Viewing archive of Sunday, 19 December 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 Dec 19 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 353 Issued at 2200Z on 19 DEC 1999IA. Analysis of Solar Active Regions and Activity from 18-2100Z to 19-2100Z SOLAR ACTIVITY HAS BEEN LOW. MINOR FLARES HAVE
CONTINUED IN ACTIVE REGIONS 8798 (S13W05) AND 8806 (N19E50). A
TYPE II RADIO BURST, UNASSOCIATED WITH ANY OTHER ACTIVITY, WAS
REPORTED AT 19/1231Z.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGIONS 9798 AND 8806 ARE EXPECTED TO CONTINUE TO
PRODUCE MINOR EVENTS. REGION 8798 HAS A MORE COMPLEX STRUCTURE
WHILE REGION 8806 HAS A LARGE, COMPLEX SPOT GROUP OFTEN ASSOCIATED
WITH MAJOR FLARE ACTIVITY BUT IT DOES NOT YET HAVE AS WELL DEVELOPED
PLAGE STRUCTURE AND COMPLEXITY.
IIA. Geophysical Activity Summary 18-2100Z to 19-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED WITH A CHANCE IT MAY REACH ACTIVE
LEVELS LATE IN THE THREE-DAY PERIOD.
III. Event Probabilities 20 DEC to 22 DEC
| Class M | 45% | 50% | 50% |
| Class X | 15% | 20% | 20% |
| Proton | 05% | 05% | 10% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 19 DEC 207 Predicted 20 DEC-22 DEC 205/200/195 90 Day Mean 19 DEC 170
V. Geomagnetic A Indices
OBSERVED AFR/AP 18 DEC 004/005 ESTIMATED AFR/AP 19 DEC 007/005 PREDICTED AFR/AP 20 DEC-22 DEC 006/006-008/012-010/012
VI. Geomagnetic Activity Probabilities 20 DEC to 22 DEC
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 05% | 10% | 10% |
| Minor storm | 02% | 02% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 12% | 10% | 10% |
| Minor storm | 03% | 03% | 06% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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