Numerical Prediction of The Heavy Rainfall Events During Armex phase- I of The Summer Monsoon, 2002 D.V. Bhaskar Rao, D. Hari Prasad and Satyaban B. Ratna Department of Meteorology and Oceanography Andhra University, Visakhapatnam- 530 003.
Objectives Simulation of heavy rainfall events during ARMEX-I Impact of the assimilation of station observations Impact of analysis nudging Medium range weather forecasting of weak and active phases of monsoon Sensitivity of cloud microphysics on heavy rainfall event simulation Preliminary experiments with WRF model for the simulation of heavy rainfall events during ARMEX-I.
Details of NCAR MM5 Model version: Vertical resolution: Horizontal resolution: MM5V3, Non-hydrostatic 23 sigma levels Three nested domains; Two-way interactive a) domain 1 with 81 km b) domain 2 with 27 km c) domain 3 with 9 km
Model Physics Explicit cloud schemes: Convection schemes: Planetary Boundary Layer Schemes: Radiation Schemes: Soil: --Simple Ice --Grell --M.R.F --Cloud --Multi layer soil temperature model
Design of numerical experiment Prediction experiments were conducted with the initial and boundary conditions adapted from NCEP FNL data (1 degree interval) Experiments with analysis nudging. Experiments with assimilation of observations and with nudging
Model domain Domain 3 Domain 2 Domain 1
Terrain height in 81, 27 and 9 km domains Domain 1 Domain 3 Domain 2
Observed heavy rainfall episodes during ARMEX-I 14-16 June 2002 20-22 June 2002 26-28 June 2002 7-10 August 2002
Heavy rainfall episode 1 (14-16 June 2002) 14 June Cochin (17) Cannanore (17) Mangalore (16) Kottayam (12) Alleppy (11) Punalur (9) 15 June Ratnagiri (22) Goa (18) Shirali (12) Karwar (8) Mangalore (8) Cannanore (7) 16 June Ratngiri (16) Agumbe (16) Karwar (10) Goa (9) Mangalore (9) Panmbur (9) Observed rainfall shown in brackets (cm/day)
Synoptic situation 14-16 June 2002: An off-shore trough of low on the sea level chart extending from Konkan-Goa to Kerala coast was observed A cyclonic circulation between 1.5 km to 4.5 km was observed in the Arabian sea lying off Kerala-Karnataka coast and another in the Bay of Bengal over and off Tamilnadu coast. A WNE-ESE oriented shear line running across the peninsula joining the two circulations The two circulations and the shear line showing moved northwards from 14-16 June 2002
Day 1 rainfall (cm/day) from 9km domain valid at 00 UTC 14 JUNE 2002 TRMM ARMEX Report CTL NUD
Day 2 rainfall (cm/day) from 9km doamin valid at 00 UTC 15 JUNE 2002 TRMM ARMEX Report CTL NUD
Day 3 rainfall (cm/day) from 9km domain valid at 00 UTC 16 JUNE 2002 TRMM ARMEX Report CTL NUD
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Day 1 (14 June) Day 2 (15 June) Day 3 (16 June) IMD CTL NUD
Heavy rainfall episode 2 (20-22 June 2002) 20 June Alibag (8) Dahanu (6) Panjim (5) Mangalore (4) Mumbai (4) 21 June Dahanu (25) Ratnagiri (22) Panjim (16) Honavar (14) Mumbai (7) 22 June Alibag (8) Ratnagiri (7) Panjim (4) Surat (3) Mumabi (3) Observed rainfall shown in brackets (cm/day)
Synoptic situation (20-22 June 2002) An off-shore trough of low on the sea level chart extending from south Gujarat to Kerala was present (all 3 days) On 20 June 2002, a low pressure area lay over northwest Bay with cyclonic circulation extending up to midtropospheric levels. A cyclonic circulation between 0.9 km to 7.5 km also lay over south Gujarat, tilting southwards with height A shear line across the peninsula joining the two circulations is noticed between 4.5 to 7.5 km.
