BOB: GIRI (04B) - Depression

[SouthDadeFish]

WOW!!!!!!!!!

[supercane]

[supercane]

TROPICAL CYCLONE ADVISORY

RSMC – TROPICAL CYCLONES, NEW DELHI



TROPICAL STORM ‘GIRI’ ADVISORY NO SIX ISSUED AT 0000 UTC OF 22nd OCTOBER 2010 BASED ON 2100 UTC CHARTS OF 21ST OCTOBER.



THE CYCLONIC STORM “GIRI” OVER EASTCENTRAL AND ADJOINING NORTHEAST BAY OF BENGAL MOVED NORTHEASTWARDS AND LAY CENTRED AT 2100 UTC OF THE 21ST OCTOBER 2010 OVER THE SAME AREA CENTRED NEAR LAT. 18.50N AND LONG. 92.50E, ABOUT 200 KM SOUTH-SOUTHWEST OF SITTWE (48062), 280 KM SOUTH-SOUTHEAST OF TEKNAF (41998 ) AND 620 KM SOUTHEAST OF DIGHA (42901).



SUSTAINED MAXIMUM SURFACE WIND SPEED IS ESTIMATED TO BE ABOUT 55 KNOTS GUSTING TO 65 KNOTS. THE STATE OF THE SEA IS VERY HIGH AROUND THE SYSTEM CENTRE. THE ESTIMATED CENTRAL PRESSURE IS ABOUT 986 HPA.



SATELLITE IMAGERY INDICATES BANDING PATTERN WITH FURTHER ORGANISATION. THE INTENSITY OF THE SYSTEM IS T 3.5 ASSOCIATED BROKEN INTENSE TO VERY INTENSE CONVECTION IS SEEN OVER EASTCENTRAL AND ADJOINING NORTHEAST BAY OF BENGAL BETWEEN LATITUDE 15.5º N AND 20.0ºN AND LONGITUDE EAST OF 90.0º E.THE LOWEST CLOUD TOP TEMPERATURE (CTT) DUE TO CONVECTION IS AROUND ( -70 TO -800C) IN ASSOCIATION WITH THE SYSTEM.



STORM SURGE AT THE TIME OF LANDFALL IS EXPECTED 2-3 METERS NEAR THE LANDFALL POINT.



THE CURRENT ENVIRONMENTAL CONDITIONS AND NUMERICAL WEATHER PREDICTION (NWP) MODELS SUGGEST THAT THE SYSTEM WOULD INTENSIFY FURTHER. IT WOULD MOVE NORTHEASTWARDS AND CROSS NORTH MYANMAR AND ADJOINING BANGLADESH COASTS BETWEEN TEKNAF, BANGLADESH (41998) AND KYAUKPYU, MYANMAR (48071) BETWEEN 1200 UTC AND 1800 UTC OF TODAY, THE 22ND OCTOBER 2010.



BASED ON LATEST ANALYSIS WITH NWP MODELS AND OTHER CONVENTIONAL TECHNIQUES, ESTIMATED TRACK AND INTENSITY OF THE SYSTEM ARE GIVEN IN THE TABLE BELOW:



DATE/TIME(UTC)

POSITION (LAT. 0N/ LONG. 0E)

SUSTAINED MAXIMUM SURFACE WIND SPEED (KMPH)

