April 3, Atlas 5, DMSP-F19F19 means it will be the 19th Defense Meteorological Satellite launched. This is the second to last one; only 20 were manufactured.
Launch window: 1446-1456 GMT (10:46-10:56 a.m. EDT; 7:46-7:56 a.m. PDT)
Launch site: SLC-3E, Vandenberg Air Force Base, California
A United Launch Alliance Atlas 5 rocket, designated AV-044, will launch the Defense Meteorological Satellite Program 19 spacecraft for the U.S. Air Force. Built by Lockheed Martin, this polar-orbiting weather satellite will be used by the military for global weather forecasting. The rocket will fly in the 401 vehicle configuration with a four-meter fairing, no solid rocket boosters and a single-engine Centaur upper stage.
I've previously pulled my kid out of school for the entire day to drive her to Vandenburg AFB for a prior DMSP satellite launch. This time, I think we will just watch the satellite fly by from the Manhattan Beach Pier.
Spaceflight Now 101 has a page about the launch with links to the launch webcast and the ascent ground track. As I explained before, polar-orbiting weather satellites fly nearly due south from Vandenburg AFB. Tomorrow morning's sky is forecast to be clear so the entire Santa Monica bay should get a good view of the satellite as it flies by.
In case you missed it, you can watch the video.