NWS Weather Alerts via APRS
The UI-View32 APRS application has the ability to plot National Weather Service (NWS) advisories and warnings on high resolution maps. These NWS Weather advisories are available on the APRS-IS network as APRS messages. Once your software is properly configured, generation of the NWS overlay is automatic.
NWS weather message setup for UI-View
UI-View plots the NWS data on high resolution PrecisionMaps v8. An example showing a recent winter storm advisory is shown below:
The screen capture here is actually from APRSPlus, but you get the same results in UI-View.
Quick Start to generating NWS Maps in UI-View:
Download the following files (note that
they are very large): These were found on http://www.aprs-is.net/Wx/
AWIPS Shapefiles CONUS County http://www.nws.noaa.gov
Forecast CONUS Zones http://www.nws.noaa.gov
Costal Marine Zones http://www.nws.noaa.gov
YOU ALSO NEED TO DOWNLOAD UI-NWS FROM THE UI-VIEW WEB SITE. There is a HELP file recommended reading for UI-NWS.
Unzip the shape files into the NWS subdirectory under your UI-View directory.
Ensure UI-View is running.
Either wait for NWS messages via RF (transmit interval depends upon the weather, obviously), or connect to an APRServer via the internet to obtain national messages
The NWS messages that decode are generated by a server written by Dale Huguley, KG5QD. These message are in the following format. This information is from the following URL:
http://www.ae5pl.net/html/nws_databases.htm.
CWAPID>NWS-TTTTT:DDHHMMz,ADVISETYPE,zcs{seq#
CWA is the NWS office (See databases to the left).
PID is the product Code (See database to the left).
TTTTT is ADVISE, WARN, WATCH, etc.
DDHHMMz is the expiration time.
ADVISETYPE is things like FLOOD, FLASHFLOOD, SVRTSM, SEVERE_WEATHER, etc.
zcs are the zone codes, county codes (See databases to the left), or statement text.
{seq# is decoded as:
The first three characters are the "issue time" compressed by assigning 0-9 as themselves A-Z as 10 thru 36 a-z as 37 - 62 --where it is DHM (Day of the Month-Hour in 24 hour format and Minute). Up to 16 this reads as hexadecimal so {A8B** was issued on the 10th at 08:11 Z.
The next two characters are line numbers which (along with the "From Call" ) make the packet unique. Any packet with the "from Call" and the first 4 digits of the sequence matching are "associated" packets- in
other words they are from the same product or portion of product that is defined by UGC codes.
The final character is for sorting and for assigning some priority to the various outputs (objects, headlines, packets that highlight counties, background info).
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From, To, Expires, Type, Zones/Codes, Posted, Sequence, and Path.
From: This is the CWA of the NWS office, and PID
To: is the TTTTT, or level of warning
Expires: is the Expiration time of the message
Type: is the ADVISETYPE
Zones/Codes: are the zone and county codes. There can be multiple zones or counties in one message.
Posted: This is the date/time the message was posted. This is taken from the Sequence number
Sequence: is the sequence number of the message.
Path: is the APRS path by which the packet was received.