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Here is this week's space weather and geophysical report, issued 2015 Jun 29 0647 UTC.
Highlights of Solar and Geomagnetic Activity
22 - 28 June 2015
Solar activity was at low to high levels. The period began at high
levels when Region 2371 (N13, L=302, class/area Fkc/1180 on 21 June)
produced an M6/2b flare at 22/1823 UTC with an associated Castelli-U
spectral burst, Type II radio sweep (1480 km/s), 1000 sfu Tenflare,
and a full halo coronal mass ejection (CME) with an approximate
speed of 1047 km/s. Solar activity returned to high levels again on
25 June as Region 2371 produced a long-duration M7/3b flare at
25/0816 UTC with associated Type II (2056 km/s) and Type IV radio
sweeps, 3800 sfu Tenflare, and an asymmetric full halo CME with an
approximate speed of 1500 km/s. Region 2371 remained relatively
quiet and stable after 25 June, only producing low-level C-class
flaring for the rest of the period.
A greater than 10 MeV proton event was in progress at the beginning
of the period. The event began at 21/2135 UTC, likely associated
with an M2/1n flare at 21/0142 UTC from Region 2371, reached a
maximum flux value of 1070 pfu at 22/1900 UTC and ended 24/0705 UTC.
A brief enhancement to the S3 (Strong) levels was observed due to a
shock enhancement from the arrival of the 21 June CME. Another
greater than 10 MeV proton event began at 26/0350 UTC in association
with an M7/3b flare at 25/0816 UTC from Region 2371, reached a
maximum of 22 pfu (S1-Minor) at 27/0030 UTC and ended at 27/0755
UTC.
The greater than 2 MeV electron flux at geosynchronous orbit was
high levels through the period with the exception of 23 June. A
maximum flux of 26,376 pfu was observed at 24/1620 UTC.
Geomagnetic field activity ranged from quiet to severe storm
conditions. At 22/0451 UTC, a small shock was observed at the
NASA/ACE spacecraft. Total field increased from 8 nT to 17 nT with a
corresponding solar wind increase from 360 km/s to 431 km/s. The
shock was associated with the arrival of the 19 June CME caused by a
filament eruption in the SE quadrant observed in SDO/AIA imagery
beginning at 19/0500 UTC. A geomagnetic sudden impulse (SI) of 19 nT
(Guam) was observed at 22/0545 UTC. The geomagnetic field responded
with unsettled to active levels. At 22/1759 UTC, another shock was
observed in ACE data from the 21 June CME associated with a double
peak M2 flare from Region 2371 at 21/0142 UTC. Total field increased
to a maximum of 41 nT at 22/1935 UTC, solar wind speed increased to
737 km/s and the Bz component went negative to -39 nT at 22/1850
UTC. A prolonged period of mostly southward Bz occurred between
23/0013 UTC and 23/1246 UTC reaching as high as -25 nT. An SI of 48
nT (Hartland) was observed at 21/1650 UTC. The geomagnetic field
responded with minor to major storm levels with severe storm periods
observed between 22/1800-2100 UTC and 23/0000-0600 UTC. At 24/1258
UTC, the 22 June CME associated with the M6/2b flare on 22 June was
observed in ACE data. Solar wind speeds increased from approximately
550 km/s to around 760 km/s with a relatively weak increase in total
field from 5 nT to 13 nT. The Bz component was mostly positive
during this event with negative values reaching a maximum of -11 nT
between 25/0547 UTC and 25/1357 UTC. The geomagnetic field responded
with only quiet to active periods on 24 June, but increased to minor
to major storm levels mid-period on 25 June. Another CME associated
with the M7/3b flare on 25 June arrived at 27/0223 UTC at the ACE
spacecraft. Solar wind speeds increased from near 475 km/s to 860
km/s before slowly decreasing to 480 km/s by the end of the day.
Total field reached a maximum of 13 nT at 27/0304 UTC and the Bz
component was variable between +9 nT and -7 nT. As a result, the
geomagnetic field never increased beyond unsettled conditions.
Forecast of Solar and Geomagnetic Activity
29 June - 25 July 2015
Solar activity is expected to be at low levels with a chance for
M-class flare (R1-R2, Minor-Moderate) activity from 30 June through
24 July with the return of old Regions 2365 (S13, L=079) on 30 June,
2367 (S20, L=002) on 05 July, and 2371 (N13, L=302) on 11 July.
There is a chance for a greater than 10 MeV proton event from 11
July through 24 July with the return of old Region 2371 to the
visible disk.
The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at high levels from 29-30 Jun and again from 08-19
July due to residual CME effects and recurrent coronal hole high
speed streams (CH HSS).
Geomagnetic field activity is expected to be at active to minor
storm (G1-Minor) levels from 06-08 July and again from 11-12 July
due to recurrent CH HSS activity.
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![Weekly Propagation Summary - 2015 Jun 29 16:10 UTC]()
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