\n<\/p>\n
Solar activity returned to low levels this past week. The strongest
event of the period was a C1.8 flare on February 17 from region
4374. This region was also responsible for a C1.4 flare on February
18. The only other flare of note was a C1.1 flare on February 17
from an unnumbered plage region near S05E85. (A plage region is a
bright, intensely hot region in the Sun’s chromosphere, typically
found in active areas surrounding sunspots.)<\/p>\n
Region 4374 exhibited minor decay through the dissipation of its
trailing spots. Regions 4375 and 4377 were largely unchanged in area
and complexity.
\u00a0
A large filament eruption beyond the southwest limb was seen in SDO
and SUVI imagery starting approximately February 18. It was
associated with a Type II radio sweep that began on February 18 with
an estimated shock velocity of 310 km\/s. The eruption was first
visible in coronagraph imagery on February 18, but initial analysis
indicates no Earth-directed component. Solar activity is forecast to
be at low levels, with a slight chance for M-class
(R1-R2\/minor-moderate) flares through February 20.
\u00a0
Solar wind parameters continued to reflect the waning influence of a
positive polarity Coronal Hole High-Speed Stream (CH HSS). Solar
wind speed followed a general declining trend, decreasing from an
initial peak near 600 km\/s to approximately 500 km\/s by the end of
the reporting period. The solar wind environment is expected to
remain enhanced through February 20 due to continued but weakening
CH HSS influences.<\/p>\n
Weekly Commentary on the Sun, the Magnetosphere, and the Earth’s
Ionosphere, February 19, 2026, by F. K. Janda, OK1HH:<\/p>\n
“Overall solar activity was relatively high in the first week of
February, with the number of sunspot groups on the solar disk
ranging from seven to nine. Over the next ten days, we observed an
almost uninterrupted decline, at the end of which there were only
three sunspot groups remaining on the disk.<\/p>\n
“Significant eruptions could only occur in one of them: AR 4374.
Before it set behind the western limb of the solar disk, one of the
few more powerful eruptions was observed in it. It happened on
February 16, with the peak at 0436 UT, accompanied by a CME,
partially heading towards Earth. The arrival was expected on
February 19. Although it did so at 1501 UT, Earth only encountered
the edge of the particle cloud – and in fact, almost nothing
happened.<\/p>\n
“Geomagnetic activity was elevated on February 15-16. The phenomenon
began with a positive phase of disturbance in the evening hours,
during which there was a noticeable improvement in shortwave
propagation conditions. A significant deterioration naturally
followed on February 16, partially also on February 17.<\/p>\n
“Any geomagnetic disturbance at the beginning of the predicted
period should be short (on 19th), while another disturbance can be
expected around February 24. Given that solar activity will be on
the rise again at that time, a positive phase of the disturbance can
be expected.”<\/p>\n
Geomagnetic field activity is expected to be at unsettled to active
levels on February 24 and 25, and on March 5 to 7 due to recurrent
negative polarity CH HSS effects. Active conditions are likely on
March 12 following a solar sector boundary crossing, then again on
March 14 with the onset of a positive polarity CH HSS.\u00a0 Barring the
potential for CME activity, mostly quiet to unsettled levels are
expected until February 23, and then February 26 to March 4.<\/p>\n
The Predicted Planetary A Index for February 21 to 27 is 5, 5, 8,
20, 20, 8, and 5, with a mean of 10.1.\u00a0 The Predicted Planetary K
Index is 2, 2, 3, 5, 5, 3, and 2, with a mean of 3.1.
10.7-centimeter flux is 105, 120, 130, 135, 130, 130, and 140, with
a mean of 127.1.<\/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