:Product: 19990428RSGA.txt
:Issued: 1999 Apr 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 118 ISSUED AT 2200Z ON 28 APR 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  27/2100Z
TO 28/2100Z:  SOLAR ACTIVITY WAS LOW DUE TO A C3 X-RAY FLARE AT
28/2032UT. NO OPTICAL FLARE REPORTS CORRELATED TO THIS C-FLARE WERE
RECEIVED. REGION 8524 (N22W02) CONTINUED TO GROW BUT APPEARS TO BE
MATURING AS A MODERATE-SIZED E-TYPE GROUP. OTHER DISK REGIONS HAVE
CHANGED LITTLE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
C-CLASS ACTIVITY IS POSSIBLE IN REGIONS 8523 (N32W09) AND 8524
(N22W02).
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. MOST ACTIVITY OCCURRED
DURING THE 06-12UT PERIODS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED. ISOLATED ACTIVE PERIODS ARE
POSSIBLE. ACTIVITY LEVELS MAY INCREASE BY THE END OF THE FORECAST
PERIOD DUE TO CORONAL HOLE EFFECTS.
III.  EVENT PROBABILITIES 29 APR-01 MAY
CLASS M    05/05/05
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           28 APR 110
PREDICTED   29 APR-01 MAY  110/110/115
90 DAY MEAN        28 APR 128
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 27 APR  009/014
ESTIMATED AFR/AP 28 APR  012/018
PREDICTED AFR/AP 29 APR-01 MAY  010/025-015/025-015/030
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 29 APR-01 MAY
A.  MIDDLE LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           10/10/10
MAJOR-SEVERE STORM    05/05/05