Seven M-Class Solar Flares, Long-Duration X2.2 Flare and Major X9.3 Flare: Direct CME hit expected & G3 Geomagnetic Storm Watch

Geoeffective Region 2673 unleashed M1.2 solar flare, Earth-directed CMEs possible

By The Watchers

Geoeffective Region 2673 unleashed M1.2 solar flare, Earth-directed CMEs possible

September 4, 2017

A large and geoeffective Active Region 2673 (beta-gamma) unleashed a moderately strong M1.2 solar flare at 05:49 UTC on September 4, 2017. The event started at 05:36 and ended at 06:05 UTC. The region increased 10-fold in a single day, suddenly becoming one of the largest regions of the year. It is currently located near the center of the Earth-facing Sun, making Earth-directed CMEs possible over the coming days.

There were no radio signatures that would suggest a Coronal Mass Ejection (CME) was produced during today’s M1.2 flare. However, we are still waiting for coronagraph imagery to confirm.

M1.2 solar flare September 4, 2017

M1.2 solar flare September 4, 2017M1.2 solar flare September 4, 2017 - AIA image

M1.2 solar flare September 4, 2017 - D-RAP

Region 2673, responsible for today’s M1.2 and a series of C-class flares, grew vigorously in the past 24 hours with the intermediate spots contributing most of the development.

It now has a ‘beta-gamma’ magnetic configuration, making it capable of producing strong M-class solar flares.

Since the region is currently located near the center of the Earth-facing Sun, moderately-strong shortwave radio blackouts are possible and CMEs produced by this huge region would be Earth-directed.

Sunspots on September 4, 2017

“On Saturday, September 2, AR 2673 was an unremarkable speck largely ignored by forecasters,” SpaceWeather’s Dr. Tony Phillips reports. “On Sunday, September 3, it underwent a furious transformation, expanding more than 10-fold in a single day and suddenly becoming one of the largest sunspots of the year. ”

Earth-directed CMEs are possible today and in the days ahead.

Featured image: M1.2 solar flare at 05:49 UTC on September 4, 2017. Credit: NASA/SDO AIA131

Source: The Watchers

7 M-class solar flares from geoeffective region, Earth-directed CME produced, S1 radiation storm

September 5, 2017

7 M-class solar flares from geoeffective region, Earth-directed CME produced, S1 radiation storm

Geoeffective Active Region 2673 produced 7 M-class and at least 8 C-class solar flares on September 4, 2017. The strongest was M5.5 at 20:33 UTC associated with an asymmetric full halo Coronal Mass Ejection (CME). This region has the potential to produce more strong to major eruptions on the Sun, including X-class flares. Its location currently favors Earth-directed CMEs.

This impressive region grew vigorously over the past 48 hours, suddenly becoming one of the largest regions of the year. It now has ‘beta-gamma-delta’ magnetic configuration and is capable of producing strong to major eruptions on the Sun. Since the region will remain geoeffective today and in the days ahead, Earth-directed CMEs are likely.

Sunspots on September 4, 2017

Sunspots on September 4, 2017. Credit: NASA/SDO HMI

Sunspots on September 4, 2017 - HMI Colorized Magnetogram

Sunspots on September 5, 2017 – Colorized Magnetogram. Credit: NASA/SDO HMI

The first solar flare of the day was produced at 05:49 UTC measuring M1.2. It was followed by M1.5 at 15:30 UTC, M1.0 at 18:22 UTC, M1.7 (associated with a Type IV Radio Emission) at 19:37 UTC, M1.5 at 20:02 UTC, M5.5 (associated with a Type II Radio Emission and 10cm Radio Burst) at 20:33 UTC, and M2.1 at 22:14 UTC.

The strongest event from this region, thus far, is M5.5 solar flare which started at 20:28, peaked at 20:33 and ended at 20:37 UTC. This flare was associated with a Type II radio sweep with an estimated velocity of 1 472 km/s and a 10cm Radio Burst lasting 52 minutes with peak flux of 1 600 sfu.

Type II emissions occur in association with eruptions on the Sun and typically indicate a CME was produced. A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

Xray Flux - September 3 - 5, 2017

SWX overview September 3 - 6, 2017DRAP at 20:33 UTC, following M5.5 solar flare

Initial available SOHO/LASCO coronagraph imagery indicated a likely asymmetric full halo CME was associated with the M5 flare.

