[SFDXA] ARLP005 The ARRL Solar Report

[Bill]

ARLP005 The ARRL Solar Report

	

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://arrl.informz.net/z/cjUucD9taT0zNTQwNjQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT00MTM5NTk2NQ/index.html>.

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 
<https://arrl.informz.net/z/cjUucD9taT0zNTQwNjQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT00MTM5NTk2Ng/index.html> 
and the ARRL Technical Information Service web page at 
www.arrl.org/propagation-of-rf-signals 
<https://arrl.informz.net/z/cjUucD9taT0zNTQwNjQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT00MTM5NTk2Nw/index.html>. 
For an explanation of numbers used in this bulletin, see 
www.arrl.org/the-sun-the-earth-the-ionosphere 
<https://arrl.informz.net/z/cjUucD9taT0zNTQwNjQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT00MTM5NTk2OA/index.html>. 
Information and tutorials on propagation can be found at http://k9la.us 
<https://arrl.informz.net/z/cjUucD9taT0zNTQwNjQyJnA9MSZ1PTUyNTQ3MzY2NCZsaT00MTM5NTk2OQ/index.html>.

Also, check this:

"Understanding Solar Indices" from September 2002 QST.

NNNN

/EX

	

	

ARRL The National Association for Amateur Radio®

	

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