Pakistan monsoon floods kill at least 800

By: Dr. Jeff Masters , 5:56 PM GMT on July 31, 2010

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The deadliest weather disaster of 2010 is unfolding in Pakistan, where heavy monsoon rains have triggered flooding that has left at least 817 people dead. A death toll may reach 3000, according to the local head of Pakistan's largest rescue service, and more monsoon rains are on the way. Monsoon floods have also hit southeastern Afghanistan hard, where at least 64 have been killed. The heavy rains were caused by a monsoon depression (also called a monsoon low) that formed over the Bay of Bengal on July 24, crossed over India, and reached Pakistan on July 27. The rains increased in intensity over the next two days, peaking on July 29 and 30, when a low pressure system that moved across Pakistan from the west enhanced rainfall from the monsoon depression. Over the 3-day period July 28 - 30, torrential rains in excess of 8 inches (203 mm) fell in many regions of northwest Pakistan, resulting in that nation's worst floods since at least 1929. Rainfall amounts at two stations in the catchment basins of the Jhelum River and Indus River reached 19.49" (495 mm) for the month of July, and 7.56" (192 mm) fell in a single day, July 30, at Tarbela.

A monsoon depression is similar to a tropical depression, but forms in the Indian Southwest Monsoon over the Bay of Bengal. Like tropical depressions, monsoon depressions are hundreds of miles in diameter, have nearly calm winds near the center, and can have sustained winds of 30 - 35 mph. Four monsoon depressions originated in the Bay of Bengal in 2009; the average is 6 - 7. A new monsoon depression developed over the Bay of Bengal yesterday, and is headed westward towards Pakistan. Heavy rains from this new monsoon depression will begin affecting Pakistan on Monday, according to the Pakistan Meteorological Department.


Figure 1. The heavy thunderstorms of a monsoon depression lie over northwestern Pakistan near Islamabad in this visible satellite image taken by NASA's MODIS instrument on July 29, 2010. Image credit: NASA.

Tropical Atlantic may get active by mid-week
The Invest 90L tropical wave off the coast of Africa has grown disorganized, and NHC is no longer generating forecast tracks for the system. A tropical wave that moved of the coast of Africa Thursday is in the eastern Atlantic near 10N 25W, a few hundred miles south of the Cape Verdes Islands. This morning's 12Z run of the NOGAPS model predicts that this wave will develop into a tropical storm by Wednesday, and reach the Lesser Antilles Islands Friday. This morning's 12Z run of the GFS and ECMWF models predict that an area of disturbed weather near 8N 37W, in the east-central Atlantic, will develop into a tropical storm that will move through the Lesser Antilles on Thursday. Wind shear is low to moderate, sea surface temperatures are at record highs, and the dust and dry air of the Saharan Air Layer (SAL) are far enough to the north of these disturbed areas to potentially allow formation of a tropical storm. However, the Madden-Julian Oscillation currently favors downward motion over the tropical Atlantic, which will act to decrease the chances of tropical storm formation. NHC is giving a 30% chance that a tropical depression will form by Monday afternoon from one of these areas of disturbed weather.

Next update
I'll have an update Monday morning at the latest.

Jeff Masters

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Quoting hurricane23:


Acutally iam quite suprised model plots aren't currently running based on organization this evening.In my view it is much better organized now than it ever has been maybe on the 00z suite.
I agree, but models are probably going to be large in error if we don't have a good initialization point.
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1668. Drakoen
Looks like convection has become more concentrated with 90L east of the low pressure center located near 9N 35.5W.
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Quoting AllStar17:


They did have TD Six-E. But that's it. As expected in a La Nina year.




i for got about TD 6 E
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1666. ssmate
Quoting FloridaHeat:


what does that mean
Your not wearing a tie.
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Quoting Levi32:


LOL I wanted to comment on the avatar but decided it would be wise to stay silent.


I couldn't pass it up!!..LOL I love Rich(SSI), but can we keep the shirts on guys! Please!:-)
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1664. JLPR2


90L's spin is strengthening a little, I wonder if instead of merging they will end up canceling each other out. XD
Now that would be fun LOL!
Member Since: September 4, 2007 Posts: 7 Comments: 8698
how come i have to click on show to see posts for some people
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Quoting Tazmanian:
so far in july we have seen Bonnie and TD 2



why the E pac had seen no storms


They did have TD Six-E. But that's it. As expected in a La Nina year.
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1659. pottery
Quoting Orcasystems:


Look at #1617, I think some of it is going to you.

Yeah, I see that. Been coming down in truck-loads the last couple days. Yard is a bog.
I was pulling your dorsal. I mean your leg. Earlier.
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Member Since: May 21, 2006 Posts: 5091 Comments: 115125
Quoting Orcasystems:


Start here


thank you
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Levi -

Is that interaction going to happen soon? If not, is there any chance that this disturbance alone develops without the help from the tropical wave behind?

TIA.
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Quoting MiamiHurricanes09:
I would wait until the circulation tightens up some before tagging it an invest.


