African Tropical Wave 98L a Marginal Threat to Develop

By: Dr. Jeff Masters , 3:38 PM GMT on July 22, 2013

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A strong and well-organized tropical wave moved off the coast of Africa on Monday, and has been designated 98L by NHC. This disturbance is headed west at 10 - 15 mph, and is under a moderate 10 - 15 knots of wind shear. A large amount of dry air lies to the north and west of 98L, and will likely interfere with development. The SHIPS model predicts that wind shear will stay in the moderate range through Thursday, then rise to the high range, 20 - 30 knots, on Friday and Saturday. Ocean temperature are warm off the coast of Africa (27 - 28°C,), but will cool to 25 - 26°C on Tuesday through Thursday, a temperature that is quite marginal for development. None of the computer models predict that 98L will develop, not even the usually aggressive Canadian (CMC) model. In their 8 am EDT Monday Tropical Weather Outlook, NHC gave 98L a 10% chance of developing into a tropical cyclone by Wednesday. 98L should maintain a west to west-northwest track through the week, and may bring heavy rains and gusty winds to the northern Lesser Antilles Islands beginning on Saturday night.


Figure 1. Satellite image of 98L off the coast of Africa taken at 8 am EDT Monday July 22, 2013, with a satellite analysis of where dry air is, as well. A large amount of dry air lies to the north and west of 98L, and will likely interfere with development. Image credit: University of Wisconsin CIMSS and NOAA/HRD.


Figure 2. MODIS satellite image of 98L taken at approximately 8 am EDT July 22, 2013. Image credit: NASA.

Jeff Masters

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1793. unknowncomic
9:28 AM GMT on July 24, 2013
The model intensity must be based on land contact in the Caribbean. No land contact means much stronger.
Member Since: August 2, 2011 Posts: 0 Comments: 2108
1792. GTstormChaserCaleb
4:17 PM GMT on July 23, 2013
PWAT values are good way to measure the amount of precipitation in the atmosphere, not much in the way of the dry air here on this run:

Member Since: June 30, 2013 Posts: 12 Comments: 8682
1791. Grothar
2:34 PM GMT on July 23, 2013
Quoting 1748. GeoffreyWPB:


You are a good friend to all. :)


Thanks for the tip on clicking on the right. This long wait is getting annoying.
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1790. Patrap
2:24 PM GMT on July 23, 2013
Its only 7:30 almost in SF with the server so the issue may take a spell to fix.

Member Since: July 3, 2005 Posts: 426 Comments: 129093
1789. WunderAlertBot (Admin)
2:23 PM GMT on July 23, 2013
JeffMasters has created a new entry.
1788. hu2007
2:21 PM GMT on July 23, 2013
time to work. later guys for more updates :)
Member Since: August 6, 2007 Posts: 0 Comments: 325
1787. GatorWX
2:21 PM GMT on July 23, 2013
Quoting 1778. 69Viking:


I kid you not I've had well over 20" at my house since the beginning of July. I wish I would have kept detail records to give the exact amount, it's staggering for sure!


I wouldn't say it's a staggering amount here in sw fl, but there has been a lot of training storms dumping 3-6 inches in a very short time in isolated areas. There has also been a lot of storms moving in off the gulf which is somewhat unusual although not for this early in the summer. We went about 20 days with rain every single day and about 15-20 inches in that period. Conditions have become a bitter stable and usual in the last week. We certainly haven't had many sea breeze induced tstms like we normally get, but that seems to be changing. Between my area, yours and especially the Carolina's and NE, much rain has fallen on the east.
Member Since: January 1, 2008 Posts: 0 Comments: 3785
1786. cat6band
2:19 PM GMT on July 23, 2013
Quoting 1775. weathermanwannabe:
Here is the nice original EUMET African visible satt link shot (again) for the wave showing the evolution through this morning; much slower than the NHC link which tends to run very fast:

Link



Very cool....
Member Since: May 11, 2011 Posts: 0 Comments: 322
1785. JRRP
2:17 PM GMT on July 23, 2013
Member Since: August 16, 2007 Posts: 0 Comments: 6165
1784. weatherlover94
2:16 PM GMT on July 23, 2013
be back on later.
Member Since: September 8, 2010 Posts: 0 Comments: 2218
1783. Autistic2
2:15 PM GMT on July 23, 2013
Quoting 1776. washingtonian115:
I wouldn't get excited about 98L if I were you.


