FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 270
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 26 SEP 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 25/2100Z
TO 26/2100Z:  SOLAR ACTIVITY WAS LOW. OCCASIONAL C-CLASS FLARES
OCCURRED WITH THE LARGEST A C6/0F FROM REGION 5158 (S36W51) AT
0300Z. NEWLY NUMBERED REGION 5171 (S26E73) IS A MATURE SPOT AND
SCATTERED PLAGE. SURGING WAS OBSERVED AT WEST LIMB NEAR N20.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW. THERE IS A CHANCE OF AN ISOLATED M-CLASS EVENT DURING
THE NEXT THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:
THE GEOMAGNETIC FIELD HAS BEEN MOSTLY QUIET AT MID-LATITUDES.
GENERALLY UNSETTLED CONDITIONS PREVAILED AT HIGH LATITUDES.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT ACTIVE TO MINOR STORM LEVELS THE NEXT 24
HOURS DUE TO A WELL-LOCATED CORONAL HOLE. ACTIVITY THE LAST
TWO DAYS MAY RANGE FROM UNSETTLED TO MAJOR STORM CONDITIONS AS
THE POTENTIAL GEOEFFECTIVENESS OF THE M2/2B FLARE OF 25 SEPT.
IS DIFFICULT TO ASCERTAIN.
III.  EVENT PROBABILITIES 27 SEP-29 SEP
CLASS M    25/25/25
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           26 SEP  172
PREDICTED   27 SEP-29 SEP  169/166/162
90 DAY MEAN        26 SEP  153
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 25 SEP  010/019
ESTIMATED AFR/AP 26 SEP  010/015
PREDICTED AFR/AP 27 SEP-29 SEP  020/030-010/070-010/055