Seasonal Forecasts of the Summer 2016 Yangtze River Basin Rainfall

Bett, Philip E.; Scaife, Adam A.; Li, Chaofan; Hewitt, Chris; Golding, Nicola; Zhang, Peiqun; Dunstone, Nick; Smith, Doug; Thornton, Hazel; Lu, Riyu; Ren, Hong‐Li

doi:10.1007/s00376-018-7210-y

Cited by 37 publications

(31 citation statements)

References 40 publications

(39 reference statements)

Supporting

Mentioning

Contrasting

Order By: Relevance

“…The Met Office Global Seasonal forecast system version 5, GloSea5 (MacLachlan et al ), shows significant skill for seasonal predictions of TCs over the WNP (Camp et al ) and the JJA WPSH index over the period 1996–2009 (linear correlation of 0.80; MacLachlan et al ). Significant skill has also been shown for other variables in China, such as wind, temperature and precipitation (Lu et al ; Bett et al ), including summer rainfall in the Yangtze river basin region (Li et al ; Golding et al ; Bett et al ) and its asymmetric response to El Niño and La Niña events (Hardiman et al ). However, the relationship between the WPSH and TC landfall in East Asia has not yet been explored.…”

Section: Introductionmentioning

confidence: 99%

The western Pacific subtropical high and tropical cyclone landfall: Seasonal forecasts using the Met Office GloSea5 system

Camp

Roberts

Comer

et al. 2019

Quart J Royal Meteoro Soc

Self Cite

View full text Add to dashboard Cite

We investigate the relationship between the western Pacific subtropical high (WPSH) and tropical cyclone (TC) landfall in the ERA-Interim reanalysis and two configurations of the UK Met Office Global Seasonal forecasting system version 5 (GloSea5): Global Atmosphere 3.0 (GA3) and Global Coupled configuration 2 (GC2). Both model configurations have the same horizontal and vertical resolution in the ocean and the atmosphere, but differ in terms of model physics. The WPSH strongly modulates TC activity over the subtropical western North Pacific (WNP) and TC landfall over East Asia (Japan, Korea and East China). Here we show that both model configurations GA3 and GC2 show significant skill for predictions of the WPSH and TC variability over the subtropical WNP, as well as TC frequency along the coast of East Asia, during the boreal summer (June-August). An extension of the analysis to include the full WNP typhoon season (June-November) is also examined; however, only a weak significant relationship between the WPSH index and the observed TC frequency over East Asia is found during this period, and no significant relationship is present in either GloSea5 GA3 or GC2. Results highlight the potential for operational seasonal forecasts of TC landfall risk for Japan, Korea and East China over the June-August period using predictions of the WPSH indices from GloSea5. 1This article is published with the permission of the Controller of HMSO and the Queen's Printer for Scotland.

show abstract

Section: Introductionmentioning

confidence: 99%

The western Pacific subtropical high and tropical cyclone landfall: Seasonal forecasts using the Met Office GloSea5 system

Camp

Roberts

Comer

et al. 2019

Quart J Royal Meteoro Soc

Self Cite

View full text Add to dashboard Cite

show abstract

“…These need not be the same physical variable, or cover the same geographical region. The forecast system described in Bett et al (2018) used the GloSea5 model precipitation in a box covering the Yangtze River Basin (YRB) region (91-122° E, 25-35° N), to forecast the rainfall observed in the same box. In this scheme, the historical relationship between model and observations is characterised by the linear regression between the hindcast ensemble-mean rainfall and the observed rainfall, for a given season each year, and at a given lead time.…”

Section: Forecast Methodologymentioning

confidence: 99%

“…For the u850 and PMSL panels, the patterns of the full-field values are indicated by green contour lines, dashed for negative values. The Yangtze River Basin and the box used in Bett et al (2018) are drawn in black, with the Yangtze River itself in blue. The basin is subdivided at 111°E (thin grey dashed line) near the Three Gorges Dam (red point).…”

