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 LargoFl:
..more like up the east coast, this could be bad if this does unfold
At least it won't be as strong as Irene unless 99L suddenly decided to develops rapidly.
Member Since: August 1, 2011 Posts: 28 Comments: 7981
Solution Pollution?
Member Since: July 3, 2005 Posts: 423 Comments: 127807
Quoting LargoFl:
..sure is something to keep an eye on this week huh


Not really. If this storm goes over haiti it wont be anywhere near like Irene.


Irene maintained strength hovering over puerto rico.
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Expect models to shift more North on each run.

Member Since: July 17, 2009 Posts: 71 Comments: 25996
Quoting SFLWeatherman:
2PM are going up to FL now!!
..more like up the east coast, this could be bad if this does unfold
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Morehead City
NEXRAD Radar
Type
Base Reflectivity 0.50° Elevation
Range 248 NMI




Member Since: July 3, 2005 Posts: 423 Comments: 127807
Quoting TropicalAnalystwx13:

The Atlantic really warmed.


Come on, you can say it. "So did the ENSO regions." :-D
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Quoting MississippiWx:
Nags Head, NC today. Three at a time:

1441 3 NNW OREGON INLET MAINLAND DARE NC 3584 7556 DARE COUNTY 911 RELAYED REPORT OF A WATERSPOUT THAT MOVED ONSHORE NORTH OF THE BODIE ISLAND LIGHTHOUSE HEADING WEST. (MHX)
1501 WANCHESE DARE NC 3584 7564 DARE COUNTY 911 REPORTED WATERSPOUT AGAIN CAME ONSHORE IN WANCHESE. (MHX)
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting Stormchaser2007:
Keep an eye on that EC blob

The HRRR blows it up into some 60knt+ system lol (unrealistic)



..could change into a sub tropical storm like we had a few months ago
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Quoting TropicalAnalystwx13:

This storm reminds me so much of Irene in terms of track.
..sure is something to keep an eye on this week huh
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Quoting MississippiWx:
Here is a GIF loop I made of the global SST anomalies at the end of each month. Starts at January and goes up until today, July 30th. Interesting to watch the changes in anomalies throughout the globe the past 7 months.


The Atlantic really warmed.
Member Since: July 6, 2010 Posts: 113 Comments: 31883
Getting slammed by thunderstorm from this blob in Garner/Clayton area. This one is a real soaker, but not very windy.
Member Since: August 1, 2011 Posts: 28 Comments: 7981
No!.Please!.Don't mention that name!.
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Here is a GIF loop I made of the global SST anomalies at the end of each month. Starts at January and goes up until today, July 30th. Interesting to watch the changes in anomalies throughout the globe the past 7 months.

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Quoting SFLWeatherman:
2PM are going up to FL now!!

This storm reminds me so much of Irene in terms of track.
Member Since: July 6, 2010 Posts: 113 Comments: 31883
Quoting Neapolitan:
Very nice. I've seen dozens--maybe hundreds. And I've seen three at once many times; five at once twice; and nine at once a single very memorable time.


Nine is pretty amazing and rare. However, if you hang around the coast enough, you are almost assured to see one eventually.
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Keep an eye on that EC blob

The HRRR blows it up into some 60knt+ system lol (unrealistic)



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Quoting Tropicsweatherpr:
The BAMS continue to develop a hurricane at 18z run.


BAMS is a simple trajectory model, it does not include intensity.
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Quoting Civicane49:
the blob near NC remind me of ts Cristobal of 2008.
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Quoting MississippiWx:
Nags Head, NC today. Three at a time:>
Very nice. I've seen dozens--maybe hundreds. And I've seen three at once many times; five at once twice; and nine at once a single very memorable time.
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2PM are going up to FL now!!
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Look at all that warm water just below the surface of the eastern ENSO regions!!!

