Rose Parade to Display Massive Police Presence in Wake of Vegas Massacre

Authorities responsible for the Rose Parade have the Vegas massacre on their minds -- in fact, front and center -- TMZ has learned.

Law enforcement sources say the Parade is now a national matter ... authorities from the Pasadena as well as surrounding police departments will be all over the parade route, along with state police and federal agents.

We're told so far there are no credible threats that could put parade-goers in harm's way, but these are different times. There was no real warning with the Vegas shooter and authorities are keenly aware these attacks increasingly materialize without any warning.

And more signs of the times ... there will be barricades preventing terrorists from entering the route and going on a rampage. The area will be shut down 24 hours in advance so it can be fully secured.

There will be a full compliment of cops and equipment ... magnetometers, undercover officers, cops on horseback. The presence of law enforcement will be massive.

Cops want to stress what you've been hearing ... if you see something, say something.