Acutally iam quite suprised model plots aren't currently running based on organization this evening.In my view it is much better organized now than it ever has been maybe on the 00z suite.
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1654. Levi32
Quoting TropicalAnalystwx13:


That should happen tomorrow, right?


They will be merging during the course of tomorrow yes, but the wave may not be fully integrated until Monday or Tuesday.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
nuthin is nuthin til it becomes somethin.

goodnight!
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Quoting FloridaHeat:
how long do you know before a hurricane is going to hit


When the hurricane watches and warnings to up for your area, pay attention to your local forecasters and emergency management.

Get a hurricane guide for your area and know your evacuation zone, your closest shelter and have a plan. Get supplies well in advance of any storm.
Member Since: August 18, 2008 Posts: 0 Comments: 884
so far in july we have seen Bonnie and TD 2



why the E pac had seen no storms
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1650. Greyelf
Quoting deautschlandfutbol:
Mine isn't working I see it on my profile but not here.


When you have uploaded a photo, there is an option to choose it as your "primary portrait". That's what you need to do to have it as your avatar. Just click on that button and wait for it to be approved.
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Quoting Levi32:


Eh I'm ok with them keeping it the way it is until the tropical wave at 28W catches up and merges with ex-90L, making it one system instead of two. At that point it will likely be redesignated an invest.
From Non-invest to TD?
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Quoting Levi32:


Eh I'm ok with them keeping it the way it is until the tropical wave at 28W catches up and merges with ex-90L, making it one system instead of two. At that point it will likely be redesignated an invest.


Thanks Levi.
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Quoting GeoffreyWPB:
In your opinion cchs...should this be an invest? Or anyone's opinion?


In my opinion, it should just due to the potential that exists for development.
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Quoting Levi32:


Eh I'm ok with them keeping it the way it is until the tropical wave at 28W catches up and merges with ex-90L, making it one system instead of two. At that point it will likely be redesignated an invest.


That should happen tomorrow, right?
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Quoting FloridaHeat:
is there a hurricanes for dummies book now that i live in florida i need to learn about this stuff


Start here
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1643. Patrap
N-o-x-z-e-m-a
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1642. pottery
Quoting Orcasystems:


Apparently..... you :)
I am well known for my S&I nature in the blog :)

Just ask Pottery

I know Nothing.........
heheheheh
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AUG is all most here all YAY
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Quoting Levi32:


LOL I wanted to comment on the avatar but decided it would be wise to stay silent.


what does that mean
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1638. Levi32
Quoting GeoffreyWPB:
In your opinion cchs...should this be an invest? Or anyone's opinion?


Eh I'm ok with them keeping it the way it is until the tropical wave at 28W catches up and merges with ex-90L, making it one system instead of two. At that point it will likely be redesignated an invest.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting MiamiHurricanes09:
It just got a whole lot difficult to pin point where it is because of 1) the recent convective burst and 2) it is very broad. I would put the it somewhere between 8.5N-9.5N and 35.5W-36.5W. The 850mb vort max interestingly enough is near 11N 31W near the surface trough. However vorticity has been increasing at a quick rate near 8N 36W.
Thanks Very much.Big help. by the way graduated from UM 1975.
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Mine isn't working I see it on my profile but not here.
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Quoting GeoffreyWPB:
In your opinion cchs...should this be an invest? Or anyone's opinion?
I would wait until the circulation tightens up some before tagging it an invest.
Member Since: September 2, 2009 Posts: 130 Comments: 21193
1634. Levi32
Quoting weatherguy03:


You and St.SimonsIslandGuy may be brothers! Just sayin';)


LOL I wanted to comment on the avatar but decided it would be wise to stay silent.
Member Since: November 24, 2005 Posts: 635 Comments: 26647
Quoting pottery:

sounds interesting..........
you mean, like any minute??


Look at #1617, I think some of it is going to you.
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is there a hurricanes for dummies book now that i live in florida i need to learn about this stuff
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Quoting TropicalAnalystwx13:


The MLC is all the way back to the SW of the Cape Verde Islands...


There's both a low level and mid level vorticity maxima associated with the disturbance at around 8.5N and 35.5W.
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Quoting weatherguy03:


You and St.SimonsIslandGuy may be brothers! Just sayin';)



what
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In your opinion cchs...should this be an invest? Or anyone's opinion?
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Blog Update! (Earlier)

Tropical Weather Analysis - July 31 2010 - Caribbean wave and Ex-Invest 90L...
Member Since: July 6, 2010 Posts: 113 Comments: 32072
how long do you know before a hurricane is going to hit
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Maybe this will go from disturbance to TD because we STILL do not have an invest.
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2004 - Hurricane Ivan became a Category 3 at 9.6°N latitude, the lowest latitude ever recorded for a major hurricane.
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Quoting FloridaHeat:
testing 1 2 3


You and St.SimonsIslandGuy may be brothers! Just sayin';)
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1620. pottery
Quoting Orcasystems:


Your going to get a lot wetter very soon

sounds interesting..........
you mean, like any minute??
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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.