Excited, not exactly but it is something, besides a naked ULL to watch!
Member Since: August 29, 2008 Posts: 0 Comments: 480
1782. wunderkidcayman
2:15 PM GMT on July 23, 2013
Quoting 1773. EyEtoEyE:
Good morning, Patrap , the center looks like , it's at 12.5 N and 23.5 W ? Let me know , what you see?

12.2N 23.5W that is clear seen on vis sat images
Member Since: June 13, 2009 Posts: 2 Comments: 12521
1781. Patrap
2:15 PM GMT on July 23, 2013


Member Since: July 3, 2005 Posts: 426 Comments: 129093
1780. 62901IL
2:14 PM GMT on July 23, 2013
Quoting 1779. Autistic2:
F5 taking 75 seconds. Did some one kill or injure the blog today?

Happening to me too!
Member Since: June 14, 2013 Posts: 2 Comments: 1712
1779. Autistic2
2:12 PM GMT on July 23, 2013
F5 taking 75 seconds. Did some one kill or injure the blog today?
Member Since: August 29, 2008 Posts: 0 Comments: 480
1778. 69Viking
2:12 PM GMT on July 23, 2013
Quoting 1737. GatorWX:


I think we'll see many top ten wettest summers for lots of folks. I almost want to think this is perhaps more of a harbinger than Chantal was. The amount of precipitately water over the eastern US and surrounding water has seemed very high to me. I can imagine what effect it would have on a strong system.


I kid you not I've had well over 20" at my house since the beginning of July. I wish I would have kept detailed records to give the exact amount, it's staggering for sure!
Member Since: August 25, 2006 Posts: 1 Comments: 3078
1777. GatorWX
2:11 PM GMT on July 23, 2013
Quoting 1766. TimSoCal:
Satellite presentation looks like a TD or even a TS. Wonder why it hasn't been classified as such yet.


Convection is warming. They like persistence. Also the path takes it in a much less conducive environment. Today is its window in the short term I think.
Member Since: January 1, 2008 Posts: 0 Comments: 3785
1776. washingtonian115
2:11 PM GMT on July 23, 2013
Quoting 1774. Autistic2:
Good Morning all,

Doing well today!

Well now, NHC says we have something worth watching in the MDR, season starting for real?
I wouldn't get excited about 98L if I were you.
Member Since: August 14, 2010 Posts: 10 Comments: 17486
1775. weathermanwannabe
2:10 PM GMT on July 23, 2013
Here is the nice original EUMET African visible satt link shot (again) for the wave showing the evolution through this morning; much slower than the NHC link which tends to run very fast:

Link

Member Since: August 8, 2006 Posts: 0 Comments: 9330
1774. Autistic2
2:09 PM GMT on July 23, 2013
Good Morning all,

Doing well today!

Well now, NHC says we have something worth watching in the MDR, season starting for real?
Member Since: August 29, 2008 Posts: 0 Comments: 480
1773. EyEtoEyE
2:09 PM GMT on July 23, 2013
Good morning, Patrap , the center looks like , it's at 12.5 N and 23.5 W ? Let me know , what you see?
Member Since: July 6, 2013 Posts: 0 Comments: 460
1772. hu2007
2:08 PM GMT on July 23, 2013
hi everyone ,the invest 98 look like is getting there but not yet, if you all watch closely you will see on the visible image that the wave/ low is struggling with drier air from the east and some dry easterlie shear from africa, but as it move farther west from africa the system should improve developing but not for long cause there will be an upper trof by friday near the island that as the future dorian moves wnw it may not kill dorian if the storm pass south of 25 and ever get strong like a moderate t.s or stronger if is stay weak it may well avoid the trof by the island passing beneath and move more west as it develops close to the western carribean still a lot could happen but this my thinking after seeing the trend and the maps you guys posted :)
Member Since: August 6, 2007 Posts: 0 Comments: 325
1771. wunderkidcayman
2:08 PM GMT on July 23, 2013
Quoting 1758. GatorWX:


It's not overly hard to discern where the center is and west it goes.


yep

Quoting 1762. Patrap:
If 12 N was Hwy 1, it's running right down the centerline seems this am.

