FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 203
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 21 JUL 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 20/2100Z
TO 21/2100Z:  SOLAR ACTIVITY HAS BEEN LOW.  REGION 5075
(S22W52) HAS DECAYED SINCE YESTERDAY, SHOWING SIMPLIFICATION
IN THE CENTRAL PORTION OF THE REGION.  THIS REGION CONTINUED
TO PRODUCE LOW LEVEL C-CLASS X-RAY ACTIVITY DURING THE PAST
24 HOURS.  A LONG DURATION X-RAY FLARE REACHED A MAXIMUM OF
C4.5 AT 21/1838UT.  THE SOURCE OF THIS ACTIVITY APPEARS TO
BE FROM BEYOND THE SOUTHEAST LIMB.  NEW REGION 5083 (N32E26)
EMERGED AS A SMALL UNIPOLAR SPOT GROUP.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
LOW TO MODERATE.  THE NEW REGION ROTATING AROUND THE SOUTHEAST
LIMB WILL MOST LIKELY INCREASE ACTIVITY LEVELS AS IT APPEARS
ON THE SOLAR DISK.  ENERGETIC ACTIVITY IS LESS PROBABLE FROM
REGION 5075.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 20/2100Z TO 21/2100Z:
THE GEOMAGNETIC FIELD AT MIDDLE LATITUDES HAS BEEN AT QUIET
TO MINOR STORM LEVELS FOR THE PAST 24 HOURS.  THE HIGH
LATITUDE FIELD HAS RANGED FROM UNSETTLED TO SEVERE STORM
LEVELS.  A SUDDEN IMPULSE WAS RECORDED AT MIDDLE LATITUDE
STATIONS AT 21/0317UT, FOLLOWING A SLIGHT ENHANCEMENT OF
THE 10 MEV PROTON FLUX AT ABOUT 20/2100UT.  THE PROTON
FLUX DID NOT CROSS EVENT THRESHOLDS.  THIS ACTIVITY MAY BE
THE RESULT OF THE LONG DURATION X-RAY EVENT ON 19 JULY.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT UNSETTLED TO ACTIVE LEVELS AT MIDDLE
LATITUDES AND AT ACTIVE TO MINOR STORM LEVELS AT HIGH
LATITUDES.
III.  EVENT PROBABILITIES 22 JUL-24 JUL
CLASS M    50/50/50
CLASS X    10/10/10
PROTON     10/10/10
PCAF       GREEN
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           21 JUL  141
PREDICTED   22 JUL-24 JUL  145/150/150
90 DAY MEAN        21 JUL  131
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 20 JUL  005/013
ESTIMATED AFR/AP 21 JUL  027/065
PREDICTED AFR/AP 22 JUL-24 JUL  018/035-018/035-010/026