Viewing archive of Monday, 18 January 1999
Solar activity report
Any mentioned solar flare in this report has a scaling factor applied by the Space Weather Prediction Center (SWPC). Because of the SWPC scaling factor, solar flares are reported as 42% smaller than for the science quality data. The scaling factor has been removed from our archived solar flare data to reflect the true physical units.
Report of Solar-Geophysical Activity 1999 Jan 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 018 Issued at 2200Z on 18 JAN 1999IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z SOLAR ACTIVITY WAS MODERATE. THIS WAS DUE TO A SINGLE
M-CLASS EVENT, AN M2/1N FLARE AT 18/0804UT, FROM REGION 8440
(S18E64). REGIONS 8439 (S24E00) AND 8440 WERE THE MOST ACTIVE
REGIONS, BOTH PRODUCING NUMEROUS C-CLASS EVENTS. REGION 8442
(N25W28) HAS BEGUN TO SHOW SOME ACTIVITY THIS PERIOD, PRODUCING A
C1/SF AT 18/1839UT. REGION 8442 HAS ALSO SHOWN AN INCREASE IN THE
NUMBER OF SPOTS FROM 8 TO 15 AND A CHANGE IN MAGNETIC CLASSIFICATION
FROM A SIMPLE BETA TO A BETA-GAMMA-DELTA. A NEW REGION WAS NUMBERED
TODAY; 8443 (S18E64). CURRENTLY A 3 SPOT BXO BETA SPOT GROUP.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGIONS 8439 AND 8440 ARE STILL CAPABLE OF PRODUCING
M-CLASS EVENTS.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT WAS A HIGH LEVELS FOR THE DAY
UNTIL AROUND 18/1900UT WHEN IT DROPPED WELL BELOW THRESHOLD LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 19 JAN to 21 JAN
| Class M | 70% | 70% | 70% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 18 JAN 171 Predicted 19 JAN-21 JAN 175/180/185 90 Day Mean 18 JAN 139
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 JAN 005/005 ESTIMATED AFR/AP 18 JAN 005/008 PREDICTED AFR/AP 19 JAN-21 JAN 008/010-008/010-012/015
VI. Geomagnetic Activity Probabilities 19 JAN to 21 JAN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 20% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 20% | 30% |
| Minor storm | 10% | 10% | 15% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
Latest news
Sunday, 7 December 2025
M8.1 solar flare with earth-directed CME
Monday, 1 December 2025
X1.9 solar flare, Coronal hole faces Earth
Friday, 14 November 2025
X4.0 solar flare
Latest forum messages
AR4299 M8.1 CME 2025/12/06 305Growth of Cycle 25 976Ask a powergrid operator anything 45Light pillar 11AR4294 / 4296 / 4298 441
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Solar activity or if there is a chance to see the aurora, but with more traffic comes higher costs to keep the servers online. If you like SpaceWeatherLive and want to support the project you can choose a subscription for an ad-free site or consider a donation. With your help we can keep SpaceWeatherLive online!
Space weather facts
| Last X-flare | 2025/12/08 | X1.1 |
| Last M-flare | 2025/12/10 | M1.2 |
| Last geomagnetic storm | 2025/12/04 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| November 2025 | 91.8 -22.8 |
| December 2025 | 157.7 +65.9 |
| Last 30 days | 108.9 +11.4 |