diff --git a/da/analysis/siteseries.py b/da/analysis/siteseries.py
index bdee911f8ce2b198aff3ddd844b0146c21b1c2f5..8e1ef48a4f4b70239be67349a296f856d7512f97 100755
--- a/da/analysis/siteseries.py
+++ b/da/analysis/siteseries.py
@@ -164,9 +164,11 @@ def timehistograms_new(fig,infile):
     f.close()
 
     pydates = np.array([dt.datetime(1970,1,1)+dt.timedelta(seconds=int(d)) for d in date])
-    sampled  = (simulated.mask == False)
 
-    if len(sampled.nonzero()[0]) < 2:
+    sampled  = (np.ma.getmask(simulated) == False)
+
+    if len(sampled.nonzero()[0]) < 2: 
+        logging.warning("Too few simulated values found, continuing...")
         return fig
 
     simulated = simulated.compress(sampled)
@@ -349,7 +351,11 @@ def timevssite_new(fig,infile):
     f.close()
 
     pydates = np.array([dt.datetime(1970,1,1)+dt.timedelta(seconds=int(d)) for d in date])
-    sampled  = (simulated.mask == False)
+    sampled  = (np.ma.getmask(simulated) == False)
+
+    if len(sampled.nonzero()[0]) < 2: 
+        logging.warning("Too few simulated values found, continuing...")
+        return fig
 
     simulated = simulated.compress(sampled)
     obs       = obs.compress(sampled)
@@ -549,9 +555,10 @@ def residuals_new(fig,infile):
     f.close()
 
     pydates = np.array([dt.datetime(1970,1,1)+dt.timedelta(seconds=int(d)) for d in date])
-    sampled  = (simulated.mask == False)
+    sampled  = (np.ma.getmask(simulated) == False)
 
-    if len(sampled.nonzero()[0]) < 2:
+    if len(sampled.nonzero()[0]) < 2: 
+        logging.warning("Too few simulated values found, continuing...")
         return fig
 
     simulated = simulated.compress(sampled)