Subject: Weekly Highlights of Solar and Geomagnetic Activity, 17 - 23 July 2023

:Product: Weekly Highlights and Forecasts
:Issued: 2023 Jul 24 0213 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# https://www.swpc.noaa.gov/content/subscription-services
#
# Weekly Highlights and Forecasts
#
Highlights of Solar and Geomagnetic Activity
17 - 23 July 2023

Solar activity reached high levels on 18 Jul due to an M5 flare
(R2-Moderate) at 18/0006 UTC from Region 3363 (S22, L=345,
class/area=Dko/700 on 17 Jul); the largest event of the period. In
addition to the M5 flare on 18 Jul, five R1-Minor events were
registered. Minor levels of solar activity were observed on 17, 19
and 22 Jul with R1-Minor events observed from Regions 3363, 3372
(N23, L=270, class/area=Fho/700 on 17 Jul), and 3373 (N08, L=248, class/area=Ekc/550 on 21 Jul). Low levels were observed on 20-21 and
23 Jul.

Following the long-duration M5 flare at 18/0006 UTC from Region
3363, the greater than 10 MeV proton flux increased sharply and
exceeded 10 pfu (S1-Minor) at 18/0115 UTC. S2 (Moderate) storm
levels were reached beginning at 18/0200 UTC, and a peak of 620 pfu
was observed at 18/0615 UTC. The 10 MeV proton flux levels gradually
decreased, but persisted above the S1 (Minor) threshold on 19 Jul,
and decreased below event threshold at 20/0610 UTC.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels on 19-20 Jul, with normal to moderate levels observed
throughout the remainder of the period.

Geomagnetic field activity reached G1 (Minor) storm levels late 17
Jul through early 18 Jul due to the passage of a CME that began on
16 Jul. Active levels were observed on 20 Jul following the passage
of a CME from 17 Jul, and again on 21 Jul due to the passage of a
CME from 18 Jul. Quiet or quiet and unsettled conditions were
observed throughout the remainder of the week.

Forecast of Solar and Geomagnetic Activity
24 July - 19 August 2023

Solar activity is expected to be low with a chance for M-class flare
activity throughout the outlook period.

No proton events are expected at geosynchronous orbit, barring
significant flare activity.

The greater than 2 MeV electron flux at geosynchronous orbit is
expected to reach high levels on 31 Jul-02 Aug, with normal to
moderate levels expected to persist throughout the remainder of the
period.

Geomagnetic field activity is expected to reach active levels on 24
Jul due to negative polarity CH HSS influences, and again on 27-28
Jul due to the anticipated arrival of a CME from 22 Jul and positive
CH HSS influences. Quiet and quiet to unsettled levels are expected
to persist throughout the remainder of the outlook period.


--- MBSE BBS v1.0.8 (Linux-x86_64)
* Origin: NOAA Space Weather Prediction Center (3:633/280.2@fidonet)