:Product: 19980528RSGA.txt
:Issued: 1998 May 28 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 148 ISSUED AT 2200Z ON 28 MAY 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  27/2100Z
TO 28/2100Z:  SOLAR ACTIVITY WAS MODERATE. REGION 8226 (N18W81)
PRODUCED A M1/SF WITH AN ERUPTIVE PROMINENCE AND MINOR RADIO BURSTS
AT 28/1353Z. THIS REGION IS ALSO RESPONSIBLE FOR SEVERAL C-CLASS
SUBFLARES INCLUDING A C8 AT 26/1912Z WHICH ALSO PRODUCED AN ERUPTIVE
PROMINENCE. LIMB PROXIMITY HAS MADE MEASUREMENTS DIFFICULT BUT
MAGNETIC ANALYSIS SUGGEST A BETA-GAMMA CONFIGURATION. REGION 8224
HAS ROTATED AROUND THE WEST LIMB NEAR S24 BUT DID PRODUCE A C3/SF AT
26/0101Z. REGION 8227 (N26E53), A D-TYPE BETA GROUP, PRODUCED A
C2/SF WITH MINOR RADIO BURSTS AT 28/1126Z.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGION 8226 IS CAPABLE OF FURTHER M-CLASS ACTIVITY AS
IT ROTATES THE WEST LIMB. ISOLATED C-CLASS FLARES ARE POSSIBLE FROM
REGION 8227.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO REMAIN QUIET TO UNSETTLED THROUGH 30/1600Z. WE EXPECT
PERIODS OF ACTIVE TO MINOR STORM CONDITIONS ON 30-31 MAY IN RESPONSE
TO THE LONG DURATION C7 X-RAY EVENT ON 27/1335Z. A CME OCCURRED WITH
THIS EVENT AND EJECTA APPEARS EARTHBOUND.
III.  EVENT PROBABILITIES 29 MAY-31 MAY
CLASS M    20/10/10
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           28 MAY 098
PREDICTED   29 MAY-31 MAY  098/098/096
90 DAY MEAN        28 MAY 108
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 27 MAY  008/007
ESTIMATED AFR/AP 28 MAY  006/008
PREDICTED AFR/AP 29 MAY-31 MAY  007/008-012/015-018/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 29 MAY-31 MAY
A.  MIDDLE LATITUDES
ACTIVE                10/30/40
MINOR STORM           01/10/15
MAJOR-SEVERE STORM    01/01/05
B.  HIGH LATITUDES
ACTIVE                15/40/45
MINOR STORM           05/20/25
MAJOR-SEVERE STORM    01/05/05