Earth-orbiting satellites have just detected an X6.3-class solar flare from sunspot AR3590 (Feb. 22 @ 2234 UT). This is the strongest flare of Solar Cycle 25, and the third X-flare the sunspot has produced in a 24 hour period. This sucker was big.. This most recent X class flare is rated as a X 6.3. It generated an R3 radio blackout, which is considered “strong” on a 5-point scale, where R1 is “minor” with weak or minor degradation of HF radio communications and navigation signals while 5 is “extreme” with a complete radio blackout on the entire sunlit side of the Earth lasting for a number of hours; such an event would also knock navigation systems off-line, which could lose to loss of positioning, especially by boats and planes. For real.. No more of this recent X1-class nonsense, this X6.4-class flare is now the largest confirmed flare since September 2017.