On Friday, June 13, Spaceweather.com reports a CIR, or co-rotating
interaction region, hit Earth's magnetic field, sparking a G2-class
geomagnetic storm. There is a chance that this ongoing storm could
intensify to category G3 (Strong).

Overall, solar activity was at low levels, with only C-class flares
observed the past 48 hours. There were flares observed beyond the
east limb, but no responsible region has yet come into view. Flaring
was also observed just before 0600 UTC June 12 from near region
AR4105 and while modeling is not yet complete, is not expected to
have an Earth-directed component. All other regions were mostly
quiet and stable in their size.

Moderate geomagnetic storming returns on June 14, with a slight
chance for G3 (Strong) levels, due to recurrent positive polarity CH
HSS influence. By June 15, conditions are anticipated to slowly
diminish as CH/CME effects weaken, resulting in periods of G1
(Minor) geomagnetic storming.

A gradual trend towards a less disturbed solar wind environment is
expected to transpire.  By June 14, positive polarity Coronal Hole
High-Speed Stream influences are expected to begin with elevated
conditions likely to linger into June 15.

Weekly Commentary on the Sun, the Magnetosphere, and the Earth's
Ionosphere, June 12, 2025, by F. K. Janda, OK1HH:

"The observed number of sunspot groups ranged between five and six
until June 10. A change occurred on June 11, when four more groups
appeared in the northeast of the solar disk, followed immediately by
a fifth. Which quickly manifested itself in a slight increase in
solar flux. However, since the afternoon of June 11, the activity of
the Earth's magnetic field increased, so therefore a noticeable
decrease in MUF followed on June 12.

"Fortunately, propagation conditions in the shortwave DX bands
(usually understood to mean frequencies above 14 MHz) were
diversified by the more frequent occurrence of the sporadic-E layer.
Although irregular and with only short rises in MOF Es towards 30
MHz, it revived the DX bands despite the decline in MUF F2 (by up to
several MHz during the day).

"Solar activity will temporarily increase slightly in the second
half of June, but this will have little effect on shortwave
propagation conditions. There is greater hope for a slight
improvement and more interesting developments from mid-June onwards.
However, shortwave propagation conditions in the last days of the
month will again be less regular and slightly disrupted."

For customizable propagation charts, visit the VOACAP Online for Ham
Radio website at, https://www.voacap.com/hf/ .

For more information concerning shortwave radio propagation, see
http://www.arrl.org/propagation and the ARRL Technical Information
Service web page at, http://arrl.org/propagation-of-rf-signals. For
an explanation of numbers used in this bulletin, see
http://arrl.org/the-sun-the-earth-the-ionosphere . Information and
tutorials on propagation can be found at, http://k9la.us/ .

Also, check this:

https://bit.ly/3Rc8Njt

"Understanding Solar Indices" from September 2002 QST.

The Predicted Planetary A Index for June 14 to 20 is 32, 22, 15, 12,
10, 8, and 8, with a mean of 15.3.  The Predicted Planetary K Index
is 6, 5, 4, 4, 3, 3, and 3, with a mean of 4.  Predicted 10.7
centimeter flux is 120, 118, 120, 120, 125, 130, and 130, with a
mean of 123.3.