diff --git a/README.md b/README.md
index 3859ca9184..17d0383508 100644
--- a/README.md
+++ b/README.md
@@ -1,4 +1,4 @@
-MPAS-v5.2
+MPAS-v5.3
 ====
 
 The Model for Prediction Across Scales (MPAS) is a collaborative project for
diff --git a/src/core_atmosphere/Registry.xml b/src/core_atmosphere/Registry.xml
index 752216937f..2336a7b030 100644
--- a/src/core_atmosphere/Registry.xml
+++ b/src/core_atmosphere/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="atmosphere" core_abbrev="atm" version="5.2">
+<registry model="mpas" core="atmosphere" core_abbrev="atm" version="5.3">
 
 <!-- **************************************************************************************** -->
 <!-- ************************************** Dimensions ************************************** -->
@@ -1633,35 +1633,35 @@
 
                 <!-- scalar tendencies -->
                 <var_array name="scalars_tend" type="real" dimensions="nVertLevels nCells Time">
-                        <var name="tend_qv" name_in_code="qv" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of water vapor mixing ratio"/>
+                        <var name="tend_qv" name_in_code="qv" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of water vapor mass per unit volume divided by d(zeta)/dz"/>
 
-                        <var name="tend_qc" name_in_code="qc" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of cloud water mixing ratio"
+                        <var name="tend_qc" name_in_code="qc" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of cloud water mass per unit volume divided by d(zeta)/dz"
                              packages="bl_mynn_in;bl_ysu_in;cu_tiedtke_in;mp_kessler_in;mp_thompson_in;mp_wsm6_in"/>
 
-                        <var name="tend_qr" name_in_code="qr" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of rain water mixing ratio"
+                        <var name="tend_qr" name_in_code="qr" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of rain water mass per unit volume divided by d(zeta)/dz"
                              packages="mp_kessler_in;mp_thompson_in;mp_wsm6_in"/>
 
-                        <var name="tend_qi" name_in_code="qi" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of ice mixing ratio"
+                        <var name="tend_qi" name_in_code="qi" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of ice mass per unit volume divided by d(zeta)/dz"
                              packages="bl_mynn_in;bl_ysu_in;cu_tiedtke_in;mp_thompson_in;mp_wsm6_in"/>
 
-                        <var name="tend_qs" name_in_code="qs" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of snow ratio"
+                        <var name="tend_qs" name_in_code="qs" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of snow mass per unit volume divided by d(zeta)/dz"
                              packages="mp_thompson_in;mp_wsm6_in"/>
 
-                        <var name="tend_qg" name_in_code="qg" array_group="moist" units="kg kg^{-1} s^{-1}"
-                             description="Tendency of graupel mixing ratio"
+                        <var name="tend_qg" name_in_code="qg" array_group="moist" units="kg m^{-3} s^{-1}"
+                             description="Tendency of graupel mass per unit volume divided by d(zeta)/dz"
                              packages="mp_thompson_in;mp_wsm6_in"/>
 
-                        <var name="tend_ni" name_in_code="ni" array_group="number" units="nb kg^{-1} s^{-1}"
-                             description="Tendency of cloud ice number concentration"
+                        <var name="tend_ni" name_in_code="ni" array_group="number" units="nb m^{-3} s^{-1}"
+                             description="Tendency of cloud ice number concentration multiplied by dry air density divided by d(zeta)/dz"
                              packages="bl_mynn_in;mp_thompson_in"/>
 
-                        <var name="tend_nr" name_in_code="nr" array_group="number" units="nb kg^{-1} s^{-1}" 
-                             description="Tendency of rain number concentration"
+                        <var name="tend_nr" name_in_code="nr" array_group="number" units="nb m^{-3} s^{-1}" 
+                             description="Tendency of rain number concentration multiplied by dry air density divided by d(zeta)/dz"
                              packages="mp_thompson_in"/>
                 </var_array>
         </var_struct>
diff --git a/src/core_init_atmosphere/Registry.xml b/src/core_init_atmosphere/Registry.xml
index fbbe4c8569..bb4d157384 100644
--- a/src/core_init_atmosphere/Registry.xml
+++ b/src/core_init_atmosphere/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="init_atmosphere" core_abbrev="init_atm" version="5.2">
+<registry model="mpas" core="init_atmosphere" core_abbrev="init_atm" version="5.3">
 
