New Caribbean disturbance 93L a major concern; flooding in Asia kills over 200

By: Dr. Jeff Masters , 2:50 PM GMT on June 21, 2010

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A concentrated region of intense thunderstorms associated with a tropical wave has developed in the central Caribbean, a few hundred miles south of Puerto Rico. This disturbance was designated Invest 93L by NHC this morning, and has the best chance to become Tropical Storm Alex of any system we've seen so far this year. The disturbance is located near Buoy 42059, and this buoy has been reporting winds of 5 - 15 knots this morning. So far, pressures are not falling. Water vapor satellite loops show that 93L is embedded in a large region of moist air. Some dry continental air from North America is over the western Caribbean, but this dry air is too far away to interfere with development today and Tuesday. Wind shear is a low 5 - 10 knots. The high wind shear associated with the strong winds of the subtropical jet stream are over the northern Caribbean, too far north to interfere with development. Sea Surface Temperatures are plenty warm, a record 29 - 30°C. The Madden-Julian oscillation currently favors upward motion over the Caribbean, which will act to increase the chances of tropical storm formation this week. The Madden-Julian oscillation is a pattern of enhanced rainfall that travels along the Equator from west to east. The pattern has a wet phase with large-scale rising air and enhanced thunderstorm activity, followed by a dry phase with large-scale sinking air and suppressed thunderstorm activity. Each cycle lasts approximately 30 - 60 days. When the Madden-Julian oscillation is in its wet phase over a hurricane-prone region, the chances for tropical storm activity are greatly increased. The only negative for 93L would seem to be the lack of spin; the University of Wisconsin 850 mb relative vorticity analysis is showing only meager amounts of spin at 850 mb (roughly 5,000 feet in altitude.)


Figure 1. Morning visible satellite image of the central Caribbean disturbance 93L.

Forecast for 93L
NHC is giving 93L a 20% chance of developing into a tropical depression by Wednesday morning, which is a reasonable forecast. With wind shear expected to drop to low values less than 10 knots over the central and western Caribbean this week (Figure 2), I don't see any major impediments to the storm becoming a tropical depression by Friday. The ECMWF model is the most aggressive in developing this system, taking it into the Gulf of Mexico as a hurricane next week. The NOGAPS model keeps the storm weak and farther south, predicting that 93L will bring heavy rains to northern Honduras as a tropical disturbance or tropical depression on Friday and Saturday. The GFS model does not develop 93L. Expect 93L to bring flooding rains of 3 - 6 inches to Jamaica, eastern Cuba, and extreme southwestern Haiti on Wednesday. These rains will spread to the Cayman Islands and central Cuba by Thursday.


Figure 2. Predicted wind shear for Friday, June 25, as forecast by this morning's 2am EDT run of the GFS model. Shear is given in meters per second; multiply by about two to convert to knots. Low wind shear values less than 6 m/s (12 knots) are predicted for much of the Western Caribbean this week.

Elsewhere in the tropics
The tropical wave (92L) that brought heavy rains of 2 - 5 inches to Puerto Rico on Saturday has weakened and is no longer a threat to bring flooding rains to the Caribbean.

Floods in China and Burma kill over 200
The deadliest and most destructive weather-related disaster on the planet so far this year is occurring in southern China and northern Burma, where a week of heavy rains has caused flooding that has claimed over 200 lives. The death toll stands at 175 in China and 63 in Burma, with more than 100 people still missing in China. Damage so far in China has been estimated at $4.3 billion.


Figure 3. Tree branches hung on a bridge at Taining County, southeast China's Fujian Province, June 19, 2010. Taining recorded 225 mm (9 inches) of rain in six hours on Friday. Image credit: Xinhua/Jiang Kehong.

Montana tornado rips roof off entertainment complex
A EF-2 tornado with winds of at least 100 mph ripped the roof of an entertainment complex in Billings, Montana on Sunday, causing up to $15 million in damage. No injuries were reported. It was the strongest tornado to hit the Billings area since 1958.


