Viewing archive of Tuesday, 27 July 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 Jul 27 2200 UTCPrepared by the NOAA © SWPC and processed by SpaceWeatherLive.com
Joint USAF/NOAA Report of Solar and Geophysical Activity
SDF Number 208 Issued at 2200Z on 27 JUL 1999IA. Analysis of Solar Active Regions and Activity from 26-2100Z to 27-2100Z SOLAR ACTIVITY WAS MODERATE. A LONG DURATION C2 EVENT
WAS OBSERVED AT 27/0254Z AS A RESULT OF AN ERUPTIVE PROMINENCE ON
THE NE LIMB. THE LARGEST EVENT OF THE PERIOD WAS AN M3/1B FROM
REGION 8636 (N21W54) AT 27/1405Z. THREE NEW REGIONS WERE NUMBERED
TODAY AS REGION 8649 (S15E09), REGION 8650 (N17E75), AND REGION 8651
(N24E73).
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE WITH A CHANCE FOR AN ISOLATED X-CLASS EVENT FROM REGION
8636.
IIA. Geophysical Activity Summary 26-2100Z to 27-2100Z
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. ISOLATED ACTIVE CONDITIONS ARE
POSSIBLE FOR DAY ONE OF THE FORECAST.
III. Event Probabilities 28 JUL to 30 JUL
| Class M | 75% | 75% | 75% |
| Class X | 15% | 15% | 15% |
| Proton | 15% | 15% | 15% |
| PCAF | GREEN | ||
IV. Penticton 10.7 cm Flux
Observed 27 JUL 175 Predicted 28 JUL-30 JUL 175/170/170 90 Day Mean 27 JUL 159
V. Geomagnetic A Indices
OBSERVED AFR/AP 26 JUL 004/007 ESTIMATED AFR/AP 27 JUL 008/007 PREDICTED AFR/AP 28 JUL-30 JUL 010/012-008/008-008/006
VI. Geomagnetic Activity Probabilities 28 JUL to 30 JUL
| A. Middle Latitudes | |||
|---|---|---|---|
| Active | 30% | 15% | 15% |
| Minor storm | 15% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
| B. High Latitudes | |||
|---|---|---|---|
| Active | 30% | 20% | 20% |
| Minor storm | 15% | 05% | 05% |
| Major-severe storm | 05% | 01% | 01% |
All times in UTC
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