WARNING Geomagnetic Storm ALERT - 18-04-2011 - Warning Condition: Onset

Space Weather Message Code: WARK04
Serial Number: 1721
Issue Time: 2011 Apr 18 0739 UTC

WARNING: Geomagnetic K-index of 4 expected
Valid From: 2011 Apr 18 0740 UTC
Valid To: 2011 Apr 18 1600 UTC
Warning Condition: Onset


Space Weather Message Code: SUMSUD
Serial Number: 116
Issue Time: 2011 Apr 18 0705 UTC

SUMMARY: Geomagnetic Sudden Impulse
Observed: 2011 Apr 18 0654 UTC
Deviation: 24 nT
Station: Boulder