JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY
SDF NUMBER 013 ISSUED AT 2200Z ON 13 JAN 1992
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 12/2100Z
TO 13/2100Z:  SOLAR ACTIVITY WAS MODERATE. AN M2 X-RAY EVENT WAS
OBSERVED AT 1734Z ACCOMPANIED BY MODEST RADIO BURSTS. THE EVENT
WAS ASSOCIATED WITH A LOOP PROMINENCE SYSTEM ON WEST LIMB AT S18
IN THE VICINITY OF REGION 6994 (S16W87). AN M1 X-RAY EVENT WAS
OBSERVED LATER AT 1913Z. THIS EVENT DID NOT HAVE AN OBVIOUS
SOURCE, ALTHOUGH A BRIGHT POINT WAS OBSERVED ON THE EAST LIMB
NEAR S10 DURING THE EVENT. THE LOCATION SUGGESTS THAT OLD REGION
6982 (S13, L-142, DUE BACK TOMORROW) MAY HAVE PRODUCED THE
FLARE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MOSTLY LOW. THERE IS A SLIGHT CHANCE FOR AN ISOLATED M-CLASS
EVENT FROM REGION 6994 OR FROM RETURNING REGION 6982.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 12/2100Z TO 13/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MINOR STORM LEVELS
DURING THE PERIOD. MOST OF THE MINOR STORMING OCCURRED FROM
0300-1200Z. THE REST OF THE ACTIVITY CONSISTED OF OCCASIONAL
SPORADIC ACTIVE PERIODS SUPERPOSED ON A QUIET BACKGROUND.
THE MOST LIKELY SOURCE FOR THE ACTIVITY IS A FAVORABLY
POSITIONED CORONAL HOLE.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE ACTIVE FOR THE NEXT 24 HOURS. GENERALLY UNSET-
TLED LEVELS SHOULD PREVAIL THEREAFTER. A SLIGHT INCREASE MAY
OCCUR ON THE THIRD DAY DUE TO EFFECTS FROM ANOTHER CORONAL HOLE
WHICH WILL ROTATE TO A FAVORABLE POSITION BY THEN.
III.  EVENT PROBABILITIES 14 JAN-16 JAN
CLASS M    30/30/30
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           13 JAN  183
PREDICTED   14 JAN-16 JAN  185/190/185
90 DAY MEAN        13 JAN  207
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 12 JAN  019/017
ESTIMATED AFR/AP 13 JAN  022/023
PREDICTED AFR/AP 14 JAN-16 JAN  020/020-010/010-015/015