BOB 03 LANDFALL NEARS!

METD WEATHER

AKSHAY DEORAS

SEVERE WEATHER FORECASTER

The well set Tropical Depression BOB 03 in Bay of Bengal is all set to begin its journey towards India from now. Thursday,14th Oct was full of ups and downs for the depression as the classic 20kt wind shears continued to affect the shape of system and its intensification with continued excellent upper conditions for intensification.

The forecast estimated by GFS went nearly correct with the position and timing but went WRONG with intensity.

BOB 03 PATH FOR LANDFALL IN ORISSA

14TH OCT 2010- BOB 03 IS SITUATED OFFSHORE ANDHRA PRADESH AND ORISSA WILL MOVE IN NORTH , NORTH-WEST DIRECTION

15TH OCT 2010-

HEAVY RAINS WILL BEGIN JUST BY 0100HRS IN ORISSA ( heavy rains alert begins) ALONG WITH STRONG WINDS UPTO 40KM/HR IN PURI

FLOODING POTENTIALS ALSO EXIST.

THE TROPICAL DEPRESSION WILL MAKE A LANDFALL IN THE MARKED REGION ON METD WEATHER ALERT SECTION ON 15TH OCT 2010 AFTERNOON HOURS

LANDFALL TIME- 0900-1400,15TH OCT

STORM SURGE POSSIBLE WITH STRONG WINDS AND HEAVY RAINS.

Wind shears acting as a problem for BOB 03

ABOVE-

THE MORNING SATELLITE IMAGERY SHOWING WEAK CONVECTION ORGANIZATION!

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

BOB 03 continues to be a tropical depression with a fairly developed structure. Located 410NM south-south east of Kolkata, the system continues to be a in a continuous problem due to the persistent and INCREASING wind shear!

The anticyclone present over China is causing strong easterlies to blow around this low and its definitely affecting the system.

Early morning satellite imagery indicates massive convection happening at the Western quadrant of the low since a well set 10kt wind shear to the NE of low is shearing the environment for organization.

Low level convergence has started building up to 10kt around the low with upper level conditions continue to remain very good.

It seems that the tropical depression is not going to strengthen any more on significant scale since I don't find the wind shears decreasing which are the biggest problem associated with this setup. SST continues to be 29C around and favorable.

The Min air pressure in this low seems to be 998mb at afternoon hours of today

Maximum winds are near to 25kt.

METD WEATHER forecasts that this tropical depression will remain A tropical depression with maximum winds rise little on 14th Oct and then start declining.

System might have good Western Symmetric shape since shears dominate in east and convergence building in west at lower levels

I don't find this one becoming a Tropical Storm and max pressure will fall upto 996mb by 15th Oct 2010.

LANDFALL WILL BE ON 15TH OCT 2010 IN AFTERNOON-EVENING HRS

(EXACT TIME TO BE CONVEYED LATER)

THREAT FOR ROUGH SEAS,HEAVY RAINS,GALE WINDS AND STORM SURGES CONTINUE.

SEE THE METD WEATHER SEVERE WEATHER MAP OF INDIA ON THE BLOG!

Tropical Depression BOB 03 intensifying after wind shear reduces

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

Recent Satellite imagery of evening is showing that Depression BOB 03 is re-intensifying after was affected by a 20kt shear region

Shear has a tendency of decreasing which is happening and again rainbands are forming centering the low

Attachment is of the IR enhanced image of 12z,13th Oct 2010

BOB 03 WILL INTENSIFY TO A TROPICAL STORM ATLEAST AND NOT CYCLONE!

MORE DETAILS LATER

METD WEATHER ALERT MAP WILL BE UPDATED AT 0930HRS,14TH OCT 2010

Tropical Depression BOB 03 forms in Bay of Bengal. Intensification more!

Above-

The GFS model 700 mb precipitation and satellite imagery showing rainband building on East and south of low

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

The morning satellite imagery coupled with 00z GFS 700mb precipitation plot are suggestive or rainbands formation. Banding feature around a developing low level circulation has picked up today early morning as the low strengthens to 1002mb. Situated in an environment of 29-30C SST at 15-17N at 90-93E and little deep layer shear and little convergence building, the system will continue to organize today (not becoming symmetric today only due to the shear).

A nice upper divergent flow of 20kt causing low intensification in moist environment.

As seen from the NHC enhancement, and infrared BD enhancement, deep convection is still exploding with intense cloud tops of -70C

Indian Meteorological Dept announced a Tropical Depression 97B (BOB 03) on 13th Oct 2010 just as METD WEATHER had estimated and pre-warned since last 5 days.

The depression has a low pressure of 1002 mb since morning and maximum surface wind of 45km/hr at center. As per IMD, the state of sea is very rough at the center.

Forecast

At present, the system lies in a little wind shear that definitely has affected the symmetry of the system since morning satellite images. The recent 14z satellite imagery is showing a total vanish of the rainbands,Low level circulation center and super symmetry as was looking in the morning

Right now 10-20kt deep layer shear is present that is definitely affecting the setup.

SST continues to be around 29C.

The CIMSS models are indicating that wind shear tendency HAS BEEN decreasing SINCE LAST 24hrs around this low pressure. The models indicate the decrease by a factor of 5kt! This means by tomorrow wind shears will become near to 5kt -10kt...

Upper level continues to remain good with very favorable upper divergence encouraging the system to release the latent heat.

Situated at South-East of Subtropical ridge, I estimate THAT THE TROPICAL DEPRESSION WILL INTENSIFY ON 14TH OCT 2010 GIVEN THE DECREASING SHEAR AND PROMINENT MORE LLC ORGANIZATION.