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Quoting MississippiWx:


Yep. Saw one off the balcony of my condo in Perdido Key, FL a few weeks ago. It was very large and less than a mile off the coast.
cool
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting allancalderini:
Good morning again.... the lights had been going on and off hate this thing of living in here.do anyone think the blob near NC has a chance to develop?I was looking at it at the morning but I want to see your thoughts in of this system.

No.
Member Since: July 6, 2010 Posts: 113 Comments: 31883
The BAMS continue to develop a hurricane at 18z run.
Member Since: April 29, 2009 Posts: 75 Comments: 14214
393. SLU
613

WHXX01 KWBC 301846

CHGHUR

TROPICAL CYCLONE GUIDANCE MESSAGE

NWS NATIONAL HURRICANE CENTER MIAMI FL

1846 UTC MON JUL 30 2012



DISCLAIMER...NUMERICAL MODELS ARE SUBJECT TO LARGE ERRORS.

PLEASE REFER TO NHC OFFICIAL FORECASTS FOR TROPICAL CYCLONE

AND SUBTROPICAL CYCLONE INFORMATION.



ATLANTIC OBJECTIVE AIDS FOR



DISTURBANCE INVEST (AL992012) 20120730 1800 UTC



...00 HRS... ...12 HRS... ...24 HRS. .. ...36 HRS...

120730 1800 120731 0600 120731 1800 120801 0600



LAT LON LAT LON LAT LON LAT LON

BAMS 8.7N 35.8W 9.1N 38.9W 9.6N 42.2W 9.6N 45.7W

BAMD 8.7N 35.8W 8.8N 37.7W 9.0N 39.6W 9.4N 41.5W

BAMM 8.7N 35.8W 8.9N 38.0W 9.3N 40.3W 9.6N 42.6W

LBAR 8.7N 35.8W 8.7N 37.5W 8.9N 39.7W 9.1N 42.0W

SHIP 20KTS 22KTS 27KTS 34KTS

DSHP 20KTS 22KTS 27KTS 34KTS



...48 HRS... ...72 HRS... ...96 HRS. .. ..120 HRS...

120801 1800 120802 1800 120803 1800 120804 1800



LAT LON LAT LON LAT LON LAT LON

BAMS 9.4N 49.1W 8.4N 54.7W 7.8N 59.3W 7.9N 62.5W

BAMD 9.8N 43.4W 10.5N 47.0W 11.9N 51.1W 14.3N 56.5W

BAMM 10.0N 44.7W 10.7N 48.7W 11.8N 52.8W 13.4N 57.6W

LBAR 9.3N 44.5W 9.4N 49.2W 10.0N 53.4W 12.4N 57.7W

SHIP 45KTS 63KTS 72KTS 75KTS

DSHP 45KTS 63KTS 72KTS 75KTS



...INITIAL CONDITIONS...

LATCUR = 8.7N LONCUR = 35.8W DIRCUR = 270DEG SPDCUR = 4KT

LATM12 = 8.7N LONM12 = 35.1W DIRM12 = 270DEG SPDM12 = 4KT

LATM24 = 8.7N LONM24 = 34.4W

WNDCUR = 20KT RMAXWD = 80NM WNDM12 = 20KT

CENPRS = 1010MB OUTPRS = 1011MB OUTRAD = 160NM SDEPTH = S

RD34NE = 0NM RD34SE = 0NM RD34SW = 0NM RD34NW = 0NM



$$

NNNN

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Good morning again.... the lights had been going on and off hate this thing of living in here.do anyone think the blob near NC has a chance to develop?I was looking at it at the morning but I want to see your thoughts in of this system.
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We are headed back up the Nino ladder:



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18z Best Track.

AL, 99, 2012073018, , BEST, 0, 87N, 358W, 20, 1010, DB
Member Since: April 29, 2009 Posts: 75 Comments: 14214
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Quoting yonzabam:


Oddest looking tornado I ever saw. Looks much more like a waterspout. Also pretty strange that a 'stormchaser' should actually be up there in that remote altitude in the mountains and be just in the right place to snap a photo.

