African tropical wave 99L has potential to develop

By: Dr. Jeff Masters , 3:10 PM GMT on July 30, 2012

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The first African tropical wave of 2012 with a potential to develop is Invest 99L, located in the Eastern Atlantic near 9°N 36°W, midway between the Lesser Antilles Islands and the coast of Africa. Visible satellite loops show a large area of the surrounding atmosphere has a pronounced counter-clockwise spin, though there is no surface circulation. The disturbance's heavy thunderstorm activity is pretty sparse, but appears to be slowly increasing. Water vapor satellite loops show that 99L has a reasonably moist environment, and the latest Saharan air layer analysis shows that the dry air from the Sahara lies well to the north of 99L. WInd shear over the disturbance is a light 5 - 10 knots, and ocean temperatures are 28°C, (82°F) which is well above the 26.5°C (80°F) threshold typically needed to allow formation of a tropical depression.


Figure 1. Morning satellite image of Invest 99L.

Forecast for 99L
Wind shear is expected to remain light for the next five days, and ocean temperatures will remain near 28°C, according to the 8 am EDT run of the SHIPS model. The disturbance is at 9°N, which is close enough to the Equator that the storm will have some difficultly getting spinning. Most of the models are showing some slow development of 99L, with the storm reaching the Lesser Antilles Islands on Saturday, August 3. NHC gave 99L a 20% chance of developing into a tropical depression by Wednesday morning. I expect the storm will have trouble with dry air at times this week as it crosses the Atlantic, but I give 99L a 50% chance of eventually developing into Tropical Storm Ernesto sometime in the next ten days. Residents and visitors to the Lesser Antilles Islands should anticipate heavy rains and strong winds from 99L beginning to affect the islands as early as Friday night. The long-range fate of 99L is uncertain, but a trough of low pressure is expected to be present over the Eastern U.S. early next week, which would be capable of turning 99L more to the northwest.

Hot in the Central U.S.
The heat in America's heartland continued on Sunday, with Wichita, KS hitting 111°F, just 3° short of their all-time hottest temperature of 114° set on 8/12/1936. Other notable highs on Sunday:

111° Coffeyville, KS
111° Winfield, KS
110° Chanute, KS
110° Parsons, KS
109° Joplin, MO (all-time record is 115° on July 14, 1954)

The low temperature in Tulsa, Oklahoma this Monday morning dropped to only 88°F. This is the all-time warmest low temperature in the city since record keeping began in 1905. The previous record warmest minimum temperature was 87°F set on August 2, 2011 and July 16, 1980. The high in Tulsa Monday - Wednesday is expected to reach 110° - 111°, close to the city's all-time hottest temperature of 115° set on August 10, 1936.

Jeff Masters

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Quoting robert88:
I'm thinking SA or Yucatan...if it can even survive. One thing is for sure the GFS and ECMWF are not too excited about this system. The ECMWF does have a lot to prove after the last disaster. Going by atmospheric conditions in the Caribbean you would think that anything taking that route is doomed.
I doubt South America, anything from the Mosquito Coast northward, like you said though if it can make it out of the Caribbean alive. Best atmospheric conditions would be north of the islands, which is why the CMC seems the most bullish in terms of strength.
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GFS 114hrs, 99L enters stage right


144hrs


162hrs. and 99L is gooooooooooooooooone
Member Since: September 30, 2007 Posts: 9 Comments: 15962
Quoting KoritheMan:


I've always wanted to browse through Linda's as well, for the sole reason the forecast track literally had her going into southern California.


At 902mb,strongest east pacific hurricane on record. A trof was forecast to lift her NE into Soo Cal as a TS, Alas the trof that was forecast to lift her NE into Soo Cal was too weak and the ridge following the trof turned her back to the west.



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Quoting AussieStorm:
Has anyone checked out the what the GFS for the WPAC for the next 192hrs....

Saola and Damrey.


54hrs


144hrs


I guess this is what the MJO pulse does.
Coming soon to an ATL near you...
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Quoting BahaHurican:
Hey, ya'll... how's our invest doing this fine a.m.?