21-10-2010/2100

18.5/92.5

90-100 gusting to 110

22-10-2010/0300

19.0/93.0

100-110 gusting to 120

22-10-2010/0900

19.5/93.5

110-120 gusting to 135

22-10-2010/1500

20.0/94.0

110-120 gusting to 135

22-10-2010/2100

21.5/95.0

80-90 gusting to 100

23-10-2010/0900

22.5/96.0

55-65 gusting to 75

23-10-2010/2100

23.0/96.5

30-40 gusting to 50



VERTICAL WIND SHEAR OF HORIZONTAL WIND OVER THE REGION IS LOW (5-10 KNOTS) AROUND THE SYSTEM CENTRE. 24 HOUR TENDENCY OF VERTICAL WIND SHEAR SHOWS DECREASING TREND AROUND SYSTEM CENTRE. SEA SURFACE TEMPERATURE (280-300 C), AND THE OCEAN HEAT CONTENT OVER CENTRAL BAY OF BENGAL ARE FAVOURABLE FOR INTENSIFICATION. HOWEVER, OCEAN HEAT CONTENT IS LESS THAN 100 KJ/CM2. THE RELATIVE VORTICITY AT 850 HPA LEVEL AND UPPER LEVEL DIVERGENCE AROUND THE SYSTEM CENTRE ARE ALSO FAVOURABLE FOR INTENSIFICATION. THE SYSTEM LIES CLOSE TO THE UPPER TROPOSPHERIC RIDGE, WHICH ROUGHLY RUNS ALONG 180N AT 200 HPA LEVEL. THERE IS AN ANTICYCLONIC CIRCULATION OVER CENTRAL INDIA TO THE WEST-NORTHWEST OF THE SYSTEM CENTRE AT MID-TROPOSPHERIC LEVEL AND IS EXPECTED TO INFLUENCE THE MOVEMENT OF THE SYSTEM TOWARDS THE NORTHEAST DIRECTION.

[supercane]

WTIO31 PGTW 220300
MSGID/GENADMIN/NAVMARFCSTCEN PEARL HARBOR HI/JTWC//
SUBJ/TROPICAL CYCLONE 04B (GIRI) WARNING NR 005//
RMKS/
1. TROPICAL CYCLONE 04B (GIRI) WARNING NR 005
01 ACTIVE TROPICAL CYCLONE IN NORTHIO
MAX SUSTAINED WINDS BASED ON ONE-MINUTE AVERAGE
WIND RADII VALID OVER OPEN WATER ONLY
---
WARNING POSITION:
220000Z --- NEAR 18.5N 92.6E
MOVEMENT PAST SIX HOURS - 035 DEGREES AT 05 KTS
POSITION ACCURATE TO WITHIN 020 NM
POSITION BASED ON EYE FIXED BY SATELLITE
PRESENT WIND DISTRIBUTION:
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
REPEAT POSIT: 18.5N 92.6E
---
FORECASTS:
12 HRS, VALID AT:
221200Z --- 19.7N 93.4E
MAX SUSTAINED WINDS - 085 KT, GUSTS 105 KT
WIND RADII VALID OVER OPEN WATER ONLY
RADIUS OF 064 KT WINDS - 025 NM NORTHEAST QUADRANT
025 NM SOUTHEAST QUADRANT
025 NM SOUTHWEST QUADRANT
025 NM NORTHWEST QUADRANT
RADIUS OF 050 KT WINDS - 035 NM NORTHEAST QUADRANT
040 NM SOUTHEAST QUADRANT
040 NM SOUTHWEST QUADRANT
035 NM NORTHWEST QUADRANT
RADIUS OF 034 KT WINDS - 065 NM NORTHEAST QUADRANT
080 NM SOUTHEAST QUADRANT
075 NM SOUTHWEST QUADRANT
070 NM NORTHWEST QUADRANT
VECTOR TO 24 HR POSIT: 035 DEG/ 09 KTS
---
24 HRS, VALID AT:
230000Z --- 21.1N 94.5E
MAX SUSTAINED WINDS - 040 KT, GUSTS 050 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATING AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
VECTOR TO 36 HR POSIT: 035 DEG/ 09 KTS
---
36 HRS, VALID AT:
231200Z --- 22.6N 95.7E
MAX SUSTAINED WINDS - 025 KT, GUSTS 035 KT
WIND RADII VALID OVER OPEN WATER ONLY
DISSIPATED AS A SIGNIFICANT TROPICAL CYCLONE OVER LAND
---
REMARKS:
220300Z POSITION NEAR 18.8N 92.8E.
TROPICAL CYCLONE (TC) 04B (GIRI), LOCATED APPROXIMATELY 235 NM SOUTH-
SOUTHEAST OF CHITTAGONG, BANGLADESH, HAS TRACKED NORTH-NORTHEASTWARD
AT 05 KNOTS OVER THE PAST SIX HOURS. THE CURRENT POSITION IS BASED
ON A 212330Z PGTW SATELLITE FIX. THE CURRENT INTENSITY ESTIMATE OF
70 KNOTS IS CONSISTENT WITH DVORAK T-NUMBER ESTIMATES OF T=5.0 FROM
PGTW AT 212330Z AND T=4.0 FROM KNES AT 212030Z. TC 04B HAS CONTINUED
TO INTENSIFY OVER THE PAST SIX HOURS UNDER THE INFLUENCES OF LOW
VERTICAL WIND SHEAR, STRONG POLEWARD OUTFLOW, AND HIGH OCEAN HEAT
CONTENT. THE CYCLONE CONTINUES TO TRACK NORTH-NORTHEASTWARD ALONG
THE PERIPHERY OF A NEAR-EQUATORIAL STEERING RIDGE TO THE SOUTH AND
EAST. GENERALLY NORTH-NORTHEASTWARD MOTION IS EXPECTED TO CONTINUE
THROUGHOUT THE FORECAST PERIOD AND CARRY THE SYSTEM INLAND JUST
AFTER TAU 12, WITH DISSIPATION BELOW THE WARNING INTENSITY THRESHOLD
OF 35 KNOTS OVER THE RUGGED TERRAIN OF WESTERN MYANMAR OCCURRING BY
TAU 36. THE NUMERICAL GUIDANCE IS IN GOOD AGREEMENT WITH THE CURRENT
FORECAST, WHICH LIES CLOSE TO THE MULTI-MODEL CONSENSUS. THE CYCLONE
IS EXPECTED TO MAINTAIN INTENSITY OR PERHAPS INTENSIFY SLIGHTLY
PRIOR TO LANDFALL DUE TO FAVORABLE UPPER LEVEL SUPPORT AND PASSAGE
OVER VERY WARM WATER. MAXIMUM SIGNIFICANT WAVE HEIGHT AT 220000Z IS
15 FEET. NEXT WARNINGS AT 220900Z, 221500Z, 222100Z AND 230300Z.//
NNNN

