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 KEEPEROFTHEGATE:
not that i know of but i have seen dummies in hurricanes


Okay, I am so tired, but that still made me laugh .
Member Since: Posts: Comments:
1719. bappit
Quoting StormW:


I guess not, bappit. How are ya this evening?

Tired from reading that paper all day. Interesting stuff.
Member Since: May 18, 2006 Posts: 10 Comments: 6061
1718. 7544
invest at anytime now imo waiting
Member Since: Posts: Comments:
Quoting TropicalAnalystwx13:


Out of the ITCZ? No it doesn't.

They can declare an Invest even if the AOI is in the ITCZ.

The ITCZ is beginning to look like a W PAC monsoonal flow.
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting pottery:

I want Perfection. In fact I DEMAND perfection.
Rain at night, sunlit days of 28c, wafts of breezes to make the flowers dance.
Am I asking too much or what?
heheheheheh


Sounds reasonable to me
Member Since: Posts: Comments:
Quoting Tazmanian:



or they could be come both TDS


exactly !!!
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1714. Levi32
Quoting StSimonsIslandGAGuy:
Levi32 I owe you big time!


You're welcome :)
Member Since: November 24, 2005 Posts: 635 Comments: 26661
Quoting pottery:

I want Perfection. In fact I DEMAND perfection.
Rain at night, sunlit days of 28c, wafts of breezes to make the flowers dance.
Am I asking too much or what?
heheheheheh

I hear your Calabash Tree from here, several thousand miles away.

It's saying, "Tomorrow at 9AM local time, we are going to build and ark"!!
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting KEEPEROFTHEGATE:


they will its got to lift up and out


Out of the ITCZ? No it doesn't.
Member Since: July 6, 2010 Posts: 113 Comments: 32286
Just wrote a blog on the EATL tropical wave.
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Quoting WeatherfanPR:
Maybe the reason why we don't have any official Invest out there is because the NHC is waiting to see if in fact the two separate systems merge together or if in fact we still have 90L and a possibly 91L with the wave closer to the CV Islands so they can named both systems appart with the possibility for each one of them to become a Tropical Cyclone.



or they could be come both TDS
Member Since: May 21, 2006 Posts: 5091 Comments: 115244
Quoting Bordonaro:

The folks in Norfolk, VA need to wake up and smell the freaking coffee already..


They have nothing to do with it being declared an invest, all up to NHC.
Member Since: September 23, 2005 Posts: 14 Comments: 11215
Maybe the reason why we don't have any official Invest out there is because the NHC is waiting to see if in fact the two separate systems merge together or if in fact we still have 90L and a possibly 91L with the wave closer to the CV Islands so they can named both systems appart with the possibility for each one of them to become a Tropical Cyclone.
Member Since: Posts: Comments:
1707. bappit
Quoting KEEPEROFTHEGATE:
REQUIREMENTS FOR Tropical Cyclone Formation Alert

If a system gets 35 to 38 points, a TCFA may be issued depending on Dvorak trends, and if a system gets 39 points or more a TCFA should be issued.

Surface
Condition Points
A circulation is evident using visible satellite, shortwave infrared, microwave imagery or QuikSCAT/Windsat ambiguities 3 points
A circulation has been evident for at least 24 hours 5 points
A westerly surface- or gradient-level wind of 5 kt that is within 200 nm (370 km, 230 mi) south of the centre of the disturbance 5 points
Any wind associated with the system is at least 20 kt 2 points
Any wind associated with the system is at least 25 kt 3 points
Any wind associated with the system is at least 30 kt 4 points
A weather station within 200 nm of the system has reported had a pressure drop of 2 mb over 24 hours 3 points
A weather station within 200 nm of the system has had a pressure drop of 3 mb over 24 hours 4 points
The estimated MSLP of the system is less than 1010 to 1009 mb 3 points
The estimated MSLP of the system is 1008 mb or less 4 points

500 mb height
Condition Points
There is evidence of at least an inverted trough 2 points
There is evidence of a closed circulation in the system 4 points

200 mb height
Condition Points
Westerly flow of at least 15 kt over the disturbance -4 points
There is evidence of anticyclonic outflow over the centre of the disturbance 4 points
Easterly flow of at most 20 kt over the disturbance 3 points

