Viewing archive of Tuesday, 13 April 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 Apr 13 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 103 Issued at 2200Z on 13 APR 1999IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z
SOLAR ACTIVITY HAS BEEN LOW. THE CURRENT ACTIVE
REGIONS REMAIN SMALL AND GENERALLY UNINTERESTING. CLASS C EVENTS
ARE OCCURRING AT THE RATE OF ABOUT ONE PER DAY. A NEW REGION
(REGION 8515, S20E06) HAS APPEARED. ONGOING CORONAL ACTIVITY IN THE
EASTERN HEMISPHERE HAS CULMINATED IN A PARTIAL HALO CME FIRST
VISIBLE AT 14/0330UT. THE EVENT EXTENDED 220 DEGREES OVER THE
EAST AND SOUTHEAST SOLAR LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY, AS MEASURED BY FLARE
OCCURRENCE, IS EXPECTED TO REMAIN LOW. CORONAL MASS EJECTION
ACTIVITY MAY WELL CONTINUE AT A LEVEL ENHANCED FROM THE LEVELS OF
THE LAST FEW DAYS.
IIA. Geophysical Activity Summary 12-2100Z to 13-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET.
IIB. Geophysical Activity Forecast
GEOMAGNETIC ACTIVITY IS
EXPECTED TO INCREASE FROM QUIET TO ACTIVE OR MINOR STORM LEVELS OVER
THE NEXT THREE DAYS.
III. Event Probabilities 14 APR to 16 APR
| Class M | 15% | 15% | 15% |
| Class X | 05% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 13 APR 130 Predicted 14 APR-16 APR 128/125/123 90 Day Mean 13 APR 135
V. Geomagnetic A Indices
OBSERVED AFR/AP 12 APR 006/007 ESTIMATED AFR/AP 13 APR 004/005 PREDICTED AFR/AP 14 APR-16 APR 010/012-040/030-020/020
VI. Geomagnetic Activity Probabilities 14 APR to 16 APR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 15% | 15% | 15% |
| Minor storm | 05% | 25% | 05% |
| Major-severe storm | 05% | 25% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 10% | 10% | 15% |
| Minor storm | 05% | 05% | 05% |
| Major-severe storm | 05% | 05% | 05% |
All times in UTC
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