Monday, May 13, 2013

Cyclone "Mahasen" - No sign of Northerly movement yet !

Latest analysis show that the system has moved N-W during past 6 hrs.
Present location is 12.8N , 85.7E.
From morning, the pressure and wind speed has remained the same.


JTWC warning and path projection at 8:30pm IST

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
TROPICAL CYCLONE 01B (MAHASEN), LOCATED APPROXIMATELY 630 NM SOUTH-
SOUTHWEST OF KOLKATA, INDIA, HAS TRACKED NORTHWESTWARD AT 09 KNOTS 
OVER THE PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY 
(MSI) SHOWS A LARGE CENTRAL DENSE OVERCAST FEATURE WITH A PARTIALLY 
EXPOSED LOW-LEVEL CIRCULATION CENTER (LLCC). A 131116Z SSMIS 37 GHZ 
MICROWAVE IMAGE SHOWS THE BULK OF THE DEEP CONVECTION IS SHEARED 
WEST OF THE LLCC WITH SOME SHALLOW FRAGMENTED CONVECTIVE BANDING TO 
THE NORTH. THE INITIAL POSITION IS BASED UPON THE MICROWAVE IMAGE 
WITH FAIR CONFIDENCE. THE INITIAL INTENSITY REMAINS ASSESSED AT 50 
KNOTS WHICH IS SLIGHTLY HIGHER THAN A DVORAK CURRENT INTENSITY 
ESTIMATE OF 45 KNOTS FROM PGTW DUE TO THE TIGHTLY WRAPPED STRUCTURE 
OF THE SYSTEM. UPPER LEVEL ANALYSIS INDICATES FAVORABLE WESTWARD 
OUTFLOW IS BEING OFFSET BY MODERATE (15-20 KNOTS) VERTICAL WIND 
SHEAR (VWS), WHICH IS EVIDENT IN THE PARTIALLY EXPOSED NATURE OF THE 
SYSTEM. TC 01B IS CURRENTLY IN A WEAK STEERING ENVIRONMENT AS THE 
SUBTROPICAL STEERING RIDGE EAST OF THE SYSTEM IS WEAKENING AND RE-
ORIENTING IN RESPONSE TO AN APPROACHING MIDLATITUDE SHORTWAVE 
TROUGH, WHICH IS CURRENTLY OVER NORTHEASTERN INDIA. TC 01B IS 
EXPECTED TO SLOWLY TRACK NORTH FOR THE NEXT DAY AS THE STEERING 
RIDGE REMAINS WEAK AND CONTINUES TO RE-ORIENT. AFTER TAU 24, THE 
SYSTEM IS EXPECTED TO ACCELERATE AND TRACK NORTHEAST AHEAD OF THE 
TROUGH. AS THE SYSTEM GAINS LATITUDE, GRADUAL INTENSIFICATION IS 
EXPECTED AS VWS RELAXES AND INCREASING POLEWARD OUTFLOW FROM THE 
STRONG WESTERLIES NORTH OF THE SYSTEM ALLOWS FOR A PEAK INTENSITY OF 
70 KNOTS AT TAU 72. AFTER TAU 72, TC 01B WILL BEGIN TO WEAKEN AS VWS 
INCREASES AND LAND INTERACTION ALLOWS FOR DISSIPATION OVER LAND AT 
TAU 120. DYNAMIC MODEL GUIDANCE HAS COME INTO BETTER AGREEMENT AS 
NAVGEM HAS STARTED TO SHOW THE RECURVE SCENARIO, ALTHOUGH IT REMAINS 
THE WESTERN OUTLIER. ALTHOUGH THERE IS A GENERAL AGREEMENT IN THE 
RECURVE, MODELS CONTINUE TO VARY IN THE TIMING AND SPEED OF THE 
TURN. IN LIGHT OF THIS, THE JTWC FORECAST IS LAID CLOSE TO MULTI-
MODEL CONSENSUS WITH LOW CONFIDENCE DUE TO THE LARGE SPREAD IN 
SOLUTIONS. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 131200Z IS 21 FEET.
All weather models other than NAVGEM model has predicted a Odisha coast landfall as Cyclone on 17-May.

