edu.ucar.opensky::articles:25373 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-24T22:54:40.288146 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d7gt5rwd https://doi.org/10.5065/D65D8PWK https Related Dataset #1 NCEP GFS 0.25 Degree Global Forecast Grids Historical Archive Comparing partial and continuously cycling Ensemble Kalman Filter data assimilation systems for convection-allowing ensemble forecast initialization 2022-01-01T00:00:00Z publication https://n2t.org/ark:/85065/d7gt5rwd https://doi.org/10.1175/WAF-D-21-0069.1 Schwartz, Craig S. author Poterjoy, J. author Carley, J. R. author Dowell, D. C. author Romine, Glen author Ide, K. author UCAR/NCAR - Library publisher Several limited-area 80-member ensemble Kalman filter (EnKF) data assimilation systems with 15-km horizontal grid spacing were run over a computational domain spanning the conterminous United States (CONUS) for a 4-week period. One EnKF employed continuous cycling, where the prior ensemble was always the 1-h forecast initialized from the previous cycle's analysis. In contrast, the other EnKFs used a partial cycling procedure, where limited-area states were discarded after 12 or 18 h of self-contained hourly cycles and reinitialized the next day from global model fields. "Blended" states were also constructed by combining large scales from global ensemble initial conditions (ICs) with small scales from limited-area continuously cycling EnKF analyses using a low-pass filter. Both the blended states and EnKF analysis ensembles initialized 36-h, 10-member ensemble forecasts with 3-km horizontal grid spacing. Continuously cycling EnKF analyses initialized similar to 1-18-h precipitation forecasts that were comparable to or somewhat better than those with partial cycling EnKF ICs. Conversely, similar to 18-36-h forecasts with partial cycling EnKF ICs were comparable to or better than those with unblended continuously cycling EnKF ICs. However, blended ICs yielded similar to 18-36-h forecasts that were statistically indistinguishable from those with partial cycling ICs. ICs that more closely resembled global analysis spectral characteristics at wavelengths >200 km, like partial cycling and blended ICs, were associated with relatively good similar to 18-36-h forecasts. Ultimately, findings suggest that EnKFs employing a combination of continuous cycling and blending can potentially replace the partial cycling assimilation systems that currently initialize operational limited-area models over the CONUS without sacrificing forecast quality. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2022 American Meteorological Society. None eng geoscientificInformation