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Initial Experiments on Simulation of Windshear and Significant Convection Events using Aviation Model (AVM). Wai-Kin Wong 1 , C.S. Lau 2 and P.W. Chan 1 1- Hong Kong Observatory 2- Hong Kong Polytechnic University CMOS 2012 / General NWP-WAF Part 2
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Initial Experiments on Simulation of Windshear and Significant Convection Events using Aviation Model (AVM) Wai-Kin Wong1, C.S. Lau2 and P.W. Chan1 1- Hong Kong Observatory 2- Hong Kong Polytechnic University CMOS 2012 / General NWP-WAF Part 2 29 May 2012 (1E3.2 ID 5345 16:45-17:00H)
Operational Mesoscale NWP System in HKO Atmospheric Integrated Rapid-cycle (AIR) Forecast Model System based on JMA Non-Hydrostatic Model (NHM) and 3DVAR Meso-NHM - 10 km horizontal res. - 585x405x50 7.3 - 42.2 N; 89.9-146.6E model top: 22.7 km - 72 hour forecast - 3-hourly update RAPIDS-NHM - 2 km res., 305x305x60 - 19.5 - 25.0 N; 111.2 - 117.1 E - model top: 20.3 km - 15 hour forecast - hourly update
Development of Aviation Model (AVM) • Sub-kilometre resolution NWP to enhance support in aerodrome forecasts and development: • Wind and windshear forecast guidance • Windshear alerting service • Headwind changes encountered by aircrafts under terrain-induced and sea-breeze windshear conditions • Forecasttechniques on: • Significant convection • Visibility
Pearl River Delta (PRD) domain dx = 600 m Forecast range = 9 hr HK Airport (HKA) domain dx = 200 m Forecast range = 6-9hr HK Airport (HKA) domain dx = 200 m Forecast range = 6-9hr HK International Airport Target completion time for PRD+HKA = 1 hour Update frequency = 1 hr Initial and boundary conditions: RAPIDS-NHM (dx=2km)
Feasibility Study • WRF-ARW (ver. 3.2.1) and JMA-NHM for PRD and HKA domains • Estimate computation requirement for running AVM in real-time basis • Numerical experiments • sea-breeze convergence • terrain-induced windshear • significant convection • low visibility (fog) • Performance of two models are similar and WRF-ARW has higher code running efficiency
Sea-breeze simulation WRF T+4h forecast NHM forecast
Headwind profile “simulator” (PRD-AVM)- Simulated headwind change / windshear “encountered” by the flight during descending
Terrain-induced windshear 2009-12-26 21 UTC Surface AWS WRF T+6 h Forecast NHM Forecast HKIA LIDAR
Headwind profile simulator (PRD-AVM)- Terrain-induced windshear
Headwind profile simulator (HKA-AVM)- Terrain-induced windshear
Significant convection PRD-AVM WRF T+4 h forecast Late evening thunderstorms and organized convections developed inland and passed over HK (8-9 September 2010) N.B. model forecast at a time lag of about 1.5 hr on the passage of squall line NHM T+4 h forecast
Widespread convection blocking airspace and traffic near HKIA on 18 September 2011 Please refer to 3B2.4 Rapid development of convection over airspace to the south Radar seq. 06:00-16:00 HKT
03:00 UTC 09-18 02:00 UTC 03:30 UTC 02:30 UTC Simulated maximum reflectivity for model run at 2011-09-17 23:00 UTC 04:30 UTC 05:00 UTC 05:30 UTC 04:00 UTC
Selecting optimal physics scheme and parameters to simulate sea-breeze convergence and low-level windshear near take-off/landing zone
And the effect of model tuning Original “Test3”
On-going development • Sensitivity tests on the physics options and new version of WRF codes • Data assimilation techniques to ingest high resolution observations (surface AWS and LIDARs etc).