But call me suspicious.


here is another picture of the tornado from a random driver:
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387. ARiot
Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



I'll squint and pick C, but I think if the Central US high (ring of fire) is around, it'll stay south and go in around Brownsville/N.Mex.

That high pressure is pretty amazing, IMHO, but it could break up in another 5-8 days (?)
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Looks off North Carolina coast...

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Quoting MississippiWx:
Nags Head, NC today. Three at a time:


Nice beach day today.
Member Since: July 6, 2010 Posts: 113 Comments: 31883
Quoting wxchaser97:
That looks pretty close to the coast those waterspouts. I've never seen one, have you MSWx?


Yep. Saw one off the balcony of my condo in Perdido Key, FL a few weeks ago. It was very large and less than a mile off the coast.
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.
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Quoting Tropicsweatherpr:


EURO is stronger at this run?


Yes, it shows the wave surviving the cross over the islands..
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Quoting MississippiWx:
Nags Head, NC today. Three at a time:

That looks pretty close to the coast those waterspouts. I've never seen one, have you MSWx?
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



B,C or D but mainly C or D
Member Since: June 13, 2009 Posts: 2 Comments: 11736
Nags Head, NC today. Three at a time:

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Quoting ncstorm:
168 hours


EURO is stronger at this run?
Member Since: April 29, 2009 Posts: 75 Comments: 14214
Published on May 25, 2012 by TheCSUEngineer

Jonathan Vigh, Atmospheric Science graduate student, researches the ensemble prediction of hurricane tracks to simulate the uncertainty of forecasts. The opportunity to work with tropical meteorology and hurricanes and the abundant activities Fort Collins offers brought Jonathan, an avid skier and hiker, to CSU.

Member Since: July 3, 2005 Posts: 423 Comments: 127807
168 hours
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Watch #540
Member Since: March 16, 2012 Posts: 127 Comments: 7940
Only mention of the wave we are looking at in the afternoon NCEP Caribbean discussion:

TROPICAL DISCUSSION - INTERNATIONAL DESKS
NWS HYDROMETEOROLOGICAL PREDICTION CENTER CAMP SPRINGS MD
210 PM EDT MON JUL 30 2012

A TROPICAL WAVE INITIALIZED AT 37W AND TO THE SOUTH OF 14N IS WELL DEFINED WHILE CROSSING THE TROPICAL ATLANTIC. THIS WAVE WILL ARRIVE INTO FRENCH GUIANA AND SURINAME BY 84 HRS ENHANCING CONVECTION TO PRODUCE ACCUMULATIONS OF 15-20MM/DAY AND MAXIMA OF 25-50MM/DAY.


Link

They are waiting to see how it looks in a few days before turning to more detailed discussions if merited by model guidance and increased percentages from NHC if development becomes likely.
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The NWS Storm Prediction Center has issued a
Severe Thunderstorm Watch for portions of

Upper Peninsula of Michigan
northeast Wisconsin
Lake Michigan
Lake Superior

Effective this Monday afternoon and evening from 130 PM until 800
PM CDT.

Hail to 2 inches in diameter... thunderstorm wind gusts to 70
mph... and dangerous lightning are possible in these areas.

The Severe Thunderstorm Watch area is approximately along and 75
statute miles east and west of a line from 20 miles northeast of
Marquette Michigan to 40 miles southwest of Green Bay Wisconsin.
For a complete depiction of the watch see the associated watch
outline update (wous64 kwns wou0).

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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



D

If it makes it into the GOMEX that will be a nightmare. For the 1st time this year, in fact for the last couple years, I'm concerned.
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Quoting trHUrrIXC5MMX:





Kinda Alberto did early this year.

If it develops it better be better than Alberto, but not hit land.
Member Since: March 16, 2012 Posts: 127 Comments: 7940

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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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