\n<\/p>\n
Geomagnetic field activity is expected to be at minor storm levels
for March 18, and then from March 27 and 27 all due to recurrent
Coronal Hole influences.<\/p>\n
Solar activity was at low levels. Multiple C-Class flares were
observed from newly numbered Region 4028. More spots are rotating
around the Southeast limb that maybe connected to the spot group.
The largest flare of the period was a C6.8 on March 13 at 0752 UTC
from old Region 4012 that recently rotated around the Southwest
limb.<\/p>\n
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere – March 13, 2025, by F. K. Janda, OK1HH:<\/p>\n
“The two geomagnetic disturbances (8-9 March and 12-13 March) were
both triggered by an enhanced solar wind blowing from the border
between the coronal holes and the adjacent active sunspot group. OM
Kevin VE3EN has largely restored the content of his website at
so that we could conveniently observe the
entire solar evolution in the five images at the top of the main
page (HMI Intensity, HMI Magnetogram, Coronal Holes, AIA 131, and
SUVI 304).<\/p>\n
“Again, it is not surprising that both disturbances were correctly
predicted, including the expected worsening on the second day of
each disturbance (March 9 and March 13).<\/p>\n
“Even with thanks to relative simplicity of the situation and the
clear images, it was not surprising that both disturbances were
predicted (including the likely deterioration on the second day of
each disturbance, i.e., 9 and 13 March). Both disturbances were
followed by only gradual improvement, i.e., a return to normal.<\/p>\n
“If solar activity had been higher, the improvement after the
disturbances would have been faster. However, there was no large
area of spots on the Sun this time, and certainly not any with a
more complex configuration of magnetic fields.<\/p>\n
“In the second half of March, solar activity will increase slightly,
and the Spring Equinox will occur. While until recently it appeared
that the increase in solar activity would be more rapid, even the
current expectation of solar flux values only slightly above 200
s.f.u. should result in a noticeable overall improvement, including
an increase in MUF at mid-latitudes during the day up to the VHF
region.”<\/p>\n
Spaceweatherlive.com contains informative charts and graphs on
Real-time auroral and solar activity.<\/p>\n
Slight growth was observed in Regions 4025, 4026, and in the leader
spots of 4019. The rest of the spotted regions were either stable or
in decay. No Earth-directed CMEs were observed.<\/p>\n
Solar activity is expected to be low with a chance for M-class (R1
to R2, Minor to Moderate) flares on March 13 to 15.<\/p>\n
A persistent connection to a negative polarity Coronal Hole is
expected to cause unsettled to active levels, with periods of G1
(Minor) storm conditions possible through March 15.<\/p>\n
The Space Weather Prediction Center also reports there is an
increased chance for M-class flaring (R1-R2, Minor to Moderate) on
March 14 to 16.\u00a0 The SWPC predicts that Geomagnetic Activity
Probabilities for March 14 to 16 are calling for 40, 20, and 10%
chances of a Minor storm during this reporting period.<\/p>\n
For more information concerning shortwave radio propagation, see
and the ARRL Technical Information
Service web page at, For
an explanation of numbers used in this bulletin, see
. Information and
tutorials on propagation can be found at, .<\/p>\n
Also, check this:<\/p>\n
https:\/\/bit.ly\/3Rc8Njt<\/p>\n
“Understanding Solar Indices<\/em>” from September 2002 QST<\/em>.<\/p>\n The Predicted 10.7 centimeter flux for March 14 to 20 is 160, 170,
175, 180, 180, 185, and 190 with a mean of 177.1.\u00a0 The Predicted
Planetary A Index is 15, 8, 8, 15, 20, 8, and 5, with a mean of
11.3.\u00a0 The Predicted Planetary K Index is 4, 3, 3, 4, 5, 3, and 2,
with a mean of 3.4.<\/p>\n<\/p><\/div>\n