:Product: 19980515RSGA.txt
:Issued: 1998 May 15 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 135 ISSUED AT 2200Z ON 15 MAY 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  14/2100Z
TO 15/2100Z:  SOLAR ACTIVITY WAS LOW. THE LARGEST FLARE SINCE
YESTERDAY WAS A C1/SF AT 15/0221Z IN REGION 8218 (S21W45). OTHER
ACTIVE REGIONS WERE RELATIVELY STABLE.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
ADDITIONAL C-CLASS ACTIVITY IS PROBABLE, ESPECIALLY IN REGION 8218.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 14/2100Z TO 15/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET UNTIL 15/1453Z WHEN A SUDDEN IMPULSE
(SI) WAS DETECTED ON GROUND MAGNETOMETERS (ABOUT 6 NT AT THE BOULDER
STATION). THIS SI WAS APPARENTLY IN RESPONSE TO THE PASSAGE OF A
SOLAR WIND SHOCK THAT WAS OBSERVED BY THE ACE SPACECRAFT AT ABOUT
15/1356Z. THE GREATER THAN 2 MEV ELECTRON FLUX REMAINED HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.
III.  EVENT PROBABILITIES 16 MAY-18 MAY
CLASS M    10/10/10
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           15 MAY 116
PREDICTED   16 MAY-18 MAY  115/110/105
90 DAY MEAN        15 MAY 098
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 14 MAY  003/005
ESTIMATED AFR/AP 15 MAY  008/005
PREDICTED AFR/AP 16 MAY-18 MAY  010/010-005/005-005/005
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 16 MAY-18 MAY
A.  MIDDLE LATITUDES
ACTIVE                15/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    02/01/01
B.  HIGH LATITUDES
ACTIVE                15/10/10
MINOR STORM           05/05/05
MAJOR-SEVERE STORM    02/01/01