Pakistan monsoon floods kill at least 800

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

Share this Blog
3
+

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

Reader Comments

Comments will take a few seconds to appear.

Post Your Comments

Please sign in to post comments.

or Join

Not only will you be able to leave comments on this blog, but you'll also have the ability to upload and share your photos in our Wunder Photos section.

Display: 0, 50, 100, 200 Sort: Newest First - Order Posted

Viewing: 1070 - 1020

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61Blog Index

1070. IKE
Quoting StormSurgeon:


Is that the spin at the far right in Miami's post 996? that's what I see.


Yeah.
Member Since: Posts: Comments:
1069. KEEPEROFTHEGATE (Mod)
AOI/XX/XL
MARK
8.4N/35.3W
Member Since: Posts: Comments:
Quoting Jeff9641:
With all the crap I got yesterday while I was saying the steering is straight forward and that this would be a SE US threat well guess what I told you guys. The same ridge that has been baking FL is going to give us many fits this hurricane season in FL. C FL looks to get hammered by what will be Colin.


Still far to early to determine that.
Member Since: Posts: Comments:
1067. bappit
Interesting comment from footnote 42 in appendix C (LOL):

Large-amplitude easterly waves, that is, with large meridional extent, may be ineffective for TC genesis owing to the latter reason [that they draw air in from the north].

So we've seen some large waves this season which all went pffffft.
Member Since: Posts: Comments:
Quoting SouthALWX:

You sped it up to fast.You are seeing the earth spin ... =P


My head is spinning.......
Member Since: Posts: Comments:
1065. IKE
Quoting SouthALWX:

You sped it up to fast.You are seeing the earth spin ... =P


LOL.

Quoting Twinkster:


still a broad low it seems with possible multiple vortices. I do see the spin you are seeing but i see others as well. Even though convection is on the increase NHC always looks for convection they will most likely stay at 30% code orange but i wouldn't be shocked to see 40%


Yeah...I don't see the heaviest convection over the spin at 35W. They could up it to 40% or leave it at 30%. I doubt they go higher than 40% for now. Wait til Sunday morning.
Member Since: Posts: Comments:
I think the actual LLC that is developing with the CATL AOI is around 8.5N/33.5W
Member Since: Posts: Comments:
90L or 91L, that's the question.
Member Since: August 23, 2006 Posts: 0 Comments: 1569
Thanka Levi,
Very informative.
Member Since: Posts: Comments:
1061. KEEPEROFTHEGATE (Mod)
Quoting hydrus:
It looks like a large spin is just now starting to organize.
slow but sure got to lift up and out maybe 12 n would be good still may be affected by ITCZ enhancement
Member Since: Posts: Comments:
so basically we are looking either at a stronger weaker system rotating around each other or one eating the other so to speak
Member Since: Posts: Comments:
Quoting IKE:
I see another spin near 9N and 35W on this flash loop. Speed it up all the way...Link


Is that the spin at the far right in Miami's post 996? that's what I see.
Member Since: Posts: Comments:
Quoting IKE:
I see another spin near 9N and 35W on this flash loop. Speed it up all the way...Link


still a broad low it seems with possible multiple vortices. I do see the spin you are seeing but i see others as well. Even though convection is on the increase NHC always looks for convection they will most likely stay at 30% code orange but i wouldn't be shocked to see 40%
Member Since: Posts: Comments:
I think the developing COC in under the big blow up of convection
Member Since: Posts: Comments:
Quoting IKE:
I see another spin near 9N and 35W on this flash loop. Speed it up all the way...Link

You sped it up to fast.You are seeing the earth spin ... =P
Member Since: Posts: Comments:
1053. Levi32
A little meso-analysis since I'm a bit bored lol:

Now if very slow organization continues with ex-90L and convection continues to fire healthily, this is how we may see things go down over the next 48 hours.