Hey Baha. Looks like not much change from earlier. Still hanging in there.
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I'm thinking SA or Yucatan...if it can even survive. One thing is for sure the GFS and ECMWF are not too excited about this system. The ECMWF does have a lot to prove after the last disaster. Going by atmospheric conditions in the Caribbean you would think that anything taking that route is doomed.
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UKMET

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Hey, ya'll... how's our invest doing this fine a.m.?
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Has anyone checked out the what the GFS for the WPAC for the next 144hrs....

Saola and Damrey.


54hrs


144hrs


I guess this is what the MJO pulse does.
Member Since: September 30, 2007 Posts: 9 Comments: 15962
Euro 144 hrs. out:



GFS 144 hrs. out:



Euro is faster than the GFS, but both heading in a general westward path.
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1610. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #35
SEVERE TROPICAL STORM SAOLA (1209)
15:00 PM JST July 31 2012
=============================================

SUBJECT: Category Two Typhoon South Of Okinawa

At 6:00 AM UTC, Severe Tropical Storm Saola (970 hPa) located at 21.1N 123.7E has 10 minute sustained winds of 60 knots with gusts of 85 knots. The cyclone is reported as moving west northwest slowly.

Dvorak Intensity: T3.5

Storm Force Winds
=================
40 NM from the center

Gale Force Winds
================
400 NM from the center

Forecast and Intensity
==========================

24 HRS: 22.7N 123.1E - 75 knots (CAT 3/Strong Typhoon) - south southwest of Ishigaki Island
45 HRS: 24.7N 122.4E - 80 knots (CAT 3/Strong Typhoon) - west northwest of Yonaguni Island
69 HRS: 27.3N 120.8E - 70 knots (CAT 3/Strong Typhoon) - East China Sea
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Quoting stormchaser19:



This looks like when debby,the majority of the models showed west and GFS showed east to florida....rigth now the majority of the models shows more west-northwest and the GFS is shows more to the west

The GFS will win the second round ?


Win round 2? GFS delivered a 14 punch combo to the EURO'S face to knock the EURO out!! If it wants it's respectibility back.......the EURO needs to tell us now where 99L/Ernesto is going to be in 10 days.
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Canadian Model 144 hrs. out in Isotachs:

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1607. HadesGodWyvern (Mod)
Japan Meteorological Agency
Tropical Cyclone Advisory #35
SEVERE TROPICAL STORM DAMREY (1210)
15:00 PM JST July 31 2012
=============================================

SUBJECT: Category Two Typhoon In Sea South Of Japan

At 6:00 AM UTC, Severe Tropical Storm Damrey (975 hPa) located at 28.6N 138.9E has 10 minute sustained winds of 55 knots with gusts of 80 knots. The cyclone is reported as moving west at 18 knots.

Dvorak Intensity: T3.5

Storm Force Winds
====================
40 NM from the center

Gale Force Winds
=================
300 NM from the center in northeast quadrant
180 NM from the center in southwest quadrant

Forecast and Intensity
==========================

24 HRS: 30.7N 131.3E - 55 knots (CAT 2/Severe Tropical Storm) - east northeast of Tanega shima
48 HRS: 33.1N 124.9E - 50 knots (CAT 2/Severe Tropical Storm) - Yellow Sea
72 HRS: 37.7N 120.1E - 45 knots (CAT 1/Tropical Storm) - Bohai Sea
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Quoting wxgeek723:


LOLOL you did not just call them beliefs.


I missed it. Does Chick Filet want to ban gay people from their stores? Are they using the old sign"We reserve the right to refuse service to anyone?
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Well this is new. Bout the time the gfs agrees with previous EURO runs. The EURO takes 99l into the western GOM.



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Quoting HurricaneHunterJoe:
Anyone seen a case of Vanilla Ensure?