[SouthDadeFish]

It looks more than a 85 knot hurricane to me....

[HURAKAN]

Very impressive

[CrazyC83]

Looks to be about 95 kt to me and still bombing out.

[Macrocane]

Just as the Euro have been predicting for several days, a small but intense cyclone making landfall in Myanmar, let's hope we don't receive bad news from that country in the next days.

[supercane]

Latest KNES Dvorak up to 6.0:
TXIO27 KNES 220250
A. 04B (GIRI)
B. 22/0230Z
C. 18.6N
D. 92.8E
E. ONE/MET-7
F. T6.0/6.0/D3.0/24HRS
G. IR/EIR/VIS
H. REMARKS...LG EYE EMBEDDED IN WHITE AND SURROUNDED BY CMG FOR
A DT OF 6.0. MET IS 4.5 AND PT IS 5.0. FT BASED ON DT DUE TO RAPID
INTENSIFICATION.
I. ADDL POSITIONS
NIL
...EARLE
=

[SouthDadeFish]

6.0 is what I would say. Remarkable intensification right before landfall. I hope everyone is prepared.

[shah8]

Hmmm, if the storm moves from the path to the north or south, it will hit pretty densely populated land. In the middle is farmland. Judging from Google Earth.

[Chacor]

3 T-numbers in 24 hours?!!

To think IMD are still at T3.5/55 kt. Even on a 10min scale this should be nearer 70kt.

[hurricaneCW]

Giri is probably equivalent to that of a U.S. major Cat 3 right now, and possibly a strong one at that. Very impressive and potentially devastating. I know that the country does not deal well with these systems.

[supercane]

To be fair to the IMD, UW-CIMSS ADT only has T numbers around 4, largely because the center temperature is relatively high.
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 22 OCT 2010 Time : 030000 UTC
Lat : 18:47:59 N Lon : 92:48:00 E


CI# /Pressure/ Vmax
4.3 / 970.0mb/ 72.2kt


Final T# Adj T# Raw T#
4.3 4.3 3.8

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -56.7C Cloud Region Temp : -77.4C

Scene Type : UNIFORM CDO CLOUD REGION w/ MW EYE

Positioning Method : FORECAST INTERPOLATION

Ocean Basin : INDIAN
Dvorak CI > MSLP Conversion Used : PACIFIC

Tno/CI Rules : Constraint Limits : MW ON
Weakening Flag : OFF
Rapid Dissipation Flag : OFF

[Chacor]

Clearly a pinhole eye. For all their improvements, IMD still lags a long way behind as an RSMC. I mean, they can't even give storm positions to accuracies greater than 0.5 degrees, even with pinhole eyes?

[btangy]

Rapid intensification is clearly underway. This is probably up to Cat. 3, if not Cat. 4, just based on latest satellite presentation with a solid ring of very deep convection around an increasingly well-defined eye. The core of high winds is likely very tight. The MIT CHIPS model seems to be the only one capturing the intensification of Giri and is showing a peak intensity of 105-125 knots at landfall, and my guess would be closer to the upper range right now.

