FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 264
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 20 SEP 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 5159 (N28E56)
PRODUCED C-CLASS EVENTS. IT WAS STABLE. NEWLY ASSIGNED REGION
5162 (N25E56) AND REGION 5163 (N21E69) BOTH ROTATED INTO BETTER
VIEW SLIGHTLY BEHIND REGION 5159. THE THIRD NEW REGION TODAY WAS
5161 (N32E20).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW. REGION 5159 PROVIDES A SLIGHT CHANCE OF MODERATE ACTIVITY.
THE X-RAY AND 10.7 CM BACKGROUND FLUX SHOULD INCREASE SLIGHTLY
THE FIRST HALF OF THE PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD WAS ACTIVE TO UNSETTLED. MINOR STORM
CONDITIONS OCCURRED AT HIGH LATITUDES VERY EARLY IN THE DAY.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE THE FIRST HALF OF THE PERIOD.
THE LAST HALF OF THE PERIOD IS EXPECTED TO BE AT ACTIVE TO
MINOR STORM LEVELS. THIS ENHANCEMENT IS EXPECTED DUE TO FLARE
ACTIVITY AND A WEAK CORONAL HOLE AT CENTRAL MERIDIAN YESTERDAY.
III.  EVENT PROBABILITIES 21 SEP-23 SEP
CLASS M    30/30/30
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           20 SEP  149
PREDICTED   21 SEP-23 SEP  155/161/168
90 DAY MEAN        20 SEP  152
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 19 SEP  018/043
ESTIMATED AFR/AP 20 SEP  010/020
PREDICTED AFR/AP 21 SEP-23 SEP  012/022-014/024-016/032