Additional analysis of the CME will be conducted as coronagraph imagery becomes available.

CME associated with M5.5 solar flare on September 4, 2017

Coronal Mass Ejection associated with M5.5 solar flare on September 4, 2017. Credit: NASA/ESA SOHO/LASCO C3

Solar activity is expected to be at moderate to high levels from September 5 to 7, mostly due to the flare potential and recent history of Region 2673. Radio blackouts reaching the R1-R2 (Minor-Moderate) levels are expected, with a chance for R3 (Strong) radio blackouts, NOAA SWPC forecasters said.

The greater than 2 MeV electron flux reached high levels with a maximum flux of 15 800 pfu observed at 18:05 UTC on September 4. The greater than 10 MeV proton flux values observed a slight enhancement that was likely associated with the M5 flare from Region 2673 and reached S1 – Minor threshold at 00:38 UTC.

DRAP at 01:06 UTC on September 5, 2017 - S1 Minor storm

Solar wind parameters remained elevated over the past 24 hours due to influences from a polar-connected, positive polarity coronal hole high speed stream (CH HSS).

Solar wind speeds began to increase to around 585 km/s near the end of the day. Total magnetic field strength was at a nominal 5 nT through about 16:00 UTC, increased to 9 nT briefly, then leveled back off late in the UTC day. Bz was predominately variable, then remained southward for several hours, seeing a maximum southward deflection to -7 nT. Phi angle was mostly in a positive orientation but began to show signs of rotation by midday.

The solar wind environment is expected to continue to trend towards background levels late on September 5. Nominal levels are expected by September 6 and 7.

The geomagnetic field was at quiet to unsettled levels over the past 24 hours with an isolated G1-Minor geomagnetic storming period at the end of the day, likely associated with sustained -Bz.

3-hour K-indices for last 7 days, ending September 5, 2017

The geomagnetic field is expected to be at quiet to active levels, with isolated periods of G1-Minor storming periods early in the period, as the CH HSS influence tapers on September 5.

Quiet conditions are expected on September 6 and 7, with a slight chance for unsettled conditions, ahead of another CH HSS of negative polarity.

Featured image: M5.5 solar flare at 20:33 UTC on September 4, 2017. Credit: NASA/SDO AIA 131

Source: The Watchers

Powerful, long-duration X2.2 solar flare erupts from geoeffective AR 2673

September 6, 2017

Powerful, long-duration X2.2 solar flare erupts from geoeffective AR 2673

A powerful, long-duration solar flare measuring X2.2 at its peak time erupted from geoeffective Active Region 2673 at 09:10 UTC on September 6, 2017. The event started at 08:48 and ended at 09:59 UTC. This is the first X-class solar flare since May 5, 2015.

There were no radio signatures that would suggest a Coronal Mass Ejection (CME) was produced during this event.

Additionally, the event was associated with a 10cm Radio Burst lasting 6 minutes with a peak flux of 569 sfu.

X2.2 solar flare September 6, 2017X2.2 solar flare September 6, 2017

X2.2 solar flare September 6, 2017 - SDO AIA 131

X2.2 solar flare September 6, 2017 DRAP

Just a couple of hours later, the same region produced a major X-class solar flare – X9.3, the strongest solar flare of the current solar cycle.

Read more about it: Major X-class flare: X9.3 from geoeffective AR 2673, CME produced

SWPC alerts

Space Weather Message Code: SUMX01
Serial Number: 114
Issue Time: 2017 Sep 06 1008 UTC

SUMMARY: X-ray Event exceeded X1
Begin Time: 2017 Sep 06 0848 UTC
Maximum Time: 2017 Sep 06 0910 UTC
End Time: 2017 Sep 06 0959 UTC
X-ray Class: X2.2

Optical Class: 2b
Location: S08W33
NOAA Scale: R3 – Strong

Potential Impacts: Area of impact consists of large portions of the sunlit side of Earth, strongest at the sub-solar point.
Radio – Wide area blackout of HF (high frequency) radio communication for about an hour.

