diff --git a/.github/pull_request_template.md b/.github/pull_request_template.md
index f15df3f4ea2b..0956918eb06d 100644
--- a/.github/pull_request_template.md
+++ b/.github/pull_request_template.md
@@ -12,7 +12,7 @@
 *Put an X by all that apply. You can fill this out after submitting the PR. If you have any questions, don't hesitate to ask! We want to help. These are a guide for you to know what the reviewers will be looking for in your contribution.*
 
 - [ ] I am submitting my contribution to the develop branch.
-- [ ] My contribution generates no new compiler warnings (try with the '-Wall -Wextra -Wno-unused-parameter -Wno-empty-body' compiler flags).
+- [ ] My contribution generates no new compiler warnings (try with the '-Wall -Wextra -Wno-unused-parameter -Wno-empty-body' compiler flags, or simply --warnlevel=2 when using meson).
 - [ ] My contribution is commented and consistent with SU2 style.
 - [ ] I have added a test case that demonstrates my contribution, if necessary.
 - [ ] I have updated appropriate documentation (Tutorials, Docs Page, config_template.cpp) , if necessary.
diff --git a/SU2_CFD/include/numerics/CNumerics.hpp b/SU2_CFD/include/numerics/CNumerics.hpp
index afd8310eb5ec..226be8107930 100644
--- a/SU2_CFD/include/numerics/CNumerics.hpp
+++ b/SU2_CFD/include/numerics/CNumerics.hpp
@@ -205,8 +205,8 @@ class CNumerics {
   su2double StrainMag_i, StrainMag_j;      /*!< \brief Strain rate magnitude. */
   su2double Dissipation_i, Dissipation_j;  /*!< \brief Dissipation. */
   su2double Dissipation_ij;
-  su2double roughness_i,                   /*!< \brief Roughness of the wall nearest to point i. */
-  roughness_j;                             /*!< \brief Roughness of the wall nearest to point j. */
+  su2double roughness_i = 0.0,             /*!< \brief Roughness of the wall nearest to point i. */
+  roughness_j = 0.0;                       /*!< \brief Roughness of the wall nearest to point j. */
 
   su2double *l, *m;
 
diff --git a/SU2_CFD/src/output/filewriter/CParaviewXMLFileWriter.cpp b/SU2_CFD/src/output/filewriter/CParaviewXMLFileWriter.cpp
index 5775045ade6c..c172e545fec0 100644
--- a/SU2_CFD/src/output/filewriter/CParaviewXMLFileWriter.cpp
+++ b/SU2_CFD/src/output/filewriter/CParaviewXMLFileWriter.cpp
@@ -71,7 +71,7 @@ void CParaviewXMLFileWriter::Write_Data(){
   char str_buf[255];
 
   OpenMPIFile();
-  
+
   dataOffset = 0;
 
   /*--- Communicate the number of total points that will be
@@ -295,7 +295,7 @@ void CParaviewXMLFileWriter::Write_Data(){
         }
       }
 
-      WriteDataArray(dataBufferFloat.data(), VTKDatatype::FLOAT32, myPoint*NCOORDS, GlobalPoint*NCOORDS, 
+      WriteDataArray(dataBufferFloat.data(), VTKDatatype::FLOAT32, myPoint*NCOORDS, GlobalPoint*NCOORDS,
                      dataSorter->GetnPointCumulative(rank)*NCOORDS);
 
       VarCounter++;
@@ -336,23 +336,21 @@ void CParaviewXMLFileWriter::WriteDataArray(void* data, VTKDatatype type, unsign
 
   /*--- Compute the size of the data to write in bytes ---*/
 
-  int byteSize;
-  byteSize = arraySize*typeSize;
+  size_t byteSize = arraySize*typeSize;
 
   /*--- The total data size ---*/
-  unsigned long totalByteSize;
-  totalByteSize = globalSize*typeSize;
+  size_t totalByteSize = globalSize*typeSize;
 
   /*--- Only the master node writes the total size in bytes as unsigned long in front of the array data ---*/
-  
-  if (!WriteMPIBinaryData(&totalByteSize, sizeof(unsigned long), MASTER_NODE)){
+
+  if (!WriteMPIBinaryData(&totalByteSize, sizeof(size_t), MASTER_NODE)){
     SU2_MPI::Error("Writing array size failed", CURRENT_FUNCTION);
   }
-  
+
   /*--- Collectively write all the data ---*/
-  
+
   if (!WriteMPIBinaryDataAll(data, byteSize, totalByteSize, offset*typeSize)){
-    SU2_MPI::Error("Writing data array failed", CURRENT_FUNCTION);    
+    SU2_MPI::Error("Writing data array failed", CURRENT_FUNCTION);
   }
 }
 
@@ -373,13 +371,13 @@ void CParaviewXMLFileWriter::AddDataArray(VTKDatatype type, string name,
   string offsetStr = ss.str();
 
   std::string typeStr;
-  unsigned long typeSize = 0, totalByteSize;
+  unsigned long typeSize = 0;
 
   GetTypeInfo(type, typeStr, typeSize);
 
   /*--- Total data size ---*/
 
-  totalByteSize = globalSize*typeSize;
+  size_t totalByteSize = globalSize*typeSize;
 
   /*--- Write the ASCII XML header information for this array ---*/
 
@@ -389,6 +387,6 @@ void CParaviewXMLFileWriter::AddDataArray(VTKDatatype type, string name,
                  string(" offset=") + offsetStr +
                  string(" format=\"appended\"/>\n"), MASTER_NODE);
 
-  dataOffset += totalByteSize + sizeof(unsigned long);
+  dataOffset += totalByteSize + sizeof(size_t);
 
 }