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 UTC
Prepared 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 1999

IA. 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 M75%75%75%
Class X15%15%15%
Proton15%15%15%
PCAFGREEN
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
Active30%15%15%
Minor storm15%05%05%
Major-severe storm05%01%01%
B. High Latitudes
Active30%20%20%
Minor storm15%05%05%
Major-severe storm05%01%01%

All times in UTC

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