Timer Intervals are multipliers for the top timer.   The top timer (WebAlert Timer/Refresh Resolution) is the only place where you specify minutes.  In the above picture i have set the timer resolution to 60 minutes.  This means weather and/or custom web alerts cannot occur more frequently than every 60 minutes.  There is only one timer controlling all web-based alerts.  The Timer interval for weather shown above is set to 1... that means it will process weather alerts every 60 minutes (since that is the resolution).  If this Timer interval had been 2, the weather alerts would be processed every 120 minutes, and so on.   Do not set the timer interval too low since they can take quite a number of seconds for x10dispatch to process and also you do not want to place a significant burden the web sites you are grabbing information from.  I see no reason for the timer resolution to be below 30 minutes.

Custom WebAlerts : Most of x10 dispatcher was designed to be very user friendly.  This isn't, sorry.  Some people who are less technically inclined may decide to avoid this feature, although i have tried to make it as intuitive as possible under circumstances. 

Ok, lets say you know of a web page which contains information which occasionally contains information which you want to be notified.  Since you are human, you read the page and look for that information.  NOAA is the United States' national weather service.  Their website lets you enter your region and this will take you to a webpage which shows your current region's weather forecast.  You could bookmark this page... its consistently available.  I also know that if there is a weather alert, they consistently add the text 'Hazzardous Weather Outlook' to the page when there is a weather alert... and this text only occurs on the page if there IS a hazzardous weather alert.  This could be turned into an x10 custom web alert. 

Simply copy the URL into the Url textbox in the x10 dispatch custom alerts screen,

Set Alert Description to something like 'NOAA Weather Alert' (this is also the email subject header if email is chosen).

Select 'If page Contains' and in the textbox below, enter 'Hazzardous Weather Outlook'. 

Grab Text  (Optional) : The NOAA webpage usually places a small description of the Hazzardous condition immediately after the words 'Hazzardous Weather Outlook', so i can 'grab' that text to include in the email.  I select 'Grab and include text near match', and leave the Start Offset at 0 and set Length to 50.  The text to be grabbed will start at the first letter of the Search phrase and extend for 50 characters after.  So the grabbed text would probably read something like 'Hazzardous Weather Outlook' 'High Winds'  and possibly run into the next 20 or characters which follow.  Since i already know about the 'Hazzardous Weather Outlook' since that is my search phrase, maybe i want to start after that, so i adjust the Start Offset to 27 to skip that... it will grab 50 characters starting 'after' the search phrase. You can also set start offset below zero... back to a minimum of -100 (100 characters before the search string was found)... this is useful if the information you are searching is in a list or table and you want information in prior columns to be visible in alert.  The maxlength you can grab is 1500.  Most cell phones limit text message to 100 - 200 so be sure to 'start' at an informative location.  X10 dispatcher strips out a lot of text from the webpage, such as most of the HTML tags, excessive whitespace, newlines, carriage returns.  While this will be refined slightly in future versions, you should be aware that some information might be different than it appears.  The test button will preview the remainder of the cleaned up webpage, which hopefully will assist you in determining starting offsets and lengths and Search criteria.  Also since it does strip HTML tags, you probably will not be able to use it for RSS alerts (if you don't know what that is, your not affected).  A future version will probably add checkbox to control stripping of tags or not.

Grab Text is usually rough, but filtered down enough that you can sift through it on the alert end.  Whether you grab text or not, your alert description will be a part of the alert, so you will know it happened even if you dont have details.  You could then find a computer and visit the web site for details about the alert.

So why bother with Weather Alert if i can do that with a Custom Alert?  Alot of people might not want to go through the trouble.  Actually more importantly for me, the NOAA site places the good detailed weather bulletin information on a separate page, while weatherroom.com taps into those feeds and displays them on one page/url.  Weatherroom.com also has a more predictable URL parameters that i can plug a zipcode into (NOAA uses obscure weather station id's)... so weatherroom is nicer as a generic, easily configurable service. 

So things to keep in mind :

Is all information on a single page?

Does that single page have a consistent url (one which can be navigated to directly without going through their home page)?

Can you define a Search Criteria which will match and only match on your Alert Condition?

WebAlerts are 'always' armed, but can be temporarily disabled from the Options menu.  Once they do fire, they will be suppressed from firing again until all WebAlerts are reset (via button on alert tab and/or msn command).

Good luck!