Figure 4. Video of the Billings tornado shows an impressive debris cloud (and a few expletives not deleted!) The clear slot on the right of the tornado is likely associated with the parent thunderstorm's rear flank downdraft.

Wind and ocean current forecast for the BP oil disaster
Southeast to east winds less than 10 knots will blow in the northern Gulf of Mexico today through Friday, according to the latest marine forecast from NOAA. The resulting weak ocean currents should cause little motion of the oil slick, according to the latest trajectory forecasts from NOAA and the State of Louisiana. The long range outlook is uncertain, as the tropical wave over the central Caribbean could enter the Gulf of Mexico early next week and develop into a tropical storm.

Resources for the BP oil disaster
My post, What a hurricane would do the Deepwater Horizon oil spill
My post on the Southwest Florida "Forbidden Zone" where surface oil will rarely go
My post on what oil might do to a hurricane
NOAA's interactive mapping tool allows one to overlay wind and ocean current forecasts, oil locations, etc.
Gulf Oil Blog from the UGA Department of Marine Sciences
Oil Spill Academic Task Force
University of South Florida Ocean Circulation Group oil spill forecasts
ROFFS Deepwater Horizon page
Synthetic Aperture Radar (SAR) imagery from the University of Miami

Jeff Masters

Billings, MT tornado (StormTeam)
Photo taken from approx. 5-6 miles east. Video here: http://www.youtube.com/watch?v=8429C0-LSlo
Billings, MT tornado

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2277. Drakoen
With the NHC 00z coordinates, 93L is more organized than I though
Member Since: October 28, 2006 Posts: 57 Comments: 30117
I hope the adminstrator starts flagging the unnecessary chit chat that is not important to the blog when that time comes and only relative things are posted....JMO
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2275. fire635
You can certainly see a decent spin at 14.9n and 70w.... when you take in the whole picture you can see how its trying to entrain the smaller "blob" to the west into a circulation with the larger "blob" to the east.
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one day dr m blog will hit 10,000 commets




will it be this year
Member Since: May 21, 2006 Posts: 5091 Comments: 114916
Quoting GatorWX:


Huh??? The moratorium means no "new rigs" can be put into operation. All the existing rigs are still producing!


Yeah I thought about that after I posted. My bad. So yippie, high dollar gas. Taz is right.
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Quoting xcool:




What is the TVCN? It curves it back towards the NE.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
2271. centex
Quoting Drakoen:
I find it intersting that the NHC incorporates the area between 75W and 65W as part of 93L.
Maybe they are, hate to say it, 92L believers. 75W is old 92L. Bring it on.
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Its my last night in Santo Domingo. Its been raining off and on all day. A good bit of rain moved through about 30 minutes ago.
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2269. GatorWX
Quoting Intimidator3:


Nah, there's no offshore rigs that a hurricane can shut down because of the Moratorium.


Huh??? The moratorium means no "new rigs" can be put into operation. All the existing rigs are still producing!
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Quoting Drakoen:
I find it intersting that the NHC incorporates the area between 75W and 65W as part of 93L.


Convection/Cumulonimbus have been firing there all day. It'll be interesting to see what happens later tonight with DMAX.

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2265. xcool


Member Since: September 26, 2009 Posts: 2 Comments: 15648
2264. Patrap
I was darn close.

Post 2183


14.5 N

68.5 W by my eye only


Member Since: July 3, 2005 Posts: 423 Comments: 127804
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Well I guess my red circle call was off by 1% but still much better than my spelling.
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2260. Drakoen
The whole time our focus has been the eastern side of 93L but not the western side
Member Since: October 28, 2006 Posts: 57 Comments: 30117
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Case and point:

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look at post # 2245 and tell me what you think
Member Since: May 21, 2006 Posts: 5091 Comments: 114916
Some of the hurricane models havnet intialized on the system yet that is why they are out to lunch. There is no low level spin yet so just wait another 24 hours and you can start to trust the models a little more.
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2254. Drakoen
Quoting Stormchaser2007:


14.9, 70

Dang.