Cyclone "Mahasen" - Drifted W-N-W again, Nearing Chennai, South Andhra !! ??

Going by 4:30pm, Satellite IR image, During the past 4hrs, the Cyclone seems to have drifted W-N-W again.


Now its "Too close for comfort" for North Tamilnadu and South,central Andhra coast.
5pm, Chennai RADAR shows the nearest HUGE cloud mass of the Cyclone is seen around 200 km East from city.

#######  UPDATED at 7:50pm  ##########################################
IMD warning at 7:30pm IST
~~~~~~~~~~~~~~~~~~~~~~~~~~

Cyclonic Storm, MAHASEN over southeast Bay of Bengal
The cyclonic storm MAHASEN over southeast Bay of Bengal moved westwards with
a speed of about 10 kmph during past 6 hrs and lay centred at 1730 hrs IST of 13th May 2013 
near latitude 12.00 N and longitude 86.00 E, about 800 km northwest of Car Nicobar, 650 km 
northeast of Trincomalee, 650 km east-southeast of Chennai and 1280 km south-southwest of 
Chittagong. It would move initially northwards during next 12 hours and thereafter recurve 
towards Bangladesh-Myanmar coast.


Cyclone Mahasen - Slowly moved to W-N-W, No weakening seen !

During the past 6 hrs, the cyclone has crawled West or W-N-W.
Present location is 12.1N , 86.3E
Pressure remains the same at 985 mb
Winds gusting up to 93 kmph.

1:30pm, Visible Satellite shot shows Good core and heavy convective activity over center and over N-E bands.

JTWC warning and path projection at 2:30pm IST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

TROPICAL CYCLONE 01B (MAHASEN), LOCATED APPROXIMATELY 660 NM SOUTH 
OF KOLKATA, INDIA, HAS TRACKED NORTHWESTWARD AT 04 KNOTS OVER THE 
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) SHOWS 
A LARGE CENTRAL DENSE OVERCAST FEATURE WITH A PARTIALLY EXPOSED LOW-
LEVEL CIRCULATION CENTER (LLCC), WHICH IS EVIDENT IN A 130321Z AMSU-
B MICROWAVE IMAGE. THE INITIAL POSITION IS BASED UPON THIS PARTIALLY 
EXPOSED LLCC IN THE MSI WITH FAIR CONFIDENCE. THE INITIAL INTENSITY 
IS ASSESSED AT 50 KNOTS WHICH IS SLIGHTLY HIGHER THAN DVORAK CURRENT 
INTENSITY ESTIMATES OF 45 KNOTS FROM PGTW AND KNES DUE TO THE 
TIGHTLY WRAPPED ORGANIZATION OF THE SYSTEM. UPPER LEVEL ANALYSIS 
INDICATES FAVORABLE WESTWARD OUTFLOW IS BEING OFFSET BY MODERATE (15-
20) VERTICAL WIND SHEAR, WHICH IS EVIDENT IN THE PARTIALLY EXPOSED 
NATURE OF THE SYSTEM. TC 01B IS CURRENTLY IN A WEAK STEERING 
ENVIRONMENT AS THE SUBTROPICAL STEERING RIDGE EAST OF THE SYSTEM IS 
WEAKENING AND RE-ORIENTING IN RESPONSE TO AN APPROACHING MIDLATITUDE SHORTWAVE TROUGH, CURRENTLY OVER NORTHEASTERN INDIA. TC 01B IS 
EXPECTED TO SLOWLY TRACK NORTH FOR THE NEXT 36 HOURS AS THE STEERING 
RIDGE REMAINS WEAK AND CONTINUES TO RE-ORIENT. AFTER TAU 36, THE 
SYSTEM IS EXPECTED TO ACCELERATE AND TRACK NORTHEAST AHEAD OF THE 
TROUGH. WHILE THE SYSTEM GAINS LATITUDE, GRADUAL INTENSIFICATION IS 
EXPECTED AS THE VWS RELAXES. INCREASING POLEWARD OUTFLOW FROM THE 
STRONG WESTERLIES NORTH OF THE SYSTEM WILL ALSO AID IN THE 
INTENSIFICATION, ALLOWING FOR A PEAK OF 70 KNOTS AT TAU 72. AFTER 
TAU 72, TC 01B WILL BEGIN TO WEAKEN AS VWS INCREASES AND LAND 
INTERACTION ALLOWS FOR DISSIPATION OVER LAND AT TAU 120. DYNAMIC 
MODEL GUIDANCE, WITH THE EXCEPTION OF NAVGEM, IS IN AGREEMENT WITH 
THE RECURVE SCENARIO ALTHOUGH AT DIFFERENT SPEEDS AND WITH THE 
EXTENT OF THE NORTHEAST TURN.  THE JTWC FORECAST IS SLIGHTLY FASTER 
AND EAST OF MULTI-MODEL CONSENSUS TO OFFSET THE NAVGEM SOLUTION WITH 
LOW CONFIDENCE DUE TO THE LARGE SPREAD IN SOLUTIONS. MAXIMUM 
SIGNIFICANT WAVE HEIGHT AT 130600Z IS 20 FEET.

