Viewing archive of Thursday, 21 January 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 Jan 21 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 021 Issued at 2200Z on 21 JAN 1999IA. Analysis of Solar Active Regions and Activity from 20-2100Z to 21-2100Z SOLAR ACTIVITY WAS VERY LOW. REGIONS 8439 (S22W42) AND
8440 (N19W37) CONTINUE TO HAVE PLAGE FLUCTUATIONS AND POINT
BRIGHTENINGS. BOTH REGIONS MAINTAINED A BETA-GAMMA MAGNETIC
CLASSIFICATION WITH APPROXIMATELY 25 SPOTS IN EACH REGION. NEW
REGION 8446 (N14E61) APPEARED AS A BXO-BETA SPOT GROUP WITH 3 SPOTS.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGIONS 8439 AND 8440 ARE EACH CAPABLE OF PRODUCING AN
ISOLATED M-CLASS EVENT. ANOTHER EVENT COULD OCCUR FROM THE REGION
JUST BEHIND THE NORTHEAST LIMB, THE SITE OF YESTERDAY'S M5 X-RAY
EVENT.
IIA. Geophysical Activity Summary 20-2100Z to 21-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. THE GREATER THAN 10
MEV PROTONS BECAME ENHANCED BUT BELOW EVENT THRESHOLD FROM
YESTERDAY'S SOLAR ACTIVITY.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. THE GREATER THAN 10 MEV PROTONS
ARE EXPECTED TO REMAIN ENHANCED FOR THE FIRST PART OF THE PERIOD.
III. Event Probabilities 22 JAN to 24 JAN
| Class M | 60% | 50% | 50% |
| Class X | 10% | 10% | 10% |
| Proton | 05% | 01% | 01% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 21 JAN 175 Predicted 22 JAN-24 JAN 180/185/180 90 Day Mean 21 JAN 141
V. Geomagnetic A Indices
OBSERVED AFR/AP 20 JAN 008/007 ESTIMATED AFR/AP 21 JAN 010/012 PREDICTED AFR/AP 22 JAN-24 JAN 012/014-012/012-010/010
VI. Geomagnetic Activity Probabilities 22 JAN to 24 JAN
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 25% | 20% | 15% |
| Minor storm | 05% | 05% | 01% |
| Major-severe storm | 01% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 25% | 20% |
| Minor storm | 10% | 10% | 05% |
| Major-severe storm | 01% | 01% | 01% |
All times in UTC
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