CAPE CANAVERAL, Fla. -

A top-secret satellite is being prepped for launch Monday at Cape Canaveral Air Force Station, and the weather looks as if it will be acceptable for flight.

The National Reconnaissance Office payload is scheduled to blast off at Launch Complex 41 at 8:26 a.m. aboard a United Launch Alliance Atlas V rocket.

The launch window Monday will extend through 9:25 a.m.

The Air Force 45th Space Wing Weather Squadron issued a forecast today that calls for an 80 percent chance that conditions will be acceptable for flight on Monday.

The only concern is a possibility that electrically charged cumulus clouds might sweep into the area during the launch window. Rockets flying through electrically charged clouds could trigger destructive bolts of lightning. So launch rules prohibit flight in those conditions.

In the event of a 24-hour delay, the forecast remains the same. The forecast for a 48-hour delay – or a launch next Wednesday – degrades slightly. There would be a 70 percent chance of acceptable weather.

The Atlas V to be launched Monday sports a four-meter payload fairing, no solid rocket boosters and a single Centaur upper stage engine.

The National Reconnaissance Office builds and operates the nation’s fleet of classified spy satellites, including photo and radar reconnaissance spacecraft, signals intelligence satellites, communications spacecraft, ocean reconnaissance satellites, and other classified payloads.

The agency was secretly formed in September 1961 and is celebrating its 50th anniversary this year.