New for version 2.2:

• Short state list now included with cancellation notices.
• Short state list now included on the e-mail list.
• Subject lines on the e-mail list shortened.
• When a watch is expired, it is now announced on Twitter (with short state list).
• When the bot affirms the likelihood of a convective watch, the mesoscale discussion that prompted the tweet is cited.

Follow @weatherwatches on Twitter.

Under The Hood

Information is ingested from the LDM network, which is nearly instantaneous.  The information being scanned is the preliminary watch box notifications, which means there will be a tweet usually about 5 minutes before the watch is actually issued (and most other media pick up on it).  The bot will tweet the type of watch, state list, and expiration time in one tweet.  Immediately after, he will list the top cities affected (in descending order of population).

Recent Improvements

Beginning in March of 2009, the bot will also tweet a warning when a watch is imminent (when the Storm Prediction Center issues a mesoscale discussion indicating that either a watch “will be needed soon” or is “likely”).  The same geographic information will be given as when a watch is issued, however, the event will be referred to as an “area of concern” until the watch is actually issued.

Jargon Alert

If you’re not familiar, these types of watches are issued by the Storm Prediction Center in Norman, Oklahoma.  If you’re not sure what Tornado or Severe Thunderstorm Watches are, the Storm Prediction Center has provided a very thorough and easy-to-read FAQ on this topic.

“Weather Watches” is just meant as a simple, heads-up service for people who like to receive timely information via Twitter (or on your phone via SMS updates).  If you have questions about the bot or what the terminology means, please tweet to me personally.  I am @blairblends on Twitter.

Future Plans

I will eventually make the bot “smarter” when day one or two outlooks indicate MDT or HIGH probabilities.  Additionally, I will phrase PDS watches differently as soon as I have time to work on the code again.  If you have other suggestions, please tweet me (see link above) or e-mail watches@wxdata.us.

For Chasers, Media, Meteorologists

There is an e-mail list with detailed information that is dispatched when a preliminary watch box goes up from WMO ID WWUS30.  If you’d like to be on this e-mail list, please send a request (along with your affiliation) to watches@wxdata.us.

When switched to version two, there will be several improvements:

• The data will be derived from the LDM server, which will afford up to a 30 second better lead time.  The data will continue to be pulled from the aviation notices, which are issued a few minutes ahead of the actual watch discussion.  (Typical lead time is 5 minutes over almost all other media.)
• A state list with local expiration time.  (Slightly updated from the current method.)
• A list of cities in the watch box, ordered by affected population.
• A link to an interactive map before the watch is even issued.
• When mesoscale discussions are designed “watch needed soon” or “watch likely”, there will be an announcement, along with the state and city list inside the area of concern.

This all happens automatically, usually less than 5 seconds after the products are sent from Norman.

Links

weatherwatches – Always the latest, the new version will appear here in a few days.
weatherwatches2 – If you’re feeling adventurous, follow the beta version!  (Tweets will stop when the switch happens, so follow weatherwatches, too.)