Viewing archive of Saturday, 10 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 10 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 100 Issued at 2200Z on 10 APR 1999

IA. Analysis of Solar Active Regions and Activity from 09-2100Z to 10-2100Z

SOLAR ACTIVITY HAS BEEN LOW. THE MOST INTERESTING ACTIVITY HAS BEEN IN REGION 8508 (N23W14) A SMALL BUT COMPLEX BETA GAMMA REGION WITH A CONVOLUTED NEUTRAL LINE EXTENDING THROUGH THE REGION. IT HAS PRODUCED SEVERAL SMALL FLARES RANGING UP TO CLASS C INTENSITY. OTHER REGIONS ARE STABLE OR DECLINING.
IB. Solar Activity Forecast
SOLAR ACTIVITY IS EXPECTED TO REMAIN LOW.
IIA. Geophysical Activity Summary 09-2100Z to 10-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET TO UNSETTLED. ACE SOLAR WIND DATA INDICATES EARTH MAY BE IN A HIGH SPEED STREAM. SOLAR WIND VELOCITY HAS INCREASED MODERATELY ALONG WITH THE TEMPERATURE WHILE THE DENSITY HAS DECREASED OVER THE PAST 12 HOURS. THE SOURCE IS INDEFINITE BUT MAY BE A SMALL, POORLY-DEFINED CORONAL HOLE VISIBLE AROUND N22W30. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT HAVE REMAINED AT MODERATE LEVELS.
IIB. Geophysical Activity Forecast
THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TO ACTIVE THROUGH THE NEXT 24 HOURS.
III. Event Probabilities 11 APR to 13 APR
Class M25%25%25%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       10 APR 136
  Predicted   11 APR-13 APR  132/130/128
  90 Day Mean        10 APR 135
V. Geomagnetic A Indices
OBSERVED AFR/AP 09 APR  007/005
ESTIMATED AFR/AP 10 APR  014/010
PREDICTED AFR/AP 11 APR-13 APR  012/010-010/010-010/008
VI. Geomagnetic Activity Probabilities 11 APR to 13 APR
A. Middle Latitudes
Active15%14%15%
Minor storm07%08%06%
Major-severe storm03%03%01%
B. High Latitudes
Active13%11%13%
Minor storm07%07%07%
Major-severe storm04%04%03%

All times in UTC

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