Sea surface temperature
Condition Points
The sea surface temperature is 26 Celsius (78.8 Fahrenheit) or higher 3 points

Satellite data
Condition Points
The system has persisted for at least 24 hours 3 points
The system has persisted for at least 48 hours 4 points
The system has persisted for at least 72 hours 5 points
The system has a Dvorak classification of T1.0 to T1.5 from all three agencies (TAFB, SAB, AFWA) 3 points
The system has a Dvorak classification of T1.5 to T2.0 from all three agencies 5 points
The Dvorak final-T number has decreased by T0.5 to T1.0 from two or more agencies -2 points

Miscellaneous
Condition Points
The cloud system is north (or south) of 5 degrees latitude 3 points
The tropical system is within 72 hours of reaching a Department of Defense resource 3 points
The cloud system center and the satellite centre fixes for the system are within 2 degrees of each other 2 points
**********************************************************

A bit like judging figure skating.
Member Since: May 18, 2006 Posts: 10 Comments: 6061
1706. pottery
Quoting Orcasystems:


Last year at this time... you were complaining about the lack of rain.... make up your mind :)

I want Perfection. In fact I DEMAND perfection.
Rain at night, sunlit days of 28c, wafts of breezes to make the flowers dance.
Am I asking too much or what?
heheheheheh
Member Since: Posts: Comments:
Here is Weather For Dummies
Member Since: Posts: Comments:
1704. KEEPEROFTHEGATE (Mod)
Quoting Bordonaro:

The folks in Norfolk, VA need to wake up and smell the freaking coffee already..


they will its got to lift up and out
Member Since: July 15, 2006 Posts: 174 Comments: 54479
Quoting MiamiHurricanes09:
00z surface analysis.



low breaking free of ITCZ?
Member Since: Posts: Comments:
1699. Drakoen
Member Since: Posts: Comments:
1698. KEEPEROFTHEGATE (Mod)
REQUIREMENTS FOR Tropical Cyclone Formation Alert

If a system gets 35 to 38 points, a TCFA may be issued depending on Dvorak trends, and if a system gets 39 points or more a TCFA should be issued.

Surface
Condition Points
A circulation is evident using visible satellite, shortwave infrared, microwave imagery or QuikSCAT/Windsat ambiguities 3 points
A circulation has been evident for at least 24 hours 5 points
A westerly surface- or gradient-level wind of 5 kt that is within 200 nm (370 km, 230 mi) south of the centre of the disturbance 5 points
Any wind associated with the system is at least 20 kt 2 points
Any wind associated with the system is at least 25 kt 3 points
Any wind associated with the system is at least 30 kt 4 points
A weather station within 200 nm of the system has reported had a pressure drop of 2 mb over 24 hours 3 points
A weather station within 200 nm of the system has had a pressure drop of 3 mb over 24 hours 4 points
The estimated MSLP of the system is less than 1010 to 1009 mb 3 points
The estimated MSLP of the system is 1008 mb or less 4 points

500 mb height
Condition Points
There is evidence of at least an inverted trough 2 points
There is evidence of a closed circulation in the system 4 points

200 mb height
Condition Points
Westerly flow of at least 15 kt over the disturbance -4 points
There is evidence of anticyclonic outflow over the centre of the disturbance 4 points
Easterly flow of at most 20 kt over the disturbance 3 points

Sea surface temperature
Condition Points
The sea surface temperature is 26 Celsius (78.8 Fahrenheit) or higher 3 points

Satellite data
Condition Points
The system has persisted for at least 24 hours 3 points
The system has persisted for at least 48 hours 4 points
The system has persisted for at least 72 hours 5 points
The system has a Dvorak classification of T1.0 to T1.5 from all three agencies (TAFB, SAB, AFWA) 3 points
The system has a Dvorak classification of T1.5 to T2.0 from all three agencies 5 points
The Dvorak final-T number has decreased by T0.5 to T1.0 from two or more agencies -2 points

Miscellaneous
Condition Points
The cloud system is north (or south) of 5 degrees latitude 3 points
The tropical system is within 72 hours of reaching a Department of Defense resource 3 points
The cloud system center and the satellite centre fixes for the system are within 2 degrees of each other 2 points
**********************************************************
Member Since: July 15, 2006 Posts: 174 Comments: 54479
Quoting Bordonaro:
Ex 90L is really firing up the ITCZ BIG TIME:
Link
Quoting KEEPEROFTHEGATE:


not as 245z


NMFC Norfolk Tropical Feed
No Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
By Maritime.CDO@navy.mil (NMFC CDO) from Naval Maritime Forecast Center Norfolk Virginia. Published on .