Nice envelope too.


yes
Member Since: June 13, 2009 Posts: 2 Comments: 12521
1770. Tazmanian
2:07 PM GMT on July 23, 2013
Quoting 1766. TimSoCal:
Satellite presentation looks like a TD or even a TS. Wonder why it hasn't been classified as such yet.




it has a long was too go be for 98L is a TD or TS and its window it closeing
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
1769. weatherlover94
2:06 PM GMT on July 23, 2013
the 12Z models are in. Some show nothing but steady strengthening. Some show it strengthening then slow weakening....others show strengthening then meeting it's death.....very hard to say right now.
Member Since: September 8, 2010 Posts: 0 Comments: 2218
1768. 62901IL
2:06 PM GMT on July 23, 2013
Under a slight risk for storms today.
Member Since: June 14, 2013 Posts: 2 Comments: 1712
1767. Tazmanian
2:06 PM GMT on July 23, 2013
Quoting 1753. Camille33:
I had to delete about 18 malware in my avast antivirus.There may be a virus infecting the blog,check on this please.




they can check on any thing if you have a virus its likey your laptop and not the blog
Member Since: May 21, 2006 Posts: 5091 Comments: 115362
1766. TimSoCal
2:06 PM GMT on July 23, 2013
Satellite presentation looks like a TD or even a TS. Wonder why it hasn't been classified as such yet.
Member Since: July 9, 2013 Posts: 0 Comments: 781
1765. Patrap
2:05 PM GMT on July 23, 2013
Check dis out.

7/22 PROPHECY *Nostradamus* Quatrain 41
Nostradamus
Century 2 Quatrain 41

The great star for seven days will burn
A cloud will make two suns appear
The big mastiff will howl all night
When a great Pope changes his territory




The Pope arrived in Brazil yesterday

A Son was Born in England

..back to your er, Stormy thingeee.

..ewww, weeee, ewww
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1764. GatorWX
2:05 PM GMT on July 23, 2013
Quoting 1762. Patrap:
If 12 N was Hwy 1, it's running right down the centerline seems this am.

Nice envelope too.



Indeed, especially west of the center. A nice shield perhaps, or one that'll disappear this afternoon. We'll see. Time marches on.
Member Since: January 1, 2008 Posts: 0 Comments: 3785
1763. LargoFl
2:04 PM GMT on July 23, 2013
THIS HAZARDOUS WEATHER OUTLOOK IS FOR WEST CENTRAL AND SOUTHWEST
FLORIDA.

.DAY ONE...TODAY AND TONIGHT.

...THUNDERSTORM IMPACT...
SHOWERS AND STORMS LOOK TO ARRIVE ALONG THE COAST TO THE NORTH OF
TAMPA BAY DURING THE MORNING HOURS. SOME SOUTHWARD PROGRESS IS
LIKELY AND STORMS MAY DEVELOP FAR ENOUGH SOUTH TO REACH THE I-4
CORRIDOR OR EVEN SARASOTA BEFORE MIDDAY. OTHERWISE A FEW MORE
SCATTERED STORMS WILL DEVELOP THROUGH THE AFTERNOON AND EVENING
ALONG THE SEA-BREEZE MOVING INLAND TO THE SOUTH OF TAMPA BAY. NO
SIGNIFICANT SEVERE WEATHER IS ANTICIPATED...HOWEVER AS IS USUAL
DURING THE SUMMER...A FEW STORMS ARE LIKELY TO BECOME STRONG WITH
GUSTY WINDS AND FREQUENT LIGHTNING.

...FLOOD IMPACT...
SOME AREAS MAY RECEIVE LOCALLY HEAVY RAIN TODAY RESULTING IN MINOR
URBAN AND STREAM FLOODING. SOME LOCAL RIVERS ARE ALSO NEAR OR
ABOVE FLOOD STAGE.
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1762. Patrap
2:02 PM GMT on July 23, 2013
If 12 N was Hwy 1, it's running right down the centerline seems this am.

