Adding plots of snow-to-liquid ratio (SLR) (#253)

* Adding functionality to plot the snow-to-liquid ratio (U. Utah method)

* Updates to plotting for snow-to-liquid ratio

adb_graphics/conversions.py

@@ -101,3 +101,9 @@ def weasd_to_1hsnw(field, **kwargs):
     ''' Conversion from snow wter equiv to snow (10:1 ratio) '''
 
     return field * 10.
+
+def sden_to_slr(field, **kwargs):
+
+    ''' Convert snow density (kg m-3) to snow-liquid ratio '''
+
+    return 1000. / field

adb_graphics/default_specs.yml

@@ -2008,6 +2008,16 @@ weasd: # Water equivalent of accumulated snow depth
     title: Snow Water Equivalent
     transform: conversions.kgm2_to_in
     unit: in
+snoliqr: # Snow-liquid ratio (from U. Utah diagnostic in UPP)
+  sfc:
+    clevs: [6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 26, 28]
+    cmap: gist_ncar
+    colors: snow_colors
+    ncl_name: SDEN_P0_L1_{grid}
+    ticks: 0
+    title: Instantaneous Snow-Liquid Ratio (U. Utah Method)
+    transform: conversions.sden_to_slr
+    print_units: false
 windmax:
   10m:
     accumulate: True

image_lists/hrrr_subset.yml

@@ -15,6 +15,8 @@ hourly:
       - sfc
     acsnw:
       - sfc
+    snoliqr:
+      - sfc
     cape:
       - mu
       - mul