Detailed Information

Solar Activity

Solar activity over the past 24 hours has been eruptive, characterized by eight C-class flares. No M-class or X-class flares were observed. The strongest event was a C6.6 flare from NOAA 14478, peaking at 15:03UT. Despite the flare activity, no solar radio bursts of Type II, Type III, or Type IV were observed. Additionally, four coronal mass ejections were detected, with one observed from the western limb exhibiting a speed of 844 km/s and an angular width of 12 degrees.

On the visible disk, seven active regions were identified by SDO/HMI, including NOAA 14470, NOAA 14473, NOAA 14475, NOAA 14476, NOAA 14477, NOAA 14478, and NOAA 14479. Two H-alpha plages, NOAA 14471 and NOAA 14472, were also observed by BBSO. Furthermore, two regions are due to return between 26 Jun and 28 Jun from the farside. 

Based on today’s conditions,
solar activity for 26 Juni 2026, 04:00 UT - 27 Juni 2026, 03.59 UT is predicted to be active,
solar activity for 27 Juni 2026, 04:00 UT - 28 Juni 2026, 03.59 UT is predicted to be active,
solar activity for 28 Juni 2026, 04:00 UT - 29 Juni 2026, 03.59 UT is predicted to be active,
driven by a forecast for M-class flares based on the Random Forest model

Geomagnetic Activity

The geomagnetic activity was on active level for the last 24 hours.

The solar wind speed decrease from 682 km/s to 376 km/s, north-south component of interplanetary magnetic field stable around -0.9 nT. There was geoeffective coronal hole at central equator, while the others at north pole and eastern equator were not geoeffective. CME on 25 June 2026 22:36 UT was mainly errupted toward south-west with speed of 305 km/s and angular width of 12°. The CME was geoeffective and is likely to have not impact until next 3 days.

Active level geomagnetic activity is expected for 26 June 2026 04:00UT - 27 June 2026 03:59UT.
Quiet level geomagnetic activity is expected for 27 June 2026 04:00UT - 28 June 2026 03:59UT.
Quiet level geomagnetic activity is expected for 28 June 2026 04:00UT - 29 June 2026 03:59UT.

Ionospheric Activity

The ionosphere was on quiet level for the last 24 hours.

There was no depression of foF2 lower than 30% of its median value. There was no increment of fmin more than 30% of its median values. There was a Spread-F layer for 75 minutes and the Sporadic-E for 1005 minutes in the night and daytime with foEs value exceeding the foF2 value. The S4 index values (condition of ionospheric scintillation) was on quiet level (S4<0,5) on the last 24 hours over Pontianak. TEC index was on quiet level (VTEC<125) on the last 24 hours over Pontianak.

The ionosphere activity on 26 June 2026, 04:00 UT - 27 June 2026, 03:59 UT is predicted to be minor.

The ionosphere activity on 27 June 2026, 04:00 UT - 28 June 2026, 03:59 UT is predicted to be minor.

The ionosphere activity on 28 June 2026, 04:00 UT - 29 June 2026, 03:59 UT is predicted to be quiet.

Navigation

Based on TEC and scintilation , the error of the single frequency GPS positioning for  the last 24 hours was in normal level.

Based on ionospheric scintilation and TEC variation, the probability of error positioning on 26 June 2026, 04:00 UT - 27 June 2026, 03:59 UT is predicted at a normal level.

Based on ionospheric scintilation and TEC variation, the probability of error positioning on 27 June 2026, 04:00 UT – 28 June 2026, 03:59 UT is predicted at a normal level.

Based on ionospheric scintilation and TEC variation, the probability of error positioning on 28 June 2026, 04:00 UT - 29 June 2026, 03:59 UT is predicted at a normal level.

HF Radio Communication

MUF Depression was in quiet condition and Short Wave Fadeout (SWF) was in quiet for the last 24 hours

The MUF depression on 26 June 2026, 04:00 UT - 27 June 2026, 03:59 UT is predicted at minor level due to previous of geomagnetic activity.

The MUF depression on 27 June 2026, 04:00 UT - 28 June 2026, 03:59 UT is predicted at minor level due to previous of geomagnetic activity.

The MUF depression on 28 June 2026, 04:00 UT - 29 June 2026, 03:59 UT is predicted at quiet level due to previous of geomagnetic activity.

The SWF on 26 June 2026, 04:00 UT – 27 June 2026, 03:59 UT is predicted at minor level due to the prediction of solar flare.

The SWF on 27 June 2026, 04:00 UT - 28 June 2026, 03:59 UT is predicted at minor level due to the prediction of solar flare.

The SWF on 28 June 2026, 04:00 UT - 29 June 2026, 03:59 UT is predicted at minor level due to the prediction of solar flare.

Satellites

The electron flux was on low level for the last 24 hours.

Low level of electron flux is expected for 26 June 2026 04:00UT - 27 June 2026 03:59UT.
Low level of electron flux is expected for 27 June 2026 04:00UT - 28 June 2026 03:59UT.
Low level of electron flux is expected for 28 June 2026 04:00UT - 29 June 2026 03:59UT.

The 10 MeV proton flux remained at quiet levels over the past 24 hours.

Based on today’s conditions,
proton flux for 26 Juni 2026, 04:00 UT - 27 Juni 2026, 03.59 UT is predicted to be quiet,
proton flux for 27 Juni 2026, 04:00 UT - 28 Juni 2026, 03.59 UT is predicted to be quiet,
proton flux for 28 Juni 2026, 04:00 UT - 29 Juni 2026, 03.59 UT is predicted to be quiet.