Viewing archive of Monday, 18 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 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 138 Issued at 2200Z on 18 MAY 1998IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z SOLAR ACTIVITY WAS VERY LOW, AS NO FLARES OCCURRED FOR
A SECOND CONSECUTIVE DAY. THE THREE ACTIVE REGIONS CURRENTLY ON THE
VISIBLE DISK, 8218 (S20W81), 8220 (S27W18), AND 8222 (N23W17),
REMAINED QUIET AND STABLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE VERY
LOW TO LOW, WITH THE CHANCE FOR MINOR C-CLASS ACTIVITY FROM REGION
8222 (N23W17).
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD HAS BEEN MOSTLY QUIET TO UNSETTLED FOR THE PAST
24 HOURS, EXCEPT FOR A SINGLE PERIOD OF ACTIVE CONDITIONS RECORDED
AT HIGH LATITUDES DURING THE INTERVAL 18/1200-1500Z. THE GREATER
THAN 2 MEV ELECTRON FLUX RANGED FROM MODERATE TO HIGH.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 19 MAY to 21 MAY
| Class M | 05% | 05% | 05% |
| Class X | 01% | 01% | 01% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 18 MAY 102 Predicted 19 MAY-21 MAY 098/095/098 90 Day Mean 18 MAY 109
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 MAY 010/009 ESTIMATED AFR/AP 18 MAY 010/015 PREDICTED AFR/AP 19 MAY-21 MAY 005/010-005/010-010/015
VI. Geomagnetic Activity Probabilities 19 MAY to 21 MAY
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 15% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 02% |
All times in UTC
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