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: Posts: Comments:
1052. KEEPEROFTHEGATE (Mod)

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 Sat 31 Jul 2010 23:15:02Z


2010 Storms
All Active Year


Atlantic
NONE
East Pacific
97E.INVEST(deactivate)
Central Pacific
92C.INVEST
West Pacific
95W.INVEST
Indian Ocean
NONE
Southern Hemisphere
NONE
Member Since: Posts: Comments:
1051. IKE
I see another spin near 9N and 35W on this flash loop. Speed it up all the way...Link
Member Since: Posts: Comments:
Quoting muddertracker:
I've got it at 9/35.5 Starting to wrap up. Link:Link


I see it know! Good eyes, thanks.
Member Since: Posts: Comments:
Caribbean AOI might be back up to 20% has a decent spin and a bit more convection CATL AOI definitely one to eyeball imo.
Member Since: Posts: Comments:
most likely the two will stay at 30% for the system at 8 pm. Reasons: It is far away, they will wait to look for persistence, and the broad nature of the system will take it a while to consolidate. they will wait imo until 2am to up the formation probability
Member Since: Posts: Comments:
http://www.ssd.noaa.gov/goes/flt/t1/avn-l.jpg

Black is showing up in the convection. It's hard to believe that it will stay @ 30%
Member Since: Posts: Comments:
Kerry Emmanuel of MIT wrote about the maximum potential intensity deepening to below 800 mb by the end of the century. He is very very smart and informed about tropical cyclone physics. It's hard for me to see that really happening however. But who knows?

If we really do get hurricanes with central pressures in the high 700 mb range I want scarier names!

Hurricane Cobra
Hurricane Sabretooth

Things like that.
Member Since: September 30, 2005 Posts: 0 Comments: 1606
1044. IKE
Quoting Huracaneer:
Anyone with sharper eyes than me, is there anything spinning in that mess between South America and Africa? While there is an awful lot of convection, I don't see low level spin, but I could be wrong.


I see a spin near 25W on this loop but it's lost convection....Link
Member Since: Posts: Comments:
Quoting Huracaneer:
Anyone with sharper eyes than me, is there anything spinning in that mess between South America and Africa? While there is an awful lot of convection, I don't see low level spin, but I could be wrong.
I've got it at 9/35.5 Starting to wrap up. Link:Link
Member Since: Posts: Comments:
Quoting hurricaneben:


No. It's like this.

TROPICAL LOW: Ah, nothing.
TROPICAL DEPRESSION: Still nothing to worry about.
TROPICAL STORM: I could totally handle this.
CATEGORY 1 HURRICANE: Gonna be a bit of a ride but handleable.
CATEGORY 2 HURRICANE: Not too great.
CATEGORY 3 HURRICANE: Oh no.
CATEGORY 4 HURRICANE: NOOOOO!!!
CATEGORY 5 HURRICANE: I'M GONNA DIIIEEEE!!!

LOL Cat 5
Member Since: Posts: Comments:
Ike if you look at history, it seems that we get an early season system that is weak, and a late season monster. Its apparently how its been for South Florida. The problem is that we are looking at two systems now that possibly give us a one two punch with a ten days difference. Oh boy.
Member Since: Posts: Comments:
1040. hydrus
Quoting KEEPEROFTHEGATE:
AOI/XX/XL
MARK
8.3N/35.5W
It looks like a large spin is just now starting to organize.
Member Since: Posts: Comments:
Anyone with sharper eyes than me, is there anything spinning in that mess between South America and Africa? While there is an awful lot of convection, I don't see low level spin, but I could be wrong.
Member Since: Posts: Comments:
1038. IKE
Quoting aquak9:
Ike- you gotta check out channel 40, Deep Tracks. I know you will LOVE it.


I'll remember next time I'm in my car. Thanks...I'll check it out.

Maybe slightly cooler tomorrow....

Sunday
Partly cloudy with a 50 percent chance of showers and thunderstorms. Heat index readings 108 to 112. Highs around 100. South winds around 5 mph.
Member Since: Posts: Comments:
1037. bappit
Nice glossary at the end of the Dunkerton, et al. paper.

Member Since: Posts: Comments:
90L or 91L, that's the question.
Member Since: August 23, 2006 Posts: 0 Comments: 1569
1035. IKE
Quoting GeoffreyWPB:
Ike...I got a Chevy HHR LS. It is nice!


Looks nice. Congrats!
Member Since: Posts: Comments:
1034. aquak9
Ike- you gotta check out channel 40, Deep Tracks. I know you will LOVE it.
Member Since: August 13, 2005 Posts: 163 Comments: 25729
Quoting StormSurgeon:


A tropical low normally preceeds a tropical depression (not necessarily the same) but both must have a closed circulation. We both know that. For those that don't, it goes like this (without wind speeds):

1. Tropical Low
2. Tropical Depression
3. Tropical Storm
4. Hurricane:
a. Cat 1
b. Cat 2 (uh oh)
c. Cat 3 (oh crap)
d. Cat 4 (Why did I stay!)
e. Cat 5 (AAAAAGGGHHHHHH!!!!!)