Nice envelope too.

Member Since: July 3, 2005 Posts: 426 Comments: 129093
1761. LargoFl
2:01 PM GMT on July 23, 2013
from daytona northward,stay alert to your local warnings,stay safe..
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1760. Hurricanes305
2:01 PM GMT on July 23, 2013
Quoting 1739. GeoffreyWPB:


The page will load quickly if you click on someones "blog post" on the Community Activity to the right.
Tried restarting and clearing cookies in google chrome and clicking on someone's blog post it still loads over 2 minutes. My also reset may internet connection. 
Edit: after testing out the speed by post this comment it took about 1.40 secs
Member Since: May 25, 2012 Posts: 0 Comments: 2043
1759. Patrap
2:00 PM GMT on July 23, 2013
But,

..her moves looked good, a touch of desperation...
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1758. GatorWX
2:00 PM GMT on July 23, 2013
Quoting 1751. Patrap:


It's not overly hard to discern where the center is and west it goes.

Member Since: January 1, 2008 Posts: 0 Comments: 3785
1757. Patrap
1:59 PM GMT on July 23, 2013
Morn...

I havent really looked close yet, still in coming alive mode here.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1756. Patrap
1:58 PM GMT on July 23, 2013
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1755. GTstormChaserCaleb
1:57 PM GMT on July 23, 2013
Quoting 1751. Patrap:
Good morning Pat...is that a wobble to the north I see? :D
Member Since: June 30, 2013 Posts: 12 Comments: 8682
1754. LargoFl
1:57 PM GMT on July 23, 2013
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1753. Camille33
1:55 PM GMT on July 23, 2013
I had to delete about 18 malware in my avast antivirus.There may be a virus infecting the blog,check on this please.
Member Since: July 2, 2013 Posts: 0 Comments: 1523
1752. GTstormChaserCaleb
1:55 PM GMT on July 23, 2013
850 mb.



700 mb.



500 mb.

Member Since: June 30, 2013 Posts: 12 Comments: 8682
1751. Patrap
1:53 PM GMT on July 23, 2013
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1750. Grothar
1:50 PM GMT on July 23, 2013
Quoting 1747. Patrap:
Make sure your own page has not defaulted to Higher comments.


If you look on the bottom left, it seems to get hung up on the tropicaltidbits link.
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1749. islander101010
1:50 PM GMT on July 23, 2013
this is like blogging back in the ninties slow,
Member Since: September 11, 2010 Posts: 1 Comments: 4892
1748. GeoffreyWPB
1:50 PM GMT on July 23, 2013
Quoting 1746. Grothar:


Suppose I don't like them?


You are a good friend to all. :)
Member Since: September 10, 2007 Posts: 0 Comments: 11432
1747. Patrap
1:48 PM GMT on July 23, 2013
Make sure your own page has not defaulted to Higher comments.
Member Since: July 3, 2005 Posts: 426 Comments: 129093
1746. Grothar
1:47 PM GMT on July 23, 2013
Quoting 1739. GeoffreyWPB:


The page will load quickly if you click on someones "blog post" on the Community Activity to the right.


Suppose I don't like them?
Member Since: July 17, 2009 Posts: 71 Comments: 26895
1745. GTstormChaserCaleb
1:46 PM GMT on July 23, 2013
Starting from the West Coast to the Atlantic: Ridge, Trough, Ridge, Trough, Ridge. The Ridge in the Atlantic and the Ridge in the Central Plains looks to want to cause a squeeze play on that front on the East Coast.

Day 7:



Member Since: June 30, 2013 Posts: 12 Comments: 8682
1744. LargoFl
1:46 PM GMT on July 23, 2013
Member Since: August 6, 2011 Posts: 4 Comments: 41000
1743. Patrap
1:46 PM GMT on July 23, 2013
No, I dont tink datz it at all. We would of had a presser on something like that fer sure
Member Since: July 3, 2005 Posts: 426 Comments: 129093

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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.

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