Viewing archive of Wednesday, 15 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 15 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 349 Issued at 2200Z on 15 DEC 1999IA. Analysis of Solar Active Regions and Activity from 14-2100Z to 15-2100Z SOLAR ACTIVITY CONTINUED AT A LOW LEVEL. REGION 8798
(S14E49) PRODUCED FREQUENT INTENSITY FLUCTUATIONS AND OCCASIONAL LOW
LEVEL C-CLASS EVENTS. THE LARGEST WAS A C2/SF AT 15/1417Z. THIS
REGION BEGAN TO GROW AT A MODERATE PACE DURING THE PERIOD. IT IS
ALSO IN CLOSE PROXIMITY TO REGION 8799 (S09E48). CONTINUED GROWTH IN
8799 WOULD RESULT IN A MERGING OF THESE TWO REGIONS. SEVERAL SMALL
FILAMENTS IN THE NORTHERN HEMISPHERE FADED DURING THE PERIOD. AN
ERUPTIVE PROMINENCE WAS REPORTED BY THE MAUNA LOA OBSERVATORY FROM
SE35 NEAR 15/1930Z. RECENT SOLAR X-RAY IMAGES SHOWED A SMALL TO
MODERATE SIZE REGION ABOUT TO ROTATE OVER THE NORTHEAST LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY SHOULD REMAIN GENERALLY
LOW. REGION 8798 SHOULD CONTINUE TO PRODUCE C-CLASS EVENTS. THERE IS
AN INCREASING POSSIBILITY OF AN M-CLASS EVENT FROM THE 8798/8799
COMPLEX.
IIA. Geophysical Activity Summary 14-2100Z to 15-2100Z
THE GEOMAGNETIC FIELD WAS QUIET FOR THE ENTIRE PERIOD. SOLAR WIND
VELOCITY WAS LOW AND BZ WAS PREDOMINANTLY NORTHWARD.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD SHOULD BE
QUIET TO UNSETTLED FOR THE NEXT THREE DAYS.
III. Event Probabilities 16 DEC to 18 DEC
| Class M | 20% | 25% | 30% |
| Class X | 05% | 05% | 05% |
| Proton | 01% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 15 DEC 179 Predicted 16 DEC-18 DEC 182/182/181 90 Day Mean 15 DEC 168
V. Geomagnetic A Indices
OBSERVED AFR/AP 14 DEC 003/003 ESTIMATED AFR/AP 15 DEC 001/008 PREDICTED AFR/AP 16 DEC-18 DEC 005/010-008/008-008/008
VI. Geomagnetic Activity Probabilities 16 DEC to 18 DEC
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 10% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 01% | 01% | 01% |
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