DOI: 10.5061/dryad.8sf7m0czg
title: GFS Storm Precipitation, 2019 and 2020 Storms

description: Operational forecast models are necessary for the prediction of weather
 events in real time. Verification of these models must be performed to
 assess model skill and areas in need of improvement, particularly with
 different types of weather events that may occur. Despite the devastating
 impacts that can be caused by tropical cyclones (TCs) that undergo
 extratropical transition (ET) and become post-tropical cyclones (PTCs),
 these storms have not been extensively studied in the context of
 short-term weather prediction. This study completes the first analysis of
 the Global Forecast System (GFS) and a pre-operational version of the
 newly operational Hurricane Analysis and Forecast System (HAFS) models in
 forecasting the occurrence of ET and the rainfall associated with ET
 storms in the North Atlantic basin. GFS's skill exceeds that of HAFS
 in forecasting the occurrence of ET, but HAFS tends to have lower track
 and rain rate errors in the fully tropical phase of ET storms' life
 cycles. Both models simulate rain rates that are often too high near the
 storm center and fail to capture the larger area of moderate rain rates
 that greatly contributes to total rainfall accumulation. The discrepancies
 in rain rates between the models and IMERG could be attributed to the
 models' tendency to keep storms too intense and too compact with an
 overly strong warm core, even throughout the ET process.
description: The data that support the findings of this study are available at
 the following URLs: IMERG Final Run: https://gpm1.gesdisc.eosdis.nasa.gov/data/GPM_L3/GPM_3IMERGHH.06/ IBTrACS v4: https://www.ncdc.noaa.gov/ibtracs/index.php?name=ib-v4-access ERA5 reanalysis: https://cds.climate.copernicus.eu/#!/search?text=ERA5&type=dataset GFS data was accessed from the UCAR Research Data Archive: https://doi.org/10.5065/D65Q4TSG TempestExtremes is publicly available on GitHub at:<br>https://github.com/ClimateGlobalChange/tempestextremes ExTraTrack software is available at https://github.com/zarzycki/ExTraTrack  
description: # GFS Storm Precipitation
 [https://doi.org/10.5061/dryad.8sf7m0czg](https://doi.org/10.5061/dryad.8sf7m0czg) ## Description of the data and file structure This dataset contains the storm-related rainfall files from the GFS model runs used in the associated manuscript. These files are generated by tracking the TC of interest in each operational simulation, including the extension of the TC trajectory into the post-tropical phase. Rainfall is then tracked using a 1 mm/hr threshold for identifying precipitation objects. The area over which to extract the storm-related rainfall is created by identifying the locations around the storm center where the geopotential height at 500 hPa (Z500) increases by 10 m from the value at the center of the storm (Z500 mask). Finally, the rainfall objects and the Z500 mask are overlaid, thus co-locating rainfall with its respective storm. The TC tracking, precipitation tracking, Z500 mask generation, and co-location are all accomplished using TempestExtremes. The extension of TC trajectories to include the post-tropical phase is done using ExTraTrack. The files named "`masked_precip_gfs_${DATE}*${STORM}ET_1MMHR.nc`" include only the precipitation related to the storm in the file name for the model run initialized at the time in the file name when using a 1 mm/hr threshold. These files include the ET phase of the storm life cycle, while the `xxx_TC_1MMHR.nc` files only include the TC phase of the storm life cycle. The "`masked***.nc`" files include precipitation in mm/hr, latitude, longitude, and time. This precipitation is filtered out so that only rainfall associated with the storm of interest is included. ## Code/software While no special software is required for viewing this data, the following resources were used to create it: TempestExtremes: [https://github.com/ClimateGlobalChange/tempestextremes/tree/master](https://github.com/ClimateGlobalChange/tempestextremes/tree/master) ExTraTrack: [https://github.com/zarzycki/ExTraTrack](https://github.com/zarzycki/ExTraTrack) ## Access information Other publicly accessible locations of the data: * N/A Data was derived from the following sources: * IMERG Final Run: [https://gpm1.gesdisc.eosdis.nasa.gov/data/GPM_L3/GPM\\](https://gpm1.gesdisc.eosdis.nasa.gov/data/GPM_L3/GPM\\)\_ 3IMERGHH.06/. * IBTrACS v4: [https://www.ncdc.noaa.gov/ibtracs/index.php?name=ib-v4-access](https://www.ncdc.noaa.gov/ibtracs/index.php?name=ib-v4-access). * ERA5 reanalysis: [https://cds.climate.copernicus.eu/#!/search?text=ERA5&type=](https://cds.climate.copernicus.eu/#!/search?text=ERA5&type=) dataset. * GFS forecast archive available from NCAR Research Data Archive: [https://doi.org/10](https://doi.org/10). 5065/D65Q4TSG. * HAFS data provided to Bower by Bin Liu, Zhan Zhang, and Matthew Green (NOAA EMC and WPC).