:Product: 19990425RSGA.txt
:Issued: 1999 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 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z
TO 25/2100Z:  SOLAR ACTIVITY WAS VERY LOW. REGIONS 8524 (N22E39) AND
8523 (N31E28) BOTH PRODUCED MINOR B-CLASS SUBFLARES. NEW REGIONS -
8522 (N17E38) AND 8524 WERE THE ONLY REGIONS ON THE VISIBLE DISK
THAT SHOWED ANY GROWTH. REMAINING REGIONS WERE EITHER STABLE OR
DECAYING.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE VERY
LOW TO LOW. REGION 8522 AND REGION 8524 MAY SOON DEVELOP C-CLASS
POTENTIAL, ESPECIALLY CONSIDERING THEIR PROXIMITY TO EACH OTHER.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET. A GREATER THAN 10 MEV PROTON EVENT
BEGAN YESTERDAY AT 24/1610Z ASSOCIATED WITH THE LARGE HALO CME FROM
BEHIND THE NORTHWEST LIMB AT AROUND 24/1230Z. THE 10 PFU THRESHOLD
WAS CROSSED AT 24/1840Z WITH A MAXIMUM OF 32 PFU OBSERVED AT
25/0055Z. THE FLUX DROPPED BACK BELOW THE 10 PFU LEVEL AT 25/1451Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. NO GEOEFFECTIVNESS IS EXPECTED
FROM YESTERDAY'S CME. THE GREATER THAN 10 MEV PROTON FLUX IS
EXPECTED TO RETURN TO BACKGROUND LEVELS BY END OF PERIOD.
III.  EVENT PROBABILITIES 26 APR-28 APR
CLASS M    05/05/05
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           25 APR 103
PREDICTED   26 APR-28 APR  110/115/115
90 DAY MEAN        25 APR 129
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 24 APR  005/007
ESTIMATED AFR/AP 25 APR  005/005
PREDICTED AFR/AP 26 APR-28 APR  010/010-010/010-010/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 APR-28 APR
A.  MIDDLE LATITUDES
ACTIVE                20/20/15
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                25/25/20
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    01/01/01