Initialize RK weights to large negative values

Initialize the various RK weights (rkSSPweights, rkTendWeights,
rkSubstepWeights) to large negative values which are overwritten
for each case. This will make it obvious if a weight is being used
when it should not be.

components/mpas-albany-landice/src/mode_forward/mpas_li_time_integration_fe_rk.F

@@ -289,25 +289,28 @@ subroutine li_time_integrator_forwardeuler_rungekutta(domain, err)
       ! by one index. e.g., the coefficients for RK4 are usually written
       ! (0, 1/2, 1/2, 1), while we use (1/2, 1/2, 1). The last entry of 1.0
       ! is simply for ease of implementation.
-      rkSSPweights(:) = 1.0_RKIND ! updated for each case below
-      rkTendWeights(:) = 1.0_RKIND ! updated for each case below
+      rkSSPweights(:) = -9999.0_RKIND ! Initialized to this value to make it obvious if
+                                      ! a weight is used that should not be. Appropriate
+                                      ! weights are updated for each case below
+      rkTendWeights(:) = -9999.0_RKIND
+      rkSubstepWeights(:) = -9999.0_RKIND
       if ( (trim(config_time_integration) == 'forward_euler') .or. &
            ((trim(config_time_integration) == 'runge_kutta') .and. &
            (config_rk_order == 1)) ) then
          nRKstages = 1
-         rkSubstepWeights(:) = 1.0_RKIND
+         rkSSPweights(1) = 1.0_RKIND
+         rkTendWeights(1) = 1.0_RKIND
+         rkSubstepWeights(1) = 1.0_RKIND
       elseif ( (trim(config_time_integration) == 'runge_kutta') .and. &
                (config_rk_order == 2) ) then
          ! use Strong Stability Preserving RK2. Could also
          ! add config option to use standard endpoint or midpoint methods, but
          ! these are algorithmically more complex and less suitable for our domains 
          nRKstages = 2
-         rkSubstepWeights(:) = 1.0_RKIND
+         rkSubstepWeights(1:2) = 1.0_RKIND
 
          rkSSPweights(1) = 1.0_RKIND
          rkSSPweights(2) = 0.5_RKIND
-         rkSSPweights(3) = 0.0_RKIND
-         rkSSPweights(4) = 0.0_RKIND
 
          rkTendWeights(1) = 0.5_RKIND
          rkTendWeights(2) = 0.5_RKIND
@@ -316,12 +319,11 @@ subroutine li_time_integrator_forwardeuler_rungekutta(domain, err)
          if (config_rk3_stages == 3) then
             ! use three-stage Strong Stability Preserving RK3
             nRKstages = 3
-            rkSubstepWeights(:) = 1.0_RKIND
+            rkSubstepWeights(1:3) = 1.0_RKIND
 
             rkSSPweights(1) = 1.0_RKIND
             rkSSPweights(2) = 3.0_RKIND / 4.0_RKIND
             rkSSPweights(3) = 1.0_RKIND / 3.0_RKIND
-            rkSSPweights(4) = 0.0_RKIND
 
             rkTendWeights(1) = 1.0_RKIND / 6.0_RKIND
             rkTendWeights(2) = 1.0_RKIND / 6.0_RKIND