Coronal Hole Prompts Long Duration Aurora Watch Dec 7th, 8th & 9th

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Northern Lights Now – A large coronal hole that crosses the Solar equator will produce conditions conducive to aurora Thursday through Saturday this week. The expected enhanced solar winds could reach 700km/s and as a result SWPC has issued a three day G1 geomagnetic storm watch. This means KP values are likely to be enhanced and there is a good chance they will exceed KP=4.67.

G1 storm watch from SWPC has been extended to three days Dec 7 though Dec 9
G1 storm watch from SWPC has been extended to three days Dec 7 though Dec 9

This coronal hole is the return of a system that produced G1 storming on previous rotations in early October and November. Looking at the form and location of the coronal hole over the last four rotations, it is clear that it is a little farther north and bigger for this rotation. Each rotation takes about 27 days. Past experience has shown that the more of the coronal hole that passes through the center of the earth strike zone, the portion of the Solar disk pointed towards Earth, the longer the period of enhanced solar winds.

Mid September View of this month's Coronal Hole
Mid September View of this month’s Coronal Hole
Mid October View of this month's Coronal Hole
Mid October View of this month’s Coronal Hole
Early November view of this month's Coronal Hole
Early November view of this month’s Coronal Hole
Current view of this month's Coronal Hole
Current view of this month’s Coronal Hole

Close NLN readers and aurora hunters will recognize that this is a different coronal hole than the large system that has been producing storming in the second half of the month September, October and November. That system appeared to have been falling losing definition in the previous rotation, so when it rotates into view over the next couple weeks, watch it to see if it has regained organization or has continued to dissapate.

For this storm, the current expect timing of G1 storming conditions is just at the beginning of each UTC day during the watch period. The timing on these specific forecasts is difficult to predict but is often a good indicator of when it is worth keeping an eye on DSCOVR Solar wind data and the current KP.

NLN AuroraCast graphic shows the G1 periods should be at the start of each UTC day during the watch
NLN AuroraCast graphic shows the G1 periods should be at the start of each UTC day during the watch

Happy Hunting!

Thanksgiving Aurora – G1 and G2 Storms Ongoing

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Northern Lights Now – Active space weather has been providing beautiful aurora and northern lights this Thanksgiving and Black Friday. A large coronal hole is producing strong solar wind which is inducing periods of dancing skies for aurora hunters across the high latitudes. As of Friday, storming levels have reached G2 conditions meaning Northern lights may be visible in a band across Northern Europe, Iceland, Canada, and the Norther US states.

This quick real-time video taken in Kiruna, Sweden Thursday night show a sky full of green and pulsating blues and whites:

At the time of this post, a new round of G2 storming is starting. Viewers with clear skies across Northern North America may be in for a treat!

Happy Hunting

G1 Storm Watch Posted for November 8

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Update 0330 GMT – 10:30pm EST

It appears the CME missed Earth, probably to the West and North. It is unlikely at this point there will be any aurora storming tonight.

Original Post
Northern Lights Now – The CME from the November 5 filament eruption is now expected to arrive at Earth late on Nov 8 and produce G1 storming. SWPC has issued a G1 geomagnetic storm watch. This forecast is lower confidence and more variable than usual. The current predicted timing shows that the period of KP=5 or higher is likely to happen at the end of the UTC day (or just after sunset on the US East coast and around midnight in Europe)

NLN AuroraCast shows the aurora forecast for potential G1 storming at the end of Nov 8 UTC
NLN AuroraCast shows the aurora forecast for potential G1 storming at the end of Nov 8 UTC

This forecast is low confidence because the majority of the CME is likely to go to the north and west of Earth. If Earth is hit, it will likely be a glancing blow. Further, it is impossible to predict the orientation of the cloud of plasma. If it happens to be oriented with a strong Bz south component, the KP could reach values higher the G1. If it is oriented with a strong positive Bz component, it’s unlikely KP values will read higher than 3 or 4. This is a classic wait-and-see storm.

Here is the WSA-Enlil model output from SWPC. It shows that when the CME arrives, it is likely to have a high proton density. This high proton density, at the same time as increasing solar wind are the primary motivations for issuing the G1 watch (click image for full size):

WSA-Enlil model shows CME arriving midday on Nov 8
WSA-Enlil model shows CME arriving midday on Nov 8

Happy Hunting!