Starlink-L21 - L-3 Days

Surface high pressure that has been dominant in the Space Coast’s weather the past several days is expected to begin breaking down during the latter half of the weekend as an area of low pressure develops over the Central Plains. The associated cold front will move across the Lower Mississippi Valley and into the southeastern US by Monday. Winds on Sunday morning will be relatively light, and it is possible there will be a few stray showers over the water that move inland and quickly dissipate. The primary concern will be the Cumulus Cloud Rule. In the event of a delay, the surface front will continue to move through the southeastern US, and as this happens, winds here on the Space Coast will veer out of the southeast. An increasing surface pressure gradient will also lead to stronger winds. The persistent onshore winds will lead to increasing low level moisture, bringing more low level clouds, but still not expected to pose a significant problem for launch. The primary concerns for the backup day are the Cumulus Cloud Rule and Liftoff Winds.