Viewing archive of Thursday, 30 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 30 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 364 Issued at 2200Z on 30 DEC 1999IA. Analysis of Solar Active Regions and Activity from 29-2100Z to 30-2100Z SOLAR ACTIVITY WAS LOW. ISOLATED MINOR C-CLASS EVENTS
OCCURRED EARLY IN THE PERIOD. COMPLEX REGION 8806 (N22W96) PRODUCED
A C2/SF WITH A LARGE BRIGHT SURGE AT 29/2151Z. THIS REGION HAS SINCE
ROTATED FROM VIEW WITH JUST MINOR SURGING EVIDENT ON THE LIMB.
REMAINING REGIONS WERE STABLE.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW.
OLD REGION 8806 MAY STILL PRODUCE ISOLATED C-LEVEL X-RAY EVENTS AS
IT ROTATES FURTHER AROUND THE WEST LIMB. REGION 8810 (N37E06),
THOUGH STABLE, HAS POTENTIAL FOR ISOLATED C-CLASS EVENTS.
IIA. Geophysical Activity Summary 29-2100Z to 30-2100Z
THE GEOMAGNETIC FIELD WAS QUIET WITH UNSETTLED CONDITIONS BEGINNING
LATE IN THE PERIOD. THE ONSET OF A HIGH SPEED CORONAL HOLE STREAM
WAS OBSERVED AROUND 30/1530Z, AND ACCOUNTED FOR THE LATE-DAY
DISTURBANCE.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT QUIET TO ACTIVE LEVELS WITH MINOR STORMING PERIODS
LIKELY AT HIGH LATITUDES. THIS CORONAL HOLE RELATED DISTURBANCE WILL
LIKELY PERSIST THROUGH THE NEXT THREE DAYS.
III. Event Probabilities 31 DEC to 02 JAN
| Class M | 20% | 10% | 10% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 30 DEC 136 Predicted 31 DEC-02 JAN 130/130/130 90 Day Mean 30 DEC 176
V. Geomagnetic A Indices
OBSERVED AFR/AP 29 DEC 005/007 ESTIMATED AFR/AP 30 DEC 005/006 PREDICTED AFR/AP 31 DEC-02 JAN 015/015-020/025-020/025
VI. Geomagnetic Activity Probabilities 31 DEC to 02 JAN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 60% | 65% | 65% |
| Minor storm | 20% | 25% | 25% |
| Major-severe storm | 05% | 10% | 10% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 60% | 60% | 60% |
| Minor storm | 30% | 30% | 30% |
| Major-severe storm | 10% | 10% | 10% |
All times in UTC
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