Playing the long game: anticipatory action based on seasonal forecasts

This clear and accessible text describes the methods underlying short-term climate prediction at time scales of 2 weeks to a year. Although a difficult range to forecast accurately, there have been several important advances in the last ten years, most notably in understanding ocean-atmosphere interaction (El Nino for example), the release of global coverage data sets, and in prediction methods themselves. With an emphasis on the empirical approach, the text covers in detail empirical wave propagation, teleconnections, empirical orthogonal functions, and constructed analogue. It also provides a detailed description of nearly all methods used operationally in long-lead seasonal forecasts, with new examples and illustrations. The challenges of making a real time forecast are discussed, including protocol, format, and perceptions about users. Based where possible on global data sets, illustrations are not limited to the Northern Hemisphere, but include several examples from the Southern Hemisphere.

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Yearly evolution of Euro-Atlantic weather regimes and of their sub-seasonal predictability

Climate Dynamics ◽

10.1007/s00382-021-05679-y ◽

2021 ◽

Author(s):

Nicola Cortesi ◽

Verónica Torralba ◽

Llorenó Lledó ◽

Andrea Manrique-Suñén ◽

Nube Gonzalez-Reviriego ◽

...

Keyword(s):

Annual Cycle ◽

Winter Season ◽

Skill Score ◽

Seasonal Forecast ◽

Forecast Skill ◽

Seasonal Forecasts ◽

Sea Level Pressure ◽

Weather Regimes ◽

Start Dates ◽

Weekly Frequency

AbstractIt is often assumed that weather regimes adequately characterize atmospheric circulation variability. However, regime classifications spanning many months and with a low number of regimes may not satisfy this assumption. The first aim of this study is to test such hypothesis for the Euro-Atlantic region. The second one is to extend the assessment of sub-seasonal forecast skill in predicting the frequencies of occurrence of the regimes beyond the winter season. Two regime classifications of four regimes each were obtained from sea level pressure anomalies clustered from October to March and from April to September respectively. Their spatial patterns were compared with those representing the annual cycle. Results highlight that the two regime classifications are able to reproduce most part of the patterns of the annual cycle, except during the transition weeks between the two periods, when patterns of the annual cycle resembling Atlantic Low regime are not also observed in any of the two classifications. Forecast skill of Atlantic Low was found to be similar to that of NAO+, the regime replacing Atlantic Low in the two classifications. Thus, although clustering yearly circulation data in two periods of 6 months each introduces a few deviations from the annual cycle of the regime patterns, it does not negatively affect sub-seasonal forecast skill. Beyond the winter season and the first ten forecast days, sub-seasonal forecasts of ECMWF are still able to achieve weekly frequency correlations of r = 0.5 for some regimes and start dates, including summer ones. ECMWF forecasts beat climatological forecasts in case of long-lasting regime events, and when measured by the fair continuous ranked probability skill score, but not when measured by the Brier skill score. Thus, more efforts have to be done yet in order to achieve minimum skill necessary to develop forecast products based on weather regimes outside winter season.

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CMIP6 model-based analog forecasting for the seasonal prediction of sea surface temperature in the offshore area of China

Geoscience Letters ◽

10.1186/s40562-021-00179-7 ◽

2021 ◽

Vol 8 (1) ◽

Author(s):

Weiying Peng ◽

Quanliang Chen ◽

Shijie Zhou ◽

Ping Huang

Keyword(s):

