FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 267
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 23 SEP 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 22/2100Z
TO 23/2100Z:  SOLAR ACTIVITY WAS LOW.  FREQUENT C-CLASS FLARE
ACTIVITY OCCURRED IN A NUMBER OF THE 14 SPOTTED REGIONS NOW ON
THE DISK.  OF THAT GROUP, REGION 5159 (N27E17) IS STILL THE MOST
IMPRESSIVE.  NEWLY NUMBERED REGION 5168 (N18E72) ROTATED
PARTIALLY INTO VIEW AS A MATURE SPOT GROUP.  BETTER ANALYSIS OF
THAT AREA MAY SHOW IT TO BE TWO DISTINCT BIPOLES.  SURGING AND
PROMINENCE ACTIVITY OCCURRED AT EAST LIMB NEAR N20 AND S20.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW TO MODERATE.  THE X-RAY BACKGROUND IS HOVERING NEAR C-LEVEL
AND THAT FACT, ALONG WITH THE NUMEROUS ACTIVE REGIONS ON THE
DISK, MAKES M-CLASS ACTIVITY DISTINCTLY POSSIBLE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 22/2100Z TO 23/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN QUIET TO UNSETTLED AT MID-
LATITUDES.  ACTIVE TO MINOR STORM CONDITIONS PREVAILED AT
HIGH LATITUDE SITES.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY UNSETTLED TO ACTIVE FOR THE NEXT THREE
DAYS. SHORT-LIVED PERIODS OF ENHANCED ACTIVITY ARE POSSIBLE
BOTH EARLY (DUE TO FILAMENT-RELATED ACTIVITY) AND LATE (DUE TO
CORONAL HOLE EFFECTS) IN THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 24 SEP-26 SEP
CLASS M    40/40/40
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           23 SEP  180
PREDICTED   24 SEP-26 SEP  183/186/189
90 DAY MEAN        23 SEP  153
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 22 SEP  021/029
ESTIMATED AFR/AP 23 SEP  010/020
PREDICTED AFR/AP 24 SEP-26 SEP  015/020-010/020-015/020