SB PROP @ ARL $ARLP007
ARLP007 The ARRL Solar Report

ZCZC AP07
QST de W1AW
Propagation Forecast Bulletin 7 ARLP007

From ARRL Headquarters

Newington, CT February 13, 2026
To all radio amateurs

SB PROP ARL ARLP007
ARLP007 The ARRL Solar Report

Solar activity reached moderate levels early this week. The strongest event
was an M1.4 flare observed on February 11 in Region 4366. This region also produced nine C-class flares.


Region 4373 produced a C1.8/Sf flare on February 11. This region displayed
some minor area growth. Regions 4369 and 4371 exhibited some minor decay. The other spotted regions remained unchanged. New Region 4375 was numbered. A
small loop structure near S22W80 erupted around February 10.


Around the same time, a large filament (located near N15W25) lifted off and disappeared from GONG H-alpha imagery. Between faint features in disk imagery and a data gap in STEREO coronagraph imagery, it is difficult to determine whether the filament is superimposed over the earlier eruption or largely
fell back down to the Sun.

Analysis of the coronagraph structure indicates there is no Earth-directed component. However, there is the potential for interaction between the
eruption and the co-rotating interaction region (CIR) ahead of an anticipated high-speed stream, which may cause the CIR to become compressed and arrive later than under ambient conditions.


Solar activity is expected to be at low levels through February 14.
Probability for M-class (R1-R2) flares dropped to a slight chance on February 14, with a slight chance for X-class (R3 or greater) flares on February 12 as Region 4366 continues to rotate behind the western limb.


Solar wind parameters continued to reflect waning influence of a negative polarity coronal hole high-speed stream (CH HSS) with discrete mild disturbances likely associated with embedded transient structures. Solar wind speeds remained generally elevated, slowly decreasing from approximately 500 km/s to 400 km/s by the end of the reporting period.


On February 14, the wind environment is expected to become more enhanced late in the day due to CIR effects from a large positive polarity coronal hole high-speed stream (CH HSS) coupled with possible weak CME effects from the February 11 eruption.


Weekly Commentary on the Sun, the Magnetosphere, and the Earth's Ionosphere, February 12, 2026, by F. K. Janda, OK1HH:


"The last largest sunspot group, also known as NOAA active region 4366, which suddenly appeared in the southeast of the solar disk on January 30, has now disappeared. Until then, it was the source of a long series of energetically significant flares. (This group could reappear on the eastern limb of the
solar disk around February 23.) Overall solar activity declined, slowly at first, and more significantly after the setting of AR 4366.


"The geomagnetic field was mostly quiet to unsettled, with the exception of a disturbance on February 5 and calm days on February 8-9. Due to the absence
of major and longer geomagnetic disturbances and despite the decline in solar radiation, ionospheric propagation conditions for short waves were mostly slightly above average.


"A slight increase in solar activity can be expected from mid-February, meanwhile it appears that geomagnetic activity could also increase slightly
at around the same time. Until then, ionospheric propagation conditions for short waves are likely to remain slightly above average.


"It is not yet possible to predict whether the minor disturbances from
January 16 to 17 and, in particular, the more significant disturbances around January 20 will recur (in the latter case, this would be around February 16, when geomagnetic activity is likely to increase, but probably only to an 'active' level)."


The latest solar report from Dr. Tamitha Skov, WX6SWW, can be found on
YouTube at https://youtu.be/BECqZ6z1yi0?si=YXv2-V23040HzMQA [ https://youtu.be/BECqZ6z1yi0?si=YXv2-V23040HzMQA ] .


Predicted Planetary A Index for February 14 to 20 is 5, 5, 15, 15, 15, 15,
and 15, with a mean of 12.1. Predicated Planetary K Index is 2, 2, 4, 4, 4,
4, and 4, with a mean of 3.4. 10.7-centimeter flux is 140, 150, 160, 170,
180, 175, and 170, with a mean of 163.6.


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)


--- PyGate Linux v1.5.11
* Origin: Dragon's Lair, PyGate NNTP<>Fido Gate (3:633/10)