Surface Temperature ◽

Sea Surface Temperature ◽

Climate Models ◽

Global Climate Models ◽

Sea Surface ◽

Seasonal Forecasts ◽

Initial State ◽

Initial Field ◽

Offshore Area ◽

Model Based

AbstractSeasonal forecasts at lead times of 1–12 months for sea surface temperature (SST) anomalies (SSTAs) in the offshore area of China are a considerable challenge for climate prediction in China. Previous research suggests that a model-based analog forecasting (MAF) method based on the simulations of coupled global climate models provide skillful climate forecasts of tropical Indo-Pacific SSTAs. This MAF method selects the model-simulated cases close to the observed initial state as a model-analog ensemble, and then uses the subsequent evolution of the SSTA to generate the forecasts. In this study, the MAF method is applied to the offshore area of China (0°–45°N, 105°–135°E) based on the simulations of 23 models from phase 6 of the Coupled Model Intercomparison Project (CMIP6) for the period 1981–2010. By optimizing the key factors in the MAF method, we suggest that the optimal initial field for the analog criteria should be concentrated in the western North Pacific. The multi-model ensemble of the optimized MAF prediction using these 23 CMIP6 models shows anomaly correlation coefficients exceeding 0.6 at the 3-month lead time, which is much improved relative to previous SST-initialized hindcasts and appears practical for operational forecasting.

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Seasonal Rainfall Forecasts for the Yangtze River Basin in the Extreme Summer of 2020

Advances in Atmospheric Sciences ◽

10.1007/s00376-021-1087-x ◽

2021 ◽

Cited By ~ 1

Author(s):

Philip E. Bett ◽

Gill M. Martin ◽

Nick Dunstone ◽

Adam A. Scaife ◽

Hazel E. Thornton ◽

...

Keyword(s):

Linear Regression ◽

River Basin ◽

Yangtze River ◽

Asian Summer Monsoon ◽

Yangtze River Basin ◽

Early Summer ◽

Lead Times ◽

Seasonal Forecasts ◽

June July ◽

The Impact

AbstractSeasonal forecasts for Yangtze River basin rainfall in June, May–June–July (MJJ), and June–July–August (JJA) 2020 are presented, based on the Met Office GloSea5 system. The three-month forecasts are based on dynamical predictions of an East Asian Summer Monsoon (EASM) index, which is transformed into regional-mean rainfall through linear regression. The June rainfall forecasts for the middle/lower Yangtze River basin are based on linear regression of precipitation. The forecasts verify well in terms of giving strong, consistent predictions of above-average rainfall at lead times of at least three months. However, the Yangtze region was subject to exceptionally heavy rainfall throughout the summer period, leading to observed values that lie outside the 95% prediction intervals of the three-month forecasts. The forecasts presented here are consistent with other studies of the 2020 EASM rainfall, whereby the enhanced mei-yu front in early summer is skillfully forecast, but the impact of midlatitude drivers enhancing the rainfall in later summer is not captured. This case study demonstrates both the utility of probabilistic seasonal forecasts for the Yangtze region and the potential limitations in anticipating complex extreme events driven by a combination of coincident factors.

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Efficacy of the use of unaffected hand containment in unimanual intensive therapy to increase visuomotor coordination in children with hemiplegia: a randomized controlled pilot study

Therapeutic Advances in Chronic Disease ◽

10.1177/20406223211001280 ◽

2021 ◽

Vol 12 ◽

pp. 204062232110012

Author(s):

Rocío Palomo-Carrión ◽

Elisabeth Bravo-Esteban ◽

Sara Ando-La Fuente ◽

Purificación López-Muñoz ◽

Inés Martínez-Galán ◽

...

Keyword(s):

