:Product: 19990518RSGA.txt
:Issued: 1999 May 18 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 138 ISSUED AT 2200Z ON 18 MAY 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  17/2100Z
TO 18/2100Z:  SOLAR ACTIVITY WAS MODERATE.  AN OPTICALLY UNCORRELATED
M1 X-RAY FLARE LED-OFF THE PERIOD FOLLOWED BY SEVERAL C-CLASS X-RAY
EVENTS.  MOST OF THESE SMALLER EVENTS ORIGINATED FROM REGION 8541
(N21W53).
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 17/2100Z TO 18/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE WITH MINOR STORM CONDITIONS
SEEN IN THE HIGH LATITUDES FROM 18/06Z TO 18/09Z.  THE DISTURBED
CONDITIONS WERE DUE TO THE EFFECT OF A RECURRENT CORONAL HOLE AND AN
ACCOMPANYING CO-ROTATING SHOCK.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE WITH POSSIBLE MINOR STORM
CONDITIONS.  THESE CONDITIONS ARE FORECAST DUE TO THE CONTINUING
EFFECTS OF A CORONAL HOLE AS WELL AS THE IMPACT OF A CME ORIGINATING
FROM THE NW LIMB ON 17/05Z.
III.  EVENT PROBABILITIES 19 MAY-21 MAY
CLASS M    20/20/20
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           18 MAY 141
PREDICTED   19 MAY-21 MAY  140/135/135
90 DAY MEAN        18 MAY 129
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 17 MAY  001/005
ESTIMATED AFR/AP 18 MAY  021/023
PREDICTED AFR/AP 19 MAY-21 MAY  020/020-010/012-008/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 19 MAY-21 MAY
A.  MIDDLE LATITUDES
ACTIVE                50/30/30
MINOR STORM           25/10/10
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                50/40/40
MINOR STORM           30/15/15
MAJOR-SEVERE STORM    15/05/05