SOLAR ACTIVITY WAS LOW. REGION 8611 (S25E47) WAS THE MOST ACTIVE REGION ON THE DISK TODAY AND PRODUCED NUMEROUS C-CLASS SUBFLARES. THE LARGEST OF THESE WAS A C6/1F AT 1934Z. THIS GROUP EXHIBITED VERY BRIGHT PLAGE ALL DAY AND IS GROWING STEADILY. REGION 8598 (N22W25) IS STILL THE LARGEST SUNSPOT GROUP ON THE DISK BUT COULD ONLY MUSTER ONE SUBFLARE, IN SPITE OF A DELTA SPOT NEAR REGION CENTER. THIS GROUP SHOWED SIGNIFICANT DECAY OF MAGNETIC FLUX AND IS CLEARLY ON THE DECLINE. A PARTIAL HALO CME WAS REPORTED BY LASCO THAT WAS ASSOCIATED WITH A SIGNATURE IN EIT IN THE NORTHWEST QUADRANT OF THE SOLAR DISK. THESE EVENTS WERE ALSO TIME COINCIDENT WITH YESTERDAY'S M1 FLARE FROM REGION 8592 AT N23W25.

SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. REGIONS 8598 AND 8611 ARE THE BEST CANDIDATES FOR PRODUCING AN ISOLATED M-CLASS EVENT OVER THE NEXT THREE DAYS. REGIONS 8602 (N18E08), AND 8603 (S15E18) MIGHT ALSO CONTRIBUTE, GIVEN THE CURRENT SLOW GROWTH TREND IN THESE REGIONS. IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z: THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MAJOR STORM LEVELS. YESTERDAY'S ACTIVE CONDITIONS DECLINED TO QUIET AROUND 28/0000Z. AROUND 28/0400Z THE SOLAR WIND VELOCITY BEGAN TO INCREASE SIGNIFICANTLY, REACHING SPEEDS AS HIGH AS 900 KM/S BY 0510Z. THE GEOMAGNETIC FIELD RESPONDED WITH A PERIOD OF MAJOR STORM FROM 0300-0600Z, FOLLOWED BY AN ACTIVE TO MINOR STORM PERIOD FROM 0600-0900Z. THE INTERPLANETARY MAGNETIC FIELD SHOWED SOME MILDLY NEGATIVE BZ FROM 0400-0600Z BUT RETURNED TO NOMINAL LEVELS THEREAFTER. IN RESPONSE THE GEOMAGNETIC FIELD ALSO CALMED TO QUIET TO UNSETTLED FROM 0900Z THROUGH THE END OF THE DAY. GIVEN THE HIGH SPEED AND VERY LOW DENSITY SEEN WITH THIS SOLAR WIND EVENT, IT IS MOST LIKELY THAT ACE OBSERVED THE RAREFACTION REGION BEHIND THE PARTIAL HALO CME OF 24 JUNE, WHICH WAS KNOWN TO BE DIRECTED SLIGHTLY TO THE WEST OF THE SUN-EARTH LINE.

THE GEOMAGNETIC FIELD IS EXPECTED TO BE UNSETTLED TO ACTIVE FOR THE NEXT 24 HOURS. MOSTLY UNSETTLED CONDITIONS SHOULD DOMINATE ON THE SECOND DAY. PREDOMINANTLY UNSETTLED LEVELS ARE ALSO EXPECTED ON THE THIRD DAY, BUT THERE WILL BE AN ENHANCED PROBABILITY FOR SOME ACTIVE PERIODS BECAUSE OF THE PARTIAL HALO CME OF THE 27TH.

  Geobserveerd       28 JUN 197
  Voorspeld   29 JUN-01 JUL  180/175/170
  90 Day Mean        28 JUN 144

OBSERVED AFR/AP 27 JUN  015/021
ESTIMATED AFR/AP 28 JUN  020/025
PREDICTED AFR/AP 29 JUN-01 JUL  012/018-010/012-012/015