Viewing archive of Wednesday, 22 September 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 Sep 22 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 265 Issued at 2200Z on 22 SEP 1999IA. Analysis of Solar Active Regions and Activity from 21-2100Z to 22-2100Z SOLAR ACTIVITY WAS LOW. A C5/1F FLARE FROM REGION 8706
(N19E38) AT 1340Z WAS THE LARGEST EVENT OF THE DAY. NEWLY ASSIGNED
REGION 8708 (S09E55) PRODUCED FREQUENT SUBFLARES DURING THE FIRST
HALF OF THE INTERVAL. ANOTHER NEW REGION, 8707 (S07W08) HAS BEEN
QUIET.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
IIA. Geophysical Activity Summary 21-2100Z to 22-2100Z
THE GEOMAGNETIC FIELD WAS AT QUIET TO MINOR STORM LEVELS. A SMALL
SUDDEN IMPULSE, MEASURED AT BOULDER TO BE 8 NANOTESLA, OCCURRED AT
1222Z. SATELLITE DATA FROM ACE SHOWED THE PASSAGE OF AN
INTERPLANETARY SHOCK JUST PRIOR. SOLAR WIND SPEEDS NEAR 600 KM/S,
AND BZ MEASURING NEAR -15 NT ARE NOW OCCURRING. THE SOLAR ORIGIN OF
THIS EJECTION IS NOT WELL-ESTABLISHED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS FOR THE NEXT 24 HOURS.
SOLAR WIND DATA INDICATE HIGH SPEEDS AND RELATIVELY STRONG SOUTHWARD
MAGNETIC FIELDS. UNSETTLED TO ACTIVE CONDITIONS SHOULD PREVAIL THE
LAST TWO DAYS.
III. Event Probabilities 23 SEP to 25 SEP
| Class M | 15% | 15% | 15% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 22 SEP 140 Predicted 23 SEP-25 SEP 140/135/135 90 Day Mean 22 SEP 163
V. Geomagnetic A Indices
OBSERVED AFR/AP 21 SEP 010/010 ESTIMATED AFR/AP 22 SEP 020/025 PREDICTED AFR/AP 23 SEP-25 SEP 020/025-015/015-015/012
VI. Geomagnetic Activity Probabilities 23 SEP to 25 SEP
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 50% | 40% | 40% |
| Minor storm | 20% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 60% | 50% | 50% |
| Minor storm | 20% | 10% | 10% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
Latest news
Sunday, 8 December 2024
X2.2 solar flare, SDO outage
Thursday, 21 November 2024
Major far side eruption, S1 radiation storm
Monday, 11 November 2024
Coronal hole faces Earth
Latest forum messages
Strong far side CME 335Power transmission for all of us. And why I believe we are better prepared than ever for major solar events 10Incoming & Unnumbered Active Regions 1353Unspecified geomagnetic activity 1750Filaments and prominences 595
More topicsSupport SpaceWeatherLive.com!
A lot of people come to SpaceWeatherLive to follow the Sun's activity or if there is aurora to be seen, but with more traffic comes higher server costs. Consider a donation if you enjoy SpaceWeatherLive so we can keep the website online!
Space weather facts
| Last X-flare | 2024/12/08 | X2.2 |
| Last M-flare | 2024/12/22 | M1.0 |
| Last geomagnetic storm | 2024/12/17 | Kp5+ (G1) |
| Spotless days | |
|---|---|
| Last spotless day | 2022/06/08 |
| Monthly mean Sunspot Number | |
|---|---|
| November 2024 | 152.5 -13.9 |
| December 2024 | 103.3 -49.2 |
| Last 30 days | 115.4 -40.8 |