SOLAR ACTIVITY DROPPED PRECIPITOUSLY TO A VERY LOW LEVEL. ONLY B-CLASS ENHANCEMENTS WERE OBSERVED. REGION 8210 (S17E31) RETAINED ITS DELTA CONFIGURATION, DEVELOPED ADDITIONAL MIXED POLARITIES, AND EXHIBITED MINOR GROWTH. H-ALPHA FIBRIL AND VECTOR MAGNETOGRAPH DATA INDICATE STRONG SHEAR IN THIS REGION WHERE THE DELTA IS LOCATED. A FILAMENT IN THIS REGION FADED RAPIDLY BETWEEN 28/1851-1914Z. TWO SMALL REGIONS EMERGED ON THE DISK NEAR S30W64 AND S25E55 AND WERE NUMBERED AS REGIONS 8212 AND 8213 RESPECTIVELY.

SOLAR ACTIVITY SHOULD BECOME LOW TO MODERATE DURING THE NEXT THREE DAYS. REGION 8210 RETAINS THE CAPABILITY OF PRODUCING ANOTHER SMALL X-CLASS EVENT. OLD REGION 8194 WILL BE RETURNING TO THE EAST LIMB NEAR S18 AROUND 01 MAY. THIS REGION PRODUCED A LONG DURATION M1 FLARE ON 20 APR FROM SEVERAL DAYS BEYOND THE WEST LIMB THAT RESULTED IN A LARGE SOLAR PROTON EVENT AT EARTH. ACTIVITY LEVELS MAY INCREASE UPON THE RETURN OF THIS REGION.

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED. SOLAR WIND VELOCITIES DECREASED DURING THE PERIOD TO BELOW 400 KM/S INDICATING AN END OF THE CORONAL HOLE RELATED DISTURBANCE OF THE LAST SEVERAL DAYS. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT WERE PREDOMINANTLY HIGH.

THE GEOMAGNETIC FIELD SHOULD BE QUIET TO UNSETTLED UNTIL NEAR MIDDAY ON 29 APR WHEN A HALO CME RELATED DISTURBANCE IS EXPECTED TO BEGIN. UNSETTLED TO MINOR STORM CONDITIONS SHOULD BE EXPERIENCED FROM THAT TIME AND THROUGH 30 APR. ISOLATED PERIODS OF MAJOR STORMING ARE POSSIBLE. PREDOMINANTLY UNSETTLED TO ACTIVE CONDITIONS ARE EXPECTED ON 01 MAY AS THE DISTURBANCE PASSES THE EARTH.

  觀測的       28 APR 098
  預測的   29 APR-01 MAY  099/100/103
  90天平均值        28 APR 104

OBSERVED AFR/AP 27 APR  012/014
ESTIMATED AFR/AP 28 APR  010/015
PREDICTED AFR/AP 29 APR-01 MAY  020/020-020/020-015/015