SOLAR ACTIVITY BECAME HIGH. REGION 9087 (S12W00) PRODUCED A LONG DURATION M6/3N FLARE AT 19/0726Z. MINOR RADIO BURSTS, INCLUDING A WEAK TYPE IV, ACCOMPANIED THIS EVENT. NO CORONAGRAPH DATA WERE AVAILABLE FROM SOHO BUT IT IS ASSUMED THAT THERE WAS A SIGNIFICANT MASS EJECTION WITH THIS EVENT BECAUSE OF SOFT X-RAY DURATION AND INTERPLANETARY PARTICLE FLUXES. REGION 9087 CONTINUED TO EMERGE RAPIDLY IN ITS NEW LEADER AREA AND TO THE SOUTH OF THE PREEXISTING SPOTS. THE DELTA CONFIGURATION REMAINED. REGION 9097 (N05E67) SHOWED ITSELF AS A MODERATELY LARGE CLASS D SUNSPOT REGION AND PRODUCED OCCASIONAL SUBFLARES. REGION 9077 (N19W72) CONTINUED TO DECLINE AND PRODUCED ONLY INFREQUENT SUBFLARES.

SOLAR ACTIVITY IS EXPECTED TO BECOME GENERALLY HIGH. THE CONTINUED GROWTH IN AREA AND MAGNETIC COMPLEXITY IN REGION 9087 MAKES IT THE PRIME CANDIDATE FOR A MAJOR EVENT. LESSER FLARES MAY COME FROM REGIONS 9077 AND 9097. IIA. GEOPHYSICAL ACTIVITY SUMMARY 18/2100Z TO 19/2100Z: THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED FOR MOST OF THE PERIOD. A SHOCK WAS OBSERVED AT ACE AT 19/1450Z AND A SUDDEN IMPULSE WAS OBSERVED AT THE EARTH AT 19/1526Z. UNSETTLED TO ACTIVE CONDITIONS FOLLOWED THE SHOCK PASSAGE. SOLAR WIND VELOCITY JUMPED FROM APPROXIMATELY 450 KM/S TO OVER 600 KM/S. THE LIKELY SOURCE OF THIS DISTURBANCE WAS A MASS EJECTION ON 17 JULY THAT APPEARED TO BE DIRECTED OFF THE EAST LIMB OF THE SUN. THE GREATER THAN 10 MEV FLUX BEGAN THE PERIOD NEAR 20 PFU AND DECAYED TO NEAR 10 PFU AT THE END OF THE PERIOD. A SLIGHT INCREASE IN FLUX WAS OBSERVED AROUND 19/1500Z WHICH MAY HAVE BEEN RELATED TO THE M6 FLARE MENTIONED ABOVE.

THE GEOMAGNETIC FIELD SHOULD RANGE BETWEEN QUIET AND ACTIVE LEVELS FOR 20 JULY. ACTIVE TO MAJOR STORM LEVELS ARE EXPECTED ON 21 JULY IN RESPONSE TO TODAY'S SUSPECTED MASS EJECTION. UNSETTLED TO ACTIVE LEVELS SHOULD RETURN ON 22 JULY. THE CURRENT SOLAR PROTON EVENT COULD END ON 20 JULY. HOWEVER, THE LARGE FLARES EXPECTED FROM REGION 9087 WILL LIKELY CAUSE NEW INJECTIONS OF ENERGETIC PROTONS DURING THE PERIOD.

  Osservato       19 JUL 250
  Previsto   20 JUL-22 JUL  252/245/235
  Media di 90 Giorni        19 JUL 188

OBSERVED AFR/AP 18 JUL  008/013
ESTIMATED AFR/AP 19 JUL  012/014
PREDICTED AFR/AP 20 JUL-22 JUL  020/015-050/040-020/015