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 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: 7948
144 hours
Member Since: August 19, 2006 Posts: 13 Comments: 15666
Member Since: July 3, 2005 Posts: 426 Comments: 128645
Quoting wxchaser97:
Test
Anyway the blob off the east coast could become yet another high latitude TS. It is looking decent right now with a good environment.





Kinda Alberto did early this year.

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Morehead City
NEXRAD Radar

Base Reflectivity 0.50° Elevation
Range 248 NMI

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This is kind of cool:

PUBLIC INFORMATION STATEMENT
NATIONAL WEATHER SERVICE TAUNTON MA
1111 AM EDT MON JUL 30 2012

...EF0 TORNADO CONFIRMED IN MANOMET SECTION OF PLYMOUTH MA ON
TUESDAY JULY 24 2012...

LOCATION...MANOMET SECTION OF PLYMOUTH IN PLYMOUTH COUNTY MA
DATE...JULY 24 2012
ESTIMATED TIME...408 PM TO 409 PM EDT
MAXIMUM EF- SCALE RATING...EF0
ESTIMATED MAXIMUM WIND SPEED...65 MPH - SEE TEXT BELOW.
MAXIMUM PATH WIDTH...15 YARDS
PATH LENGTH...45 YARDS
BEGINNING LAT/LON...41.94 N 71.57 W
ENDING LAT/LON...41.94 N 71.57 W
* FATALITIES...0
* INJURIES...0

* THE INFORMATION IN THIS STATEMENT IS PRELIMINARY AND SUBJECT TO
CHANGE PENDING ANY FINAL REVIEW OF THE EVENT AND PUBLICATION IN
NWS STORM DATA.

...SUMMARY...
THE NATIONAL WEATHER SERVICE IN TAUNTON MA HAS CONFIRMED THAT
THREE WATERSPOUTS FORMED OFF THE COAST OF MANOMET IN PLYMOUTH
COUNTY AT 406 PM ON TUESDAY JULY 24 2012. THEY THEN RAPIDLY MOVED
ONSHORE...CAUSING MINOR DAMAGE AT WHITE HORSE BEACH BETWEEN
408 PM AND 409 PM...AND THEN DISSIPATED. THESE WERE PHOTOGRAPHED
WITH A TIME STAMP. TECHNICALLY...A WATERSPOUT MOVING ONSHORE AND
CAUSING DAMAGE IS CLASSIFIED AS A TORNADO.

DAMAGE WAS VERY MINIMAL. A WINDOW OF THE CRANK-OUTWARD TYPE WAS
RIPPED OFF ITS HINGES AND THEN SHATTERED WHEN IT HIT THE SIDE OF A
HOUSE. A BEACH UMBRELLA AND A FEW AWNINGS WERE DAMAGED. SAND AND
OTHER DEBRIS WERE HURLED INTO THE AIR ABOVE THE LEVEL OF BEACHSIDE
CONDOS.

WIND SPEEDS WERE LIKELY LESS THAN 65 MPH...HOWEVER THAT IS THE
MINIMUM SPEED ALLOWED FOR A CLASSIFICATION OF AN EF-0 TORNADO.
THE PATH LENGTH WAS ONLY 45 YARDS AND THE WIDTH WAS NO MORE THAN
15 YARDS. THERE WERE NO INJURIES OR FATALITIES.
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Avation Weather for the Carolina's and shore's..



This one indicates a less than favorable conditions for flight plans of 6 or more hours..
Meaning the weather in 6hrs is liable to change quickly to un-favorable flying conditions..
I'm thinking they do have a wary eye on that area as a trouble maker..



Quoting MAweatherboy1:
This is from the SPC's latest discussion... It talks about the Carolina blob:

REGIONAL RADAR IMAGERY OVER NERN SC INDICATED AN AREA OF BROAD LOW
LEVEL CIRCULATION CENTERED OVER HORRY COUNTY SC...WITH THIS
CIRCULATION A SUB-SYNOPTIC LOW LOCATED ALONG A WIND SHIFT EXTENDING
NEWD FROM THE PRIMARY LOW OVER SERN GA. THE NERN SC LOW WILL ACT TO
ENHANCE LOW LEVEL SHEAR OVER NERN SC AND ERN NC AND...ANY
WATERSPOUTS FORMING OFFSHORE COULD POSE A THREAT AS THEY MOVE TOWARD
THE COAST WITHIN ELY LOW LEVEL FLOW ALONG THE TRACK OF THE SURFACE
LOW FROM NERN SC TO THE NC COAST.
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Member Since: August 19, 2006 Posts: 13 Comments: 15666
Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)


Between A and B eventually, but before it reaches the island, a mixture of B and C.
Member Since: July 6, 2010 Posts: 113 Comments: 32267
Quoting GeorgiaStormz:
Photographer captures 2nd highest-altitude tornado on record in U.S.

the tornado i showed the pics of was 2nd highest on record


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.
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.............................................gee we were only supposed to have a mere 30% chance of rain today,and florida just exploded huh,tons of lightning and thunder,power surges etc,..stay safe out there florida,dont tempt that lightning,its a killer
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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



B.
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Quoting aspectre:
Who cares when "...last year...peanut butter surged a whopping 42%"
That got my attention more than four dollar gas.
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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



Way too early for me to forecast a path until we have something more than an invest.
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.
Member Since: August 19, 2006 Posts: 13 Comments: 15666
Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)


B/C
Member Since: March 16, 2012 Posts: 127 Comments: 7948
Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)


If it develops, probably C.
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Euro has a much stronger wave than the 00z run at the 120 hour
Member Since: August 19, 2006 Posts: 13 Comments: 15666
Lot of thunderstorms in Eastern NC from the blob. Couple of them severe.

