Spaces in RegExp pattern

[RaS!]

Hy guys,
I'm working on a metar and I've this tring:
"MON CLD CIME VAL INVIS"

I've set my regexp pattern as this:

xeFM.Pattern = "^(MON|VAL)?(LIB|CLD SCT|VERS INC|CNS POST|CLD CIME|CIME INC|GEN INC|INC|INVIS)?(NIL|FOSCHIA SKC SUP|NEBBIA SCT|NEBBIA|CLD SCT|CLD SCT NEBBIA INF|MAR CLD|INVIS)?$"

It works fine, but it cannot recognize expressions wich contains a space such 'CLD CIME'. How can I
fix my pattern? thanks!