BoB: Very Severe Cyclonic Storm SIDR

[HURAKAN]

The sun has already set in Bangladesh. Landfall will occur late evening.

Yep.

Bangladesh's time is 11 hours ahead of EDT.

[wxman57]

Just measured the movement in GARP. I get a 2-hr movement of just under 15 kts toward about 7 degrees. Projected landfall near 15Z (9pm BDT) This is actually closer to low tide, but the tide will be on the rise through the night.

[HURAKAN]

wxman57, since the strongest storm surge will impact the delta region of the Ganges River, could this cause the river the back-up and flood inland?

[wxman57]

wxman57, since the strongest storm surge will impact the delta region of the Ganges River, could this cause the river the back-up and flood inland?

Let's compare with Katrina. Katrina hit near the LA/MS border. If Sidr hits just east of the India/Bangladesh border, then the mouth of the Ganges would be about 100 miles to the east of landfall, about as far as the MS/AL border was for Katrina. Katrina produced a 14-16 ft storm surge that far east. However, Bangladesh is more vulnerable to surge than LA/MS, meaning the same storm would produce a larger surge in Bangladesh than in LA/MS given the topography. And there are several Ganges River inlets west of the mouth of the MS which could funnel the water up into the Dhaka area. It's still going to be very bad in Dhaka, but not nearly as bad as if the center crossed land 60 miles farther east. Much (if not all) of the city will probably be underwater in about 3-4 hours. But the water could have been another 5-10 feet deeper with a landfall farther east.

[Crostorm]

BOB 09/2007/31 Dated: 15 November, 2007






Sub: Cyclone Warning for West Bengal-Orissa coast (Red Message)


The very severe cyclonic storm “SIDR” over north Bay of Bengal moved rapidly further northwards and
lay centred at 1430 hours IST of today, the 15th November 2007 over north Bay of Bengal near Lat. 20.00 N and Long 89.00 E
about 300 km south of Kolkata. It is likely to intensify further and move in a northerly direction. The system with maximum sustained
surface.wind speed of 200 kmph is likely to cross West Bengal-Bangladesh coast near Long. 89.00 E by today around midnight.

For West Bengal coast

Under its influence, rain/thundershowers at most places with heavy to very heavy falls at a few places and isolated extremely heavy
falls (25 cm or more) are likely over coastal districts of West Bengal during next 48 hours causing floods in low lying areas.

Gale winds speed reaching 150-180 kmph are likely along and off the west Bengal coast during next 24 hours.

Storm surge of height 6-7 metres above normal astronomical tide is likely over coastal areas of south 24- Parganas
and Midnapore districts at the time of landfall.

Sea condition will be phenomenal. Fishermen of the above areas are advised not to venture into the sea.

Damage Expected: - Extensive damage to kutcha houses. Some damage to old buildings. Large scale disruption

of power and communication lines. Disruption of rail and road traffic due to extensive flooding. Potential threat from flying debris.



Action Suggested: - Total suspension of fishing operations. Extensive evacuation from coastal areas. Diversion or suspension

of rail and road traffic. People in affected areas to remain indoors.


For Orissa

In association with the system, rain/thundershowers at most places with heavy to very heavy falls at a few places are likely over coastal districts of north Orissa during next 48 hours.

Gale winds speed reaching 120-150 kmph are likely along off north Orissa coast during next 24 hours.

Storm surge of height 5-6 metres above normal astronomical tide is likely over coastal areas of Balasore and Bhadrak districts at the time of landfall.

Sea condition will be phenomenal. Fishermen of the above areas are advised not to venture into the sea.

Damage Expected: - Extensive damage to kutcha houses. Partial disruption of power and communication lines. Minor disruption

of rail and road traffic. Potential threat from flying debris. Flooding of escape routes.



Action Suggested: - Total suspension of fishing operations. Mobilise evacuation from coastal areas. Judicious regulation of rail

and road traffic. People in affected areas to remain indoors.



Squally winds speed reaching 50-60 kmph along and off coastal districts of south Orissa and adjoining districts of north Orissa
during next 24 hours.

Sea condition will be rough to very rough. Fishermen of the above areas are advised not to venture into the sea.

POST LANDFALL OUTLOOK

As the cyclone moves inland Hoogli, Nadia, Mushirabad, Burdwan districts may also experience heavy to very heavy rainfall accompanied with gale wind speed reaching 60-90 kmph from today midnight, the 15th November 2007 for next 24 hours causing flooding in low lying areas and damage to property.

[Derecho]

Let's compare with Katrina. Katrina hit near the LA/MS border. If Sidr hits just east of the India/Bangladesh border

A bit tough because the eye is (finally) filling, but it's pretty clear landfall will end up a good distance east of the border. Looks like the east side will miss the Sundarbans, unfortunately.

[RL3AO]

I'm off to school...good luck to all.

[P.K.]

Still got it 5kts short of super cyclonic storm strength.

DEMS-RSMC TROPICAL CYCLONES NEW DELHI DATED 15-11-2007



TROPICAL STORM “SIDR” ADVISORY NO. TWENTY SEVEN ISSUED AT 1200 UTC OF 15 NOVEMBER, 2007.