Yesterday, highest maximum temperature 44.9°C was recorded  at Allahabad (Uttar Pradesh)

1:30pm, W.D has cleared out from North India except for some rain over Kashmir ... http://ow.ly/i/26iBM 

Today, the upper level W.D trough is seen from Himachal upto N.Madhyapradesh..  and it'll weaken and travel East.. http://ow.ly/i/26iEJ 

Present W.D trough's Eastward movement will play one of the role in re-curve of Cyclone Mahasen to N-N-E in 24hrs... http://ow.ly/i/26iEJ

#HOT at 1:30pm, Nagpur = 44 C, Hyderabad = 41 C, Ahmedabad = 40 C, Varanasi = 38 C, #Delhi, Jaipur = 36 C, #Kolkata, Patna = 35 C

RT @rajugana: @weatherofindia Bangalore 9.30am, Overcast sky, windy and chill weather greets Monday morning...22C. 

Chennai Airport receives 5 cm at midnight !

#Chennai - Heavy rain lashed S,S-W and Western suburbs of city ... check this out... http://ow.ly/i/26i50 

#Chennai - rainfall till 8:30am today, Nungambakkam = 0.36 cm and Airport = 5.06 cm. Yesterday Airport temperature = 39.7 C.


Cyclone "Mahasen" - Slowly moved North, intensified slightly!

Analysis show that the cyclone has moved slowly to the North as expected by most of the weather models.
Latest position is 11.8N , 86.7E
Pressure has decreased again to 985 mb
Winds gusting up to 93 kmph

11am, Satellite IR shows good convective activity and well maintained core. Most of South Peninsular India is cloudy due to over night rain and due to Mahasen's outer bands.

JTWC warning and projected path at 8:30am IST
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

TROPICAL CYCLONE 01B (MAHASEN), LOCATED APPROXIMATELY 673 NM
SOUTHWARD OF CALCUTTA, INDIA, HAS TRACKED NORTHWARD AT 08 KNOTS
OVER THE PAST SIX HOURS. ANIMATED INFRARED SATELLITE IMAGERY
SHOWS THE CENTRAL DENSE OVERCAST FEATURE THAT IS OBSCURING THE LOW
LEVEL CIRCULATION CENTER (LLCC) HAS CONTRACTED BUT SLIGHTLY DEEPENED.
THE INITIAL POSITION IS BASED ON RECENT MICROWAVE SATELLITE IMAGES
INCLUDING A 122345Z SSMI/S PASS THAT SHOW THE LLCC EAST OF THE MAIN
CONVECTION. THE INITIAL INTENSITY IS BASED ON THE HIGH END OF DVORAK
ESTIMATES FROM PGTW AND KNES. UPPER LEVEL ANALYSIS INDICATES THE
SYSTEM IS 06 DEGREES SOUTH OF THE RIDGE AXIS IN AN AREA OF MODERATE
(20 KNOT) EASTERLY VERTICAL WIND SHEAR (VWS); HOWEVER, THE VWS IS
OFFSET BY ROBUST WESTWARD OUTFLOW, AS EVIDENCED ON ANIMATED WATER
VAPOR IMAGERY. THE CYCLONE IS NOW ROUNDING THE WESTERN EDGE OF THE
SUBTROPICAL RIDGE TO THE EAST. IT IS EXPECTED TO SLOW DOWN OVER THE
NEXT 12 HOURS AS IT MAKES THE TURN BEFORE RECURVING NORTHEASTWARD ON
THE POLEWARD SIDE OF THE RIDGE AXIS. TC 01B WILL GRADUALLY INTENSIFY
AS THE VWS RELAXES ALONG THE RIDGE AXIS. ADDITIONALLY, THE POLEWARD
OUTFLOW IS EXPECTED TO OPEN UP AS THE SYSTEM BECOMES EXPOSED TO THE
PREVAILING WESTERLIES. AFTER TAU 72, TC MAHASEN WILL GRADUALLY WEAKEN
AS VWS INCREASES BEFORE MAKING LANDFALL NEAR CHITTAGONG, BANGLADESH.