A quick look at Google maps indicates that there are a number of low-lying villages along the delta where Giri is headed. It looks like this area will be susceptible to surge, and I hope that people are evacuating, but the warning is very short unlike Megi. This could be as catastrophic to the local area in Myanmar as Megi was to the coastal communities in Isabel province in Luzon.

[shah8]

Don't know...Using Wiki and Google, this is a very poor province, in a poor country. JWTC is going to miss on the track to the south a bit, and there's only one really concentrated town with an airstrip on the lee side of the north tip of the southern peninsula. The northern peninsula has the provincial capital and various tourist sites.

The storm is clearly doing the Humberto and more, though.

[btangy]

The population density in this region is broadly 25-250 people per square km (http://sedac.ciesin.columbia.edu/gpw/co ... sp?iso=MMR). It looks like people are spread out quite a bit instead of in a few towns, which will make it hard to get people out of harm's way. As you point out, it is a very poor area. Many will probably not have much warning.

[Squarethecircle]

To be fair to the IMD, UW-CIMSS ADT only has T numbers around 4, largely because the center temperature is relatively high.
UW - CIMSS
ADVANCED DVORAK TECHNIQUE
ADT-Version 8.1.1
Tropical Cyclone Intensity Algorithm

----- Current Analysis -----
Date : 22 OCT 2010 Time : 030000 UTC
Lat : 18:47:59 N Lon : 92:48:00 E


CI# /Pressure/ Vmax
4.3 / 970.0mb/ 72.2kt


Final T# Adj T# Raw T#
4.3 4.3 3.8

Latitude bias adjustment to MSLP : +0.0mb

Center Temp : -56.7C Cloud Region Temp : -77.4C

Scene Type : UNIFORM CDO CLOUD REGION w/ MW EYE

Positioning Method : FORECAST INTERPOLATION

ADT's numbers there are low because it is using a forecast interpolation to find the center, making it miss the eye entirely. The most recent one:

CI# /Pressure/ Vmax
4.3 / 970.0mb/ 72.2kt


Final T# Adj T# Raw T#
4.3 4.3 6.1

is located better, but is still only using interpolation.

[P.K.]

Now a Very Severe Cyclonic Storm.


BOB 04/2010/08 Dated: 22.10.2010

Time of issue: 1100 hours IST


Sub: Very Severe Cyclonic storm “GIRI” over eastcentral & adjoining northeast Bay of Bengal.


The severe cyclonic storm “GIRI” over eastcentral & adjoining northeast Bay of Bengal intensified into a very severe cyclonic storm and moved northeastwards, lay centred at 0830 hrs IST of today, the 22nd October 2010 over the northeast Bay of Bengal near lat. 19.00N and long.93.00E, about 150 km south of Sittwe(Myanmar) and 110 km west-southwest of Kyaukpyu (Myanmar), 240 km south-southeast of Teknaf (Bangladesh) and 650 km southeast of Digha (West Bengal, India).

The current environmental conditions and numerical weather prediction (NWP) models suggest that the system would intensify further and move northeastwards and cross Myanmar coast between Sittwe (Myanmar) and Kyaukpyu (Myanmar) by today, the 22nd October 2010 evening/night.

Based on latest analysis with NWP models and other conventional techniques, estimated track and intensity of the system are given in the Table below:

Date/Time(IST)


Position (lat. 0N/ long. 0E)


Sustained maximum surface wind speed (kmph)

22-10-2010/0830


19.0/93.0


140-150 gusting to 170

22-10-2010/1130


19.0/93.0


160-170 gusting to 190

22-10-2010/1730


19.5/93.5


170-180 gusting to 200

22-10-2010/2330


20.0/94.0


170-180 gusting to 200

23-10-2010/0530


20.5/94.5


100-110 gusting to 125

23-10-2010/1730


22.0/95.5


55-65 gusting to 75

24-10-2010/0530


23.0/96.5


30-40 gusting to 50

Since the system is likely to move towards north Myanmar and adjoining Bangladesh coasts, it is not expected to affect east coast of India. However, the system is under constant watch and concerned state Govts. will be informed accordingly.

The next bulletin will be issued at 1430 hrs IST of 22nd October 2010.