THE VERY SEVERE CYCLONIC STORM “SIDR” OVER NORTH BAY OF BENGAL MOVED RAPIDLY FURTHER NORTHWARDS AND LAY CENTRED AT 0900 UTC OF 15TH NOVEMBER 2007 OVER NORTH BAY OF BENGAL NEAR LAT. 20.00 N AND LONG 89.00 E, ABOUT 300 KM SOUTH OF KOLKATA(42809).



ESTIMATED CENTRAL PRESSURE: 944 hPa.



THE SATELLITE IMAGERIES SHOW SOLID INTENSE TO VERY INTENSE CIRCULAR CONVECTIVE CLOUDS AROUND THE SYSTEM CENTRE. EYE IS VISIBLE. CURRENT INTENSITY: T6.0 RPT T6.0. MAXIMUM SUSTAINED SURFACE WIND SPEED IS 115-125 KTS AROUND THE STORM CENTRE.



SEA: PHENOMENAL.



FORECAST: THE SYSTEM IS LIKELY TO INTENSIFY FURTHER AND MOVE IN A NORTHERLY DIRECTION AT ABOUT 14 KT AND CROSS WEST BENGAL-BANGLADESH COAST NEAR LONG 890 E AROUND 1800 UTC OF TODAY THE 15TH NOVEMBER 2007.



INTENSITY T6.5 RPT T6.5 WITH MAXIMUM SUSTAINED SURFACE WINDS OF ABOUT 200 KMPH LIKELY OVER WEST BENGAL-BANGLADESH COAST. STORM SURGE OF HEIGHT 6-7 METRES ABOVE ASTRONOMICAL TIDE LIKELY OVER COASTAL AREAS OF WEST BENGAL AND BANGLADESH AT THE TIME OF LANDFALL.

[P.K.]

From the BBC.

Bangladesh put on cyclone alert

Tens of thousands of people have left coastal districts of Bangladesh as a severe cyclone heads in across the Bay of Bengal, officials say.
Operations have been suspended at the main ports of Mongla and Chittagong, and people are being moved away from high-risk areas.

More than 40,000 policemen, soldiers, coastguards and health workers have been deployed along the coast.

The cyclone was expected to make landfall on Thursday evening.

With winds of 200km (120 miles) an hour, the cyclone may also affect eastern India and the west coast of Burma.

Thousands of families have been evacuated from their homes in over a dozen coastal districts of Bangladesh, officials said.

'Serious'

The BBC's Alastair Lawson on board a boat chartered by the BBC to assess the impact of climate change says that the weather is now taking a marked turn for the worse.

Our correspondent - located on the Jamuna river north-west of Dhaka - says that the weather is overcast and the wind has picked up significantly.

Officials say that the level of casualties from cyclones in Bangladesh has been significantly reduced in recent years because of a better early-warning system and the construction of cyclone shelters.

Bangladesh's southern seaside resort town of Cox's Bazar appeared to be deserted after the cyclone warning was issued on Wednesday evening, reports said.

Bangladesh meteorological department officials said they feared the cyclone may also trigger tidal surges up to 10ft (over three metres) in some areas.

Southern Bangladesh is often hit by cyclones, but experts say the latest one is a category four storm, the largest so far in the season.

"This is going to be a highly damaging cyclone," Samarendra Karmakar, director of the Bangladesh Meteorological Department told the BBC.

Bangladesh is frequently hit by cyclones and monsoon floods.

http://news.bbc.co.uk/1/hi/world/south_asia/7095763.stm

[Squarethecircle]

Looks more like 125-130 knots now, but still a very strong storm, and the surge is still going to be awful. The weakening trend before landfall is finally coming into play, but far too late to have any saving effect on the coast; the eye will still be clearly defined before landfall, and there are hundreds of thousands of people out there that have no protection from this tremendously powerful storm. I'm not sure what the calculations would add up to on the North Indian coast, but normally I would expect this storm to come with something like 25, maybe 27 feet of surge. Can anyone translate to Bangladesh?

[HenkL]

According to Reuters: winds 60 MPH at Saint Martins Islands, at the Bangladesh/Myanmar border, some 200 miles east of the eye.

[P.K.]

I'm not sure what the calculations would add up to on the North Indian coast, but normally I would expect this storm to come with something like 25, maybe 27 feet of surge. Can anyone translate to Bangladesh?

The last advisory is warning of a 6 to 7 metre storm surge for Bangladesh.

[Squarethecircle]

That seems very underestimated to me; it might have to do with the fact that the forecasters HAVE NO IDEA WHAT THEY'RE TALKING ABOUT! Maybe that much from a category 3, yes...

[Chacor]

That seems very underestimated to me; it might have to do with the fact that the forecasters HAVE NO IDEA WHAT THEY'RE TALKING ABOUT! Maybe that much from a category 3, yes...

6 - 7 m = 19-23 ft.

[Squarethecircle]

Yes, but it seems like the coast would enhance it, would it not? 6-7 meters (or slightly higher) is normal for a storm of this caliber.

[Crostorm]

[Squarethecircle]

Eye is still just barely visible on the B & W.

[HURAKAN]

VERY CLOSE TO THE COAST.

[HURAKAN]

[Squarethecircle]

Heh, looking better than it did fifteen minutes ago; I'd still guess slightly below 135 knots AT MOST.