Detailed Information

Solar Activity

Solar activity was eruptive in the last 24 hours. 

There were 8 C-class flares in the last 24 hours. The maximum flare class was C7.3 from NOAA 4299, which peaked at 2:09 UT. There were 2 type III solar radio bursts and 3 CME events in the last 24 hours. The east-directed CME has the highest median velocity of 1202 km/s with an angular width of 12 degrees, and no west-directed CMEs are observed. The latest SDO/HMI Intensitygram data show 7 active regions (NOAA 4294, 4295, 4296, 4298, 4299, 4300, 4301), and the latest BBSO H-Alpha data show 1 H-Alpha plage (NOAA 4297). Based on the Farside data, there is 1 region due to return from 05 Dec to 07 Dec from the east limb of the Solar disk.

Based on today's condition,
Solar activity from 5 December 2025, 04:00 UT, to 6 December 2025, 03:59 UT is predicted to be a major flare.
Solar activity from 6 December 2025, 04:00 UT, to 7 December 2025, 03:59 UT is predicted to be active.
Solar activity from 7 December 2025, 04:00 UT to 8 December 2025, 03:59 UT is predicted to be active.

Geomagnetic Activity

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

The solar wind speed increase from 355 km/s and 671 km/s, north-south component of interplanetary magnetic field fluctuate between -15.6 nT and 16.8 nT. There was a geoeffective coronal hole at western equator. The CME on 5 December 00:48 UT was mainly errupted toward western with speed of 1,011 km/s and angular width of 16°. The CME was geoeffective and is likely to have impact until next 3 days.

Minor Storm level geomagnetic activity is expected for the next 24 hours.
Active level geomagnetic activity is expected for 06 December 2025 04UT - 07 December 2025 04UT.
Active level geomagnetic activity is expected for 07 December 2025 04UT - 08 December 2025 04UT.

Ionospheric Activity

Ionosphere activity was not evaluated due to no data for the last 24 hours.

The S4 index value (condition of ionospheric scintillation) was less than 0.5 (quiet), and the TEC index was less than 120 (quiet).

The ionosphere activity on December 5th, 04:00 UT - December 6th, 03:59 UT is predicted to be minor.
The ionosphere activity on December 6th, 04:00 UT - December 7th, 03:59 UT is predicted to be minor.
The ionosphere activity on December 7th, 04:00 UT - December 8th, 03:59 UT is predicted to be minor.

Navigation

Based on TEC and scintillation, the error of the single-frequency GPS positioning for the last 24 hours was at a normal level.

Based on ionospheric scintillation and TEC variation, the probability of error positioning on December 5th, 04:00 UT - December 6th, 03:59 UT is predicted at a normal level.
Based on ionospheric scintillation and TEC variation, the probability of error positioning on December 6th, 04:00 UT - December 7th, 03:59 UT is predicted at a normal level.
Based on ionospheric scintillation and TEC variation, the probability of error positioning on December 7th, 04:00 UT - December 8th, 03:59 UT is predicted at a normal level.
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HF Radio Communication

MUF depression and Short Wave Fadeout (SWF) were not evaluated due to no data for the last 24 hours.

The MUF depression on December 5th, 04:00 UT - December 6th, 03:59 UT is predicted on a moderate level, due to previous geomagnetic activity.
The MUF depression on December 6th, 04:00 UT - December 7th, 03:59 UT is predicted on a minor level, due to previous geomagnetic activity.
The MUF depression on December 7th, 04:00 UT - December 8th, 03:59 UT is predicted on a minor level, due to previous geomagnetic activity.

The SWF on December 5th, 04:00 UT - December 6th, 03:59 UT is predicted at a strong level due to the prediction of a solar flare.
The SWF on December 6th, 04:00 UT - December 7th, 03:59 UT is predicted at a minor level due to the prediction of a solar flare.
The SWF on December 7th, 04:00 UT - December 8th, 03:59 UT is predicted at a minor level due to the prediction of a solar flare.

Satellites

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

High level of electron flux is expected for the next 24 hours.
High level of electron flux is expected for 06 December 2025 04UT - 07 December 2025 04UT.
High level of electron flux is expected for 07 December 2025 04UT - 08 December 2025 04UT.

The flux of high-energy protons in the past 24 hours was quiet.

Based on today's condition, 
The flux of high-energy protons for 5 December 2025, 04:00 UT - 6 December 2025, 03:59 UT is predicted to be quiet.
The flux of high-energy protons for 6 December 2025, 04:00 UT - 7 December 2025, 03:59 UT is predicted to be quiet.
The flux of high-energy protons for 7 December 2025, 04:00 UT - 8 December 2025, 03:59 UT is predicted to be quiet.