FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 233
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 20 AUG 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY HAS BEEN VERY LOW TO LOW. THE
LARGEST EVENT OF THE DAY WAS A C1/SF FLARE FROM REGION 5108
(S20W90) AT 20/1824Z. MINOR RADIO EMISSIONS ACCOMPANIED THE
FLARE. THE REMAINING REGIONS WERE STABLE. NO SIGNIFICANT LIMB
ACTIVITY WAS OBSERVED. THREE NEW REGIONS WERE NUMBERED: 5118
(S24E03), 5119 (N32E18), AND 5120 (S18E45). ALL WERE SMALL AND
STRUCTURALLY SIMPLE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
VERY LOW TO LOW. THERE IS A FAIR CHANCE FOR C-CLASS FLARES FROM
REGION 5115 (N14E55). THE REMAINING REGIONS PROVIDE A VERY
SLIGHT TO SLIGHT CHANCE FOR C-CLASS FLARES.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE MIDDLE LATITUDE GEOMAGNETIC FIELD HAS BEEN UNSETTLED TO
ACTIVE FOR THE PAST 24 HOURS. THE HIGH LATITUDE FIELD WAS AT
MOSTLY ACTIVE TO MINOR STORM LEVELS. THE SOURCE OF THE HIGH
LATITUDE ACTIVITY MAY BE A CORONAL HOLE PRESENTLY SITUATED
WITHIN THE NORTHWEST SOLAR QUADRANT.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED AT MIDDLE LATITUDES. THE HIGH LATITUDE
FIELD IS EXPECTED TO BE ACTIVE WITH BRIEF INTERVALS OF MINOR
STORMING EARLY IN THE PERIOD DUE TO POSSIBLE CORONAL HOLE
EFFECTS.
III.  EVENT PROBABILITIES 21 AUG-23 AUG
CLASS M    02/02/02
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           20 AUG  115
PREDICTED   21 AUG-23 AUG  113/115/119
90 DAY MEAN        20 AUG  147
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 19 AUG  009/015
ESTIMATED AFR/AP 20 AUG  012/025
PREDICTED AFR/AP 21 AUG-23 AUG  014/026-012/023-010/020