As of Sun 01 Aug 2010 02:45:01Z
2010 Storms
All Active Year

Atlantic
NONE
East Pacific
97E.INVEST
Central Pacific
92C.INVEST
West Pacific
NONE
Indian Ocean
NONE
Southern Hemisphere
NONE

The folks in Norfolk, VA need to wake up and smell the freaking coffee already..
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Does anyone know how to make and post loops/animations on the blog (similar to the blogger P451's)?
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1695. Levi32
Quoting Bordonaro:
Ex 90L is really firing up the ITCZ BIG TIME:
And we're in a downward MJO cycle?? AMAZING!
Link


Lol not anymore! It's more neutral today in the tropical Atlantic. It's running right back to mommy and the GFS was once again wrong on the major downward motion it forecasted for the first half of August.

Member Since: November 24, 2005 Posts: 635 Comments: 26661
Do you have to pay to upload pics?Maybe thats why all the empty faces?Im really not sure.
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Quoting cirrocumulus:
Note the wave axis precipitation appear now on the floater for 91L. It's at 11.8 and 27.8. This is going to be fun to watch.



there is no 91L
Member Since: May 21, 2006 Posts: 5091 Comments: 115244
based on looking at everything. steering currents are relatively straightforward that anything that would develop would head wnw-nw towards the northern islands. After that it gets a bit hazy as to where it might go. Right now it seems that a florida landfall would be most likely based on the synoptic pattern being forecast, however, the CMC brings it way north due to trough and retreating ridge to the eastand the ECMWF brings it way south due to strong high and the GFS is in the middle with a trough and then a subsequent strengthening high. what does this all mean? anything is possible. but if I were to make an educated guess based on what i am seeing now with the high not getting much stronger and my lack of belief in a cmc super trough I would lean towards the GFS solution

but it is all subject to change
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00z surface analysis.

Member Since: September 2, 2009 Posts: 130 Comments: 21194
the "center" of the disturbance seem to be at 9.3n and 35.4w with the first possible signs of an outflow channel developing to its northeast.

Link
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Quoting cirrocumulus:
Note the wave axis precipitation appear now on the floater for 91L. It's at 11.8 and 27.8. This is going to be fun to watch.


Surprisingly, it is not 91L yet. So, please do not post it as 91L. It will cause a lot of confusion. Thanks!
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Ex 90L is really firing up the ITCZ BIG TIME:
And we're in a downward MJO cycle?? AMAZING!
Link
Member Since: August 25, 2009 Posts: 20 Comments: 6785
1687. bappit
Quoting StormW:


From the NHC:

Tropical Cyclone:
A warm-core non-frontal synoptic-scale cyclone, originating over tropical or subtropical waters, with organized deep convection and a closed surface wind circulation about a well-defined center. Once formed, a tropical cyclone is maintained by the extraction of heat energy from the ocean at high temperature and heat export at the low temperatures of the upper troposphere. In this they differ from extratropical cyclones, which derive their energy from horizontal temperature contrasts in the atmosphere (baroclinic effects).

Tropical Depression:
A tropical cyclone in which the maximum sustained surface wind speed (using the U.S. 1-minute average) is 33 kt (38 mph or 62 km/hr) or less.

I guess that's not a formal definition in the opinion of the paper's authors. I dunno.
Member Since: May 18, 2006 Posts: 10 Comments: 6061
1686. KEEPEROFTHEGATE (Mod)
Quoting Bordonaro:
Still no new Invest 91L??


not as 245z


NMFC Norfolk Tropical Feed
No Active Tropical Warnings in the Atlantic, Caribbean, or Gulf of Mexico
By Maritime.CDO@navy.mil (NMFC CDO) from Naval Maritime Forecast Center Norfolk Virginia. Published on .

