Viewing archive of Tuesday, 13 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 13 2200 UTC
Prepared by the NOAA © SWPC and processed by SpaceWeatherLive.com

Joint USAF/NOAA Report of Solar and Geophysical Activity

SDF Number 103 Issued at 2200Z on 13 APR 1999

IA. Analysis of Solar Active Regions and Activity from 12-2100Z to 13-2100Z

SOLAR ACTIVITY HAS BEEN LOW. THE CURRENT ACTIVE REGIONS REMAIN SMALL AND GENERALLY UNINTERESTING. CLASS C EVENTS ARE OCCURRING AT THE RATE OF ABOUT ONE PER DAY. A NEW REGION (REGION 8515, S20E06) HAS APPEARED. ONGOING CORONAL ACTIVITY IN THE EASTERN HEMISPHERE HAS CULMINATED IN A PARTIAL HALO CME FIRST VISIBLE AT 14/0330UT. THE EVENT EXTENDED 220 DEGREES OVER THE EAST AND SOUTHEAST SOLAR LIMB.
IB. Solar Activity Forecast
SOLAR ACTIVITY, AS MEASURED BY FLARE OCCURRENCE, IS EXPECTED TO REMAIN LOW. CORONAL MASS EJECTION ACTIVITY MAY WELL CONTINUE AT A LEVEL ENHANCED FROM THE LEVELS OF THE LAST FEW DAYS.
IIA. Geophysical Activity Summary 12-2100Z to 13-2100Z
THE GEOMAGNETIC FIELD HAS BEEN QUIET.
IIB. Geophysical Activity Forecast
GEOMAGNETIC ACTIVITY IS EXPECTED TO INCREASE FROM QUIET TO ACTIVE OR MINOR STORM LEVELS OVER THE NEXT THREE DAYS.
III. Event Probabilities 14 APR to 16 APR
Class M15%15%15%
Class X05%05%05%
Proton05%05%05%
PCAFGREEN
IV. Penticton 10.7 cm Flux
  Observed       13 APR 130
  Predicted   14 APR-16 APR  128/125/123
  90 Day Mean        13 APR 135
V. Geomagnetic A Indices
OBSERVED AFR/AP 12 APR  006/007
ESTIMATED AFR/AP 13 APR  004/005
PREDICTED AFR/AP 14 APR-16 APR  010/012-040/030-020/020
VI. Geomagnetic Activity Probabilities 14 APR to 16 APR
A. Middle Latitudes
Active15%15%15%
Minor storm05%25%05%
Major-severe storm05%25%01%
B. High Latitudes
Active10%10%15%
Minor storm05%05%05%
Major-severe storm05%05%05%

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