✅ Workaround LSRs with just TRACE

CHANGELOG.md

@@ -19,6 +19,7 @@ generating plots of HRRR ptype.
 
 ### Bug Fixes
 
+- Accomodate ancient LSRs using `TRACE` as the magnitude field.
 - Ensure geometries going into masking helper are CCW, to mask outside of.
 
 ## **1.21.0** (6 Sep 2024)

data/product_examples/LSR/LSRSEW.txt

@@ -0,0 +1,23 @@
+357 
+NWUS56 KSEW 141924 CCA
+LSRSEW
+
+PRELIMINARY LOCAL STORM REPORT
+NATIONAL WEATHER SERVICE SEATTLE WA
+1124 AM PST SAT JAN 14 2012
+
+..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
+..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
+ ..REMARKS..
+
+1050 AM SNOW 4 SW EVERETT 47.92N 122.25W 
+01/14/2012 TRACE INCH SNOHOMISH WA TRAINED SPOTTER 
+
+ SLUSH ON ROADWAYS. 
+
+
+&&
+
+$$
+
+GRUB

src/pyiem/nws/lsr.py

@@ -164,6 +164,10 @@ def get_lon(self):
 
  def consume_magnitude(self, text):
  """Convert LSR magnitude text into something atomic"""
+ # Brute force this special case, which trips up the regex
+ if text.upper().strip().startswith("TRACE"):
+ self.magnitude_f = TRACE_VALUE
+ return
  self.magnitude_str = text
  tokens = MAG_UNITS.findall(text)
  if not tokens:

tests/nws/products/test_lsr.py

@@ -7,6 +7,13 @@
 from pyiem.util import get_test_file
 
 
+def test_240927_bad_qualifier():
+ """Test a product that generates an invalid qualifier."""
+ prod = parser(get_test_file("LSR/LSRSEW.txt"))
+ assert prod.lsrs[0].magnitude_qualifier is None
+ assert abs(TRACE_VALUE - prod.lsrs[0].magnitude_f) < TRACE_VALUE
+
+
 def test_240926_nolsrs():
  """Test that this processes a LSR!"""
  prod = parser(get_test_file("LSR/LSRFWD.txt"))