Index: /issm/trunk/src/m/classes/public/ismodelselfconsistent.m
===================================================================
--- /issm/trunk/src/m/classes/public/ismodelselfconsistent.m	(revision 5323)
+++ /issm/trunk/src/m/classes/public/ismodelselfconsistent.m	(revision 5324)
@@ -363,7 +363,13 @@
 
 	%OBSERVED VELOCITIES
-	fields={'vx_obs','vy_obs'};
-	checksize(md,fields,[md.numberofgrids 1]);
-	checknan(md,fields);
+	if md.analysis_type==BalancedthicknessSolutionEnum
+		fields={'thickness_obs'};
+		checksize(md,fields,[md.numberofgrids 1]);
+		checknan(md,fields);
+	else
+		fields={'vx_obs','vy_obs'};
+		checksize(md,fields,[md.numberofgrids 1]);
+		checknan(md,fields);
+	end
 
 	%DIRICHLET IF THICKNESS <= 0