That is actually not that bad looking at your sat image below
Member Since: October 28, 2006 Posts: 57 Comments: 30117
Quoting Tazmanian:
here come $4.00 too $5.00 gas if it gos too the gulf


Nah, there's no offshore rigs that a hurricane can shut down because of the Moratorium.
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2252. Patrap
"Oil-Zilla"..

Domo Arragotto,Mr Destructo..
Member Since: July 3, 2005 Posts: 423 Comments: 127804
2251. xcool
free oil best way goo
Member Since: September 26, 2009 Posts: 2 Comments: 15648
Link

Here are a few late run. Good site for models,early and late
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I have seen where the GFS is pretty deep with the trough over the eastern CONUS around days 7-8 and has been pretty consistent with that. In the short term, the subtropical ridge is strengthening, evidenced by the northward shift of the ridge axis, currently over FL/GA border region.
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2248. Drakoen
I find it intersting that the NHC incorporates the area between 75W and 65W as part of 93L.
Member Since: October 28, 2006 Posts: 57 Comments: 30117
I made this today... I will make another when the next RAOB comes out..

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I can't believe the center is where they are saying it is... Huh???
Member Since: April 26, 2009 Posts: 3 Comments: 3667




93L track








things that make you go hmmmmmmmm
Member Since: May 21, 2006 Posts: 5091 Comments: 114916
2244. Grothar
Quoting TampaSpin:




I see what you mean Tampa. I think we all agree. Can't argue with that.
Member Since: July 17, 2009 Posts: 71 Comments: 25977
Quoting Stormchaser2007:
The models will be all over the place until we have a well defined LLC, which should/could take place tomorrow if it develops some decent convection.


Exactly, the reason why the NHC bumped up from 30% is because conditions are becoming more favorable, doesn't mean it's developing a LLC, just organizing in structure. I believe a LLC will form tomorrow.
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2242. dearmas
if 93l were to make it to FL, Tampa, what time frame at we looking at???
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Quoting Drakoen:


Look at where the low is being initialized


14.9, 70

Dang.

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2240. Grothar
Quoting GeoffreyWPB:


Dog, Easy and Cleo...Sounds like my love life :)


Funniest line of the night!
Member Since: July 17, 2009 Posts: 71 Comments: 25977


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2237. centex
Quoting Tazmanian:



note even no they are doing some new this year with the % if they where still doing the old way we will be red right now
No offense but I'm holding back your cookies. Waiting for actual stuff not 2nd guesing of forecasters. I'll double the cookie count if your right because of difficulty.
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2235. Patrap
Floater - Water Vapor Loop
Member Since: July 3, 2005 Posts: 423 Comments: 127804
Quoting StadiumEffect:
In the weather segment of our local news here in Cayman, nothing was mentioned about 93L except a "large tropical wave." This is typical. Little is mentioned until something is almost right on top of us, like Ivan. And the government wonders why Caymanians are so quick to turn to outside media/bodies before looking to our own for info on hurricanes. Go figure.
Amen. 12 hrs before Ivan hit I received a call from the EOC telling me to go to a shelter.
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GFDL 18z track:

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If I was a judge on America's Next Top Model, I'd certainly pick the HWRF.
Member Since: April 26, 2009 Posts: 3 Comments: 3667
The models will be all over the place until we have a well defined LLC, which should/could take place tomorrow if it develops some decent convection.
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2229. Drakoen
Quoting Stormchaser2007:
Look at how much shear the SHIPS analyzed:

TIME (HR) 0 6 12 18 24 36 48 60 72 84 96 108 120

SHEAR (KT) 19 15 9 3 9 12 13 13 7 7 3 10 2


Look at where the low is being initialized
Member Since: October 28, 2006 Posts: 57 Comments: 30117

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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.