Northern Lights Now – Less than a week after the last active period for aurora a new storm watch has been posted by SWPC indicating the potential for G1 storming conditions. The current watch, posted for March 22nd, is due to the anticipated high speed solar wind from a center disk coronal hole.
The current coronal hole is a little further south than the one that brought aurora activity earlier this week and is much closer to center disk. It is smaller than the previous coronal hole, so NLN is forecasting a shorter duration period of activity. Here’s an image of the coronal hole from the SDO satellite.
The initial increase in winds should arrive midday on March 22nd with the KP levels rising soon afterward. Wind velocity should increase from today’s baseline of around 350 km/s to above 500km/s. The best monitor solar wind speed is by keeping an eye on the NLN Solar Wind Dynamics page. The page automatically refreshes with the latest data from DSCOVR every minute.
The timing of the expected activity is shown here on the NLN aurora clock. The period of orange (G1 storming) is expected late in the UTC day.
Northern Lights Now – High speed wind from the coronal hole mentioned in the previous NLN post is expected to arrive sometime on October 24 and should induce G1 and G2 storm conditions through the 26th. SWPC has issued storm watches for all three days with G1 watches on the 24th and 26th and a G2 storm watch on October 25. This means KP levels could reach 5.67 or more.
Models are predicting an extended period of elevated solar winds reaching as high as 650km/s for all three days. The initial winds will arrive with a CIR (co-rotating interaction Region) where densities are higher and the magnetic fields are more complex. This means you can monitor the progress of the arriving wind stream – it will show up as proton densities as measured at L1 by DSCOVR will rise. Once Earth is in the body of the high speed solar wind stream, density decreases and winds increase.
Current forecasts show geomagnetic activity reaching G1 levels (KP=4.67 and above) the second half of Oct 24, then reaching G2 (KP=5.67 and above) on the first part of Oct 25. Activity should slowly decline over the following 36 hours, but there may be spike of activity if the magnetic fields line up just right.
As an update to the features in that previous post, the filament did lift off, but was subsequently reabsorbed, so it did not generate a CME. The active regions rotating into view on the East limb seem to have lost their magnetic complexity. Space Weather forecasters are not expecting they will be active flare producers in the next several days.
Northern Lights Now – Update from yesterday’s post – SWPC has extended the geomagnetic storm watch into September 28 and is now calling for G2 storming. G2 storming means that KP values could exceed 5.67, strong enough for mid-latitudes to get a display of aurora.
The Moon is will be just shy of 1st quarter, so viewing conditions should be favorable.