Positive polarity CH HSS sparks geomagnetic storms

geomagnetic-storm-november-25-2016

Earth is under the influence of a positive polarity coronal hole high speed stream (CH HSS). A sudden escalation in overall planetary geomagnetic response from a favorable solar wind environment and elevated solar wind streams triggered periods of G1 and G2 geomagnetic storming.

Solar wind speeds increased from around 400 km/s to 500 – 550 km/s between 04:30 and 05:30 UTC on November 24. Total magnetic field strength gradually increased from 5 nT to a peak of 11 nT at 15:23 UTC. Phi angle transitioned from negative to the positive sector around 03:00 UTC on November 24.

Space weather overview - November 23 - 25, 2016

Credit: NOAA/SWPC

Coronal holes - Sun - November 23, 2016

Credit: NASA/SDO AIA, LMSAL

G1 (Minor) geomagnetic storm threshold was first reached at 05:40 UTC on November 25, 2016.

Geomagnetic K-index of 6 (G2 – Moderate geomagnetic storm) threshold was reached at 05:50 UTC and dropped to 5 (G1 – Minor) at 07:01 UTC.

Under G2 conditions, power grid fluctuations can occur, high-latitude power systems may experience voltage alarms. Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible. HF (high frequency) radio propagation can fade at higher latitudes and aurora may be seen as low as New York to Wisconsin to Washington state.

Solar wind speeds are expected to remain elevated, though gradually waning, for the next 3 days (November 25 – 27)

Unsettled to active conditions are expected through the rest of the UTC day.

Forecasters call for predominantly quiet to unsettled periods, with isolated active conditions, as the influence from the CH HSS gradually diminishes through November 26 and 27.

This increased geomagnetic activity produced intense auroras as far south in Europe as Ireland.

"These were the most intense auroras I've ever seen!" said Mia Stålnacke of Kiruna, Sweden. "And here in Kiruna I get to see them all the time. The rapidly moving greens and pinks were a real treat."

Mia Stålnacke on November 24, 2016 @ Kiruna, Sweden

Credit: Mia Stålnacke – November 24, 2016 @ Kiruna, Sweden (via SpaceWeather)

With the approaching solar minimum, there is only 1 numbered active region on the Earth side of the Sun.

Region 2621 (alpha) displayed minor growth in the umbral area of its eastern spot on November 24 and 25.

Active regions on November 25, 2016

Sunspots on November 25, 2016. Credit: NASA/SDO HMI

Solar activity is expected to be very low for the next three days with just a slight chance for C-class flares.

SWPC Alerts

Space Weather Message Code: ALTK05
Serial Number: 1052
Issue Time: 2016 Nov 25 0702 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2016 Nov 25 0701 UTC
Synoptic Period: 0600-0900 UTC

Active Warning: Yes
NOAA Scale: G1 – Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power grid fluctuations can occur.
Spacecraft – Minor impact on satellite operations possible.
Aurora – Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

***

Space Weather Message Code: ALTK06
Serial Number: 422
Issue Time: 2016 Nov 25 0550 UTC

ALERT: Geomagnetic K-index of 6
Threshold Reached: 2016 Nov 25 0550 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G2 – Moderate

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 55 degrees Geomagnetic Latitude.
Induced Currents – Power grid fluctuations can occur. High-latitude power systems may experience voltage alarms.
Spacecraft – Satellite orientation irregularities may occur; increased drag on low Earth-orbit satellites is possible.
Radio – HF (high frequency) radio propagation can fade at higher latitudes.
Aurora – Aurora may be seen as low as New York to Wisconsin to Washington state.

***

Space Weather Message Code: ALTK05
Serial Number: 1051
Issue Time: 2016 Nov 25 0540 UTC

ALERT: Geomagnetic K-index of 5
Threshold Reached: 2016 Nov 25 0540 UTC
Synoptic Period: 0300-0600 UTC

Active Warning: Yes
NOAA Scale: G1 – Minor

NOAA Space Weather Scale descriptions can be found at
www.swpc.noaa.gov/noaa-scales-explanation

Potential Impacts: Area of impact primarily poleward of 60 degrees Geomagnetic Latitude.
Induced Currents – Weak power grid fluctuations can occur.
Spacecraft – Minor impact on satellite operations possible.
Aurora – Aurora may be visible at high latitudes, i.e., northern tier of the U.S. such as northern Michigan and Maine.

Featured image: Mia Stålnacke – November 24, 2016  @ Kiruna, Sweden. (via SpaceWeather)

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4 Comments

  1. I started feeling vertigo on the 19th November 2016 and for whatever reason I was inclined to search for sites that could provide knowledge, this is now bookmarked and the most up to date site (I have been checking everyday) with an actual piece written is just an extra treat for me. Thank you!

  2. Thank U So Much for Posting This Article! I Learned alot from it. I wasn’t sure at first what G1 +G2 represented (I’m still not sure-from reading this article – I think now that it represents a scale meadurement of Geomagnetic Storms. ). This led me to investigate that. Upon doing so, I learned about a “dust type molecular cloud type uv thing tht has been observvved transiti g around th center uv th black hole uv th MILKY WAY G. The Most amazi g thing about it – it didn’t dissasemble or get sucked into th pull No! It is Intact and not only that, It had been moving away from us at Vast Speed, and since going by th Center uv th black hole, It Changed Direction. +It is now headi g toward us at reciprocal speed (or close to it).
    Th Article I C dated 5/15 I think, I’m not sure if th status uv G2 has changed since then.
    YES IT’S CALLED G2. THAT’S THE CONNECTION BY THIS ARTICLE THT LED ME TO LEARN ABT THIS PARTICULAR SUBJECT! I FIND IT FASCINATING! AND I WONDER ABOUT TH METAPHYSICAL CORRELATED ASPECTS. +AS I DO BY UR ARTICLE!!!
    I ALSO LEARNED ABOUT TH SUN’S CORONA AND ASSOCIATIONS TO+WITH IT. THANK U FOR POSTING THIS INFORMATION, IC TH LIGHTQUOTIENT+VARIABILITYFACTORPLURAL ASSOCIATED WITH TH GEOMAGNETIC STORMS +ACTIVITY, SO I AM GRATEFUL THT UR POSTING IS A NAVIGATION TOOL THT HELPS ALERT + INFORM LIGHTWORKERS ABT CONDITIONS.
    THANK U VERY MUCH.
    BLESSINGS! NAMASTE.

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