The 20 km RUC implementation scheduled for 12Z
today, 16 April, has been postponed. A critical
weather day has been declared due to the expected
severe weather outbreak over the northern plains,
and model changes are not permitted when such a
declaration is made. The implementation is now
scheduled for 12Z tomorrow - the severe weather threat
appears to be less for tomorrow, so the critical
weather day will likely not be extended, but no
guarantees can be made at this time.