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% |
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