Fix sounding merge bug

- Fix merging for MAN winds to properly mimic GEMPAK behavior
- Add testing file for this edge case

Fixes #3563

Author: nawendt

src/metpy/io/gempak.py

@@ -1652,18 +1652,6 @@ def _merge_mandatory_winds(self, merged, parts, section, qcman):
                 if merged['DRCT'][loc] == self.prod_desc.missing_float:
                     merged['DRCT'][loc] = parts[section]['DRCT'][iwind]
                     merged['SPED'][loc] = parts[section]['SPED'][iwind]
-            else:
-                if press not in qcman:
-                    size = len(merged['PRES'])
-                    loc = size - bisect.bisect_left(merged['PRES'][1:][::-1], press)
-                    if loc >= size + 1:
-                        loc = -1
-                    merged['PRES'].insert(loc, press)
-                    merged['TEMP'].insert(loc, self.prod_desc.missing_float)
-                    merged['DWPT'].insert(loc, self.prod_desc.missing_float)
-                    merged['DRCT'].insert(loc, parts[section]['DRCT'][iwind])
-                    merged['SPED'].insert(loc, parts[section]['SPED'][iwind])
-                    merged['HGHT'].insert(loc, self.prod_desc.missing_float)
 
     def _merge_winds_pressure(self, merged, parts, section, pbot):
         """Process and merge wind sections on pressure surfaces."""
@@ -1760,6 +1748,8 @@ def _merge_winds_height(self, merged, parts, nsgw, nasw, istart):
                 ]:
                     merged['DRCT'][ilev - 1] = drct
                     merged['SPED'][ilev - 1] = sped
+            elif hght <= zold:
+                    skip = True
             elif hght >= znxt:
                 while more and hght > znxt:
                     zold = znxt

src/metpy/static-data-manifest.txt

@@ -49,6 +49,8 @@ gem_model_mrg.csv 304afb3bb4b662f7adfc8803e8661fc217a691d0b1790d5e0e6d085f198c42
 gem_model_mrg.snd 6d229a7af8d3e86d8da02403023cdaf0f86b6c982eb8b6f7f84c3836811df014
 gem_multi_time.grd a11746f162f2ea3944573246a477db94026f76e72ce7ecb98bd08c8475e2ca3f
 gem_multilevel_multidate.grd a5642ad733e88e9512d979b7c95049e9572591622d9ac94645622c1723742909
+gem_nzwp_no_ttcc.csv bb37082c3f219ef261f614a9a45653714a02162c07767109cc6e4cd5fbde9e27
+gem_nzwp_no_ttcc.snd 0dae2296b3b81688883fb06a9378ed39fbc054f6eb15ebe8f892062c78e3816f
 gem_packing_dec.grd 547cda1ffb5e143623a33afce76a6cfa8c3c543eed04cf388f3005ccf1ba677d
 gem_packing_dec.npz b4b3b838b245c0e0d0d803c049a9169c34fe1c09f267d98df5a0d0586297d18d
 gem_packing_diff.grd 35de37fb378fe1c8cb1be56962ab3496ee079a3c6df4ef838cf1e2e8fd86da3f

