Viewing archive of Friday, 15 May 1998
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 1998 May 15 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 135 Issued at 2200Z on 15 MAY 1998IA. Analysis of Solar Active Regions and Activity from 14-2100Z to 15-2100Z SOLAR ACTIVITY WAS LOW. THE LARGEST FLARE SINCE
YESTERDAY WAS A C1/SF AT 15/0221Z IN REGION 8218 (S21W45). OTHER
ACTIVE REGIONS WERE RELATIVELY STABLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
ADDITIONAL C-CLASS ACTIVITY IS PROBABLE, ESPECIALLY IN REGION 8218.
IIA. Geophysical Activity Summary 14-2100Z to 15-2100Z
THE GEOMAGNETIC FIELD WAS QUIET UNTIL 15/1453Z WHEN A SUDDEN IMPULSE
(SI) WAS DETECTED ON GROUND MAGNETOMETERS (ABOUT 6 NT AT THE BOULDER
STATION). THIS SI WAS APPARENTLY IN RESPONSE TO THE PASSAGE OF A
SOLAR WIND SHOCK THAT WAS OBSERVED BY THE ACE SPACECRAFT AT ABOUT
15/1356Z. THE GREATER THAN 2 MEV ELECTRON FLUX REMAINED HIGH.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 16 MAY to 18 MAY
| Class M | 10% | 10% | 10% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 15 MAY 116 Predicted 16 MAY-18 MAY 115/110/105 90 Day Mean 15 MAY 098
V. Geomagnetic A Indices
OBSERVED AFR/AP 14 MAY 003/005 ESTIMATED AFR/AP 15 MAY 008/005 PREDICTED AFR/AP 16 MAY-18 MAY 010/010-005/005-005/005
VI. Geomagnetic Activity Probabilities 16 MAY to 18 MAY
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 02% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 15% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 02% | 01% | 01% |
All times in UTC
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