No. It's like this.

TROPICAL LOW: Ah, nothing.
TROPICAL DEPRESSION: Still nothing to worry about.
TROPICAL STORM: I could totally handle this.
CATEGORY 1 HURRICANE: Gonna be a bit of a ride but handleable.
CATEGORY 2 HURRICANE: Not too great.
CATEGORY 3 HURRICANE: Oh no.
CATEGORY 4 HURRICANE: NOOOOO!!!
CATEGORY 5 HURRICANE: I'M GONNA DIIIEEEE!!!
Member Since: Posts: Comments:
1032. bappit
Took me most of the day to read the Dunkerton, et al. Had to go off and read other stuff to have an idea of what it was talking about. Not that difficult to read compared to some of the other stuff I saw out there. A paper on potential vorticity I glanced at probably reads something like "See Spot run"--if you can read it. The problem is that the words are all calculus.
Member Since: Posts: Comments:
Ike...I got a Chevy HHR LS. It is nice!
Member Since: September 10, 2007 Posts: 0 Comments: 10971
Quoting KEEPEROFTHEGATE:
AOI/XX/XL
MARK
8.3N/35.5W
The last two frames in the animation you can really see that low affect its environment. Interesting, for sure.
Member Since: Posts: Comments:
That doesn't look good Hurricane09
Member Since: Posts: Comments:
Quoting MiamiHurricanes09:


I notice a few things on that image..

A nice pinwheel motion of the circulation carried by the wave, if that becomes dominant, 91L is tagged instead of 90L because it's a separate system merging with the remnants of what was 90L. However, if the disturbance X-90Ls circulation develops, then I believe 90L would be re-tagged. Either 90L or 91L should be tagged tonight, wouldn't surprise me if they tag both 90L and 91L.. that would be fun to track :P
Member Since: Posts: Comments:
Quoting Levi32:


That image shows the 2nd system out in the Atlantic. By Day 10 the first one is over Florida:



Not liking that path over Fl, it's just in time for school to start. Good thing the models will change numerous times if this wave keeps.
Member Since: Posts: Comments:
Quoting BenBIogger:
GFS 228Hrs
Strong Tropical Storm.


The GFS is underdoing the intensity, slightly. I think it should be a hurricane when it makes landfall, as with ample conditions, there is no way that this shouldn't be a hurricane @ landfall!
Member Since: Posts: Comments:
1024. Hhunter
Quoting JLPR2:


I'll go with 40% due to the increase in convection


60% game on
Member Since: August 19, 2007 Posts: 0 Comments: 2973
Quoting MiamiHurricanes09:


Far right....or east.
Member Since: Posts: Comments:
1022. KEEPEROFTHEGATE (Mod)
AOI/XX/XL
MARK
8.3N/35.5W
Member Since: Posts: Comments:
1021. IKE
Quoting GeoffreyWPB:
Evening Ike...Read earlier this morning you got a new car. Congrats! I also bought a new car yesterday.


Thanks. I would have had a heat stroke this week. The Sirius channel 14 is nice...classic rock. What kind did you get?


Quoting StormSurgeon:


we see it all the time, but this guy is going off the deep end. Never seen so much gray....


LOL! Thunderstorm is about 5 miles east of me. I doubt it makes it here.....
Member Since: Posts: Comments:
Quoting ho77yw00d:


GIVE ME MORE CREDIT THEN THAT (2010 HURRICANE NAMES?) I may be a female thats new to this blog but I am not dumb...lol :)


ur new? kool!
Member Since: Posts: Comments:

Viewing: 1070 - 1020

Page: 1 | 2 | 3 | 4 | 5 | 6 | 7 | 8 | 9 | 10 | 11 | 12 | 13 | 14 | 15 | 16 | 17 | 18 | 19 | 20 | 21 | 22 | 23 | 24 | 25 | 26 | 27 | 28 | 29 | 30 | 31 | 32 | 33 | 34 | 35 | 36 | 37 | 38 | 39 | 40 | 41 | 42 | 43 | 44 | 45 | 46 | 47 | 48 | 49 | 50 | 51 | 52 | 53 | 54 | 55 | 56 | 57 | 58 | 59 | 60 | 61Blog Index

Top of Page

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.