<AUR>.Weekly Highlights and Forecasts

:Product: Weekly Highlights and Forecasts
:Issued: 2021 Jul 19 0531 UTC
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# Weekly Highlights and Forecasts
Highlights of Solar and Geomagnetic Activity
12 - 18 July 2021

Solar activity was at very low to low levels over the period. Very
low levels were observed on 12-15 and 17-18 Jul while low levels
occurred on 16 Jul due to a pair of C1 flares at 16/0727 UTC and
16/0837 UTC from Region 2843 (S17, L=271, class/area Bxo/030 on 16
Jul). No Earth-directed CMEs were observed.

Other activity of note included two backsided halo CMEs beginning at
15/2136 UTC and at 17/0524 UTC in SOHO/LASCO C2 imagery. The first
was a full-halo and the second was a partial-halo just beyond the
east limb with a visible EIT wave propagating to the front-side in
SDO/AIA 193 imagery. It is not known what region was responsible for
those CMEs, however old Regions 2835 (S18, L=053) and 2840 (N27,
L=035) were near center disk during the halo CME. Both regions were
approaching the eastern limb on 17 Jul when the partial-halo CME

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was
normal to moderate levels with a peak flux of 386 pfu observed at
17/1825 UTC.

Geomagnetic field activity ranged from quiet to active levels. The
period began with solar wind speed ranging from 295-365 km/s and
total field between 2 and 10 nT. By 14/1000 UTC, a rise in total
field to near 12 nT occurred followed by an increase in solar wind
speed to near 480 km/s as a negative polarity CH HSS became
geoeffective. Solar wind speed slowly returned to nominal levels by
late on 16 Jul. The geomagnetic field responded with quiet to active
levels on 14 Jul and quiet to unsettled levels on 12 and 15 Jul.

Forecast of Solar and Geomagnetic Activity
19 July - 14 August 2021

Solar activity is expected to be at very low to low levels with a
slight chance for M-class flare (R1-R2, Minor-Moderate) activity on
20 Jul-03 Aug with the return of old Regions 2835 and 2840.

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to be at normal to moderate levels.

Geomagnetic field activity is expected to be at unsettled levels on
21-22 Jul, 02 Aug, 10-11 Aug with active levels on 10 Aug due to CH
HSS activity.