Index: /issm/trunk-jpl/src/m/classes/SMBgemb.m
===================================================================
--- /issm/trunk-jpl/src/m/classes/SMBgemb.m	(revision 24709)
+++ /issm/trunk-jpl/src/m/classes/SMBgemb.m	(revision 24710)
@@ -446,4 +446,12 @@
 			WriteData(fid, prefix, 'object', self, 'fieldname', 'steps_per_step', 'format', 'Integer');
 			%figure out dt from forcings:
+			if (any(md.smb.P(end,:) - md.smb.Ta(end,:) ~= 0) | ...
+					any(md.smb.V(end,:) - md.smb.Ta(end,:) ~= 0) | ...
+					any(md.smb.dswrf(end,:) - md.smb.Ta(end,:) ~= 0) | ...
+					any(md.smb.dlwrf(end,:) - md.smb.Ta(end,:) ~= 0) | ...
+					any(md.smb.eAir(end,:) - md.smb.Ta(end,:) ~= 0) | ...
+					any(md.smb.pAir(end,:) - md.smb.Ta(end,:) ~= 0))
+				error('All GEMB forcings (Ta, P, V, dswrf, dlwrf, eAir, pAir) must have the same time steps in the final row!');
+			end
 			time=self.Ta(end,:); %assume all forcings are on the same time step
 			dtime=diff(time,1);
Index: /issm/trunk-jpl/src/m/classes/SMBgemb.py
===================================================================
--- /issm/trunk-jpl/src/m/classes/SMBgemb.py	(revision 24709)
+++ /issm/trunk-jpl/src/m/classes/SMBgemb.py	(revision 24710)
@@ -407,4 +407,7 @@
         WriteData(fid, prefix, 'object', self, 'fieldname', 'steps_per_step', 'format', 'Integer')
         #figure out dt from forcings:
+        if (np.any(self.P[-1] - self.Ta[-1] != 0) | np.any(self.V[-1] - self.Ta[-1] != 0) | np.any(self.dswrf[-1] - self.Ta[-1] !=0) | np.any(self.dlwrf[-1] - self.Ta[-1] != 0) | np.any(self.eAir[-1] - self.Ta[-1] != 0) | np.any(self.pAir[-1] - self.Ta[-1] != 0)):
+            raise IOError('All GEMB forcings (Ta, P, V, dswrf, dlwrf, eAir, pAir) must have the same time steps in the final row!')
+
         time = self.Ta[-1]  #assume all forcings are on the same time step
         dtime = np.diff(time, n=1, axis=0)