• Weekly Highlights of Solar and Geomagnetic Activity, 20 - 26 March 2023

    From SWPC.Webmaster@noaa.gov@21:1/5 to All on Mon Mar 27 13:00:13 2023
    XPost: rec.radio.amateur.space, rec.radio.shortwave, rec.radio.info

    :Product: Weekly Highlights and Forecasts
    :Issued: 2023 Mar 27 0524 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
    20 - 26 March 2023

    Solar activity reached moderate levels on 20 March due to an
    isolated M1 flare (R1-Minor) at 20/0148 UTC from Region 3256 (S23,
    L=010, class/area, Eho/300 on 25 Mar). The large collection of
    remaining sunspot regions produced nothing higher than C-class flare
    activity throughout the rest of the reporting period.

    No proton events were observed at geosynchronous orbit.

    The greater than 2 MeV electron flux at geosynchronous orbit reached
    moderate levels throughout the reporting period.

    On 23-24 March, Earth was impacted by the most significant
    geomagnetic storm of the current solar cycle. It began as a Strong
    (G3) geomagnetic storm on 23 March at about 1500 UTC and peaked on
    24 March at around 0400 UTC as a Severe (G4) geomagnetic storm. This
    was the first Severe Geomagnetic Storm since 04 November 2021 (as
    reported from Potsdam). The storm was significantly stronger than
    expected. On 22 March, the Space Weather Prediction Center (SWPC)
    issued G1 and G2 watches for 23 and 24 March respectively. The most
    likely source of the geomagnetic storm was a long duration solar
    flare on 20 March at 1534 UTC. SWPC and international partner
    modeling suggested weak glancing impacts from the 20 March CME.
    ENLIL modeling parameters were likely degraded due to the
    unavailability of wide angle coronagraph (SOHO/LASCO C3) or STEREO
    Ahead imagery. The solar wind environment was significantly
    disturbed after the CME arrival. Total field strength peaked at 22
    nT. The Bz component reflected prolonged southward deviation of -15
    to -17 nT for over 14.5 hours. The remainder of the summary period
    observed unsettled to active geomagnetic levels.

    Forecast of Solar and Geomagnetic Activity
    27 March - 22 April 2023

    Solar activity is expected to be at low levels with a slight chance
    for (R1-R2, Minor-Moderate) events.

    No proton events are expected at geosynchronous orbit.

    The greater than 2 MeV electron flux at geosynchronous orbit is
    expected to be at high levels on 27 March - 06 April, with moderate
    levels on 07-22 April.

    Geomagnetic field activity is expected to reach G1 (Minor) storm
    levels on 20-21 April, with active conditions on 31 Mar and 01,
    10-11, 16, 18 April in response to recurrent CH HSS influence. Quiet
    to unsettled levels are anticipated for the remainder of the outlook

    --- SoupGate-Win32 v1.05
    * Origin: fsxNet Usenet Gateway (21:1/5)