Day 1 rainfall (cm/day) from 9km domain valid at 00 UTC 20 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Day 2 rainfall (cm/day) from 9km domain valid at 00 UTC 21 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Day 3 rainfall (cm/day) from 9km doamin valid at 00 UTC 22 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Day 1 (20 June) Day 2 (21 June) Day 3 (22 June) IMD CTL NUD
Heavy rainfall episode 3 (26-28 June 2002) 26 June Ahwa (25) Asti, Karjan, Majnalgaon (17) Songadh, Nandvi, Walwan (13) Patoda, Madhuban, Beed (12) Navasari, Gervai kaij (11) Baroda, Ambejogai (10) Padsana, Silvasi, Pardi (8) 27 June Pardi (61), Valsa (54) Bansada, Umbergaon (30) Navsari (26), Chikkli (22) Dharampur (21), Ahwa (19) Plitana (17), Surat, Liliya, Wankaner(15) Mahura, Amreli, Sihar(14) Wadhawvan (13) 28 June Bhavnagar (42), Pardi, Godha (28) Palitana (23), Halol, Sihor (21) Darampur (18), Karjan (17) Chikali, Ahwa (15), Madhuban, Wadhvan (14) Godhra, Morvi (12) Baroda, Daman (11) Observed rainfall shown in brackets (cm/day)
Synoptic situation(26-28 June 2002) An off-shore trough on sea level chart extending from Maharashtra coast to Kerala coast was observed The low pressure area that formed over northwest Bay on 20 June, crossed inland into Gangetic West Bengal and adjoining Orissa on 22 June It moved westwards and on 26 June lay over west Madhya pradesh and adjoining north Maharashtra, southeast Gujarat and west Madhya Pradesh On 28 June 2002 it lay over south-east Rajasthan and west Madhya Pradesh
Day 1 rainfall (cm/day) from 9km domain valid at 00 UTC 26 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Day 2 rainfall (cm/day) valid at 00 UTC 27 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Day 3 rainfall (cm/day) valid at 00 UTC 28 JUNE 2002 TRMM ARMEX Report CTL NUD ASSIM+NUD
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Day 1(26 June) Day 2 (27 June) Day 3 (28 June) IMD CTL NUD
925 hpa 700 hpa 500 hpa 300 hpa
Heavy rainfall episode 4 (7-9 August 2002) 7 August Mumbai SCZ (19) Mahabaleswar (28) Dahanu (10) Ratnagiri (4) 8 August Surat (13) Mumbai (10) Baroda (7) Bhavnagar (5) 9 August Hanovar (13) Agumba (13) Mahabaleswar (12) Ratnagiri (12) Panjim (9) Observed rainfall shown in brackets (cm/day)
Synoptic situation (7-9 August 2002) An off-shore trough in the Arabian sea lay extending from Maharashtra coast to Kerala coast was observed A cyclonic circulation between 2.1 km to 7.6 km was observed Saurashtra, Kutch and neighbourhood. It appeared to mid tropospheric circulation A low pressure area had moved inland into gangetic west Bengal and neighbourhood. The associated cyclonic circulation extended up to 7.6 km A shear line joining the circulations over Saurashtra and north west Bay was noticed between 2.1 to 7.6 kms
Day 1 rainfall (cm/day) from 9km domain valid at 00 UTC 7 AUGUST 2002 TRMM ARMEX Report CTL NUD
Day 2 rainfall (cm/day) from 9km domain valid at 00 UTC 8 AUGUST 2002 TRMM ARMEX Report CTL NUD
Day 3 rainfall (cm/day) from 9km domain valid at 00 UTC 9 AUGUST 2002 TRMM ARMEX Report CTL NUD
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Day 1 (7 Aug) Day 2 (8 Aug) Day 3 (9 Aug) IMD CTL NUD
9 days simulation Normal (weak) period followed by wet (heavy) period 22-30 June 2002
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall 22 June 23 June 24 June IMD MODEL (CTL) Cont..
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall 25 June 26 June 27 June IMD MODEL (CTL) Continue..
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall 28 June 29 June 30 June IMD MODEL (CTL)
Simulation of normal (weak) rainfall events between wet (heavy) rainfall events Normal events Case I: 11-13 June 2002 Case II: 17-19 June 2002 Case III: 23-25 June 2002 Wet events Case I: 14-16 June 2002 Case II: 20-22 June 2002 Case III: 26-28 June 2002
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Normal events Case I: 11-13 June 2002 11 June 12 June 13 June IMD MODEL (CTL)
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Wet events Case I: 14-16 June 2002 14 June 15 June 16 June IMD MODEL (CTL)
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Normal events Case II: 17-19 June 2002 17 June 18 June 19 June IMD MODEL (CTL)
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Wet events Case II: 20-22 June 2002 20 June 21 June 22 June IMD MODEL (CTL)
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Normal events Case III: 23-25 June 2002 23 June 24 June 25 June IMD MODEL (CTL)
Simulated rainfall (cm/day) from 81 km domain along with IMD gridded rainfall Wet events Case III: 26-28 June 2002 26 June 27 June 28 June IMD MODEL (CTL)
Sensitivity to cloud microphysics parameterisation on The heavy rainfall event of 26-28 June 2002 (Cloud microphysics) + Grell + MRF
Simulated rainfall (cm/day) from 9km domain 26 June 27 June 28 June TRMM Simple Ice Mixed Phase
Simulated rainfall (cm/day) from 9km domain 26 June 27 June 28 June TRMM Schultz Goddard
Simulated rainfall (cm/day) from 9km domain 26 June 27 June 28 June TRMM Warm rain Reisner 2
Simulation of the heavy rainfall events during 26-28 June 2002 using WRF model
WRF Model Non-hydrostatic Version 2.2.1 Two way interactive three nested domains Horizontal Resolution: 81,27 and 9 km Vertical Resolution: 31 Sigma levels 6 hourly boundary conditions Forecast run up to 72 hours (3 days) NCEP FNL at 1x1 lat./long. Microphysics : Cumulus parameterization: Lin et. al Grell-Devenyi ensemble scheme
Simulated rainfall (cm/day) from 9km domain 14-16 June 2002 Day 1 Day 2 Day 3 TRMM MODEL
Simulated rainfall (cm/day) from 9km domain 20-22 June 2002 Day 1 Day 2 Day 3 TRMM MODEL
Simulated rainfall (cm/day) from 9km domain 26-28 June 2002 Day 1 Day 2 Day 3 TRMM MODEL
Simulated rainfall (cm/day) from 9km domain 7-9 August 2002 Day 1 Day 2 Day 3 TRMM MODEL
conclusions The model could simulate the mesoscale circulation associated with heavy rainfall events Assimilation of station observation along with analysis nudging improves the location of the heavy precipitation events The results indicate medium range prediction capability of weak and active monsoon phases Westward propagating monsoon low pressure systems seems to trigger the heavy rainfall episodes over the west coast Simple Ice, Goddard and Reisner 2 schemes of cloud microphysics are noted to perform better than Warm rain, Mixed phase and Schultz schemes
Thank you