***

Space Weather Message Code: SUM10R
Serial Number: 696
Issue Time: 2017 Sep 06 0934 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2017 Sep 06 0903 UTC
Maximum Time: 2017 Sep 06 0904 UTC
End Time: 2017 Sep 06 0909 UTC
Duration: 6 minutes
Peak Flux: 459 sfu
Latest Penticton Noon Flux: 121 sfu

Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

Featured image: X2.2 solar flare at 09:13 UTC on September 6, 2017. Credit: NASA/SDO AIA 131

Source: The Watchers

Major X-class flare: X9.3 from geoeffective AR 2673, CME produced – the strongest flare of the current cycle

September 6, 2017

A major X-class solar flare erupted from geoeffective Active Region 2673 peaking as X9.3 at 12:02 UTC on September 6, 2017. The event started at 11:53, peaked at 12:02 and ended at 12:10 UTC. This is the second X-class solar flare of the day. It comes just hours after a long-duration X2.2 at 09:33 UTC. It is also the strongest solar flare of the current solar cycle (Solar Cycle 24).

Radio signatures suggest a strong Coronal Mass Ejection (CME) was produced during this event. The location of this region favors Earth-directed CMEs.

The event was associated with a Type IV and Type II (estimated velocity 1969 km/s). Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event. Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

In addition, this impressive event was associated with a 10cm Radio Burst lasting 3 minutes with peak flux of 12000 sfu.

Today’s X9.3 is the strongest solar flare of Solar Cycle 24. Although X-class solar flares were expected (25% chance) since Region 2673 rapidly grew into a monster region and attained ‘beta-gamma-delta’ magnetic configuration, such powerful flare comes as a huge surprise, as our star is heading toward Solar Minimum. The previous record for the strongest flare of the cycle was X6.9 of August 9, 2011.

The cycle has so far had 47 X-class flares, including today’s X2.2 and X9.3.

The last time our star erupted with an X-class flare was on May 5, 2015 – X2.7. CME was produced, but the location didn’t favor Earth-directed CMEs.

X9.3 solar flare September 6, 2017

X9.3 solar flare September 6, 2017

X9.3 solar flare September 6, 2017 - AIA 193

X9.3 solar flare September 6, 2017 - AIA 304

X9.3 solar flare September 6, 2017 - DRAP

The location of Active Region 2673 favors Earth-directed CMEs. However, analysis of the event is still in progress.

CME produced by M5.5 solar flare on September 4, 2017 is heading toward Earth and is expected to arrive later today (September 6). A G3 – Strong geomagnetic storm watch is in effect for September 6 and 7.

Note: This event is still being analyzed. The report will be updated as new information becomes available.

SWPC alerts

Space Weather Message Code: ALTTP2
Serial Number: 1058
Issue Time: 2017 Sep 06 1212 UTC

ALERT: Type II Radio Emission
Begin Time: 2017 Sep 06 1202 UTC
Estimated Velocity: 1969 km/s

Description: Type II emissions occur in association with eruptions on the sun and typically indicate a coronal mass ejection is associated with a flare event.

***

Space Weather Message Code: ALTTP4
Serial Number: 540
Issue Time: 2017 Sep 06 1210 UTC

ALERT: Type IV Radio Emission
Begin Time: 2017 Sep 06 1201 UTC

Description: Type IV emissions occur in association with major eruptions on the sun and are typically associated with strong coronal mass ejections and solar radiation storms.

***

Space Weather Message Code: SUM10R
Serial Number: 697
Issue Time: 2017 Sep 06 1209 UTC

SUMMARY: 10cm Radio Burst
Begin Time: 2017 Sep 06 1154 UTC
Maximum Time: 2017 Sep 06 1156 UTC
End Time: 2017 Sep 06 1157 UTC
Duration: 3 minutes
Peak Flux: 12000
sfu
Latest Penticton Noon Flux: 121 sfu

Description: A 10cm radio burst indicates that the electromagnetic burst associated with a solar flare at the 10cm wavelength was double or greater than the initial 10cm radio background. This can be indicative of significant radio noise in association with a solar flare. This noise is generally short-lived but can cause interference for sensitive receivers including radar, GPS, and satellite communications.

