diff --git a/Cell2Fire/FuelModelKitral.cpp b/Cell2Fire/FuelModelKitral.cpp
index 6d40918c..de6a6e5d 100644
--- a/Cell2Fire/FuelModelKitral.cpp
+++ b/Cell2Fire/FuelModelKitral.cpp
@@ -574,10 +574,12 @@ rate_of_spread_k(inputs* data,
     p1 = -12.86;
     p2 = 0.04316;
     p3 = 13.8;
-    ch = (-2.97374 + 0.262 * rh - 0.00982 * tmp);
+    float midpoint = 57.09;
+    float steepness = 0.081;
+    float sigmoid = 1.0 / (1.0 + exp(-steepness * (rh - midpoint)));
+    ch = 4 + 16 * sigmoid - 0.00982 * tmp;
     fmc = fmcs[data->nftype][0] * 60;  // factor de propagacion en m/min
-    fch = (389.1624 + 14.3 * ch + 0.02 * pow(ch, 2.0))
-          / (3.559 + 1.6615 * ch + 2.62392 * pow(ch, 2.0));  // es -14.3 segun el libro
+    fch = min(51.43, 52.3342 * pow(ch, -1.3035));
     fv = p1 * exp(-p2 * ws) + p3;
     if (ps == 0)
     {
diff --git a/test/container_test.sh b/test/container_test.sh
index eae67aed..c4eea789 100755
--- a/test/container_test.sh
+++ b/test/container_test.sh
@@ -93,4 +93,5 @@ else
 fi
 
 rm -rf target_results
+rm -rf test_results
 exit 0
diff --git a/test/target_results.zip b/test/target_results.zip
index 9895905c..0461a912 100644
Binary files a/test/target_results.zip and b/test/target_results.zip differ
diff --git a/test/target_updater.sh b/test/target_updater.sh
new file mode 100644
index 00000000..36286902
--- /dev/null
+++ b/test/target_updater.sh
@@ -0,0 +1,37 @@
+#!/bin/bash
+# run simulations from model, put them in test_results, compare to target_results
+
+# recreate targets with tests
+rm -rf target_results.zip
+# execute the for loop
+
+# add to path
+PATH=../Cell2Fire:$PATH
+
+# run
+set -x # enable debug tracing
+for format in asc tif; do
+    for model in fbp kitral sb; do
+        echo running $model-$format
+        output_folder=test_results/$model-$format
+        mkdir -p $output_folder
+        rm -rf $output_folder/*
+        if [ "$model" == "fbp" ]; then
+            additional_args="--cros"
+            sim_code="C"
+        elif [ "$model" == "sb" ]; then
+            additional_args="--scenario 1"
+            sim_code="S"
+        elif [ "$model" == "kitral" ]; then
+            additional_args=""
+            sim_code="K"
+        fi
+        Cell2Fire$1 --input-instance-folder model/$model-$format --output-folder $output_folder --nsims 113 --output-messages --grids --out-ros --out-intensity --sim ${sim_code} --seed 123 --ignitionsLog $additional_args > test_results/$model-$format/log.txt
+    done
+done
+set +x # disable debug tracing
+
+mv test_results target_results
+zip -r target_results.zip target_results
+rm -rf target_results
+
diff --git a/test/test.sh b/test/test.sh
index cb3c9265..69864fe3 100755
--- a/test/test.sh
+++ b/test/test.sh
@@ -88,4 +88,5 @@ else
 fi
 
 rm -rf target_results
+rm -rf test_results
 exit 0