FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 272
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 28 SEP 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 27/2100Z
TO 28/2100Z:  SOLAR ACTIVITY HAS BEEN LOW FOR THE PAST 24 HOURS.
THERE ARE 10 SPOTTED REGIONS ON THE VISIBLE DISK, INCLUDING ONE
NEW REGION THAT EMERGED TODAY NEAR N28W03.  REGION 5171
(S26E46), WHICH PRODUCED A MAJOR FLARE YESTERDAY, HAS PRODUCED
SEVERAL C-CLASS SUBFLARES BUT IS NOT PARTICULARLY IMPRESSIVE IN
WHITE LIGHT OR H-ALPHA.  THE SOLAR DISK AND LIMBS ARE GENERALLY
STABLE AND QUIET.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
GENERALLY LOW, BUT WITH A GOOD CHANCE FOR AN ISOLATED M-CLASS
FLARE FROM REGION 5171.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN AT QUIET LEVELS FOR
THE PAST 24 HOURS. A SUDDEN IMPULSE OF APPROXIMATELY 12 NT
AT BOULDER, COLORADO, OCCURRED AT 2046 UT.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED TOMORROW AND THE NEXT DAY,
ALTHOUGH THERE IS A POSSIBILITY OF MORE DISTURBED CONDITIONS
ESPECIALLY AT HIGH LATITUDES OWING TO FLARES ON 25 AND 27
SEPTEMBER.  GENERALLY QUIET CONDITIONS ARE EXPECTED AT MIDDLE
LATITUDES BY THE END OF THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 29 SEP-01 OCT
CLASS M    40/40/40
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           28 SEP  171
PREDICTED   29 SEP-01 OCT  170/170/170
90 DAY MEAN        28 SEP  153
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 27 SEP  006/011
ESTIMATED AFR/AP 28 SEP  004/015
PREDICTED AFR/AP 29 SEP-01 OCT  010/035-010/025-007/020