diff --git a/pyart/io/output_to_geotiff.py b/pyart/io/output_to_geotiff.py
index 8c45f59faf..7e327dfa8e 100644
--- a/pyart/io/output_to_geotiff.py
+++ b/pyart/io/output_to_geotiff.py
@@ -34,7 +34,7 @@ def write_grid_geotiff(
     sld=False,
     use_doublequotes=True,
     transparent_bg=True,
-    opacity=1.0
+    opacity=1.0,
 ):
     """
     Write a Py-ART Grid object to a GeoTIFF file.
@@ -169,8 +169,9 @@ def write_grid_geotiff(
         )
     else:
         # Assign data RGB levels based on value relative to vmax/vmin
-        rarr, garr, barr, aarr = _get_rgb_values(data, vmin, vmax, color_levels, cmap,
-                                                 transparent_bg, opacity)
+        rarr, garr, barr, aarr = _get_rgb_values(
+            data, vmin, vmax, color_levels, cmap, transparent_bg, opacity
+        )
         dst_ds = out_driver.Create(
             ofile, data.shape[1], data.shape[0], 4, gdal.GDT_Byte
         )
@@ -283,7 +284,6 @@ def _get_rgb_values(data, vmin, vmax, color_levels, cmap, transpbg, op):
             else:
                 aarr.append(0)
 
-
     rarr = np.reshape(rarr, data.shape)
     garr = np.reshape(garr, data.shape)
     barr = np.reshape(barr, data.shape)
diff --git a/tests/io/test_output_to_geotiff.py b/tests/io/test_output_to_geotiff.py
index bffa3dd14d..7f9259b0e1 100644
--- a/tests/io/test_output_to_geotiff.py
+++ b/tests/io/test_output_to_geotiff.py
@@ -26,7 +26,6 @@ def test__get_rgb_values_nan():
     assert np.isnan(garr[5])
 
 
-
 def test_raise_missingoptionaldepedency():
     backup = bool(pyart.io.output_to_geotiff.IMPORT_FLAG)
     pyart.io.output_to_geotiff.IMPORT_FLAG = False
@@ -55,6 +54,7 @@ def make_tiny_grid():
     grid.fields = {"reflectivity": rdic}
     return grid
 
+
 def make_tiny_grid_with_mask():
     """Make a tiny grid."""
     grid_shape = (2, 10, 8)
@@ -70,6 +70,7 @@ def make_tiny_grid_with_mask():
     grid.fields = {"reflectivity": rdic}
     return grid
 
+
 @pytest.mark.skipif(
     not pyart.io.output_to_geotiff.IMPORT_FLAG, reason="GDAL is not installed."
 )
@@ -150,6 +151,7 @@ def test_write_grid_geotiff_missing_field():
     grid = make_tiny_grid()
     pytest.raises(KeyError, pyart.io.write_grid_geotiff, grid, "test.foo", "foobar")
 
+
 @pytest.mark.skipif(
     not pyart.io.output_to_geotiff.IMPORT_FLAG, reason="GDAL is not installed."
 )
@@ -160,13 +162,17 @@ def test_write_grid_geotiff_transparent_background():
         with pyart.testing.InTemporaryDirectory() as tmpdir:
             tmp = Path(tmpdir)
             outname = tmp / "transparent_bg.tif"
-            pyart.io.write_grid_geotiff(grid, str(outname), "reflectivity",
-                                        rgb=True,
-                                        cmap='pyart_HomeyerRainbow',
-                                        vmin=0,
-                                        vmax=40,
-                                        transparent_bg=True,
-                                        opacity=1)
+            pyart.io.write_grid_geotiff(
+                grid,
+                str(outname),
+                "reflectivity",
+                rgb=True,
+                cmap="pyart_HomeyerRainbow",
+                vmin=0,
+                vmax=40,
+                transparent_bg=True,
+                opacity=1,
+            )
             imgname = outname.rename(tmp / "transparent_bg.tiff")
             img = Image.open(imgname)
             img.show()
@@ -174,7 +180,6 @@ def test_write_grid_geotiff_transparent_background():
         pass
 
 
-
 @pytest.mark.skipif(
     not pyart.io.output_to_geotiff.IMPORT_FLAG, reason="GDAL is not installed."
 )
@@ -184,13 +189,17 @@ def test_write_grid_geotiff_opacity():
         with pyart.testing.InTemporaryDirectory() as tmpdir:
             tmp = Path(tmpdir)
             outname = tmp / "opacity.tif"
-            pyart.io.write_grid_geotiff(grid, str(outname), 'reflectivity',
-                                        rgb=True,
-                                        cmap='pyart_HomeyerRainbow',
-                                        vmin=0,
-                                        vmax=40,
-                                        transparent_bg=False,
-                                        opacity=0.25)
+            pyart.io.write_grid_geotiff(
+                grid,
+                str(outname),
+                "reflectivity",
+                rgb=True,
+                cmap="pyart_HomeyerRainbow",
+                vmin=0,
+                vmax=40,
+                transparent_bg=False,
+                opacity=0.25,
+            )
             imgname = outname.rename(tmp / "opacity.tiff")
             img = Image.open(imgname)
             img.show()