 <!-- **************************************************************************************** -->
 <!-- ************************************** Dimensions ************************************** -->
diff --git a/src/core_init_atmosphere/mpas_init_atm_cases.F b/src/core_init_atmosphere/mpas_init_atm_cases.F
index b86c4d5aba..44b5e0bd5e 100644
--- a/src/core_init_atmosphere/mpas_init_atm_cases.F
+++ b/src/core_init_atmosphere/mpas_init_atm_cases.F
@@ -4647,8 +4647,12 @@ subroutine init_atm_case_gfs(block, mesh, nCells, nEdges, nVertLevels, fg, state
 !              es = svp1*10.*exp(svp2*(t(k,iCell)-svpt0)/(t(k,iCell)-svp3))
 !              es = min(es,0.99*0.01*pressure(k,iCell))
 !              rs = 0.622*es*100. / (pressure(k,iCell)-es*100.)
+
+               !
+               ! Note: the RH field provided by ungrib should always be with respect to liquid water,
+               !       hence, we can always call rslf; see the routine fix_gfs_rh in WPS/ungrib/src/rrpr.F .
+               !
                rs = rslf(pressure(k,iCell),t(k,iCell))
-               if(t(k,iCell) .lt. svpt0) rs = rsif(pressure(k,iCell),t(k,iCell))
                scalars(index_qv,k,iCell) = 0.01_RKIND*rs*relhum(k,iCell)
              enddo
          enddo
diff --git a/src/core_landice/Registry.xml b/src/core_landice/Registry.xml
index edab7c4c36..9de2900787 100644
--- a/src/core_landice/Registry.xml
+++ b/src/core_landice/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="landice" core_abbrev="li" version="5.2">
+<registry model="mpas" core="landice" core_abbrev="li" version="5.3">
 
 
 <!-- ======================================================================= -->
diff --git a/src/core_ocean/Registry.xml b/src/core_ocean/Registry.xml
index ba2c65f36d..6c9addc4a7 100644
--- a/src/core_ocean/Registry.xml
+++ b/src/core_ocean/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="ocean" core_abbrev="ocn" version="5.2">
+<registry model="mpas" core="ocean" core_abbrev="ocn" version="5.3">
 
 	<dims>
 		<dim name="nCells" units="unitless"
diff --git a/src/core_sw/Registry.xml b/src/core_sw/Registry.xml
index e072aba279..8e8f2de565 100644
--- a/src/core_sw/Registry.xml
+++ b/src/core_sw/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="sw" core_abbrev="sw" version="5.2">
+<registry model="mpas" core="sw" core_abbrev="sw" version="5.3">
 	<dims>
 		<dim name="nCells"/>
 		<dim name="nEdges"/>
diff --git a/src/core_test/Registry.xml b/src/core_test/Registry.xml
index 33640eb50f..c4c4ee00cb 100644
--- a/src/core_test/Registry.xml
+++ b/src/core_test/Registry.xml
@@ -1,5 +1,5 @@
 <?xml version="1.0"?>
-<registry model="mpas" core="test" core_abbrev="test" version="5.2">
+<registry model="mpas" core="test" core_abbrev="test" version="5.3">
 	<dims>
 		<dim name="nCells"/>
 		<dim name="nEdges"/>
diff --git a/src/operators/mpas_vector_operations.F b/src/operators/mpas_vector_operations.F
index db0da10e9f..98c526f5e0 100644
--- a/src/operators/mpas_vector_operations.F
+++ b/src/operators/mpas_vector_operations.F
@@ -706,21 +706,21 @@ subroutine mpas_initialize_vectors(meshPool)!{{{
 
     ! Initialize normal unit vectors at each edge
     ! These vectors point from cell to cell.
-    ! At boundaries, one cell does not exist, so it points from cell to edge.
+    ! At boundaries, one cell does not exist, so it points from cell to edge or from edge to cell.
     do iEdge = 1,nEdges
       cell1 = cellsOnEdge(1,iEdge)
       cell2 = cellsOnEdge(2,iEdge)
 
       if (cell1 == nCells+1) then ! this is a boundary edge
-        ! the normal points from the cell location to the edge location
+        ! the normal points from the edge location to the cell location
         if (is_periodic) then
-          edgeNormalVectors(1,iEdge) = mpas_fix_periodicity(xEdge(iEdge), xCell(cell2), x_period) - xCell(cell2)
-          edgeNormalVectors(2,iEdge) = mpas_fix_periodicity(yEdge(iEdge), yCell(cell2), y_period) - yCell(cell2)
-          edgeNormalVectors(3,iEdge) = zEdge(iEdge) - zCell(cell2)
+          edgeNormalVectors(1,iEdge) = xCell(cell2) - mpas_fix_periodicity(xEdge(iEdge), xCell(cell2), x_period)
+          edgeNormalVectors(2,iEdge) = yCell(cell2) - mpas_fix_periodicity(yEdge(iEdge), yCell(cell2), y_period)
+          edgeNormalVectors(3,iEdge) = zCell(cell2) - zEdge(iEdge)
         else
-          edgeNormalVectors(1,iEdge) = xEdge(iEdge) - xCell(cell2)
-          edgeNormalVectors(2,iEdge) = yEdge(iEdge) - yCell(cell2)
-          edgeNormalVectors(3,iEdge) = zEdge(iEdge) - zCell(cell2)
+          edgeNormalVectors(1,iEdge) = xCell(cell2) - xEdge(iEdge)
+          edgeNormalVectors(2,iEdge) = yCell(cell2) - yEdge(iEdge)
+          edgeNormalVectors(3,iEdge) = zCell(cell2) - zEdge(iEdge)
         end if
 
       else if (cell2 == nCells+1) then ! this is a boundary edge