[nws-changes] 20100430: [Ncep.list.rfcmemo] Special Notification - RUC Model]

• To: nws-changes@xxxxxxxxxxxxxxxx
• Subject: [nws-changes] 20100430: [Ncep.list.rfcmemo] Special Notification - RUC Model]
• From: Linda Miller <lmiller@xxxxxxxxxxxxxxxx>
• Date: Fri, 30 Apr 2010 09:55:55 -0600

-------- Original Message --------

NCEP has experienced several recent failures of the Rapid Update Cycle
(RUC) model.  These failures are due to violations of the
Courant-Friedrichs-Levy (CFL) stability condition, which can occur in
various situations, but have been experienced recently on the east side
of the Sierras with strong mountain waves.  In order to prevent these
failures, a change has been made to the operational configuration of the
RUC, specifically the model time step.  This change results in a slight
delay of the output products:  up to approximately 1 minute for the 6-hr
forecast products, approximately 2 minutes for the 12-hr forecast

notice.  The alternative is that we continue to experience intermittent
model failures which result in significantly later product arrival
times, or possibly no RUC data at all for a particular model cycle.

If you have questions or concerns about this change, please contact the
NCO Dataflow Group at ncep.pmb.dataflow@xxxxxxxx