WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability
Granularity of the grid (both horizontally and vertically) is a key consideration when conducting localised Numerical Weather Prediction (NWP) modelling. Generally speaking, an NWP model with a finer grid can explicitly resolve more processes and require less parameterisation. However, a finer grid...
| Main Authors: | , |
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| Format: | Article |
| Language: | English |
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MDPI AG
2022-04-01
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| Series: | Atmosphere |
| Subjects: | |
| Online Access: | https://www.mdpi.com/2073-4433/13/4/606 |
| _version_ | 1827621777195401216 |
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| author | Robert Huva Guiting Song |
| author_facet | Robert Huva Guiting Song |
| author_sort | Robert Huva |
| collection | DOAJ |
| description | Granularity of the grid (both horizontally and vertically) is a key consideration when conducting localised Numerical Weather Prediction (NWP) modelling. Generally speaking, an NWP model with a finer grid can explicitly resolve more processes and require less parameterisation. However, a finer grid also requires more computation and it is not always clear that a finer grid will produce a more accurate forecast. In this study, we explore the sensitivity of rainfall prediction over Singapore to grid resolution. We use the Weather and Research Forecasting model (WRF) to forecast rainfall over Singapore and explore the performance of horizontal resolutions ranging from 1 km to 12 km. We test the performance on a set of dates from across the years 2020–2021 against both ground observations and radar-derived rain rates. When compared to ground observations, we show that, overall, the higher resolution produces the highest Critical Success Index (<i>CSI</i>) for rain rates in excess of 0.5 mm/h. When compared against radar-derived rain rates, the 1 km domain produces superior <i>CSI</i> values for all rain rates. The daily-average hourly Fractional Skill Score (<i>FSS</i>) was then calculated for some dates and showed agreement with the <i>CSI</i> results with the exception of a north-east monsoon day where, for heavier rain rates, the 3 km domain has superior <i>FSS</i>. We also investigate a particularly heavy rain event on 10 January 2021 and show that the 3 km grid has highest <i>CSI</i> for rain rates of 4 mm/h and 16 mm/h (based on both ground-based and radar-derived rain rates), however, the 1 km has superior <i>FSS</i> for this event. |
| first_indexed | 2024-03-09T11:10:06Z |
| format | Article |
| id | doaj.art-70c61f277c5a4441af03ad22b872e984 |
| institution | Directory Open Access Journal |
| issn | 2073-4433 |
| language | English |
| last_indexed | 2024-03-09T11:10:06Z |
| publishDate | 2022-04-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Atmosphere |
| spelling | doaj.art-70c61f277c5a4441af03ad22b872e9842023-12-01T00:47:23ZengMDPI AGAtmosphere2073-44332022-04-0113460610.3390/atmos13040606WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General SuitabilityRobert Huva0Guiting Song1Envision Digital International Pte Ltd., Singapore 098632, SingaporeEnvision Digital International Pte Ltd., Singapore 098632, SingaporeGranularity of the grid (both horizontally and vertically) is a key consideration when conducting localised Numerical Weather Prediction (NWP) modelling. Generally speaking, an NWP model with a finer grid can explicitly resolve more processes and require less parameterisation. However, a finer grid also requires more computation and it is not always clear that a finer grid will produce a more accurate forecast. In this study, we explore the sensitivity of rainfall prediction over Singapore to grid resolution. We use the Weather and Research Forecasting model (WRF) to forecast rainfall over Singapore and explore the performance of horizontal resolutions ranging from 1 km to 12 km. We test the performance on a set of dates from across the years 2020–2021 against both ground observations and radar-derived rain rates. When compared to ground observations, we show that, overall, the higher resolution produces the highest Critical Success Index (<i>CSI</i>) for rain rates in excess of 0.5 mm/h. When compared against radar-derived rain rates, the 1 km domain produces superior <i>CSI</i> values for all rain rates. The daily-average hourly Fractional Skill Score (<i>FSS</i>) was then calculated for some dates and showed agreement with the <i>CSI</i> results with the exception of a north-east monsoon day where, for heavier rain rates, the 3 km domain has superior <i>FSS</i>. We also investigate a particularly heavy rain event on 10 January 2021 and show that the 3 km grid has highest <i>CSI</i> for rain rates of 4 mm/h and 16 mm/h (based on both ground-based and radar-derived rain rates), however, the 1 km has superior <i>FSS</i> for this event.https://www.mdpi.com/2073-4433/13/4/606precipitationforecastconvectiontropicsNWP |
| spellingShingle | Robert Huva Guiting Song WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability Atmosphere precipitation forecast convection tropics NWP |
| title | WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability |
| title_full | WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability |
| title_fullStr | WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability |
| title_full_unstemmed | WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability |
| title_short | WRF Model Sensitivity to Spatial Resolution in Singapore: Analysis for a Heavy Rain Event and General Suitability |
| title_sort | wrf model sensitivity to spatial resolution in singapore analysis for a heavy rain event and general suitability |
| topic | precipitation forecast convection tropics NWP |
| url | https://www.mdpi.com/2073-4433/13/4/606 |
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