:Product: Weekly Highlights and Forecasts
:Issued: 2025 May 19 0221 UTC
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# Weekly Highlights and Forecasts
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Highlights of Solar and Geomagnetic Activity
12 - 18 May 2025

Solar activity ranged from low to high. Region 4087 (N15, L=058, class/area=Dho/250 on 15 May) produced the strongest event of the
period, an impulsive X2.7/2b flare (R3 - Strong) at 14/0825 UTC near
the NE limb. A Type II radio sweep and Tenflare accompanied the
event. The region also produced an M5.3 flare (R2 - Moderate) at
14/0325 UTC with a Type II radio sweep and an M7.7/1n flare (R2) at
14/1119 UTC. Finally, three R1 events were produced by the region on
14 and 15 May. Region 4086 (N07, L=207, class/area=Dao/060 on 13
May) also produced R3 event, with an X1.2/1b flare observed at
13/1538 UTC. Associated with that event was a Type II radio sweep
and Tenflare.

Other activity included a DSF that lifted off of the Sun's
northern hemisphere late on 12 May. Analysis and modeling of the
event suggested the bulk of the ejecta would pass close but above
Earth early on 17 May. No other Earth-directed CMEs were identified
in available coronagraph imagery.

No proton events were observed at geosynchronous orbit. However, a
weak enhancement, which peaked below the S1 (Minor) threshold, was
observed on 13 May following the X1.2 event from Region 4086.

The greater than 2 MeV electron flux at geosynchronous orbit reached
high levels 18 May following activity associated with the onset of a
positive polarity CH HSS.

Geomagnetic field activity was quiet levels on 12-13 May. Periods of
southward Bz elevated geomagnetic activity to active levels on 14-15
May. Late on 16 May, enhancements in solar wind parameters,
associated with the onset of a positive polarity CH HSS and possible
influence from the southern periphery of the CME that left the Sun
on 12 May, increased activity to active levels. Total magnetic field
strength reached peak levels of 22 nT on 17 May and the Bz component
reached as far south as -17 nT. Solar wind speeds increased to
around 500 km/s. The geomagnetic field responded with conditions up
to G2 (Moderate) levels. Wind speeds continued to increase to around
750-800 km/s by 18 May, but the decreased in magnetic field strength
in the IMF only provoked a peak of G1 (Minor) conditions as the
high-speed stream began to wane.

Forecast of Solar and Geomagnetic Activity
19 May - 14 June 2025

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

No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is
likely to reach high levels on 19-23 May, 29 May - 05 Jun, and 14
Jun in response to recurrent coronal hole activity. The remainder of
the outlook period is expected to be at normal to moderate levels.

Geomagnetic field activity is likely to elevated above quiet levels
for most of the next 27 days due to multiple, recurrent, coronal
hole features. G2 (moderate) conditions are likely on 29 May and 13
Jun; G1 (minor) conditions likely on 19 May, 28 May, and 14 Jun;
active conditions are likely on 30 May - 01 Jun, and 10 Jun;
unsettled levels are likely on 20-23 May, 27 May, 02-07 Jun, and
11-12 Jun. Quiet conditions are expected for the few remaining days
of the outlook period.


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