:Product: 19980424RSGA.txt
:Issued: 1998 Apr 24 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 114 ISSUED AT 2200Z ON 24 APR 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  23/2100Z
TO 24/2100Z:  SOLAR ACTIVITY WAS LOW. AN UNCORRELATED C8 X-RAY BURST
WAS DETECTED AT 24/0852Z. THIS MAY HAVE BEEN ASSOCIATED WITH AN
ERUPTIVE PROMINENCE ON THE SE LIMB AT S34 WHICH BEGAN AT 24/0450Z.
THIS EPL ENDED AT 24/0940Z. THE REMAINDER OF THE VISIBLE DISK WAS
QUIET. NEW REGION 8210 (S19E70) WAS NUMBERED TODAY. THIS REGION WAS
THE SITE OF YESTERDAY'S CME ASSOCIATED WITH AN X1 FLARE, A LOOP
PROMINENCE SYSTEM AND NUMEROUS POINT BRIGHTENINGS. THE REGION
CONTAINS ONLY BRIGHT PLAGE AND ACTIVE SURGING AT THIS TIME, BUT
PRELIMINARY REPORTS OF SPOTS WERE RECEIVED LATE IN THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE AS REGION 8210 ROTATES ONTO THE VISIBLE DISK. THIS
REGION IS EXPECTED TO PRODUCE C-CLASS AND M-CLASS ACTIVITY DURING
ITS TRANSIT OF THE DISK, AS WELL AS ISOLATED X-CLASS ACTIVITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 23/2100Z TO 24/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO MINOR STORM. ACTIVE TO MINOR STORM
CONDITIONS SET IN ABOUT 23/1900Z WITH THE ARRIVAL OF A SHOCK
RESULTING FROM THE CME REPORTED ON 21 APRIL. THIS ACTIVITY LASTED
UNTIL 24/1500Z WHEN THE FIELD FINALLY SETTLED DOWN. THE GREATER THAN
10 MEV PROTON EVENT ENDED AT 24/1550Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE FOR THE NEXT 18 HOURS, THEN QUIET
TO UNSETTLED FOR THE REMAINDER OF THE FORECAST PERIOD. HIGH LATITUDE
STATIONS MAY STILL EXPERIENCE ISOLATED PERIODS OF ACTIVE TO MINOR
STORM CONDITIONS FOR THE NEXT 18 HOURS.
III.  EVENT PROBABILITIES 25 APR-27 APR
CLASS M    15/25/25
CLASS X    10/10/10
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           24 APR 091
PREDICTED   25 APR-27 APR  094/094/096
90 DAY MEAN        24 APR 104
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 23 APR  013/014
ESTIMATED AFR/AP 24 APR  027/032
PREDICTED AFR/AP 25 APR-27 APR  015/015-010/012-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 25 APR-27 APR
A.  MIDDLE LATITUDES
ACTIVE                25/20/20
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                30/25/20
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    05/05/05