SB PROP @ ARL $ARLP005
ARLP005 The ARRL Solar Report

ZCZC AP05
QST de W1AW
Propagation Forecast Bulletin 5 ARLP005

From ARRL Headquarters

Newington CT February 14, 2025
To all radio amateurs

SB PROP ARL ARLP005
ARLP005 The ARRL Solar Report

NOAA reports a G1 (Minor) geomagnetic Storm Watch has been issued for 14 Feb, 2025. A coronal hole high speed stream is expected to move into a position favorable for enhanced interaction between the high speed stream and Earth's magnetosphere. These enhancements are likely to cause elevated geomagnetic responses, with G1 (Minor) storm levels likely.

From Spaceweather.com [ http://Spaceweather.com ] : Another solar wind

stream is heading for Earth. It is flowing from a canyon-like hole in the
Sun's atmosphere. First contact with the stream on February 14th could cause
a minor G1-class geomagnetic storm with Arctic auroras for Valentine's Day.


The greatest observed 3 hr Kp over the past 24 hours was 4. The greatest expected 3 hr Kp for February 13 to 15 is 4.67.


No Minor S1 or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast.


Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at February 13 at 1109 UTC.


Solar activity is expected to be low with a chance for R1 to R2, and Minor to Moderate activity on February 13 to 15.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere - February 13, 2025, by F. K. Janda, OK1HH:


"Total solar activity was highest last October in the current 11-year cycle. Since then, it has been declining, but slowly. This is also true for flare activity. Medium strong solar flares were produced mainly by the active
region of AR3981. Some of these were accompanied by CMEs, none of which hit
the Earth directly, but passed close enough to affect its atmosphere.


"NOAA predicted on February 8 that there was a possibility of G1 class geomagnetic storms on February 10 and 11. The prediction turned out to be fairly accurate - although geomagnetic field activity increased as early as February 9, it was highest on February 10 and was elevated on February 11. Therefore, ionospheric shortwave propagation conditions were at their worst
on 10 February and subsequently improved only very slowly in the following days.


"We now observe a large coronal hole, resembling a canyon, on the Sun, which could be another source of enhanced solar wind. Earth should be hit by it on Valentine's Day, or February 14. The days ahead will also be rather
unsettled, but the active regions now rising near the southeastern limb of
the solar disk will cause an uptick in solar activity, nevertheless, causing improved propagation conditions.


"The good news at the end: at www.solarham.com [ https://www.solarham.com ]
on the bottom left, after an eleven-week hiatus, we can see a map of the
entire Sun, especially the Sun's far side, under the 'Farside Watch' banner.
So the JSOC glitch has been fixed, and after another click on http://jsoc.stanford.edu/data/timed [ http://jsoc.stanford.edu/data/timed ]
we can read more under the heading 'Time-Distance Helioseismic Far-Side Imaging.'"


The latest report from Dr. Tamitha Skov, WX6SWW, can be found online at: https://youtu.be/v5H2QsbiCqo [ https://youtu.be/v5H2QsbiCqo ] .

NNNN
/EX

ARRL The National Association for Amateur Radio(R)
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SB PROP @ ARL $ARLP005
ARLP005 The ARRL Solar Report

ZCZC AP05
QST de W1AW
Propagation Forecast Bulletin 5 ARLP005

From ARRL Headquarters

Newington, CT January 30, 2026
To all radio amateurs

SB PROP ARL ARLP005
ARLP005 The ARRL Solar Report

Solar activity continued at low levels this week. Low-level C-class flares
were observed from Regions 4342 and 4353. The majority of the regions were either stable or in decay. New Regions 4359, 4360, and 4361 emerged on the
disk and were numbered. No Earth-directed Coronal Mass Ejections (CMEs) were observed. The forecast calls for solar activity to remain at low levels with
a chance for M-class flares (R1-R2/Minor-Moderate) through January 31.


Solar wind parameters reflected a solar sector boundary crossing followed by the likely onset of high-speed stream (HSS) conditions. On January 27, phi angle switched into a negative sector. Solar wind speed began to increase
after January 28 to around 610 km/s. Enhancements in the solar wind
environment are expected through January 31 under negative polarity Coronal Hole High Speed Streams CH HSS) influences.


The geomagnetic field is expected to quiet to unsettled levels on January 31, and quiet levels on February 1.


Solar activity is expected to be predominantly low with a varying chance for M-class flares (R1-R2/Minor-Moderate) through February 21.


No proton events are expected at geosynchronous orbit.

The greater than 2 MeV electron flux at geosynchronous orbit is expected to reach high levels on January 31, and then on February 1 to 3. Normal to moderate flux levels are expected to persist through the remainder of the period.


Geomagnetic field activity is likely to reach G1 (Minor) storm levels on February 13, with active periods likely on February 4 and 5 due to the influences of multiple, recurrent CH HSSs. Quiet and quiet-to-unsettled conditions are expected to prevail throughout the remainder of the outlook period.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, January 29, 2026, by F. K. Janda, OK1HH:


"The number of sunspot groups has ranged between eight and ten in recent
days, but these are mostly magnetically simple areas with low eruptive activity.

However, the solar wind is blowing faster and faster from the Sun, resulting
in increased geomagnetic activity, especially since January 28. Although this was expected, the combination of fast solar wind, while rapid and significant changes in the polarity of the interplanetary magnetic field has had atypical consequences in the ionosphere.

These include numerous occurrences of ionospheric waveguides on January 28
and during the night of January 29.


"In the coming days, solar and geomagnetic activity should continue to
decline. The next increase in geomagnetic activity can be expected in the middle of the first week of February, but this time without the major
influence of high-speed solar wind. Therefore, only a decrease in critical frequencies and an increase in attenuation are expected in the ionosphere
until February 6, followed by a return to average values is expected."


The latest solar report by Dr. Tamitha Skov, WX6SWW, can be found on YouTube
at https://youtu.be/JXKADnd1E8w?si=pTrl5bAwGvvajUuF [ https://youtu.be/JXKADnd1E8w?si=pTrl5bAwGvvajUuF ] .


The Predicted Planetary A Index for January 31 to February 6 is 8, 5, 5, 5,
15, 12, and 10, with a mean of 8.6. Predicted Planetary K Index is 3, 2, 2,
2, 4, 4, and 3, with a mean of 2.9. 10.7-centimeter flux is 120, 120, 130,
140, 140, 130, and 120, with a mean of 128.6.


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


Also, check this:
"Understanding Solar Indices" from September 2002 QST. https://bit.ly/3Rc8Njt
[ https://bit.ly/3Rc8Njt ]

NNNN
/EX

ARRL The National Association for Amateur Radio(R)


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