diff --git a/R/forecast_output_validator.R b/R/forecast_output_validator.R
index d4b091e..84b2f1a 100644
--- a/R/forecast_output_validator.R
+++ b/R/forecast_output_validator.R
@@ -4,7 +4,17 @@
 #' @export
 
 forecast_output_validator <- function(forecast_file){
+
+  config <- yaml::read_yaml("https://raw.githubusercontent.com/eco4cast/neon4cast-ci/main/challenge_configuration.yaml")
+
+  allowed_combinations <- NULL
+  for(i in 1:length(config$variable_groups)){
   
+    curr_tibble <- data.frame(variable = unlist(config$variable_groups[i][[1]]$variable),
+                                duration = unlist(config$variable_groups[i][[1]]$duration))
+  
+    allowed_combinations <- rbind(allowed_combinations, curr_tibble)
+  }
   
   file_in <- forecast_file
   
@@ -30,7 +40,18 @@ forecast_output_validator <- function(forecast_file){
       usethis::ui_warn("missing the variable and prediction columns")
       valid <- FALSE
     }
-    
+
+    unique_variables <- unique(out$variable)
+  
+    for(i in 1:length(unique_variables)){
+     if (unique_variables[i] %in% allowed_combinations$variable) {
+       usethis::ui_done(paste0(unique_variables[i], " is a valid variable name"))
+     }
+     else {
+      usethis::ui_warn(paste0(unique_variables[i], " is not a valid variable name"))
+     }
+   }
+  
     if(lexists(out, "ensemble")){
       usethis::ui_warn("ensemble dimension should be named parameter")
       valid <- FALSE