battle against dust, and water vapor imagery shows that dry air is having little effects on 99L....

http://cimss.ssec.wisc.edu/tropic/real- ... wg8wxc.GIF

http://www.ssd.noaa.gov/goes/flt/t1/wv-l.jpg


All that being said, chances of 99L to become a TD are decreasing, because of wind shear- 15%.

Any thoughts about that statement ?

[cycloneye]

A tropical wave about 600 miles east of the Lesser Antilles Islands continues to be a threat as it moves west-northwest at 15-20 mph. A good pass by the QuikSCAT satellite this morning at 5:38 EDT revealed that a center of low pressure was located near 10N 51W, but the wave did not have a closed surface circulation. The main thunderstorm activity was to the north of the low's center, with winds in the 30-35 mph range at the surface. Visible satellite imagery from this morning confirm that the wave has no surface circulation, and shows a few heavy thunderstorms to the north of the center. The wave is surrounded by a large area of dry, dust-laden air to its north and west. This dry air, plus wind shear of 10-20 knots, should make any development slow to occur. However, for the first time, we do have a model that develops the wave. Last night's run of the GFDL model has the wave developing into a tropical storm by Monday night, when it crosses through the Leeward Islands near Guadeloupe. The GFDL then brings the tropical storm across the Dominican Republic on Wednesday night. None of the other models buy this solution, and predict that wind shear and dry air will keep this wave from developing. That is my expectation as well. Even if the wave does develop, a strong upper-level cold low north of the Bahamas will bring very hostile wind shear to any storm that tries to approach the U.S. East Coast. The GFDL model reflects this, and has the storm weakening as it crosses into the Bahama Islands late in the week.

The above from Jeff Masters about 99L.

Jeff Masters

Link

[Extremeweatherguy]

A tropical wave about 600 miles east of the Lesser Antilles Islands continues to be a threat as it moves west-northwest at 15-20 mph. A good pass by the QuikSCAT satellite this morning at 5:38 EDT revealed that a center of low pressure was located near 10N 51W, but the wave did not have a closed surface circulation. The main thunderstorm activity was to the north of the low's center, with winds in the 30-35 mph range at the surface. Visible satellite imagery from this morning confirm that the wave has no surface circulation, and shows a few heavy thunderstorms to the north of the center. The wave is surrounded by a large area of dry, dust-laden air to its north and west. This dry air, plus wind shear of 10-20 knots, should make any development slow to occur. However, for the first time, we do have a model that develops the wave. Last night's run of the GFDL model has the wave developing into a tropical storm by Monday night, when it crosses through the Leeward Islands near Guadeloupe. The GFDL then brings the tropical storm across the Dominican Republic on Wednesday night. None of the other models buy this solution, and predict that wind shear and dry air will keep this wave from developing. That is my expectation as well. Even if the wave does develop, a strong upper-level cold low north of the Bahamas will bring very hostile wind shear to any storm that tries to approach the U.S. East Coast. The GFDL model reflects this, and has the storm weakening as it crosses into the Bahama Islands late in the week.

The above from Jeff Masters about 99L.

Jeff Masters

keep in mind though that this was written at 9:24am EST. Not like it makes a big difference, but some things may have changed between now and then.

[ammmyjjjj]

http://www.skeetobiteweather.com/picser ... p?t=m&m=99


Looks like models are shifting more & more to the northeast.

[kenl01]

New comment just out about 99L, for whatever it's worth, from Jeff Masters Blog:


Wind shear has increased to 25knots around 99L. 99L has done well in the battle against dust, and water vapor imagery shows that dry air is having little effects on 99L....

http://cimss.ssec.wisc.edu/tropic/real- ... wg8wxc.GIF

http://www.ssd.noaa.gov/goes/flt/t1/wv-l.jpg


All that being said, chances of 99L to become a TD are decreasing, because of wind shear- 15%.

Any thoughts about that statement ?

wait a second? Jeff Masters says that 99L is doing very well against all the dry air and dust, yet this now has a lesser chance of becoming a TD? I don't think so...

BTW: Next time post a link to Jeff Master's blog when mentioning him.

Hold that thought please !
The shear is caused by severeal ULL's in the Atlantic. That shear chart does show some significant shear around 99L. This wave really is not a good candidate IMO. His entire link can be found at http://www.weatherunderground.com/blog/ ... amp=200607

[Scorpion]

Significant shear? The shear maps disagree.
http://cimss.ssec.wisc.edu/tropic/real- ... wg8sht.GIF

[Recurve]

Steering wind layer current image (700-850hPa) from http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8dlm1.html



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[storms in NC]

http://www.skeetobiteweather.com/picservice.asp?t=m&m=99


Looks like models are shifting more & more to the northeast.

looks to me like the Northwest not northeast

[kenl01]

Well the map does show NW shear in that vicinity at around 15N and 55W or so. Some maps might be different than others. But when reading Jeff's link carefully, he explains very well why this system is not expected to develop.

