SOLAR ACTIVITY BECAME MODERATE. A CLASSIC HYDER FLARE WAS OBSERVED NEAR S17W09 BETWEEN APPROXIMATELY 12/1130 - 1330Z. THE M1/2N LONG DURATION, TWO RIBBON FLARE BEGAN FOLLOWING THE ERUPTION OF A 23 DEGREE FILAMENT THAT EXTENDED FROM S12W18 TO S28E01. A TYPE II RADIO SWEEP (SHOCK SPEED NEAR 1000 KM/S) AND MINOR, GRADUAL RISE-FALL CENTIMETRIC BURSTS ACCOMPANIED THE EVENT. A FULL HALO CME WAS ALSO OBSERVED ON LASCO IMAGERY BEGINNING AT 12/1331Z. THIS SIGNIFICANT EVENT OCCURRED ON AN OTHERWISE REMARKABLY DORMANT SUN. NEW REGIONS 9162 (S32W36) AND 9163 (S19W10) WERE NUMBERED TODAY, AND JOIN REGION 9161 (N05E38) AS THE ONLY SUNSPOT GROUPS ON THE VISIBLE DISK.

SOLAR ACTIVITY IS EXPECTED TO BE LOW. VERY ISOLATED LOW C-CLASS ACTIVITY IS EXPECTED. IIA. GEOPHYSICAL ACTIVITY SUMMARY 11/2100Z TO 12/2100Z: THE GEOMAGNETIC FIELD WAS MOSTLY QUIET TO ACTIVE WITH PERIODS OF MINOR STORMING OBSERVED AT HIGH LATITUDES BETWEEN 12/09 - 15Z. POSSIBLE TRANSIENT EFFECTS INITIALLY INDUCED THIS DISTURBANCE, BUT WE TRANSITIONED INTO A HIGH SPEED STREAM BY THE END OF THE PERIOD. THE M1/2N FLARE THAT OCCURRED AT 12/1213Z PRODUCED A PROTON EVENT AT GREATER THAN 10 MEV WHICH REMAINS IN PROGRESS AT THIS TIME. THE >10 MEV - 10 PFU THRESHOLD WAS CROSSED AT 12/1555Z AND REACHED 100 PFU AT ISSUE TIME. A >100 MEV PROTON ENHANCEMENT IS ALSO IN PROGRESS, BUT HAS YET TO REACH EVENT THRESHOLD. A PCA BEGAN NEAR 12/1830Z AND IS CURRENTLY IN PROGRESS. CURRENT (12/2100Z) PCA ABSORPTION AT THULE, GREENLAND IS ESTIMATED TO BE 2.5 DB.

THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO ACTIVE THROUGH DAY ONE WITH ISOLATED MINOR STORM PERIODS AT HIGH LATITUDES. EFFECTS FROM TODAY'S M1/2N FLARE AND HALO CME ARE EXPECTED BY DAY TWO - EXPECT MINOR TO MAJOR STORMING TO DEVELOP ON DAY TWO AND LAST THROUGH DAY THREE BEFORE TAPERING OFF TO UNSETTLED TO ACTIVE LATE ON DAY THREE. THE >10 MEV PROTON EVENT CURRENTLY IN PROGRESS IS EXPECTED TO LAST THROUGH MOST OF DAY ONE BEFORE SLOWLY RETURNING TO BACKGROUND LEVELS.

  Observed       12 SEP 133
  Predicted   13 SEP-15 SEP  125/125/130
  90 Day Mean        12 SEP 178

OBSERVED AFR/AP 11 SEP  003/005
ESTIMATED AFR/AP 12 SEP  015/020
PREDICTED AFR/AP 13 SEP-15 SEP  012/012-040/045-040/040