staticdata/gem_nzwp_no_ttcc.csv

@@ -0,0 +1,91 @@
+PRES,TEMP,DWPT,DRCT,SPED,HGHT
+1022.0,8.0,7.0,140.0,2.06,27.0
+1021.0,8.8,5.1,139.1,2.29,35.14
+1009.0,10.8,3.8,128.23,5.09,133.91
+1000.0,10.6,4.6,120.0,7.21,209.0
+988.54,10.41,4.41,100.0,10.81,305.0
+988.0,10.4,4.4,99.88,10.83,309.56
+925.0,6.0,4.4,85.0,12.87,854.0
+924.0,6.0,4.5,84.26,13.02,862.88
+918.22,5.73,3.79,80.0,13.9,914.0
+884.5,4.11,-0.44,75.0,16.47,1219.0
+854.0,2.6,-4.4,65.63,15.5,1505.02
+852.0,2.4,-3.55,65.0,15.44,1524.0
+850.0,2.2,-2.7,65.0,14.41,1543.0
+838.0,1.2,-2.0,63.01,13.59,1657.62
+820.19,0.01,-3.22,60.0,12.36,1829.0
+789.42,-2.12,-5.39,70.0,10.81,2134.0
+770.0,-3.5,-6.8,76.51,8.8,2332.65
+759.78,-4.04,-9.95,80.0,7.72,2438.0
+744.0,-4.9,-14.9,77.3,7.86,2603.38
+702.87,-7.33,-19.19,70.0,8.24,3048.0
+700.0,-7.5,-19.5,45.0,6.18,3080.0
+649.33,-11.82,-37.7,35.0,5.15,3658.0
+635.0,-13.1,-43.1,46.19,5.15,3829.67
+623.95,-14.09,-41.0,55.0,5.15,3962.0
+599.21,-16.36,-36.17,110.0,3.09,4267.0
+583.0,-17.9,-32.9,174.09,4.48,4473.74
+575.34,-18.3,-35.62,205.0,5.15,4572.0
+552.19,-19.56,-44.05,225.0,7.21,4877.0
+532.0,-20.7,-51.7,222.74,10.23,5153.65
+508.5,-22.16,-50.24,220.0,13.9,5486.0
+500.0,-22.7,-49.7,220.0,14.93,5610.0
+485.0,-23.5,-57.5,223.41,16.83,5833.52
+474.0,-22.7,-61.7,225.98,18.26,6001.86
+400.0,-30.5,-69.5,245.0,28.83,7230.0
+392.0,-31.9,-69.9,245.0,30.2,7373.04
+362.3,-34.48,-66.37,245.0,35.52,7925.0
+349.0,-35.7,-64.7,247.02,36.97,8186.88
+301.0,-43.72,-62.94,255.0,42.73,9197.28
+300.0,-43.9,-62.9,255.0,42.73,9220.0
+289.83,-45.94,-63.92,255.0,42.73,9449.0
+271.0,-49.9,-65.9,255.0,42.26,9894.8
+250.0,-52.5,-67.5,255.0,41.7,10420.0
+236.0,-53.9,-66.9,255.0,40.67,10789.72
+229.38,-52.81,-70.95,255.0,41.18,10973.0
+216.0,-50.5,-79.5,255.0,36.67,11360.42
+200.0,-50.7,-81.7,255.0,30.89,11860.0
+199.17,-50.74,-81.73,250.0,29.86,11887.0
+164.94,-52.71,-83.04,255.0,28.83,13106.0
+150.09,-53.69,-83.7,265.0,23.68,13716.0
+150.0,-53.7,-83.7,260.0,23.17,13720.0
+130.08,-55.04,-84.68,240.0,18.02,14630.0
+118.24,-55.93,-85.34,245.0,11.84,15240.0
+112.72,-56.38,-85.67,265.0,14.41,15545.0
+107.47,-56.83,-86.0,250.0,17.5,15850.0
+102.47,-57.27,-86.33,245.0,14.93,16154.0
+100.0,-57.5,-86.5,255.0,11.33,16310.0
+97.67,-57.42,-86.42,255.0,11.33,16459.0
+95.0,-57.32,-86.32,235.0,12.87,16634.38
+91.0,-57.16,-86.16,265.0,7.21,16906.43
+86.0,-56.96,-85.96,245.0,9.27,17263.82
+84.0,-56.87,-85.87,255.0,8.24,17412.63
+81.0,-56.74,-85.74,240.0,7.21,17642.62
+80.0,-56.7,-85.7,247.45,6.7,17721.18
+79.0,-56.86,-85.75,255.0,6.18,17799.85
+76.0,-57.37,-85.89,285.0,11.84,18041.96
+74.0,-57.72,-85.99,290.0,15.44,18208.74
+70.0,-58.45,-86.2,245.0,11.33,18556.27
+66.0,-59.22,-86.42,225.0,7.21,18924.25
+62.0,-60.04,-86.66,235.0,9.78,19315.24
+55.0,-61.61,-87.1,200.0,7.72,20064.46
+54.0,-61.86,-87.17,205.0,5.66,20179.21
+53.0,-62.1,-87.24,185.0,4.63,20296.11
+52.2,-62.3,-87.3,188.99,5.05,20391.22
+52.0,-62.27,-87.3,190.0,5.15,20415.06
+50.0,-61.96,-87.35,230.0,7.21,20658.62
+48.0,-61.63,-87.4,215.0,6.69,20912.12
+45.0,-61.11,-87.48,230.0,5.15,21312.9
+40.0,-60.17,-87.63,205.0,6.69,22044.33
+37.7,-59.7,-87.7,216.09,7.38,22412.08
+35.0,-61.15,-88.25,230.0,8.24,22871.16
+33.0,-62.31,-88.68,195.0,12.36,23234.66
+30.0,-64.17,-89.38,210.0,7.21,23823.46
+29.5,-64.5,-89.5,217.31,7.21,23927.29
+28.0,-62.6,-88.96,240.0,7.21,24250.3
+26.0,-59.9,-88.18,235.0,12.36,24708.98
+25.3,-58.9,-87.9,245.23,12.53,24877.91
+24.0,-58.84,-87.84,265.0,12.87,25208.88
+22.0,-58.75,-87.75,245.0,14.41,25754.82
+21.0,-58.7,-87.7,265.0,10.3,26046.71
+20.6,-59.1,-88.1,-9999.0,-9999.0,26167.31

