diff --git a/fortran/wrf_vinterp.f90 b/fortran/wrf_vinterp.f90
index bbcf168..3357050 100644
--- a/fortran/wrf_vinterp.f90
+++ b/fortran/wrf_vinterp.f90
@@ -20,24 +20,24 @@ SUBROUTINE wrf_monotonic(out, in, lvprs, cor, idir, delta, ew, ns, nz, icorsw)
 
 !NCLEND
 
-    INTEGER :: i, j, k, k300
+    INTEGER :: i, j, k, ripk, k300
 
-    !$OMP PARALLEL DO COLLAPSE(2)
+    k300 = 1 ! removes the warning
+
+    !$OMP PARALLEL DO COLLAPSE(2) PRIVATE(i, j, k, ripk) FIRSTPRIVATE(k300)
     DO j=1,ns
         DO i=1,ew
-
             IF (icorsw .EQ. 1 .AND. cor(i,j) .LT. 0.) THEN
                 DO k=1,nz
                     in(i,j,k) = -in(i,j,k)
                 END DO
             END IF
 
-            k300 = nz
-
             ! First find k index that is at or below (height-wise)
             ! the 300 hPa level.
-            DO k = nz,1,-1
-                IF (lvprs(i,j,k) .GE. 300.D0) THEN
+            DO k = 1,nz
+                ripk = nz-k+1
+                IF (lvprs(i,j,k) .LE. 300.D0) THEN
                     k300 = k
                     EXIT
                 END IF
diff --git a/src/wrf/interp.py b/src/wrf/interp.py
index 8741596..a2e67aa 100755
--- a/src/wrf/interp.py
+++ b/src/wrf/interp.py
@@ -584,6 +584,9 @@ def vinterp(wrfin, field, vert_coord, interp_levels, extrapolate=False,
     terht = get_terrain(wrfin, timeidx, units="m", 
                         method=method, squeeze=squeeze, cache=cache,
                         meta=False, _key=_key)
+    t = get_theta(wrfin, timeidx,  units="k", 
+                  method=method, squeeze=squeeze, cache=cache, 
+                  meta=False, _key=_key)
     tk = get_temp(wrfin, timeidx, units="k",  
                   method=method, squeeze=squeeze, cache=cache, 
                   meta=False, _key=_key)
@@ -593,6 +596,9 @@ def vinterp(wrfin, field, vert_coord, interp_levels, extrapolate=False,
     ght = get_height(wrfin, timeidx, msl=True, units="m", 
                      method=method, squeeze=squeeze, cache=cache,
                      meta=False, _key=_key)
+    ht_agl = get_height(wrfin, timeidx, msl=False, units="m",
+                        method=method, squeeze=squeeze, cache=cache,
+                        meta=False, _key=_key)
     
     smsfp = _smooth2d(sfp, 3)        
 
@@ -607,18 +613,10 @@ def vinterp(wrfin, field, vert_coord, interp_levels, extrapolate=False,
         vcord_array = np.exp(-ght/sclht)
         
     elif vert_coord == "ght_agl":
-        ht_agl = get_height(wrfin, timeidx, msl=False, units="m",
-                        method=method, squeeze=squeeze, cache=cache,
-                        meta=False, _key=_key)
-        
         vcor = 3
         vcord_array = np.exp(-ht_agl/sclht)
     
     elif vert_coord in ("theta", "th"):
-        t = get_theta(wrfin, timeidx,  units="k", 
-                  method=method, squeeze=squeeze, cache=cache, 
-                  meta=False, _key=_key)
-        
         vcor = 4
         idir = 1
         icorsw = 0