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repost

Quoting Tazmanian:
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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120 Hours
Member Since: August 19, 2006 Posts: 13 Comments: 15666
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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)

A or C
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Quoting MAweatherboy1:
Euro is running... Doesn't look like it will show anything:



Wouldn't be surprised if the EURO didn't show anything 2 days before development occurs even.
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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)


Maybe B or C
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Quoting mermaidlaw:
Hello everyone. Get ready Largo, I lost power for a bit from the storms here in Hernando county. Alot of T&L with these storms.

I am lurking on and off watching 99L.

Have a great day all!
oh yes...had several power hits already and the cable keeps going out..these are powerful cells coming in ...stay safe up there ok
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Quoting stormchaser19:
Possible path of ernesto? choose what you think
A)
B)
C)
D)



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

Member Since: Posts: Comments:
Quoting MAweatherboy1:
This is from the SPC's latest discussion... It talks about the Carolina blob:

REGIONAL RADAR IMAGERY OVER NERN SC INDICATED AN AREA OF BROAD LOW
LEVEL CIRCULATION CENTERED OVER HORRY COUNTY SC...WITH THIS
CIRCULATION A SUB-SYNOPTIC LOW LOCATED ALONG A WIND SHIFT EXTENDING
NEWD FROM THE PRIMARY LOW OVER SERN GA. THE NERN SC LOW WILL ACT TO
ENHANCE LOW LEVEL SHEAR OVER NERN SC AND ERN NC AND...ANY
WATERSPOUTS FORMING OFFSHORE COULD POSE A THREAT AS THEY MOVE TOWARD
THE COAST WITHIN ELY LOW LEVEL FLOW ALONG THE TRACK OF THE SURFACE
LOW FROM NERN SC TO THE NC COAST.
..had a tornado this morning police said,a dangerous storm
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From NHC 2 p.m. Discussion:
...TROPICAL WAVES...

A TROPICAL WAVE WITH AN ASSOCIATED SURFACE LOW EMBEDDED IN THE MONSOON TROUGH EXTENDS FROM 16N35W TO 10N36W MOVING W AT 15 KT.
WIDELY SCATTERED MODERATE CONVECTION IS FROM 7N-13N BETWEEN 34W-38W.

Link to full Discussion here
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Possible path of ernesto? choose what you think
A)
B)
C)
D)

Member Since: June 20, 2012 Posts: 0 Comments: 2159
I have never seen the atlantic look like that....
sorry referring to the wpac..
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Quoting pcola57:
Lesser Antilles



Puerto Rico




twc.said.a.model.develops.thisnorht.of.hispanola
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This is from the SPC's latest discussion... It talks about the Carolina blob:

REGIONAL RADAR IMAGERY OVER NERN SC INDICATED AN AREA OF BROAD LOW
LEVEL CIRCULATION CENTERED OVER HORRY COUNTY SC...WITH THIS
CIRCULATION A SUB-SYNOPTIC LOW LOCATED ALONG A WIND SHIFT EXTENDING
NEWD FROM THE PRIMARY LOW OVER SERN GA. THE NERN SC LOW WILL ACT TO
ENHANCE LOW LEVEL SHEAR OVER NERN SC AND ERN NC AND...ANY
WATERSPOUTS FORMING OFFSHORE COULD POSE A THREAT AS THEY MOVE TOWARD
THE COAST WITHIN ELY LOW LEVEL FLOW ALONG THE TRACK OF THE SURFACE
LOW FROM NERN SC TO THE NC COAST.
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Quoting Bluestorm5:
Anyway... what's people's thought about that blob off coast of NC?


It's frontal in nature and the convection is being enhanced by the large ULL Tutt cell-Low just inland; you can see it below at the 250mb level.

Link

It's baroclinic in nature and nothing tropical.
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this is the ensemble spread for 12z GFS

180 hours


216 hours


240 hours
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Mesoscale discussion
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Euro is running... Doesn't look like it will show anything:

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The 12z UKMET was very unimpressive with 99L... Made it a TD at best.
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Hello everyone. Get ready Largo, I lost power for a bit from the storms here in Hernando county. Alot of T&L with these storms.

I am lurking on and off watching 99L.

Have a great day all!
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Photographer captures 2nd highest-altitude tornado on record in U.S.

the tornado i showed the pics of was 2nd highest on record
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Test
Anyway the blob off the east coast could become yet another high latitude TS. It is looking decent right now with a good environment.
Member Since: March 16, 2012 Posts: 127 Comments: 7948
12z CMC 180 hours out
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Quoting TropicalAnalystwx13:
New WPAC invest:



Another one? That's 5 storms now in WPAC
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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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Jeff co-founded the Weather Underground in 1995 while working on his Ph.D. He flew with the NOAA Hurricane Hunters from 1986-1990.