Reaction Time ◽

Upper Limb ◽

Visual Information ◽

Intensive Therapy ◽

Action Planning ◽

Reaction Time Task ◽

Group Differences ◽

Visuomotor Coordination ◽

Therapy Program ◽

Anticipatory Action

Background: The capacity of children with hemiplegia to be engaged in anticipatory action planning is affected. There is no balance among spatial, proprioceptive and visual information, thus altering the affected upper limb visuomotor coordination. The objective of the present study was to assess the improvement in visuomotor coordination after the application of a unimanual intensive therapy program, with the use of unaffected hand containment compared with not using unaffected hand containment. Methods: A simple blind randomized clinical trial was realized. A total of 16 subjects with congenital infantile hemiplegia participated in the study with an age mean of 5.54 years old (SD:1.55). Two intensive protocols for 5 weeks of modified constraint-induced movement therapy (mCIMT) or unimanual therapy without containment (UTWC) were executed 5 days per week (2 h/day). Affected upper limb visuomotor coordination (reaction time, task total time, active range, dynamic grasp) was measured before–after intensive therapy using a specific circuit with different slopes (10°/15°). Results: Statistically significant inter-group differences were found after the intervention, with clinically relevant results for the mCIMT group not seen in UTWC, in the following variables: reaction time 10°slope ( p = 0.003, d = 2.44), reaction time 15°slope ( p = 0.002, d = 2.15) as well as for the task total time 10°slope ( p = 0.002, d = 2.25), active reach 10°slope ( p = 0.002, d = 2.7), active reach 15°slope ( p = 0.003, d = 2.29) and dynamic grasp 10°/15°slopes ( p = <0.001, d = 2.69). There were not statistically significant inter-group differences in the total task time with 15°slope ( p = 0.074, d = 1.27). Conclusions: The use of unaffected hand containment in mCIMT would allow improvements in the affected upper limb’s visuomotor coordination. Thus, it would favor clinical practice to make decisions on therapeutic approaches to increase the affected upper limb functionality and action planning in children diagnosed with infantile hemiplegia (4–8 years old).

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Operational real-time seasonal forecasts for coral reef management

Journal of Operational Oceanography ◽

10.1080/1755876x.2011.11020119 ◽

2011 ◽

Vol 4 (1) ◽

pp. 13-22 ◽

Cited By ~ 17

Author(s):

C M Spillman

Keyword(s):

Coral Reef ◽

Real Time ◽

Seasonal Forecasts ◽

Reef Management ◽

Coral Reef Management

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Analog Downscaling of Seasonal Rainfall Forecasts in the Murray Darling Basin

Monthly Weather Review ◽

10.1175/mwr-d-12-00098.1 ◽

2013 ◽

Vol 141 (3) ◽

pp. 1099-1117 ◽

Cited By ~ 18

Author(s):

Andrew Charles ◽

Bertrand Timbal ◽

Elodie Fernandez ◽

Harry Hendon

Keyword(s):

General Circulation ◽

Large Scale ◽

Seasonal Prediction ◽

General Circulation Models ◽

Meridional Wind ◽

Seasonal Forecasts ◽

Local Climate ◽

Continental Scale ◽

Predictive Skill ◽

Murray Darling Basin

Abstract Seasonal predictions based on coupled atmosphere–ocean general circulation models (GCMs) provide useful predictions of large-scale circulation but lack the conditioning on topography required for locally relevant prediction. In this study a statistical downscaling model based on meteorological analogs was applied to continental-scale GCM-based seasonal forecasts and high quality historical site observations to generate a set of downscaled precipitation hindcasts at 160 sites in the South Murray Darling Basin region of Australia. Large-scale fields from the Predictive Ocean–Atmosphere Model for Australia (POAMA) 1.5b GCM-based seasonal prediction system are used for analog selection. Correlation analysis indicates modest levels of predictability in the target region for the selected predictor fields. A single best-match analog was found using model sea level pressure, meridional wind, and rainfall fields, with the procedure applied to 3-month-long reforecasts, initialized on the first day of each month from 1980 to 2006, for each model day of 10 ensemble members. Assessment of the total accumulated rainfall and number of rainy days in the 3-month reforecasts shows that the downscaling procedure corrects the local climate variability with no mean effect on predictive skill, resulting in a smaller magnitude error. The amount of total rainfall and number of rain days in the downscaled output is significantly improved over the direct GCM output as measured by the difference in median and tercile thresholds between station observations and downscaled rainfall. Confidence in the downscaled output is enhanced by strong consistency between the large-scale mean of the downscaled and direct GCM precipitation.

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