A G1 (Minor) Watch has been issued for 19 February and the G1 geomagnetic storm warning was extended, and is now in effect until 19/0400 UTC (18 February at 2300 ET). The solar wind continues at elevated speeds around 600 km/s due to a coronal hole high speed stream (CH HSS). These wind speeds coupled with an enhanced interplanetary magnetic field (IMF) strength and occasional periods of prolonged southward Bz component of the IMF, are expected to elicit isolated periods of G1 storming levels into the first half of the 19 February UTC day. Since the CH HSS geomagnetic storming activity began on 16 February, there have been nine periods of G1 storming and two periods of G2 (Moderate) storming. The most recent storming reached the G1 level at 18/1910 UTC (18/1410 ET). The effects from the CH HSS are expected to begin waning on 20 February and SWPC forecasters are expecting only active or less conditions beginning 20 Feb.
NOAA Scales mini
HF Radio: Weak or minor degradation of HF radio communication on sunlit side, occasional loss of radio contact.
Navigation: Low-frequency navigation signals degraded for brief intervals.
More about the NOAA Space Weather Scales
Navigation: Low-frequency navigation signals degraded for brief intervals.
G1 (Minor) geomagnetic storm conditions to continue into 19 Feb
G1 (Minor) geomagnetic storm conditions to continue into 19 Feb