SOLAR ACTIVITY WAS VERY LOW. REGION 8339 (S16E30) EXHIBITED SOME MINOR GROWTH AND PRODUCED SEVERAL SUBFLARES DURING THE LATTER HALF OF THE PERIOD. NO SIGNIFICANT X-RAY ENHANCEMENTS ACCOMPANIED THESE FLARES. REGION 8340 (N22E64) IS LIKELY THE MOST COMPLEX REGION ON THE VISIBLE DISK BUT ITS LIMB PROXIMITY IS STILL HAMPERING A DETAILED ANALYSIS. PERIODS OF SURGING WITH SEVERAL PLAGE FLUCTUATIONS WERE NOTED IN THIS REGION AND A SMALL FILAMENT ERUPTED LATE IN THE PERIOD. A PROMINENCE ERUPTED OFF THE SW LIMB AT 17/2250Z. THE REMAINING REGIONS WERE QUIET.

SOLAR ACTIVITY IS EXPECTED TO BE VERY LOW TO LOW. THOUGH NO FLARING HAS YET OCCURRED IN REGION 8340, ITS SIZE AND APPARENT COMPLEXITY WILL LIKELY PRODUCE ISOLATED C-CLASS FLARING.

THE GEOMAGNETIC FIELD WAS QUIET UNTIL APPROXIMATELY 18/1100Z. A DISTURBANCE BEGAN AT THAT TIME PRODUCING UNSETTLED TO ACTIVE CONDITIONS WITH AN ISOLATED PERIOD OF MAJOR STORMING AT HIGH LATITUDES. PREDOMINANTLY UNSETTLED TO ACTIVE CONDITIONS HAVE BEEN OBSERVED AT ALL LATITUDES SINCE 18/1500Z.

THE GEOMAGNETIC FIELD IS EXPECTED TO REMAIN UNSETTLED TO ACTIVE. A LARGE EXTENSION OF THE NORTHERN CORONAL HOLE WILL MOVE INTO FAVORABLE POSITION FOR GEOEFFECTIVENESS BY LATE TOMORROW. DISTURBED CONDITIONS ARE EXPECTED TO PERSIST THROUGH THE EARLY PART OF NEXT WEEK.

  觀測的       18 SEP 123
  預測的   19 SEP-21 SEP  125/130/130
  90天平均值        18 SEP 127

OBSERVED AFR/AP 17 SEP  005/007
ESTIMATED AFR/AP 18 SEP  017/010
PREDICTED AFR/AP 19 SEP-21 SEP  015/015-015/015-015/020