The workaround I found out works for the most of the time is to upload to all three servers, that way if one stops, then you can get it online with the other two.
It might be worth a try.
Of course I would also see some people either from WU or TWC to respond and set up the ftp like it should been in the first place.
The ip-addresses of the FTP servers are:
$ dig -q webcam.wunderground.com
; <<>> DiG 9.9.7-P3 <<>> -q webcam.wunderground.com
;; global options: +cmd
;; Got answer:
;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 8153
;; flags: qr rd ra; QUERY: 1, ANSWER: 3, AUTHORITY: 0, ADDITIONAL: 1
;; OPT PSEUDOSECTION:
; EDNS: version: 0, flags:; udp: 4096
;; QUESTION SECTION:
;webcam.wunderground.com. IN A
;; ANSWER SECTION:
webcam.wunderground.com. 60 IN A
54.148.11.142webcam.wunderground.com. 60 IN A
52.37.52.183webcam.wunderground.com. 60 IN A
52.36.136.128;; Query time: 126 msec
;; SERVER: 192.168.1.1#53(192.168.1.1)
;; WHEN: Mon Feb 05 20:05:05 CET 2018
;; MSG SIZE rcvd: 100
$
Hope it works.
You can read more how I do it here:
https://www.facebook.com/weathern3b/posts/1629822633752054