LAND INTERACTION WILL RAPIDLY ERODE AND DISSIPATE THE SYSTEM BEFORE
THE END OF THE FORECAST. THE AVAILABLE NUMERICAL GUIDANCE IS IN
AGREEMENT WITH THE RECURVE SCENARIO WITH THE EXCEPTION OF NAVGEMS AND
GFDN THAT OFFER A CONTINUED NORTHWARD PROGRESSION. THE JTWC FORECAST
IS LAID CLOSE TO MODEL CONSENSUS WITH POOR CONFIDENCE IN VIEW OF THE
LARGE VARIANCES IN THE MODEL MEMBERS.
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 130000Z IS 18 FEET

Latest COLA GFS model suggests that the cyclone will continue to move North for another 24hrs and then N-E towards Bangladesh. Landfall expected over S.Bangladesh on 16-May.

Chennai Rain !

RT @k_t_l: Rain in Chennai....!!! Hurray....!!! Chennayil oru mazhaikaalam :-) (12:28am)

#Chennai - 12:35am, Rain started over Polichalur zone, South chennai.


Ask_Qs_Later12:36am via Web
@weatherofindia @ranganaathan a little relief from the agni-nakshatram It was stifling hot in chennai just a week ago! #stiflingHot
Show Conversation
naveenkumars8412:24am via Twitter for Android
@weatherofindia Oh my god finally its Rain in#Chennai hope it will pour and reduce the heat...
ranganaathan12:00am via Web
Wow its raining in Chennai @weatherofindia , such a surprise. Hope the temp reduces, & rain continues.

Cyclone "Mahasen" - Very slow Movement, maintaining intensity, next 12 hrs is crucial for direction.

Latest analysis show that Cyclone "Mahasen" has only moved a bit in past 8 hrs and in N-W direction.
This slowing down is expected by the previous JTWC warnings.
Present position as of 8:30pm is 10.5N , 86.9E
Pressure remains the same at around 989 mb and winds gusting up to 85 kmph.

JTWC warning and projected path at 8:30pm
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

TROPICAL CYCLONE 01B (MAHASEN), LOCATED APPROXIMATELY 750 NM SOUTH 
OF KOLKATA, INDIA, HAS TRACKED NORTHWESTWARD AT 04 KNOTS OVER THE 
PAST SIX HOURS. ANIMATED MULTISPECTRAL SATELLITE IMAGERY (MSI) 
REVEALS PULSATING DEEP CENTRAL CONVECTION WITH FRAGMENTED CONVECTIVE 
BANDING WRAPPING INTO A POORLY DEFINED AND BROAD LOW-LEVEL 
CIRCULATION CENTER (LLCC). A 121128Z SSMIS 37GHZ MICROWAVE IMAGE 
SHOWS CONVECTION REMAINS FRAGMENTED AND BROKEN WHILE THE LLCC 
REMAINS FAIRLY AMBIGUOUS. SURFACE OBSERVATIONS FROM COASTAL INDIA 
SHOW LARGE (>20 DEGREES) DEW POINT TEMPERATURE SPREADS INDICATIVE OF 
A DRY AIR MASS WHILE THE LATEST MICROWAVE DERIVED TOTAL PRECIPITABLE 
WATER LOOP CONTINUES TO SHOW THIS DRY CONTINENTAL AIR IS BEING 
