:Product: 19981225RSGA.txt
:Issued: 1998 Dec 25 2200 UTC
# Prepared jointly by the U.S. Dept. of Commerce, NOAA,
# Space Environment Center and the U.S. Air Force.
#
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY
SDF NUMBER 359 ISSUED AT 2200Z ON 25 DEC 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8421 (N28E53)
PRODUCED SEVERAL C-CLASS EVENTS DURING THE PERIOD AND A M1/SF AT
25/0634Z. THERE WERE TWO OPTICALLY UNCORRELATED EVENTS, A C2 AT
25/0414Z AND A C1 AT 25/2020Z.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE THROUGH THE PERIOD. REGION 8421 REMAINS CAPABLE OF
PRODUCING OCCASIONAL M-CLASS EVENTS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. THE FIELD WAS EFFECTED
SLIGHTLY BY A TRANSIENT SIGNATURE FROM AN UNKNOWN SOURCE. THIS WAS
REFLECTED IN THE SOLAR WIND DATA (SPEED INCREASED WHILE DENSITY
DECREASED) AT 25/0535Z RECEIVED FROM THE ACE SPACECRAFT.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO SLIGHTLY UNSETTLED FOR THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 26 DEC-28 DEC
CLASS M    40/40/40
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 DEC 144
PREDICTED   26 DEC-28 DEC  150/154/158
90 DAY MEAN        25 DEC 133
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 DEC  004/003
ESTIMATED AFR/AP 25 DEC  010/010
PREDICTED AFR/AP 26 DEC-28 DEC  005/009-005/009-005/009
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 DEC-28 DEC
A.  MIDDLE LATITUDES
ACTIVE                10/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05