SpaceX NASA Launch Weather Forecast: 50 Percent Chance of Unfavorable Conditions on Saturday at Kennedy Space Center

Wednesday's historic SpaceX launch was scrubbed shortly before liftoff due to stormy conditions along Florid's Atlantic coast. Forecasters now say there is a significant chance poor weather could delay the postponed launch on Saturday, which is currently scheduled for 3:22 p.m. ET.

Weather Channel meteorologist Jacqui Jeras told Newsweek that there is currently a 50 percent chance that the weather on Saturday will violate the criteria for a safe launch. The Crew Dragon Demo-2 mission will see NASA astronauts Robert Behnken and Doug Hurley fly to the International Space Station aboard SpaceX's next-generation crew capsule.

"Weather may once again be the deciding factor if the SpaceX Falcon 9 rocket will launch on Saturday. The main rules of concern include flight through precipitation, the anvil cloud rule and the cumulus cloud rule," Jeras said.

"Basically, scattered storms with lightning and/or thick clouds within 10 nautical miles of the historic launch pad 39A [at the Kennedy Space Center] will be the most likely cause of another scrub."

Large rockets can actually trigger lightning when they fly through a strong enough atmospheric field. This phenomenon—alongside natural lightning—can cause serious damage to the rocket and endanger the life of the crew. A high probability of rocket-triggered lighting was part of the reason why Wednesday's launch was postponed.

Jeras said at this time of year, it is common for a sea breeze to develop along Florida's Space Coast, bringing scattered thunderstorms in the afternoon and evening.

"It is very difficult to pinpoint the exact location and time in the region the thunderstorms will ignite. Because of this, we may very well be looking at a down-to-the-wire decision yet again. The launch has to happen at exactly 3:22 p.m. on Saturday so that it catches up with the International Space Station on time. There is no option to wait ten minutes until skies may clear."

A team of meteorologists will not only be tracking the weather conditions in the area of the Kennedy Space Center, but also downrange from the Falcon 9 rocket's planned northeasterly trajectory over the Atlantic.

"They need favorable conditions along the way and in the water in case an emergency escape and splashdown is required," Jeras said.

SpaceX Falcon 9 rocket
The SpaceX Falcon 9 rocket with the Crew Dragon spacecraft attached is seen on launch pad 39A at the Kennedy Space Center on May 29, 2020 in Cape Canaveral, Florida. Joe Raedle/Getty Images

If Saturday's launch is postponed again, NASA and SpaceX have a backup launch opportunity on Sunday at 3 p.m. ET. However, the weather conditions for Sunday look fairly similar to Saturday, with the 45th Space Wing Weather Squadron currently forecasting a 40 percent probability that the safe launch criteria will be violated.

"If Saturday is scrubbed due to weather, there are similar conditions expected on Sunday," Jeras said. "Right now, I'm seeing slightly drier air returning on Sunday, so it may be marginally more favorable."

Meteorologists have to be convinced that no safe launch criteria will be violated in order for the Crew Dragon Demo-2 mission to be given the green light for liftoff.

The Demo-2 mission will be the first crewed launch from American soil in more than a decade since the Space Shuttle program ended in 2011.