Cat 4 Cyclone heading towards Calcutta & Bangaladesh

Cat 4 Cyclone Sidr heading towards Calcutta & Bangaladesh
by FishOutofWater
Tue Nov 13, 2007 at 08:55:40 PM PST

Extremely dangerous tropical cyclone Sidr is on a path to disaster, if the Navy's forecast holds. Wind shear is forecast to cause weakening before landfall, but Sidr will bring a major storm surge and flooding into Bangaladesh on its present track threatening tens of thousands of lives. Bangaladesh is especially vulnerable to flooding because tens of thousands of people live in a river delta, much like New Orleans.

This year's La Nina has driven warm water into the Indian ocean and the Bay of Bengal, promoting a very active tropical storm season in the Indian ocean. Earlier in the year a landfalling storm caused massive destruction in Pakistan. Sidr could be even worse if it stays on the forecast track.

Sidr has a tight eye, but is beginning to show the effects of wind shear on its outflow pattern. High clouds stream from south to north.

From the Joint Typhoon Warning Center (not my shouting).

REMARKS:
140300Z POSITION NEAR 14.7N 89.5E.
TROPICAL CYCLONE (TC) 06B (SIDR) LOCATED 500 NM SOUTH OF
CALCUTTA, INDIA, HAS TRACKED NORTHWARD AT 06 KNOTS OVER THE
PAST 06 HOURS. TC 06B HAS MAINTAINED INTENSITY OVER THE PAST
06 HOURS AS EVIDENT ON BOTH INFRARED SATELLITE IMAGERY AND
RECENT MICROWAVE IMAGERY. THE CURRENT INTENSITY IS BASED ON
DVORAK ESTIMATES OF 115 KNOTS FROM PGTW AND KNES. THE CURRENT
POSITION AND MOTION ARE BASED ON HIGH CONFIDENCE EYE FIXES.
POLEWARD OUTFLOW REMAINS VERY GOOD AHEAD OF AN UPPER-LEVEL
TROUGH SITUATED OVER EASTERN INDIA. TC 06B CONTINUES TO
TRACK NORTHWARD ALONG THE WESTERN PERIPHERY OF THE MID-
LEVEL SUBTROPICAL RIDGE TOWARD A BROAD WEAKNESS IN THE
STR LOCATED OVER THE NORTHERN BOB. AFTER TAU 24, VERTICAL
WIND SHEAR SHOULD INCREASE AS THE STORM APPROACHES
STRENGTHENING UPPER LEVEL WINDS ASSOCIATED WITH THE
TROUGHING TO THE NORTH AND THE SYSTEM IS EXPECTED TO
SIGNIFICANTLY WEAKEN NORTH OF 18N. THE DYNAMIC AIDS ARE IN
GOOD AGREEMENT ON A NORTHWARD TRACK INTO BANGLADESH.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 140000Z IS 32 FEET.
NEXT WARNINGS AT 140900Z, 141500Z, 142100Z AND 150300Z.//
NNNN

My efforts to post the imagery failed. Please go to the JTWC link for further images of the tropical cyclone.

Winds are forecast to drop to 70 knots - a category 1 storm - but coastal conditions in Bangaladesh are so bad that this will be a catastrophe if the forecast is followed by the cyclone. Desperately poor people will have no way to evacuate in time to escape the flooding.

http://www.dailykos.com/story/2007/11/13/232343/26