FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 209
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 27 JUL 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 26/2100Z
TO 27/2100Z:  SOLAR ACTIVITY HAS BEEN LOW. REGION 5084 (S22E18)
PRODUCED SEVERAL C-CLASS FLARES DURING THE PERIOD. THE LARGEST
WAS A C8/2N AT 27/0746Z ACCOMPANIED BY MINOR RADIO EMISSIONS.
FRAGMENTATION OF THE TRAILER PENUMBRA WAS REPORTED TODAY WHICH
MAY INDICATE THAT THE REGION IS BEGINNING A PERIOD OF SLOW
DECAY. STRONG CALCIUM XV EMISSIONS HAVE BEEN ASSOCIATED WITH
REGION 5084 AND 5092 (N26E70). REGION 5092, ORIGINALLY CLASSED
AS AN H-TYPE SPOT, CONTINUED TO ROTATE INTO VIEW TODAY AND IS
NOW CLASSIFIED AS AN E-TYPE GROUP. A LARGE FILAMENT DISAPPEARED
DURING THE PERIOD. ITS CENTROID WAS NEAR S38W16 WHEN LAST
OBSERVED. THREE NEW REGIONS WERE ASSIGNED TODAY: 5093 (N26W48),
5094 (S22E10), AND 5095 (N32E81).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW TO MODERATE. M-CLASS FLARES ARE LIKELY FROM REGION 5084.
THERE IS ALSO A SLIGHT CHANCE OF AN X-CLASS FLARE FROM THIS
REGION.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE MIDDLE LATITUDE GEOMAGNETIC FIELD HAS BEEN AT ACTIVE TO
UNSETTLED LEVELS DURING THE PAST 24 HOURS. THE HIGH LATITUDE
FIELD HAS RANGED FROM UNSETTLED TO MAJOR STORM LEVELS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE ACTIVE AT MIDDLE LATITUDES AND AT MINOR STORM
LEVELS AT HIGH LATITUDES.
III.  EVENT PROBABILITIES 28 JUL-30 JUL
CLASS M    60/60/60
CLASS X    25/25/25
PROTON     25/25/25
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           27 JUL  157
PREDICTED   28 JUL-30 JUL  160/164/166
90 DAY MEAN        27 JUL  134
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 26 JUL  016/038
ESTIMATED AFR/AP 27 JUL  012/028
PREDICTED AFR/AP 28 JUL-30 JUL  016/035-025/032-020/035