:Product: 19980425RSGA.txt
:Issued: 1998 Apr 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 115 ISSUED AT 2200Z ON 25 APR 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8210 (S16E67) PRODUCED
TWO C-CLASS FLARES, A C3/SF LONG DURATION EVENT AT 25/1439Z AND A
C1/1F AT 25/1806Z WITH AN ASSOCIATED HIGH SPEED SURGE. BOTH FLARES
WERE ACCOMPANIED BY MINOR DISCRETE RADIO ACTIVITY. THIS REGION HAS
GROWN TO A DAO SPOT GROUP, BUT APPEARS TO BE MAGNETICALLY SIMPLE
THUS FAR. A THIRD C-CLASS EVENT, AN UNCORRELATED C1 X-RAY BURST, WAS
DETECTED AT 25/1123Z. NEW REGION 8211 (S22W12), A SIMPLE AXX SPOT,
WAS NUMBERED TODAY. THIS REGION RESIDES IN AN EXTENSIVE PLAGE FIELD
THAT APPEARS RIPE FOR DEVELOPMENT.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. REGION 8210 HAS A GOOD CHANCE OF PRODUCING FURTHER
C-CLASS ACTIVITY, A FAIR CHANCE OF M-CLASS ACTIVITY, AND A CHANCE OF
ISOLATED X-CLASS ACTIVITY OVER THE ENTIRE FORECAST PERIOD.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE FOR MOST OF THE PERIOD WITH
A SHORT PERIOD OF MINOR STORMING AT THE BEGINNING OF THE UT DAY. THE
GREATER THAN 2 MEV ENERGETIC ELECTRON FLUX REACHED  HIGH LEVELS AT
25/1650Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED FOR THE ENTIRE FORECAST PERIOD.
III.  EVENT PROBABILITIES 26 APR-28 APR
CLASS M    15/20/20
CLASS X    10/10/10
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 APR 092
PREDICTED   26 APR-28 APR  094/096/096
90 DAY MEAN        25 APR 104
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 APR  023/035
ESTIMATED AFR/AP 25 APR  018/015
PREDICTED AFR/AP 26 APR-28 APR  015/012-010/010-005/008
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 APR-28 APR
A.  MIDDLE LATITUDES
ACTIVE                25/15/10
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                25/20/15
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05