There was one in my fridge. Daughter drank em all. Lil brat!!! ;)
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Anyone seen a case of Vanilla Ensure?
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Quoting wxwonder1:
http://www.ssd.noaa.gov/PS/TROP/floaters/99L/imag er y/vis0-lalo.jpg
Image didnt appear, got the right URL but you didnt paste it in the image part.
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Good night everyone
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Quoting PedleyCA:
Hey Pat, This was a good one......



I was at this concert, and 17.....


The Chamber Brothers seem a bit out of character with the top two bands on the poster list.
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Quoting RussianWinter:
So uhh, do you guys think the Euro is going to get back in the game or no?


EURO ran away and hid in shame after Debby. I don't think it needs to do that as it's the one that usually get the "A'.
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144 hours
Member Since: March 16, 2012 Posts: 127 Comments: 7959
http://www.ssd.noaa.gov/PS/TROP/floaters/99L/imager y/vis0-lalo.jpg
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Quoting nofailsafe:
Beat me to it. Looks like 99L is making its turn to the north during the 120 hr frame of the 00z ECMWF.
Yes I did, that is different from previous runs and the gfs.
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Quoting Patrap:
Nothing like a Huge Haboob..
I reckon that I do prefer Very Large HaBOOB'S
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Quoting JLPR2:
One last thing before I go.

3hrs ago:


Now:
Looks to be getting stronger/ more circular.
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1593. JLPR2
One last thing before I go.

3hrs ago:


Now:
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Quoting JLPR2:
99L still has a long way to go, but it is slowly getting there.



With that I'm off to bed, good night/morning everyone!

Good night JLPR2!
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Beat me to it. Looks like 99L is making its turn to the north during the 120 hr frame of the 00z ECMWF.
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120 hours
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1589. JLPR2
99L still has a long way to go, but it is slowly getting there.



With that I'm off to bed, good night/morning everyone!
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96 hours
Member Since: March 16, 2012 Posts: 127 Comments: 7959
72 hours
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Quoting wxchaser97:

Looks good!


Thanks man!!!!
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Quoting wxwonder1:


Okay think I have the grasp! Thanks for your time and teaching me how to do that
Your welcome, I don't mind doing that.
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Quoting wxwonder1:

Looks good!
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Quoting wxchaser97:
Copy the image's URL(not the pages URL), click the image button, and then paste the URL and then post comment.


Okay think I have the grasp! Thanks for your time and teaching me how to do that
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Quoting Bluestorm5:
Off topic, but I just lol'd at Japan using cash to bride the judges to get them a silver in Men's team gymnastics...

Best laugh of the day so far ...
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1580. JLPR2
Quoting JLPR2:


Nah, I'm good. XD Actually ended July a little above average.


Scratch that, I'm actually slightly below average.

Actual month total 5.32
Normal month total 5.43

Maybe the TW could help fill that gap today.
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48 hours
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Quoting wxwonder1:
Can any one tell me how to post images on the blog?
Copy the image's URL(not the pages URL), click the image button, and then paste the URL and then post comment.
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Can any one tell me how to post images on the blog?
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euro at 24 hours
Member Since: March 16, 2012 Posts: 127 Comments: 7959
I want... I want....
to go to bed... goodnight....
Member Since: August 2, 2010 Posts: 21 Comments: 9874
MI line looks to be weakening slightly, warnings dropped.
Member Since: March 16, 2012 Posts: 127 Comments: 7959
Quoting sunlinepr:


I DO.... I WANT RAIN.... LOTS OF RAIN....


*does a rain dance*
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1572. JLPR2
Quoting KoritheMan:


Is that your way of saying "I want rain"? :P


Nah, I'm good. XD Actually ended July a little above average.
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Quoting KoritheMan:


Is that your way of saying "I want rain"? :P


I DO.... I WANT RAIN.... LOTS OF RAIN....
THE BACKYARD TANK CISTERN IS YELLING ALSO... I WANT RAIN...
Member Since: August 2, 2010 Posts: 21 Comments: 9874
Member Since: March 16, 2012 Posts: 127 Comments: 7959

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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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