Detailed Information

Solar Activity

Solar activity from 25 September at 04:00 UT to 26 September at 03:59 UT was eruptive.

Solar activity from 26 September at 04:00 UT to 27 September at 03:59 UT was eruptive.

Solar activity from 27 September at 04:00 UT to 28 September at 03:59 UT was eruptive.

Three C-class solar flares were observed, with no M-class or X-class flares. The most significant event was a C1.9 flare originating from NOAA 14536, peaking at 4:37 UT. Associated with this activity, no solar radio bursts of Type II, Type III, or Type IV were observed. Furthermore, no coronal mass ejections were observed during this period. On the visible disk, four active regions were identified by SDO/HMI: NOAA 14535, NOAA 14536, NOAA 14542, and NOAA 14543. Additionally, four H-alpha plages were reported by BBSO, encompassing NOAA 14533, NOAA 14537, NOAA 14538, and NOAA 14539. Looking beyond the visible disk, four regions are due to return to the visible disk between September 28 and September 30.

For the next 24 hours, solar activity is predicted to remain eruptive, with a maximum flare class of C predicted by the Random Forest model.

Geomagnetic Activity

The geomagnetic activity was at minor storm level on 25 September 2026 07UT - 26 September 2026 07UT.The geomagnetic activity was at active level on 26 September 2026 07UT - 27 September 2026 07UT.
The geomagnetic activity was on quiet level for the last 24 hours.

The solar wind speed decrease from 506 km/s to 440 km/s, north-south component of interplanetary magnetic field stable around -0.6 nT Corona hole at was not geoeffective.

Quiet level geomagnetic activity is expected for the next 24 hours.

Ionospheric Activity

Ionosfer was in Moderate conditions on 25 September 2026, 04:00 UT - 26 September 2026 03:59 UT.
Ionosfer was in Quite conditions on 265 September 2026 04:00 UT - 27 September 2026 03:59 UT.
Ionosfer was in Minor conditions on 27 September 2026 04:00 UT - 28 September 2026 03:59 UT.

There was depression of foF2 lower than 30% of its median value for 165 and 60 minutes in 25-26 September and 27-28 September 2026. There was an increment of fmin more than 30% of its median values for 15 and 15 minutes in 25-26 September and 27-28 September 2026. The Spread-F was occurred for 45 minutes, 15 minutes and 240 minutes 25-26 September and 27-28 September 2026. The Sporadic-E did occurred in the night and daytime with foEs value exceeding the foF2 value for 90 minutes, 165 minutes and 120 minutes in 25-26 September and 27-28 September 2026. The S4 index values (condition of ionospheric scintillation) was S4 < 0.5 (quite) in 25-27 September and S4 < 0.8 (minor) Moderate in 27-28 September 2026. The TEC were less than 125 in the last three days. Both are observed over Agam.

The ionosphere activity in the next 24 hours is predicted to be Quite.

Navigation

Based on TEC, the error of the single-frequency GPS positioning on 25 September 04:00 UT - 26 September 2026 03:59 UT was at a Normal level.
Based on TEC, the error of the single-frequency GPS positioning on 26 September 04:00 UT - 27 September 2026 03:59 UT was at a Normal level.
Based on TEC, the error of the single-frequency GPS positioning on 27 September 04:00 UT - 28 September 2026 03:59 UT was at a Slight level.

Based on ionospheric scintillation and TEC variation, the probability of error positioning in the next 24 hours is predicted at a Slight level.

 

HF Radio Communication

MUF depression was in Strong condition and Short Wave Fadeout (SWF) was in Quite level on 25 September 04:00 UT - 26 September 2026 03:59 UT.
MUF depression was in Quite condition and Short Wave Fadeout (SWF) was in Quite level 26 September 04:00 UT - 27 September 2026 03:59 UT.
MUF depression was in Moderate condition and Short Wave Fadeout (SWF) was in Quite level on 27 September 04:00 UT - 28 September 2026 03:59 UT.

The MUF depression in the next 24 hours is predicted on a Quite level, due to previous of geomagnetic activity.

The SWF for the next 24 hours is predicted at a Quite level due to the prediction of the solar flare.

Satellites

The electron flux was at low level on 25 September 2026 07UT - 26 September 2026 07UT.
The electron flux was at high level on 26 September 2026 07UT - 27 September 2026 07UT.
The electron flux was on high level for the last 24 hours.

High level of electron flux is expected for the next 24 hours.

The high-energy proton flux from 25 September at 04:00 UT to 26 September at 03:59 UT was quiet.

The high-energy proton flux from 26 September at 04:00 UT to 27 September at 03:59 UT was quiet.

The high-energy proton flux from 27 September at 04:00 UT to 28 September at 03:59 UT was quiet.

This quiet condition is expected to continue for the next 24 hours.