release_notes_v5.0.9

Release Notes:  RAP v5.0.9

v5.0.9 - released July 23, 2021
* RAPv5 WRF source code change to address an operational RAP failure on July 9th
   * Implicit-Explicit Vertical Advection (IEVA) is disabled during the backwards integration of the DFI and then immediately turned back on
   * The impact of this change on the model forecast is in the range of noise


* Repository Details
   * After cloning the rap.v5.0.9 tag of the EMC_rap git repository using the command below, retrieve the new code from the rap.v5 directory.
  	* git clone -b rap.v5.0.9 https://${USER}@vlab.noaa.gov/code-review/a/EMC_rap
  	* git clone -b rap.v5.0.9 ssh://${USER}@vlab.noaa.gov:29418/EMC_rap


* sorc files changed
   * sorc/rap_wrfarw.fd/WRFV3.9/share/dfi.F


* resource changes
   * N/A


* implementation instructions
   * Retrieve the new sorc file and re-compile the rap_wrfarw source code