Thanks Gazzatsv! That probably is the best radar image I have seen so far from Bangladesh. You really have to wonder what this storm was capable of.

Well I jinxed it. I will just have to assume the cap was too strong yesterday since there were no noteworthy storms across Bangladesh (I haven't seen the radar between 12:30Z and 13:20Z or after 13:20- so something could have happened after dark). There was very little cloud across Bangladesh and from memory Agartala (India) got to ~34/25 (2:30 pm obs I think). Interesting really since the morning sounding the previous day had similiar CIN but the cap broke that afternoon. I wonder if subtle short wave trough is all that was needed to initiate convection?

I should also note there were storms north of the Meghalaya Plateau, pretty poor radar coverage up there so I won't comment on those storms.

Oh and how is this for a funky sounding?-
http://weather.uwyo.edu/cgi-bin/sounding?region=seasia&TYPE=GIF%3ASKEWT&YEAR=2012&MONTH=04&FROM=2412&TO=2412&STNM=42809

I assuming something seriously went wrong there! No buying the CAPE of 10000 J/kg!

Just looking through satellite images from last night and it would seem some strong storms did form over the eastern portion of the Meghalaya Plateau (and maybe into NE Bangladesh). This storm/or cluster of storms can be seen on the 17:31Z satellite image. The radar was off line at this time though.

Great Stuff MC Thomas!

My eyes and mind have been opened up to probable supercell storms in a region i didn't realize they frequent. Its awesome to see these SC's form with amazing regularity!. Im not sure of the topography of the region so perhaps you can fill me in, but i thought most of the 'desh was quite low (below sea level in many areas) which made it prone to massive flooding during the wet season? It also appears on the radar to have a set of high mountains to the east and north which probably aides in keeping the surface features planted in the region as you described in a previous post.

Anyways, Thanks for the great work and persistence in updating the thread. I'll def be back to read more

Simon

Glad you are interested Simmah. I'm a bit busy now so I will keep it short. Storms did form yesterday afternoon east of Bangladesh in India (before moving into Bandgladesh). Yesterdays obs for Alipore (Kolkata) for 2:30 pm local time were 35.4/26. Just insanely hot and humid and consequently potentially very unstable.

Here is a radar image from the storms yesterday-


If there were any supercells they were probably on the HP side of things. Anyway, strong storms in high/extreme CAPE are probably going to cause damage regardless of storm mode.

Today looks interesting too. Here is the 0Z sounding for Kolkata-
http://weather.uwyo.edu/cgi-bin/sounding?region=seasia&TYPE=GIF%3ASKEWT&YEAR=2012&MONTH=04&FROM=2600&TO=2600&STNM=42809

This shows very high surface-based CAPE (CAPE of 4600 J/kg indicated). Obs for Alipore (Kolkata) for 8:30 am were already at 31.6/25.7. With temps in the mid-30's this afternoon, CAPE will truely be through the roof based on the sounding shown above (provided moisture depth is sufficient in the afternoon).

Been reading this thread the entire time, great work MC Thomas! Never realised how storm prone this area of the world is!

Some pretty impressive obs for Kolkata at 2 pm. Temp is 34-36 C with a dew point of 26-27 C! Currently a storm about 100 km NW of Kolkata. Excellent shape on radar, wish the radar would update though.

Edit: Radar updated, the storm has exploded (emotive term I know). Very compact shape with a small inflow notch/hook and V-notch.

I would love to know how to replot the Kolkata sounding with the obs previously posted. I would guess surface-based CAPE is around 6000-7000 J/kg. One lone storm tapping into that massive amount of CAPE-

Okay, I had to post this sounding-

Yesterday I was speculating on the possibility of extreme CAPE. It seems if anything my guess of SBCAPE of 6000-7000 J/kg was too conservative as the sounding above shows CAPE of 9500 J/kg!!!! There was still a fairly strong cap in place which explains the limited number of storms. Wind shear in lowest 6 km was quite weak; less than what is generally required for supercells (though stronger mid-level flow probably existed to the north of Kolkata). In my opinion, the storm shown in the post above exhibited supercell characteristics ie. V-notch, sight inflow notch and strong deviation from the mean flow. Possibly this may be a case of extreme CAPE making up for the apparent lack of deep-layer shear.