staticdata/gem_nzwp_no_ttcc.snd

@@ -427,3 +427,34 @@ def test_multi_time_grid():
 
     assert dattim1 == datetime(1991, 8, 19, 0, 0)
     assert dattim2 == datetime(1991, 8, 20, 0, 0)
+
+def test_unmerged_no_ttcc():
+    """Test loading an unmerged sounding.
+
+    Sounding will have a PPCC group, but no TTCC group. This
+    tests for proper handling of MAN winds on pressure surfaces
+    without any temp/dewpoint/height data.
+    """
+    gso = GempakSounding(get_test_data('gem_nzwp_no_ttcc.snd')).snxarray()
+    gpres = gso[0].pressure.values
+    gtemp = gso[0].temp.values.squeeze()
+    gdwpt = gso[0].dwpt.values.squeeze()
+    gdrct = gso[0].drct.values.squeeze()
+    gsped = gso[0].sped.values.squeeze()
+    ghght = gso[0].hght.values.squeeze()
+
+    gempak = pd.read_csv(get_test_data('gem_nzwp_no_ttcc.csv', as_file_obj=False),
+                         na_values=-9999)
+    dpres = gempak.PRES.values
+    dtemp = gempak.TEMP.values
+    ddwpt = gempak.DWPT.values
+    ddrct = gempak.DRCT.values
+    dsped = gempak.SPED.values
+    dhght = gempak.HGHT.values
+
+    np.testing.assert_allclose(gpres, dpres, rtol=1e-10, atol=1e-2)
+    np.testing.assert_allclose(gtemp, dtemp, rtol=1e-10, atol=1e-2)
+    np.testing.assert_allclose(gdwpt, ddwpt, rtol=1e-10, atol=1e-2)
+    np.testing.assert_allclose(gdrct, ddrct, rtol=1e-10, atol=1e-2)
+    np.testing.assert_allclose(gsped, dsped, rtol=1e-10, atol=1e-2)
+    np.testing.assert_allclose(ghght, dhght, rtol=1e-5, atol=1e-2)