NOAA/USAF Report of Solar-Geophysical Activity 1 October 2000
:Product: Report of Solar-Geophysical Activity :Issued: 2000 Oct 01 2200 UT # Prepared jointly by the U.S. Dept. of Commerce, NOAA, #Space Environment Center and the U.S. Air Force. # JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY SDF NUMBER 275 ISSUED AT 2200Z ON 01 OCT 2000 IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 30/2100Z TO 01/2100Z: SOLAR ACTIVITY WAS HIGH. TWO OPTICALLY UNCORRELATED X-RAY FLARES, AN X1 AT 30/2321Z AND M5 AT 01/0701Z, ARE BELIEVED TO HAVE BEEN PRODUCED BY REGION 9169 THAT JUST RECENTLY PASSED BEHIND THE WEST LIMB. A 200 SFU TENFLARE ACCOMPANIED THE M5 EVENT. A LONG-DURATION M2 FLARE AT 01/1410Z IS BELIEVED TO HAVE ORIGINATED FROM REGION 9178 (S22E24); THIS REGION ALSO PRODUCED NUMEROUS C-CLASS FLARES. REGION 9176 (S10E15) PRODUCED A C3/SF FLARE WITH AN ASSOCIATED TYPE II RADIO SWEEP (SHOCK SPEED 1100 KM/S). A 12-DEGREE FILAMENT DISAPPEARED OVERNIGHT FROM N22W37. NEW REGION 9180 (S34W21) WAS NUMBERED TODAY. IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW TO MODERATE. WHILE REGION 9169, WHICH IS BELIEVED TO HAVE CAUSED THE RECENT MAJOR FLARES, IS NOW WELL BEHIND THE LIMB, BOTH REGIONS 9176 (S09E18) AND 9178 REMAIN CAPABLE OF PRODUCING M-FLARES. IIA. GEOPHYSICAL ACTIVITY SUMMARY 30/2100Z TO 01/2100Z: THE GEOMAGNETIC FIELD RANGED FROM ACTIVE TO QUIET CONDITIONS. ACTIVE CONDITIONS WERE OBSERVED UNTIL APPROXIMATELY 01/06Z, AT WHICH POINT THE SOLAR WIND SPEED AND INTERPLANETARY MAGNETIC FIELD BEGAN TO DROP TO NOMINAL LEVELS. RELATIVISTIC ELECTRONS AT GEO-SYNCHRONOUS ORBIT REACHED MODERATE LEVELS. IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS EXPECTED TO BE QUIET TO UNSETTLED FOR THE FIRST DAY, WITH ACTIVITY INCREASING FOR THE SECOND AND THIRD DAYS. A RECURRENT CORONAL HOLE WILL BE GEO-EFFECTIVELY POSITIONED BY DAY TWO. IN ADDITION, EFFECTS FROM ANY OF THE MANY SOLAR EVENTS TODAY COULD IMPACT THE EARTH LATE ON DAY TWO INTO DAY THREE. III. EVENT PROBABILITIES 02 OCT-04 OCT CLASS M 50/50/50 CLASS X 05/05/05 PROTON 05/05/05 PCAF GREEN IV. PENTICTON 10.7 CM FLUX OBSERVED 01 OCT 202 PREDICTED 02 OCT-04 OCT 190/190/185 90 DAY MEAN 01 OCT 183 V. GEOMAGNETIC A INDICES OBSERVED AFR/AP 30 SEP 025/045 ESTIMATED AFR/AP 01 OCT 015/015 PREDICTED AFR/AP 02 OCT-04 OCT 010/010-012/012-015/015 VI. GEOMAGNETIC ACTIVITY PROBABILITIES 02 OCT-04 OCT A. MIDDLE LATITUDES ACTIVE 15/25/25 MINOR STORM 05/10/15 MAJOR-SEVERE STORM 01/01/05 B. HIGH LATITUDES ACTIVE 20/25/25 MINOR STORM 05/15/20 MAJOR-SEVERE STORM 01/05/10 VII. COMMENTS EFFECTIVE 2 OCT 2000, SEC WILL ISSUE ITS TEXT PRODUCTS IN MIXED CASE VS. ALL UPPER CASE. THIS CHANGE WILL BE VISIBLE ON ALL SEC PRODUCT DELIVERY SYSTEMS EXCEPT FOR TELETYPE CIRCUITS. ONLY THE CASE OF THE TEXT IN EACH PRODUCT WILL CHANGE, NOT THE FORMAT OR SPACING WITHIN THE PRODUCT. FOR DETAILS SEE OUR WEBSITE AT SEC.NOAA.GOV/MIXEDCASE.HTML