The last week has seen pretty much daily storms across Bangladesh and adjacent parts of India. When searching for news articles I came across a few noteworthy events.

First, over 100 people were killed and many are still missing after a ferry sunk during a storm in the Indian state of Assam close to the border of Bangladesh-
http://www.theaustralian.com.au/news/wor...o-1226343236416
http://www.accuweather.com/en/weather-news/india-ferry-sinks-in-severe-st/64644

A tornado is also reported to have occurred in the Indian state of Tripura (borders eastern Bangladesh) killing one person and injuring over 175-
http://www.ianslive.in/index.php?param=news/385901/LatestNews/31

This article also makes reference to the fact that 33 people were killed by lightning strikes in West Bangal on April 29-
http://www.hindustantimes.com/India-news...le1-849439.aspx

And more news articles from Bangladesh-

http://www.unbconnect.com/component/news/task-show/id-75371
http://www.unbconnect.com/component/news/task-show/id-75428
http://www.unbconnect.com/component/news/task-show/id-74837
http://www.unbconnect.com/component/news/task-show/id-75042
http://www.unbconnect.com/component/news/task-show/id-75087

Quite saddening to see how many deaths occur in Bangladesh and India from thunderstorms.

Today looks like a pretty big day in Bangladesh and parts of India. One absolute bruiser of a storm formed in NE Bangladesh about 3 hours ago and is still going strong. This storm is an obvious right moving supercell. Interesting really since GFS has quite weak mid-level flow across Bangladesh (30 knots at 500 mbar in NE Bangladesh, 10-15 knots to the south). Forecast CAPE is 2000-3000 J/kg. Unfortunately I can't get any obs, I will have to assume since dew points are very high since 500 mbar temps are around -4 to -6 C (to get high CAPE with such warm mid-level temps requires very rich low-level moisture).

Here is the storm mentioned above-


0Z Agartala sounding-
http://weather.uwyo.edu/cgi-bin/sounding?region=seasia&TYPE=GIF%3ASKEWT&YEAR=2012&MONTH=05&FROM=1200&TO=1200&STNM=42724

Nothing particularly interesting about this sounding, though it is about 200 km SE of where the storm formed and 11-12 hrs earlier.

Note: above should be NW Bangladesh, not NE. Also, "Unfortunately I can't get any obs, I will have to assume (that) dew points are very high since 500 mbar temps are around -4 to -6 C"

Another active period of weather over Bangladesh. This radar image is from yesterday-

I suspect these two storms are HP supercells since they took a sharp turn to the right just before the radar went off line. Today again looks interesting with the GFS forecasting CAPE of 3000-4000 J/kg with 40 knot 500 mbar winds over northern Bangladesh.

It seems that several people may of been killed by lightning on the 12th of May (see above for corresponding radar image - location seem and time seems to match http://en.wikipedia.org/wiki/Jamalpur_District)-

http://www.newagebd.com/detail.php?date=2012-05-14&nid=10208

Quite staggering the number of people that are killed by lightning in Bangladesh with about 100 fatalities reported this April alone (or ~3.3 per day average)-

http://www.unbconnect.com/component/news/task-show/id-76260

From yesterday-


This later transitioned into a squall line. Quite a large convective complex over northern Bangladesh and into India at the moment. I suspect this may influence storms later today by laying down a outflow boundary across north/central Bangladesh.

Mid/upper-level winds over Bangladesh/NE India are currently very weak as the jetstream has shifted north. This probably signals the end of supercell thunderstorms over Bangladesh/NE India for this season. Such a fascinating place with a very short but intense pre-monsoonal storm season.