diff --git a/definitions/grib2/section.1.def b/definitions/grib2/section.1.def
index a9bca14ce..719a9399c 100644
--- a/definitions/grib2/section.1.def
+++ b/definitions/grib2/section.1.def
@@ -93,6 +93,8 @@ concept stepType {
     "ratio"   = {selectStepTemplateInterval=1; stepTypeInternal="ratio";}
     "stdanom" = {selectStepTemplateInterval=1; stepTypeInternal="stdanom";}
     "sum"     = {selectStepTemplateInterval=1; stepTypeInternal="sum";}
+    "severity" = {selectStepTemplateInterval=1; stepTypeInternal="severity";}
+    "mode"    = {selectStepTemplateInterval=1; stepTypeInternal="mode";}
 }
 
 # 0=atmospheric chemical constituents
diff --git a/definitions/grib2/template.4.statistical.def b/definitions/grib2/template.4.statistical.def
index 35390d536..c9307b04e 100644
--- a/definitions/grib2/template.4.statistical.def
+++ b/definitions/grib2/template.4.statistical.def
@@ -68,6 +68,8 @@ if (numberOfTimeRange == 1 || numberOfTimeRange == 2) {
     "ratio"   = {typeOfStatisticalProcessing=9;}
     "stdanom" = {typeOfStatisticalProcessing=10;}
     "sum"     = {typeOfStatisticalProcessing=11;}
+    "severity" = {typeOfStatisticalProcessing=100;}
+    "mode"     = {typeOfStatisticalProcessing=101;}
   }
   meta startStep step_in_units(forecastTime,indicatorOfUnitOfTimeRange,stepUnits,
     indicatorOfUnitForTimeRange,lengthOfTimeRange) : no_copy;
diff --git a/tests/grib_step.sh b/tests/grib_step.sh
index 362bf9d03..1bc7e208b 100755
--- a/tests/grib_step.sh
+++ b/tests/grib_step.sh
@@ -62,6 +62,7 @@ diff ${data_dir}/step_grib1.log ${templog}
 rm -f ${templog}
 
 # GRIB-180
+# ------------
 # Set PDT 4.8 where you can find the EndOfOverallTimeInterval keys
 grib2File=${data_dir}/reduced_latlon_surface_constant.grib2
 ${tools_dir}/grib_set -sproductDefinitionTemplateNumber=8 $grib2File ${grib2File}.p8tmp
@@ -81,6 +82,7 @@ hourEnd=$1; dayEnd=$2
 
 
 # ECC-134 case-sensitivity
+# --------------------------
 grib1_sample=$ECCODES_SAMPLES_PATH/GRIB1.tmpl
 grib2_sample=$ECCODES_SAMPLES_PATH/GRIB2.tmpl
 temp=temp.step.$$.grib
@@ -93,6 +95,7 @@ unit=`${tools_dir}/grib_get -p indicatorOfUnitOfTimeRange $temp`
 [ "$unit" = "3" ]
 
 # m is for Minute (code 0)
+# -------------------------
 ${tools_dir}/grib_set -s indicatorOfUnitOfTimeRange=m $grib1_sample $temp
 unit=`${tools_dir}/grib_get -p unitOfTimeRange $temp`
 [ "$unit" = "0" ]
@@ -101,9 +104,18 @@ unit=`${tools_dir}/grib_get -p indicatorOfUnitOfTimeRange $temp`
 [ "$unit" = "0" ]
 
 # ECC-457
+# ---------
 input=${data_dir}/tp_ecmwf.grib
 stepRange=`${tools_dir}/grib_get -w count=1 -p stepRange,startStep,endStep,stepType $input`
 [ "$stepRange" = "12 12 12 instant" ]
 
+# ECC-1430: stepType: 'severity' and 'mode'
+# -----------------------------------------
+${tools_dir}/grib_set -s stepType=severity,paramId=260318 $grib2_sample $temp
+grib_check_key_equals $temp productDefinitionTemplateNumber,typeOfStatisticalProcessing '8 100'
+${tools_dir}/grib_set -s stepType=mode,paramId=260320     $grib2_sample $temp
+grib_check_key_equals $temp productDefinitionTemplateNumber,typeOfStatisticalProcessing '8 101'
+
+# Clean up
 rm -f $temp
 rm -f $grib2File.p8tmp ${grib2File}.tmp x.grib