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 19N81W:
wow the wpac ir looks like fireworks going off


West Pacific -- 96W, 97W, 98W, Damrey and Saola
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Quoting GeorgiaStormz:


thx for the help
Lol, I actually figures it out now.
Member Since: August 1, 2011 Posts: 28 Comments: 8009
Lesser Antilles



Puerto Rico




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Quoting TropicalAnalystwx13:

Use "big" in replacement for "strong" after you bold something.

Just remove the brackets.


thx for the help
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....................................alot of thunders with these cells just about to come onshore by me...Jedkins..you online?
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Anyway... what's people's thought about that blob off coast of NC?
Member Since: August 1, 2011 Posts: 28 Comments: 8009
wow the wpac ir looks like fireworks going off
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312. yoboi
Quoting Tazmanian:
here are this weeks #

Niño 4 0.1ºC
Niño 3.4 0.6ºC
Niño 3 1.0ºC
Niño 1+2 0.7ºC



cha ching....
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Quoting Patrap:
Morehead City
NEXRAD Radar
Base Reflectivity 0.50° Elevation
Range 248 NMI

sure is gaining rotation
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Quoting TropicalAnalystwx13:
New WPAC invest:





The WPac is one enormous blob of tropical cyclones.
Member Since: July 15, 2006 Posts: 17 Comments: 10247
I didnt think it was supposed to rain today... haha

The National Weather Service in State College PA has issued an

* Urban and Small Stream Flood Advisory for...
Adams County...
eastern Cumberland County...
southern Dauphin County...
western Lancaster County...
Lebanon County...
south central Schuylkill County...
York County...

* until 430 PM EDT...

* at 137 PM EDT Doppler radar showed very heavy rain moving into the
area. Up to 2 inches of rain is expected to fall in an hour. Expect
flooding to begin shortly after the rain begins.

* Locations that may experience minor flooding include but are not
limited to... Loganville... York... New Salem... Gettysburg and Carlisle.

Slow moving showers continue to move to the north at 10 mph with
local heavy rain that could cause localized flooding.
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hello
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Quoting TropicalAnalystwx13:

Use "big" in replacement for "strong" after you bold something.

Just remove the brackets.


Like this?

EDIT: didn't work, lol.

EDIT2:Ok... now I'm confused. Going back on topic now.
Member Since: August 1, 2011 Posts: 28 Comments: 8009
Link shortwavew loop 99L



Link 99L Visible Loop
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Member Since: March 16, 2012 Posts: 127 Comments: 7942



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The NHC most likely won't show much more interest in 99L until it departs from the ITCZ. If it can still be as impressive as it is now, then I think the NHC will have no choice but to increase the percentage.

Member Since: July 15, 2006 Posts: 17 Comments: 10247
New WPAC invest:



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While 99L is certainly the most interesting feature in our area keep in mind there's a very large typhoon impacting Taiwan right now:

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Member Since: March 16, 2012 Posts: 127 Comments: 7942
Still 20% at 2pm
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99L:

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here are this weeks #

Niño 4 0.1ºC
Niño 3.4 0.6ºC
Niño 3 1.0ºC
Niño 1+2 0.7ºC
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Quoting TropicalAnalystwx13:

It's just rain moving ashore. That's what my NWS said anyways.


1. It's not moving ashore. Maybe on the north side of the newly developed low (lol).

2. I think they are going to be eating their words. The rotation is getting better every hour.

3. I hope they are right because I hate these things.
Member Since: July 15, 2006 Posts: 17 Comments: 10247
Quoting BVI:


Which island are you on? i have heard 1 or 2 rumbles of thunder here but nothing major as yet


St Maarten
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294. yoboi
Quoting Tribucanes:
Yoboi, Andrea did a blog entry yesterday where she addressed the study of climate scientists "cherry picking" data. That notion has been studied and found not to be lacking, but has been fully debunked when talking about credited climate scientists. I don't know if you read her entry yesterday, but she addressed a lot of things you've said over the last month. Not trying to start up the debate when we've got an invest that has high probability of being a lanfaller. Just wanted you to know she specifically addressed "cherry picking." If this is going to be the likely track area of storms this year then we're in for a long season. Jeff's only giving it 50/50 to develop in the next ten, so maybe we'll luck out with this first wave invest.


yeah she answered some of my questions cleared my thoughts about a few things...
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Morehead City
NEXRAD Radar
Base Reflectivity 0.50° Elevation
Range 248 NMI

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Quoting GeorgiaStormz:
how do you make things big (bigger than double bolding)

Use "big" in replacement for "strong" after you bold something.