INGESTED INTO THE LOWER LEVELS OF THE SYSTEM. THIS DRY AIR INGESTION 
CONTINUES TO BE THE REASON FOR THE FRAGMENTED AND FLARING NATURE OF 
THE CONVECTION DESPITE FAVORABLE SEA SURFACE TEMPERATURES. THE 
INITIAL POSITION IS BASED UPON THE MSI LOOP AND AFOREMENTIONED SSMIS 
MICROWAVE IMAGE WITH LOW CONFIDENCE DUE TO THE POOR DEFINITION AND 
BROAD NATURE OF THE LLCC. THE INITIAL INTENSITY REMAINS AT 45 KNOTS 
BASED ON A DVORAK CURRENT INTENSITY ESTIMATE OF 45 KNOTS FROM PGTW 
AND THE OVERALL ORGANIZATION OF THE SYSTEM. UPPER-LEVEL ANALYSIS 
REVEALS A MARGINAL ENVIRONMENT OF STRONG DIFFLUENCE ALOFT PROVIDING 
FAVORABLE OUTFLOW WHILE VERTICAL WIND SHEAR (VWS) HAS INCREASED TO 
MODERATE TO STRONG LEVELS (20-30 KNOTS). TC 01B IS FORECAST TO TURN 
NORTH IN THE NEXT 12 HOURS ALONG THE SOUTHWESTERN PERIPHERY OF THE 
SUBTROPICAL RIDGE (STR) SITUATED OVER THE NORTHERN ANDAMAN SEA. 
AFTER TAU 12, TC 01B IS EXPECTED TO SLOWLY TRACK NORTH THROUGH TAU 
36 BEFORE IT TURNS NORTHEASTWARD AS THE STR RE-ORIENTS IN RESPONSE 
TO AN APPROACHING MID-LATITUDE SHORTWAVE TROUGH, WHICH IS CURRENTLY 
OVER NORTHERN INDIA. TC 01B IS EXPECTED TO OVERCOME THE CURRENT DRY 
AIR ENTRAINMENT AND INTENSIFY TO A PEAK OF 75 KNOTS BY TAU 72 AS THE 
SYSTEM CROSSES THE RIDGE AXIS INTO AN AREA OF INCREASED POLEWARD 
OUTFLOW WITH ITS EXPOSURE INTO THE STRONG WESTERLIES. AFTER TAU 96, 
THE SYSTEM WILL MAKE LANDFALL NEAR CHITTAGONG, BANGLADESH, AS A 
SIGNIFICANT CYCLONE ALL WHILE WEAKENING DUE TO THE LAND INTERACTION. 
DYNAMIC MODEL GUIDANCE CONTINUES TO SHOW TWO DIFFERENT TRACK 
SOLUTIONS. GFDN AND NAVGEM CONTINUE TO TRACK THE SYSTEM TO THE 
NORTHWEST INTO NORTHEASTERN INDIA, WHICH SEEMS UNLIKELY AS THE MODEL 
TRACKERS SEEM TO BE ERRONEOUSLY TRACKING INTO THE PREVIOUSLY 
MENTIONED SHORTWAVE TROUGH. GFS, ECMWF AND EGRR HAVE STAYED 
CONSISTENT WITH THE RECURVE SCENARIO INTO BANGLADESH ALBEIT AT 
DIFFERENT TRANSLATIONAL SPEEDS. DUE TO THIS, THE JTWC FORECAST 
REMAINS FASTER AND EAST OF MULTI-MODEL CONSENSUS TO OFFSET THE 
NAVGEM AND GFDN SOLUTIONS AND IS CONSISTENT WITH THE PREVIOUS 
FORECAST. DUE TO THE LARGE SPREAD IN THE MODEL SOLUTIONS AND THE LOW 
CONFIDENCE IN THE INITIAL POSITION, FORECAST CONFIDENCE REMAINS LOW. 
MAXIMUM SIGNIFICANT WAVE HEIGHT AT 121200Z IS 19 FEET.
The past 3 NAVGEM model data has stated that "Mahasen" will make landfall over Odisha coast on 16-May.

While the COLA model is persisting with the Bangladesh coast landfall on 16-May.