Viewing archive of Thursday, 18 March 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 Mar 18 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 077 Issued at 2200Z on 18 MAR 1999IA. Analysis of Solar Active Regions and Activity from 17-2100Z to 18-2100Z SOLAR ACTIVITY WAS MODERATE. REGION 8485 (N24W64)
PRODUCED AN M3 X-RAY FLARE WITH MINOR RADIO BURSTS AT 18/0831Z. THIS
REGION WAS ALSO RESPONSIBLE FOR A C9 X-RAY FLARE AT 17/2156Z AND
PRODUCED SEVERAL OTHER C-CLASS EVENTS THROUGHOUT THE PERIOD. REGION
8485 RETAINS MODERATE COMPLEXITY AND SIZE AS IT APPROACHES THE WEST
LIMB. REGION 8488 (S26W17) GREW IN WHITE LIGHT AREA, DEVELOPING A
D-TYPE GROUP WITH SOME COMPLEXITY, BUT HAS YET TO PRODUCE ANY
SIGNIFICANT ACTIVITY. ANOTHER STRONG CORONAL MASS EJECTION OCCURRED
OFF THE NE LIMB, BUT NO MATERIAL APPEARED EARTHBOUND. NEW REGION
8491 (N19W09) WAS NUMBERED TODAY.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO MODERATE
WITH ISOLATED M-CLASS FLARES FROM REGION 8485.
IIA. Geophysical Activity Summary 17-2100Z to 18-2100Z
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET WITH ISOLATED UNSETTLED
PERIODS LATE IN THE DAY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III. Event Probabilities 19 MAR to 21 MAR
| Class M | 50% | 50% | 25% |
| Class X | 10% | 05% | 05% |
| Proton | 05% | 05% | 05% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 18 MAR 148 Predicted 19 MAR-21 MAR 145/135/130 90 Day Mean 18 MAR 142
V. Geomagnetic A Indices
OBSERVED AFR/AP 17 MAR 005/005 ESTIMATED AFR/AP 18 MAR 010/012 PREDICTED AFR/AP 19 MAR-21 MAR 012/010-005/008-005/007
VI. Geomagnetic Activity Probabilities 19 MAR to 21 MAR
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 30% | 30% | 20% |
| Minor storm | 10% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 35% | 35% | 30% |
| Minor storm | 10% | 10% | 10% |
| Major-severe storm | 01% | 01% | 01% |
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