As an additional . . . I run the script in cron every minute, even
when NOAAPort is up . . . it certainly doesn't hurt anything.
Stonie
On Apr 28, 2007, at 12:19 PM, Gilbert Sebenste wrote:
Hello all,
As you know, last Saturday we had a tornado outbreak in Texas, and
the National Weather Service (NWS) NOAAport feed went down. When a
satellite broadcaster interfered by sending a rogue signal on the
same frequency that NOAAPort broadcasted on, it knocked just about
everyone's data feed out in the U.S., from the UNIDATA community,
to the media...in short, almost all external NWS data users. When
this happened, the only ways to get data were:
1. NOAAport feed fed directly by fiber from the NWS (very expensive)
2. Family Of Services, a slower speed with fewer text products and
model data, but high speed radar (also very $$$$)
3. NOAA All-Hazards Radio (fed by the AWIPS WAN)
4. Some NWS web sites (and not all data were available, especially
on NWS Region servers)...and they were generally very slow as
everyone hit them when the NOAAport feed went down
5. EMWIN
Should this ever happen again (it will), I have now set up an LDM
server that grabs the EMWIN feed via the Internet in near-real time.
Because of EMWIN's slow data feed (9600 baud), and how the NWS
sends out the files on their public server, there is a delay of
about 2-3 minutes with the feed in total. However, when you're in a
tornado outbreak and you have nothing else, you'll take ANYTHING
you can get your hands on!
So in that vein I am pleased to announce a new EMWIN feed site that
is fed directly from EMWIN's public FTP server. Here are the
caveats/legal stuff:
1. Data delayed a minimum of 2 minutes
2. Unsupported in that I won't have much time to work on it if it
goes down
3. This is an unofficial feed; as is, with all legal disclaimers
applying that you should not use this feed to save your life or the
lives of others, or use in any official way so that you don't get
into trouble when the warning comes in too late, or not at all if
the feed is down, etc etc etc.
4. I reserve the right to terminate the feed if my office gets hit
with a data outage; this server is used as a backup in case my main
office building has a major network connectivity problem that last
for days or weeks or longer. If that happens, I will feed NOAAport
to this backup machine and shut off EMWIN and access to all except
those who have already requested a NOAAPort feed from me. That
hasn't happened in the 8+ years I've been here, but you never know.
5. How do you save the images and what is available on the EXP
feed? Sorry, I don't know, and won't have time to play with it. I
can grab satellite/radar via the Internet and with more current
data, so I don't care. OK, disclaimers aside...
HOW I DO IT: Using a script developed by Stonie Cooper from
Planetary Data, Inc. (Thanks, Stonie!) under the GNU Public
License, it downloads the data from the public NWS EMWIN server
which itself updates with all products sent over the last 2
minutes; I grab it every 60 seconds. Once the file updates, the
script grabs it, unzips the data, uploads the products which
contain WMO headers to the LDM software running the IDS|DDPLUS|EXP
protocols. I then use the LDM to grab the data being injected into
it and send the warnings to the Web site, and to feed *anyone* who
wants it via the LDM. Remember, EMWIN is only a 9600 baud feed, and
it only contains the most critical of information. You can learn
exactly what comes across EMWIN by seeing this page, which has the
complete data listing:
http://www.weather.gov/emwin/windat.htm
THE SITE: If you are using the LDM, request IDS|DDPLUS for text
products, and EXP for image products, to the following site:
www.ehs.niu.edu
When you request IDS|DDPLUS, you'll get the products with standard
WMO headers; there is no need to change your pqact.conf to
accomodate the EMWIN feed, UNLESS you want the images on the EXP
feed, which are typically delayed images from NWS web sites. NOTE:
LDM 6.6.3 is absolutely recommended to get this feed successfully.
Because of the "bursty" nature of this feed, LDM's 6.5 and before
can miss a product as the feed starts back up after a delay. There
may be 1-3 minutes where you get nothing, depending on the time of
day and if there's no severe weather going on.
The UNIX-based bash script is freely available if you wish to do
this locally. It will work on UNIX/Linux (I'm running it on Fedora
Core),
and I'll send you the script if you want it. It is very easy to
integrate it into your NOAAport feed. You do have to turn the
script on manually, which means that if NOAAport goes down, you
have to know that (easy to tell), but you have to be at a machine
to monitor your feed to see it happening.
So there it is. Nothing earth-shaking here, just a decent backup in
case all heck breaks loose and NOAAport croaks. I hope you DON'T
find it useful, as I hope the NOAAport feed always stays on! :-)
Gilbert
**********************************************************************
*********
Gilbert
Sebenste ********
(My opinions
only!) ******
Staff Meteorologist, Northern Illinois
University ****
E-mail:
sebenste@xxxxxxxxxxxxxxxxxxxxx ***
web: http://
weather.admin.niu.edu **
**********************************************************************
*********