As of Sun 01 Aug 2010 02:45:01Z
2010 Storms
All Active Year

Atlantic
NONE
East Pacific
97E.INVEST
Central Pacific
92C.INVEST
West Pacific
NONE
Indian Ocean
NONE
Southern Hemisphere
NONE
Member Since: July 15, 2006 Posts: 174 Comments: 54479
Note the wave axis precipitation appear now on the floater for orangecrush40. It's at 11.8 and 27.8. This is going to be fun to watch.
Member Since: September 30, 2005 Posts: 0 Comments: 1606
1684. SLU
HIRES

Member Since: July 13, 2006 Posts: 13 Comments: 5262
1683. Levi32
Quoting AllStar17:
Another question for you Levi -

Is this interaction going to cause any bit of a temporary less-organized system, or will it just add organization without any lag? Do you know what I am asking? Kind of a confusing question.


Well, it would likely only result in elongation of the system, but it can't get much more elongated than it already is lol. The whole thing will look like a big, slowly-organizing mess for the next couple of days but once it gets concentrated and starts gaining latitude away from the ITCZ we just may have something significant on the map.
Member Since: November 24, 2005 Posts: 635 Comments: 26661
1682. SLU
Member Since: July 13, 2006 Posts: 13 Comments: 5262
1681. KEEPEROFTHEGATE (Mod)
Quoting FloridaHeat:
is there a hurricanes for dummies book now that i live in florida i need to learn about this stuff
not that i know of but i have seen dummies in hurricanes
Member Since: July 15, 2006 Posts: 174 Comments: 54479
Ex-90L is moving towards the W at 5-10mph.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
Another question for you Levi -

Is this interaction going to cause any bit of a temporarily less-organized system, or will it just add organization without any lag? Do you know what I am asking? Kind of a confusing question.
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Still no new Invest 91L??
Member Since: August 25, 2009 Posts: 20 Comments: 6785
Quoting pottery:

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.


Last year at this time... you were complaining about the lack of rain.... make up your mind :)
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Actually adrian said the state of florida it isn't look good for east central florida either according to where that a/b high is. Anywhere from they keys and up.
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1675. Levi32
Quoting AllStar17:
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.


They are already beginning to interact, and it's pretty much unavoidable that they are going to get together because the wave is catching up from behind and ex-90L is still not moving very fast so they are going to collide.

This was a post I put up earlier about the potential evolution of this merging over the next 48 hours and how it could result in a developing tropical cyclone next week.

Visible satellite imagery shows the broad low center of ex-90L near 8N, 36.5W with an elongated trough extending ENE from the center towards the north side of the new area of convection that has recently developed to the east. This trough appears to be trying to work its way north, and during the course of the next few days we may see this continue to work north and try to rotate around the broad low center's north side. Meanwhile, the tropical wave and associated mid-level circulation will be closing in from behind as it is moving faster, and its motion should take it just north of the broad low center as well. This should result in all of these features coming closer together and conglomerating.

Again, if the system continues to organize instead of falling apart, the net effect will be the system appearing to "wrap around" on the north side and bring everything into a slowly tightening low pressure center that may start to become more concentrated by 48 hours and onward. This is how the merging process may work, and the end-result could be a developing tropical cyclone if conditions allow. This is what the northern Antilles Islands, Virgin Islands, and Puerto Rico should be watching for, as this low will be there in 5-6 days.

Member Since: November 24, 2005 Posts: 635 Comments: 26661
Quoting cchsweatherman:


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


Thank you cchs and Miami.
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Quoting clwstmchasr:


I disagree. They label invests with some systems that have no business being labeled. Didn't they designate 98L after it moved on-shore in Mexico?
99L was supposedly designated as an invest over water according to the NHC.
Member Since: September 2, 2009 Posts: 130 Comments: 21194
1672. JLPR2
Quoting Chicklit:


What a mess!
Member Since: September 4, 2007 Posts: 7 Comments: 8735
1640 -- looks like a catepillar
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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.
Member Since: September 2, 2009 Posts: 130 Comments: 21194

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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.