"wind shear and dry air will keep this wave from developing. That is my expectation as well. Even if the wave does develop, a strong upper-level cold low north of the Bahamas will bring very hostile wind shear to any storm that tries to approach the U.S. East Coast. The GFDL model reflects this, and has the storm weakening as it crosses into the Bahama Islands late in the week."

[Extremeweatherguy]

Steering wind layer current image (700-850hPa) from http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8dlm1.html

Looks like a more NW movement, then W, and then NW again. This kind of path could be bad for both FL and the Gulf.

[Extremeweatherguy]

Well the map does show NW shear in that vicinity at around 15N and 55W or so. Some maps might be different than others. But when reading Jeff's link carefully, he explains very well why this system is not expected to develop.

"wind shear and dry air will keep this wave from developing. That is my expectation as well. Even if the wave does develop, a strong upper-level cold low north of the Bahamas will bring very hostile wind shear to any storm that tries to approach the U.S. East Coast. The GFDL model reflects this, and has the storm weakening as it crosses into the Bahama Islands late in the week."

Another thing to remember is that Jeff Masters expected the wave in the eastern Bahamas last week to reach the Carolinas. That never happened. Also, the post he made this morning is now 5 hours old and his thoughts may have changed.

[cycloneye]

ATTENTION...NATIONAL HURRICANE CENTER

NCEP COUPLED GFDL HURRICANE MODEL FORECAST MADE FOR

TROPICAL DEPRESSION INVEST 99L

INITIAL TIME 12Z JUL 30

DISCLAIMER ... THIS INFORMATION IS PROVIDED AS GUIDANCE. IT
REQUIRES INTERPRETATION BY HURRICANE SPECIALISTS AND SHOULD
NOT BE CONSIDERED AS A FINAL PRODUCT. PLEASE SEE THE TPC/NHC
OFFICIAL FORECAST.


FORECAST STORM POSITION

HOUR LATITUDE LONGITUDE HEADING/SPEED(KT)

0 11.9 51.6 295./18.0
6 12.2 53.5 280./18.5
12 12.1 54.8 265./12.7
18 12.6 56.3 289./15.4
24 13.3 58.1 291./18.7
30 13.7 59.2 291./12.0
36 14.1 60.6 287./14.4
42 14.6 62.0 287./14.0
48 15.4 63.4 303./15.9
54 15.9 64.8 288./14.1
60 16.3 66.2 286./14.6
66 16.6 67.8 280./15.3
72 16.9 69.2 281./13.9
78 17.3 70.4 291./11.6
84 17.6 71.5 283./10.8
90 18.2 72.7 296./13.5
96 19.1 73.6 317./12.1
102 19.9 73.9 336./ 8.4
108 20.2 74.7 292./ 7.6
114 20.9 75.4 314./10.3
120 21.5 76.4 304./10.7
126 21.7 76.9 287./ 5.4


12z GFDL text positions.

[Recurve]

Steering wind layer current image (700-850hPa) from http://cimss.ssec.wisc.edu/tropic/real-time/atlantic/winds/wg8dlm1.html

Looks like a more NW movement, then W, and then NW again. This kind of path could be bad for both FL and the Gulf.

Keep in mind that is current wind only -- 1500 UTC 30 July
not a forecast

[Scorpion]

New GFDL is weaker but at least its not killing it off.

[storms in NC]

Well with all do respecd I think you need to wait and see. This wave has made it all the way across with dry air all around it and it is still there. As far as the shears go 15-20 is really not that bad. The wave itself is running faster. It needs to slow down now that it is going WNW. And I don't think it will hit the Islands. It will be closes but will not go over them. JMO

[Dean4Storms]

GFDL @ 12z further west........


http://moe.met.fsu.edu/cgi-bin/gfdltc2. ... =Animation

[Evil Jeremy]

anyone think that this can still form today or tommarow?

[Extremeweatherguy]

anyone think that this can still form today or tommarow?

yes, by tomorrow this will already be near the islands and entering a much more favorable environment.

[HUC]

11N and 51W?????The TWD of Miami at 2pm put the Low at these coordinates...I can't see nothing in that area.I see some rotation around 13N 53W...But i'am not a forecaster...Can someone explain??????

[storms in NC]

Yes in a few days we might have a TD