Scientists in the United States warned Monday that continuing solar flares could cause significant interference with radio communications.

The National Oceanic and Atmospheric Administration said the foul weather on the sun that began last week had produced radio blackouts at the R1 level, but could cause problems up to the R3 level over the next few days.

An R3 event can knock out radio communications over large parts of the sunlit side of the Earth.

Sun spots, flares and geomagnetic storms began cropping up on the surface of the sun late last week and has caused scattered problems with electric power systems, radio communications and global positioning equipment.

NOAA said solar radiation has ranged from the moderate S2 level up to severe S4 with S2 expected over the next 24 hours. Geomagnetic storms up to G4 were expected as well.

Unstable conditions are expected for the next 10 to 11 days.

Copyright 2005 by United Press International