Just remove the brackets.
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The Conversion of a Climate-Change Skeptic
By RICHARD A. MULLER
Published: July 28, 2012

Link
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Issued by The National Weather Service
Mobile, AL
10:28 am CDT, Mon., Jul. 30, 2012

... HEAT ADVISORY IN EFFECT UNTIL 6 PM CDT THIS EVENING...

THE NATIONAL WEATHER SERVICE IN MOBILE HAS ISSUED A HEAT ADVISORY... WHICH IS IN EFFECT UNTIL 6 PM CDT THIS EVENING.

* HEAT INDEX VALUES: 106 TO 110 DEGREES THROUGH THIS AFTERNOON.

* IMPACTS: PROLONGED EXPOSURE TO THE HEAT CAN BE DANGEROUS IF THE PROPER PRECAUTIONS ARE NOT TAKEN.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A HEAT ADVISORY MEANS THAT A PERIOD OF HOT TEMPERATURES IS EXPECTED. TAKE EXTRA PRECAUTIONS IF YOU WORK OR SPEND TIME OUTSIDE. WHEN POSSIBLE... RESCHEDULE STRENUOUS ACTIVITIES TO EARLY MORNING OR EVENING. KNOW THE SIGNS AND SYMPTOMS OF HEAT EXHAUSTION AND HEAT STROKE. WEAR LIGHT WEIGHT AND LOOSE FITTING CLOTHING WHEN POSSIBLE AND DRINK PLENTY OF WATER.

TO REDUCE RISK DURING OUTDOOR WORK THE OCCUPATIONAL SAFETY AND HEALTH ADMINISTRATION RECOMMENDS SCHEDULING FREQUENT REST BREAKS IN SHADED OR AIR CONDITIONED ENVIRONMENTS. ANYONE OVERCOME BY HEAT SHOULD BE MOVED TO A COOL AND SHADED LOCATION. HEAT STROKE IS AN EMERGENCY... CALL 9 1 1.

&&
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AL992012 - INVEST

Storm Relative 16km Geostationary Water Vapor Imagery

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The National Weather Service in Tallahassee has issued a

* Severe Thunderstorm Warning for...
southern Dixie County in Florida...

* until 215 PM EDT

* at 130 PM EDT... the National Weather Service has detected a severe
thunderstorm capable of producing damaging winds in excess of 60
mph. This storm was located 29 miles west of Yellow Jacket... or 7
miles southwest of Steinhatchee... and moving east at 30 mph.

* The severe thunderstorm will otherwise remain over mainly rural
areas of the indicated County.

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...............................................ok so its Florida's turn for the severe storms today, even as far down as my area looks like
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how do you make things big (bigger than double bolding)
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No mention of the East Coast Blob.

The EPAC is quiet.
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Stays at 20%
1. A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE LOCATED
ABOUT 900 MILES SOUTHWEST OF THE CAPE VERDE ISLANDS CONTINUES TO
PRODUCE DISORGANIZED SHOWER AND THUNDERSTORM ACTIVITY.
ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR SOME GRADUAL
DEVELOPMENT OVER THE NEXT FEW DAYS...AND THIS SYSTEM HAS A LOW
CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WESTWARD AT 10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.
Member Since: March 16, 2012 Posts: 127 Comments: 7942
BULLETIN - EAS ACTIVATION REQUESTED
SEVERE THUNDERSTORM WARNING
NATIONAL WEATHER SERVICE TALLAHASSEE FL
1245 PM CDT MON JUL 30 2012

THE NATIONAL WEATHER SERVICE IN TALLAHASSEE HAS ISSUED A

* SEVERE THUNDERSTORM WARNING FOR...
CENTRAL WALTON COUNTY IN THE PANHANDLE OF FLORIDA...

* UNTIL 130 PM CDT

* AT 1243 PM CDT...THE NATIONAL WEATHER SERVICE HAS DETECTED A SEVERE
THUNDERSTORM CAPABLE OF PRODUCING DAMAGING WINDS IN EXCESS OF 60
MPH. THIS STORM WAS LOCATED NEAR DE FUNIAK SPRINGS...AND MOVING
SOUTHEAST AT 15 MPH.