Featured image: X9.3 solar flare erupts from AR 2673 – 12:13 UTC. Credit: NASA/SDO AIA 131

Source: The Watchers

Direct CME hit expected, G3 Strong geomagnetic storm watch issued

Direct CME hit expected, G3 Strong geomagnetic storm watch issued

September 5, 2017

An asymmetric full halo Coronal Mass Ejection (CME) produced by the M5.5 solar flare at 20:33 UTC on September 4, 2017 is traveling toward Earth and is expected to arrive late on September 6. G3 – Strong geomagnetic storm watch is in effect for September 6 and 7.

Region responsible for this eruption – AR 2673 – grew vigorously from September 2 to 4, quickly becoming one of the largest sunspots of the year. It now has ‘beta-gamma-delta’ magnetic configuration and harbors energy for both M-class (71% chance) and X-class (25% chance) solar flares over the next three days.

Sunspots on September 4, 2017

Sunspots on September 4, 2017. Credit: NASA/SDO HMI

The region is now moving away from the center of the Earth-facing Sun but Earth-directed CMEs are still very much likely.

Sunspots on September 4, 2017 - HMI Colorized Magnetogram

Sunspots on September 5, 2017 – Colorized Magnetogram. Credit: NASA/SDO HMI

M5.5 solar flare on September 4, 2017. Credit: NASA/SDO

Initial available SOHO/LASCO coronagraph imagery indicated a likely asymmetric full halo CME was associated with the M5.5 flare. In addition, Type-II (1 472 km/s) and Type-IV radio sweeps were observed around the time of the flare, beginning at 20:42 UTC, as well as 10cm radio bursts.

Asymmetric full halo CME observed September 4, 2017 after M5.5 solar flare. Credit: ESA/NASA SOHO/LASCO C3

Initial analysis of WSA/Enlil model output determined the CME to arrive mid-to-late September 6. However, additional analysis of the CME is in progress to gather a consensus arrival time/intensity forecast.

WSA/Enlil model for September 4th CME. Credit: NOAA/SWPC

SWPC initially issued G2 – Moderate storm watch for September 6 and 7 but later upgraded to G3 – Strong watch.

G3 storms occur approximately 200 times per one solar cycle. Voltage corrections may be required and false alarms triggered on some protection devices, under G3 conditions. Surface charging may occur on satellite components, drag may increase on low-Earth-orbit satellites, and corrections may be needed for orientation problems. Intermittent satellite navigation and low-frequency radio navigation problems may occur, HF radio may be intermittent, and aurora has been seen as low as Illinois and Oregon (typically 50° geomagnetic lat.).

Solar radiation storm

Meanwhile, the greater than 2 MeV electron flux reached high levels with a maximum flux of 15800 pfu observed at 18:05 UTC on September 4. The greater than 10 MeV proton flux values observed an enhancement that was associated with the M5 flare from Region 2673, reaching S2 – Moderate levels (peak flux 106 pfu at 07:20 UTC).

S2 – Moderate solar radiation storms occur approximately 25 times per one solar cycle. Under S2 conditions, passengers and crew in high-flying aircraft at high latitudes may be exposed to elevated radiation risk. Infrequent single-event upsets are possible in satellite operations. Small effects are possible on HF propagation through the polar regions and navigation at polar cap locations.

The greater than 2 MeV electron flux is expected to continue at high levels for the next three days. The greater than 10 MeV proton flux is expected to continue at S1 levels.

SWX overview, 3-day by September 5, 2017

Solar wind parameters

Solar wind parameters remain elevated due to influences from a polar-connected, positive polarity coronal hole high speed stream (CH HSS). Although the trend is now towards background levels, enhanced levels are again expected on September 6 and 7 due to CME impact.

Geomagnetic field forecast

The geomagnetic field was at quiet to unsettled levels over the past 24 hours with an isolated G1 – Minor geomagnetic storming period at the end of September 4, likely associated with sustained -Bz.

The field is expected to be at quiet to active levels, with isolated periods of G1 storming as CH HSS influence diminishes today. Elevated levels are expected on September 6 and 7 due to the arrival of the abovementioned CME. G2 – Moderate conditions are expected, with isolated G3 – Strong conditions likely on both days.

Featured image: WSA ENLIL model for September 4th asymmetric full halo CME. Impact exected late September 6. Credit: NOAA/SWPC

This article (Direct CME hit expected, G3 Strong geomagnetic storm watch issued) was originally published on The Watchers and syndicated by The Event Chronicle.

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