THIS TROPICAL DEPRESSION HAS BEEN TERMED "FAIR CHANCE" OF CYCLONE AS PER JTWC.

I ESTIMATE THAT THIS LOW WILL REMAIN TROPICAL DEPRESSION WITH MORE INTENSE WINDS AND RAINS. THIS LOW WILL HIT THE MARKED AREA ON METD WEATHER ALERT IMG ON 15TH OCT NIGHT(EXACT TIME WILL BE CONVEYED LATER)

The Tropical Cyclone (expected ) threatens Central India

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

Widespread convection already has fired in the central bay of bengal as was expected.

Cloud top temperatures of -50 to -60C are indicating intense convection happening with developing center of Low level circulation( signs of low pressure intensification) in an environment of light-moderate vertical shears and favorable upper divergence.

SST in the region are 29C which are very favorable for more fueling of the low as warmer sst means more latent heat release from the system as the upper conditions continue to remain favorable for it.

In the 00z GFS,12th Oct 2010

The SLP is showing that intense low pressure falling below to 992mb will happen on 16th Oct in Bay.

Also from the 700mb map, I see less banding feature around the low which might be the indicator that low might not strengthen to a Severe Cyclonic storm (Absence of well defined eyewall) . Tropical Depression looks very certain on 15th Oct 2010.

After slamming Orissa coasts and interiors as depicted by warning map, the low will travel towards central India by 17th Oct 2010 and might have pressure upto 1000mb.

This seems to be a simply low as per GFS but GFS cyclone prediction models show pressure nearing to 990mb.

Nagpur will get rains starting on 17th Oct 2010(Holy festival Dushera day) i.e Sunday

The Nagpur forecast will be put and (updated regularly ) on METD WEATHER's blog page-

nagpur weather update and on Facebook fanpage

No change in METD WEATHER alerts

Update on the low pressure in Bay of Bengal

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

Ingredients are coming together for forming a strong low pressure as is being indicated by last many GFS,CMS weather RUNS.CMS show low pressure to drop upto 980mb

The morning satellite imagery is showing -60C cloud tops in the central Bay of Bengal.

GFS is showing that a low level cyclonic circulation will soon start building up across this widespread convection and will strengthen the existing 1006mb low as of Thai map of 18z,11th Oct 2010

The GFS cyclone track is still showing a solid chance of low pressure dropping to 990 and below peak on 15-16 as this low pressure(expected to be a cyclone ) sweeps east and slams Orissa on 16th Oct

All METD WEATHER warning continue as they are. Low will start intensifying from tomorrow onwards

Its going to be Tropical Cyclone GIRI in Bay of Bengal

METD WEATHER

Akshay Deoras

Severe Weather Forecaster

All ingredients are coming together for the 4th Cyclone of 2010 North Indian Ocean Cyclone Season...

GFS solutions for Bay of Bengal are very classic and consistent showing a strong low pressure

Forecast

The already formed low pressure 1002 mb offshore Andhra Pradesh in the Bay of Bengal will quickly move towards the Eastern Bay of Bengal near Myanmar on 11th Oct 2010

Given the excellent 28-29C SST offshore Myanmar,development of a Low level

cyclonic circulation,

Less wind shears, and favorable upper atmospheric conditions,

The low pressure 1004mb as on 11th Oct will strengthen to a classic 992mb and even deeper as real Sea level pressure is more intense than that forecasted by GFS.

Given the moist atmosphere, that low pressure is most likely to become a Tropical Cyclone on 13-14th Oct 2010 in the North-Central Bay of Bengal.

It will be named Cyclone Giri as per the IMD naming process

This cyclone will head for a landfall in the 16N-20N LATITUDE WINDOW AT 80-84E LONGITUDE

I.e Landfall will be at Eastern-North Eastern Andhra Pradesh to South Eastern Orissa with areas such as Machilipatna

m,Yanam in Pondicherry,Vishakhapatnam,Srikakulam etc.....

This landfall will take place on 15th Oct 2010 late period to 16th Oct 2010 near Machilipatnam,AP

Intensity forecast by METD WEATHER

As per the GFS Cyclone Model runs of 00z,10th Oct 2010

This system will have a well

definied symmetric warm core in it as per the 900-600mb Storm Relative Thickness symmetry and the mid-upper level winds will be Deep warm core related.

This means that the inten

sity of this cyclone will remain very strong. I expect it as a Cat.1 Cyclone or even stronger than it

When I had forecaster c

yclone Phet, its air pressure (Min) on GFS models was near to 990mb which is a normal Cat.1 cyclone but Phet turned to be a Cat 4 cyclone

I w'd not be surprised to find Cyclone Giri very strong especially in the -1.5 Negative Madden Julian Oscillation.

ALERTS-

(SEE THE FRONT PAGE OF www.metdweather.blogspot.com) for the Graphical Alert Map

MARK 5 ALERT WITH PDS WILL BE SHORTLY ISSUED ON 11TH OCT 2010 FOR NORTH-EASTERN ANDHRA PRADESH,SOUTH EASTERN ORISSA

ALERT WILL BE FOR ROUGH SEA,GALE WARNING,LANDFALL WARNING WITH HEAVY RAIN WARNING

NAGPUR WEATHER-

NAGPUR CITY WILL WITNESS RAINS ON SATURDAY,16TH OCT 2010 DUE TO THE TROPICAL DEPRESSION GIRI

*** ENTIRE FORECAST SUBJECTED TO MOVEMENT AND FORMATION OF CYCLONE

PERCENTAGE

CHANCE OF TROPICAL DEPRESSION - 95%

CHANCE OF TROPICAL CYCLONE - 70%+

CHANCE OF SEVERE CYCLONE - 50%