* OTHER LOCATIONS IN THE WARNING INCLUDE BUT ARE NOT LIMITED TO ROCK
HILL...EUCHEEANNA...SHADY GROVE AND KNOX HILL.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

THIS IS A DANGEROUS STORM. IF YOU ARE IN ITS PATH...PREPARE
IMMEDIATELY. PEOPLE OUTSIDE SHOULD MOVE INSIDE A STRONG BUILDING BUT
AWAY FROM WINDOWS.



LAT...LON 3080 8615 3071 8604 3062 8592 3050 8606
3069 8628
TIME...MOT...LOC 1746Z 307DEG 14KT 3070 8613



42-DVD
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Quoting GTcooliebai:
I'm leaning towards a stronger system developing once nearing the islands which would induce a pull towards the wnw, so I'm in the middle of the consensus and this Ernesto might take a similar path to the last Ernesto.


I hear ya. I am actually surprised to see some model consensus (and a 50% from Dr. M) this early into August but we just have to see how the synoptic conditions pan out ahead of the wave as it nears the Lesser Antilles.

Alternatively, it could split down the middle and get into trouble with the island chain and westerlies. I always fear those storms that make it North of PR and into the Bahamas the worst because it's a straight shot into Florida or the Keys from there unless they turn.
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Quoting sunlinepr:


Will be on alert hearing the TV while blogging....

Yeah...I'm hoping that we'll have more entrants in swimming for the 2016 Rio Olympics and other sports other than track and field.
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Weather Station - report
Uptown, New Orleans


Mostly Cloudy

Temperature

94.9 °F

Feels Like 112 °F
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TROPICAL WEATHER OUTLOOK
NWS NATIONAL HURRICANE CENTER MIAMI FL
200 PM EDT MON JUL 30 2012

FOR THE NORTH ATLANTIC...CARIBBEAN SEA AND THE GULF OF MEXICO...

A WEAK AREA OF LOW PRESSURE ASSOCIATED WITH A TROPICAL WAVE LOCATED
ABOUT 900 MILES SOUTHWEST OF THE CAPE VERDE ISLANDS CONTINUES TO
PRODUCE DISORGANIZED SHOWER AND THUNDERSTORM ACTIVITY.
ENVIRONMENTAL CONDITIONS APPEAR CONDUCIVE FOR SOME GRADUAL
DEVELOPMENT OVER THE NEXT FEW DAYS...AND THIS SYSTEM HAS A LOW
CHANCE...20 PERCENT...OF BECOMING A TROPICAL CYCLONE DURING THE
NEXT 48 HOURS AS IT MOVES WESTWARD AT 10 TO 15 MPH.

ELSEWHERE...TROPICAL CYCLONE FORMATION IS NOT EXPECTED DURING THE
NEXT 48 HOURS.

$$
FORECASTER BRENNAN
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Quoting weathermanwannabe:
Here are two latest sample runs for 99L. CMC takes it North of PR towards the Bahamas and GFS takes it South of PR into the Northern Caribbean.

GFS

Link

CMC

Link

CMC currently has a stronger storm thus the difference in a higher trajectory while GFS has a weaker system further to the West.
I'm leaning towards a stronger system developing once nearing the islands which would induce a pull towards the wnw, so I'm in the middle of the consensus and this Ernesto might take a similar path to the last Ernesto.
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Is Hotsui in Se. La and The Miss Gulf Coast.

Orleans Parish

Heat Advisory

Statement as of 10:48 AM CDT on July 30, 2012

... Heat advisory remains in effect until 7 PM CDT this evening...

* timing... highest heat index values will occur this afternoon

* duration... heat index values over 108 will last for 3 hours this
afternoon into the early evening hours

Precautionary/preparedness actions...

A heat advisory means that a period of hot temperatures is
expected. The combination of hot temperatures and high humidity
will combine to create a situation in which heat illnesses are
possible. Drink plenty of fluids... stay in an air-conditioned
room... stay out of the sun... and check up on relatives and
neighbors.
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Quoting Skyepony:


Been watching this little guy all morning. Seems to have gained a considerable amount of size and shape just in the past 8 hours.

Hopefully something fun to keep things interesting until 99L gets its act together.
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271. BVI
Quoting CaribBoy:
We are getting much needed rain in the Leeward Islands right now thanks to the strong TWave. An interesting thing to note is the VERY STRONG wind gusts ahead of a squall earlier this morning.. probably around 60MPH. Leaves were flying, and some stuffs outside were broken as well. Right now there are still thunder and lightnings..


Which island are you on? i have heard 1 or 2 rumbles of thunder here but nothing major as yet
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About

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