Viewing archive of Tuesday, 19 October 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 Oct 19 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 292 Issued at 2200Z on 19 OCT 1999IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD
WAS A C8/SF FROM REGION 8732 (N22W52) AT 19/1941Z. THIS REGION
PRODUCED SEVERAL MINOR C-CLASS SUBFLARES THROUGHOUT THE PERIOD.
REGION 8731 (N13W45) HAS DECAYED SLIGHTLY , PRODUCING OCCASIONAL
MINOR SUBFLARES. AN EXTENDED PERIOD OF BRIGHT SURGING WAS OBSERVED
ON THE SE LIMB BETWEEN 19/0700 - 1000Z, A CME FROM THE SAME LOCATION
OCCURRED DURING THAT TIME FRAME. NEW REGION 8737 (S15E14) WAS
NUMBERED TODAY AND PRODUCED A SUBFLARE LATE IN THE PERIOD.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. THOUGH LARGE AND MAGNETICALLY COMPLEX REGION 8731 HAS
SHOWN SIGNS OF DECAY, IT MAINTAINS POTENTIAL FOR AN ISOLATED M-CLASS
EVENT. REGION 8732 IS EXPECTED TO CONTINUE PRODUCING C-CLASS
ACTIVITY. REGION 8737, IF IT MAINTAINS ITS PRESENT GROWTH RATE, WILL
SOON BECOME A GOOD CANDIDATE FOR C-CLASS ACTIVITY.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
THE GEOMAGNETIC FIELD WAS AT QUIET TO UNSETTLED LEVELS WITH
OCCASIONAL ACTIVE PERIODS OBSERVED DURING LOCAL NIGHTTIME HOURS AT
HIGH LATITUDES. THE GREATER THAN TWO MEV ELECTRON FLUX REMAINED AT
MODERATE TO HIGH LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS. OCCASIONAL ACTIVE
CONDITIONS ARE POSSIBLE ON DAYS TWO AND THREE AS A CORONAL HOLE
MOVES INTO A GEOEFFECTIVELY FAVORABLE POSITION.
III. Event Probabilities 20 OCT to 22 OCT
| Class M | 45% | 45% | 40% |
| Class X | 10% | 10% | 05% |
| Proton | 10% | 10% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 19 OCT 170 Predicted 20 OCT-22 OCT 170/165/160 90 Day Mean 19 OCT 159
V. Geomagnetic A Indices
OBSERVED AFR/AP 18 OCT 006/006 ESTIMATED AFR/AP 19 OCT 007/010 PREDICTED AFR/AP 20 OCT-22 OCT 010/008-012/015-012/012
VI. Geomagnetic Activity Probabilities 20 OCT to 22 OCT
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 20% | 25% | 25% |
| Minor storm | 05% | 10% | 10% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 20% | 30% | 30% |
| Minor storm | 10% | 15% | 15% |
| Major-severe storm | 01% | 05% | 05% |
All times in UTC
Latest news
Thursday, 11 September 2025
Coronal hole faces Earth
Sunday, 31 August 2025
M2.7 solar flare with earth-directed CME!
Tuesday, 5 August 2025
M4.4 solar flare from sunspot region 4168
Latest forum messages
Comet C/2025 A6 (Lemmon) 72CMEs from 2025/10/03 48Coronal Hole 85 2Unspecified geomagnetic activity 3204Incoming & Unnumbered Active Regions 2108
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 | 2025/06/19 | X1.9 |
| Last M-flare | 2025/10/03 | M1.2 |
| Last geomagnetic storm | 2025/10/03 | Kp5 (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| September 2025 | 129.8 -3.7 |
| October 2025 | 140.1 +10.3 |
| Last 30 days | 131.3 -1.2 |