Intercomparison of two meteorological limited area models for quantitative precipitation forecast verification

Abstract

Abstract.The demand for verification of numerical models is still very high, especially for what concerns the operational Quantitative Precipitation Forecast (QPF) used, among others, for evaluating the issuing of warnings to the population. In this study, a comparative verification of the QPF, predicted by two operational Limited Area Models (LAMs) for the Italian territory is presented: COSMO-I7 (developed in the framework of the COSMO Consortium) and WRF-NMM (developed at NOAA-NCEP). The observational dataset is the precipitation recorded by the high-resolution non-GTS rain gauges network of the National Civil Protection Department (NCPD) over two years (2007)(2008). Observed and forecasted precipitation have been treated as areal quantity (areal average of the values accumulated in 6 and 24 h periods) over the 102 "warning areas", defined by the NCPD both for administrative and hydrological purposes. Statistics are presented through a series of conventional indices (BIAS, POD and POFD) and, in addition, the Extreme Dependency Score (EDS) and the Base Rate (BS or 1-BS) have been used for keeping into account the vanishing of the indices as the events become rare. Results for long-period verification (the whole 2 yr) with increasing thresholds, seasonal trend (3 months period), diurnal error cycle and error maps, are presented. Results indicate that WRF has a general tendency of QPF overestimation for low thresholds and underestimation for higher ones, while COSMO-I7 tends to overestimate for all thresholds. Both models show a seasonal trend, with a bigger overestimation during summer and spring, while during autumn and winter the models tend to be more accurate.

FLIRE DSS: A web tool for the management of floods and wildfires in urban and periurban areas

“…The calculation of the statistical scores (Table 1) revealed a decreasing trend of the Prob- ability of Detection (POD) with increasing rain threshold, with a POD of 0.42 for the highest precipitation amounts. This result is in agreement with the verification results of similar activities of high-resolution rain forecasts in the Mediterranean area [44][45][46]. On the other hand, the calculated False Alarm Ratio (FAR) was very low (lower than 0.17) for all rain thresholds, indicating that the model has no tendency to provide false alarms.…”

Statistical modelling of rainfall-induced shallow landsliding using static predictors and numerical weather predictions: preliminary results

“…The result is given as percentages; negative values correspond to convergent flow conditions, positive to divergent ones. This predictor has been recently used in LSMs by Nefeslioglu et al (2011).…”

“…This index is related to the soil moisture (Nefeslioglu et al, 2008;Yilmaz, 2010). The main limitation of the above formula is that it assumes steady-state conditions and uniform soil properties.…”

“…The main limitation of the above formula is that it assumes steady-state conditions and uniform soil properties. However, researchers assert that the formula is applicable in a wide range of cases and it has been used in assessment in LSM (Nefeslioglu et al, 2012). …”

“…The distances from rivers are evaluated by computing the minimum distance between cells and the nearest watercourse. This layer has been considered in similar works as a predisposing factor, because it takes into account a possible activating mechanism related to erosion along the slope foot (Mossa et al, 2005;Mancini et al, 2010).…”