Subject: Weekly Highlights of Solar and Geomagnetic Activity, 12 - 18 August 2024

:Product: Weekly Highlights and Forecasts
:Issued: 2024 Aug 19 0225 UTC
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# Weekly Highlights and Forecasts
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Highlights of Solar and Geomagnetic Activity
12 - 18 August 2024

Solar activity was at high levels on 14 Aug and moderate (R1-Minor)
for the remaining days between 12-18 Aug. Region 3784 (N14, L=115, class/area=Dkc/700 on 14 Aug) produced the strongest event of the
period, an X1.1/2b (R3-Strong) flare at 14/0640 UTC. Associated with
the flare were Type II (est. 516 km/s) and Type IV radio sweeps, as
well as a subsequent CME signature observed in LASCO imagery.
Analysis and modeling of the CME suggested an Earth-directed
component from 17-18 Aug. The remaining days in the summary period,
outside of 14 Aug, observed 16 other R1 (Minor) events. The regions
associated with R1 events were 3777 (S09, L=209, class/area=Ekc/460
on 09 Aug), 3780 (S12, L=170, class/area=Fkc/1250 on 08 Aug), 3784,
3785 (S15, L=107, class/area=Dai/100 on 18 Aug), and 3790 (S12,
L=024, class/area=Dkc/280 on 18 Aug).

No proton events were observed at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit was at
low to moderate levels.

Geomagnetic field activity reached G4 (Severe) levels on 12 Aug due
to influence of a CME that left the Sun on 08 Aug. An X1.3/2b flare
at 08/1935 UTC from Region 3777 produced a Type II (est. 1,026 km/s)
and Type IV radio sweep as the CME lifted off of the Sun. Its
arrival increased total magnetic field strength to a peak of 21 nT,
and Bz reached as far south as -20 nT. Solar wind speeds peak just
over 500 km/s. The geomagnetic field responded with a series of G3
(Strong) synoptic periods and an isolated G4 (Severe) during the
12/1200-1500 UTC synoptic period. As the CME waned, G1 (Minor)
conditions on 13 Aug decreased to active levels on 14 Aug. Quiet to
unsettled conditions characterized 15-16 Aug. The onset of a CME
associated with the X-flare (R3-Strong) from Region 3784 arrived
with a shock at L1 around 17/1330 UTC. Total magnetic field strength
increased from 7 to 25 nT and Bz briefly reached -21 nT shortly
after. Solar wind speeds increased from the low 300's to around
475 km/s. The geomagnetic field responded with an isolated G3
(Strong) geomagnetic storm during the 17/1200-1500 UTC synoptic
period. Bz turned northward and remained there through the end 18
Aug. This resulted in a drop in subsequent geomagnetic activity to
below G1 (Minor) levels on 18 Aug.

Forecast of Solar and Geomagnetic Activity
19 August - 14 September 2024

Solar activity is likely to be at moderate levels throughout the
outlook period due to multiple complex regions on the visible disk
and ones anticipated to return from the Sun's farside. A slight
chance for R3 (Strong) activity is forecast over the next week due
to the currently analyzed monitored active regions on the Sun's
nearside.

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 during the outlook
period.

Geomagnetic field activity is expected to be mostly quiet. Unsettled
conditions are possible on 22-23 Aug due to coronal hole influence.
The long-term forecast only contains recurrent solar wind features
like CH HSSs and SSBCs. CMEs will be added as they occur.


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* Origin: NOAA Space Weather Prediction Center (3:633/280.2@fidonet)