Section: Forecast Methodologymentioning

confidence: 99%

“…Yellow contour lines are drawn indicating significance at the 5% level, for a Fisher z test on correlations of 24 points. As in Figure 1, the Yangtze River Basin and the box used in Bett et al (2018) are drawn in black, with a basin subdivision marked at 111°E with a thin grey dashed line, near the Three Gorges Dam (red point). The Yangtze River is marked in blue.…”

Section: Forecast Methodologymentioning

confidence: 99%

“…The dynamical seasonal forecasts showed a high probability of above-average rainfall in May-June-July (MJJ), and near-normal rainfall in June-July-August (JJA). These forecasts were borne out by observations (Yuan et al, 2017;Bett et al, 2018). The same forecast system was run again in 2017 and 2018, incorporating updates to the GloSea5 system itself to use a larger ensemble and a longer hindcast period.…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Seasonal Rainfall Forecasts for the Yangtze River Basin in Summer 2019 from an Improved Climate Service

Bett¹,

Martin²,

Scaife³

et al. 2020

Preprint

Self Cite

View full text Add to dashboard Cite

Rainfall forecasts for the summer monsoon season in the Yangtze River Basin allow decision-makers to plan for possible flooding, which can affect the lives and livelihoods of millions of people. A trial climate service was developed in 2016, producing a prototype seasonal forecast product for use by stakeholders in the region, based on forecasting rainfall directly using a dynamical model. Here we describe an improved service, based on a simple statistical downscaling approach: using a dynamical forecast of an East Asian Summer Monsoon index, seasonal-mean rainfall for the Upper and Middle/Lower Reaches of the basin can be forecast separately, with significant skill for lead times of up to at least 3 months. The skill in the different sub-basin regions depends on the target season: Rainfall skill in the Middle/Lower Reaches is significant in May–June–July (MJJ), and there is significant skill for the Upper Reaches in June–July–August (JJA). The mean rainfall for the basin as a whole can be skillfully forecast in both seasons. The forecasts issued in 2019 gave good guidance for the enhanced rainfall in the MJJ period, and the near-average conditions in JJA. Initial feedback from users in the Yangtze River Basin suggests that the improved forecast better meets their needs and will enable more robust decision-making.

show abstract

Seasonal rainfall forecasting for the Yangtze River basin using statistical and dynamical models

Qian

Chen

et al. 2019

Intl Journal of Climatology

View full text Add to dashboard Cite

Summer monsoon rainfall forecasting in the Yangtze River basin is highly valuable for water resource management and for the control of floods and droughts. However, improving the accuracy of seasonal forecasting remains a challenge. In this study, a statistical model and four dynamical global circulation models (GCMs) are applied to conduct seasonal rainfall forecasts for the Yangtze River basin. The statistical forecasts are achieved by establishing a linear regression relationship between the sea surface temperature (SST) and rainfall. The dynamical forecasts are achieved by downscaling the rainfall predicted by the four GCMs at the monthly and seasonal scales. Historical data of monthly SST and GCM hindcasts from 1982-2010 are used to make the forecast. The results show that the SST-based statistical model generally outperforms the GCM simulations, with higher forecasting accuracy that extends to longer lead times of up to 12 months. The SST statistical model achieves a correlation coefficient up to 0.75 and the lowest mean relative error of 6%. In contrast, the GCMs exhibit a sharply decreasing forecast accuracy with lead times longer than 1 month. Accordingly, the SST statistical model can provide reliable guidance for the seasonal rainfall forecasts in the Yangtze River basin, while the results of GCM simulations could serve as a reference for shorter lead times. Extensive scope exists for further improving the rainfall forecasting accuracy of GCM simulations.

show abstract

Seasonal Forecasts of the Summer 2016 Yangtze River Basin Rainfall

Cited by 37 publications

References 40 publications

The western Pacific subtropical high and tropical cyclone landfall: Seasonal forecasts using the Met Office GloSea5 system

The western Pacific subtropical high and tropical cyclone landfall: Seasonal forecasts using the Met Office GloSea5 system

Seasonal Rainfall Forecasts for the Yangtze River Basin in Summer 2019 from an Improved Climate Service

Seasonal rainfall forecasting for the Yangtze River basin using statistical and dynamical models

Contact Info

Product

Resources

About