Multi-line highlighting in Sublime Text syntax definition

I'm trying to create a syntax highlighter that matches custom headers in my logs. Here's an example:

SYSTEM INFORMATION
Memory
----------------------------------------
Total                    14841733120
Free                     12260917248
Active                   583532544
Swap Total               5009104896
Swap Free                5009104896
% Used                   3
% Swap Used              0

Disk
----------------------------------------
Total                    114272681984
Free                     107483385856
% Used                   5

What I want to match is the header line (eg, Memory) and the following line's dashes. I've developed a regex pattern to do just this:

^[\w|\ ]+(\ {0,})\n(\-{40})

Unfortunately, when I try to create a custom syntax highlighter, this regex no longer matches.

<?xml version="1.0" encoding="UTF-8"?>
<!DOCTYPE plist PUBLIC "-//Apple Computer//DTD PLIST 1.0//EN" "http://ift.tt/vvUEPL">
<plist version="1.0">
<dict>
    <key>fileTypes</key>
    <array>
        <string></string>
    </array>
    <key>name</key>
    <string>mylog</string>
    <key>patterns</key>
    <array>
        <dict>
            <key>comment</key>
            <string>section header</string>
            <key>match</key>
            <string>^[\w|\ ]+(\ {0,})\n(\-{40})</string>
            <key>name</key>
            <string>constant.character.mylog</string>
        </dict>
    </array>
    <key>scopeName</key>
    <string>text.mylog</string>
    <key>uuid</key>
    <string>unique-uuid</string>
</dict>
</plist>

Any suggestions on getting the custom syntax highlighter to match both lines?