I don't mind either way.
Attached is a minimal diff that will - of course - not make a current
build tool chain happy ("dh_builddeb: This package will soon FTBFS; time
to fix it!").
But it fixes the immediate issue of making the program usable again.
diff -Nru metar-20061030.1/debian/changelog metar-20061030.1/debian/changelog
--- metar-20061030.1/debian/changelog 2016-10-19 19:08:25.000000000 +0200
+++ metar-20061030.1/debian/changelog 2016-10-19 19:08:25.000000000 +0200
@@ -1,3 +1,10 @@
+metar (20061030.1-2.2) unstable; urgency=medium
+
+ * Non-maintainer upload
+ * Import patch for new METAR URL from Kees Leune (Closes: #839907)
+
+ -- Daniel Lange <dl....@usrlocal.de> Wed, 19 Oct 2016 19:00:00 +0200
+
metar (20061030.1-2) unstable; urgency=low
* Build-Depends on libcurl3-gnutls-dev instead of libcurl3-dev
diff -Nru metar-20061030.1/src/metar.h metar-20061030.1/src/metar.h
--- metar-20061030.1/src/metar.h 2006-04-05 22:30:28.000000000 +0200
+++ metar-20061030.1/src/metar.h 2016-10-19 19:08:25.000000000 +0200
@@ -24,7 +24,7 @@
#define METAR_MAXSIZE 512
/* where to fetch reports */
-#define METARURL
"http://weather.noaa.gov/pub/data/observations/metar/stations";
+#define METARURL "http://tgftp.nws.noaa.gov/data/observations/metar/stations";
/* clouds */
typedef struct {
