Index: /issm/trunk-jpl/src/c/modules/SurfaceMassBalancex/Gembx.cpp
===================================================================
--- /issm/trunk-jpl/src/c/modules/SurfaceMassBalancex/Gembx.cpp	(revision 22431)
+++ /issm/trunk-jpl/src/c/modules/SurfaceMassBalancex/Gembx.cpp	(revision 22432)
@@ -655,7 +655,7 @@
 
 	// determine minimum acceptable delta t (diffusion number > 1/2) [s]
-	// NS: 2.16.18 divided dt by 9 for stability (changed 3 to 27)
+	// NS: 2.16.18 divided dt by 11 for stability (changed 3 to 33)
 	dt=1e12; 
-	for(int i=0;i<m;i++)dt = fmin(dt,CI * pow(dz[i],2) * d[i]  / (27 * K[i]));
+	for(int i=0;i<m;i++)dt = fmin(dt,CI * pow(dz[i],2) * d[i]  / (33 * K[i]));
 
 	// smallest possible even integer of 60 min where diffusion number > 1/2
Index: /issm/trunk-jpl/test/NightlyRun/test243.m
===================================================================
--- /issm/trunk-jpl/test/NightlyRun/test243.m	(revision 22431)
+++ /issm/trunk-jpl/test/NightlyRun/test243.m	(revision 22432)
@@ -45,5 +45,5 @@
 %Fields and tolerances to track changes
 field_names      ={'SmbDz','SmbT' ,'SmbD' ,'SmbRe','SmbGdn','SmbGsp','SmbA' ,'SmbEC','SmbMassBalance'};
-field_tolerances ={1e-10,1e-10,1e-10,1e-10,1e-10,1e-10,1e-10,1e-10,1e-12};
+field_tolerances ={1e-11,1e-12,1e-11,1e-11,1e-11,1e-11,1e-12,1e-12,1e-12};
 
 field_values={...
Index: /issm/trunk-jpl/test/NightlyRun/test243.py
===================================================================
--- /issm/trunk-jpl/test/NightlyRun/test243.py	(revision 22431)
+++ /issm/trunk-jpl/test/NightlyRun/test243.py	(revision 22432)
@@ -58,5 +58,5 @@
 #Fields and tolerances to track changes
 field_names      = ['SmbDz','SmbT' ,'SmbD' ,'SmbRe','SmbGdn','SmbGsp','SmbA' ,'SmbEC','SmbMassBalance']
-field_tolerances = [5e-4,5e-5,0.0006,0.0002,1e-5,0.0003,2e-5,2e-7,1e-7]
+field_tolerances = [1e-11,1e-12,1e-11,1e-11,1e-11,1e-11,1e-12,1e-12,1e-12]
 #shape is different in python solution (fixed using reshape) which can cause test failure:
 field_values = [