FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 271
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 27 SEP 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 5171 (S25E58)
PRODUCED TWO M-CLASS EVENTS, AN M1/2F AT 0958Z AND AN M7/2B AT
1621Z. THE LATTER FLARE HAD A BURST OF 310 FLUX UNITS AT 10 CM.
AND A TYPE II SWEEP. THE REGION IS NOT PARTICULARLY DISTINCTIVE
IN WHITE LIGHT OR H-ALPHA, BUT DOES DISPLAY SOME DEGREE OF
MAGNETIC COMPLEXITY. NEWLY NUMBERED REGION 5172 (S21W59) IS
SIMPLE. THE LIMBS WERE QUIET.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO
CONTINUE AT A MODERATE LEVEL. PERIODIC M-CLASS ACTIVITY IS
LIKELY FROM REGION 5171.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN GENERALLY QUIET AT MID-
LATITUDES. HIGH LATITUDES WERE MOSTLY UNSETTLED. CORONAL
HOLE EFFECTS FORECAST FOR TODAY DID NOT OCCUR.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD
MAY FLUCTUATE BETWEEN UNSETTLED TO MAJOR STORM LEVELS
DURING THE NEXT THREE DAYS. THE M2/2B FLARE OF 25 SEPT.
IS DIFFICULT TO JUDGE AND MAKES ELEVATED ACTIVITY, HOWEVER
UNLIKELY, POSSIBLE.
III.  EVENT PROBABILITIES 28 SEP-30 SEP
CLASS M    60/60/60
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           27 SEP  173
PREDICTED   28 SEP-30 SEP  170/167/164
90 DAY MEAN        27 SEP  153
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 26 SEP  008/011
ESTIMATED AFR/AP 27 SEP  010/017
PREDICTED AFR/AP 28 SEP-30 SEP  010/070-010/055-010/035