:Product: 19970522RSGA.txt
:Issued: 1997 May 22 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 142 ISSUED AT 2200Z ON 22 MAY 1997
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  21/2100Z
TO 22/2100Z:  SOLAR ACTIVITY BECAME VERY LOW. ONLY SMALL B-CLASS
ENHANCEMENTS WERE OBSERVED AFTER THE M1 EVENT ON 21 MAY. REGION 8040
(N05W25) STABILIZED AND THE MAGNETIC DELTA THAT WAS FORMING
YESTERDAY HAS FADED.  OTHER REGIONS ON THE DISK ARE STABLE OR IN
SLOW DECLINE. LARGE, CURRENTLY QUIESCENT, PROMINENCES WERE VISIBLE
ON THE SOUTHEAST LIMB.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE VERY
LOW TO LOW. OCCASIONAL C-CLASS FLARES ARE POSSIBLE FROM REGION 8040.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 21/2100Z TO 22/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET AT ALL LATITUDES. ENERGETIC ELECTRONS
AT GEOSYNCHRONOUS ORBIT AGAIN REACHED HIGH LEVELS DURING THE PERIOD.
CORONAL MASS EJECTIONS WERE OBSERVED FROM THE WEST LIMB AND ALSO AS
A VERY WEAK HALO FOLLOWING THE M1 EVENT ON 21 MAY. THE WEST LIMB
EVENT APPEARS TO BE RELATED FROM A SLOW EVENT IN REGION 8043
(N27W79) WHILE THE HALO CME IS LIKELY EARTH DIRECTED FROM THE M1
EVENT. THE WIND SPACECRAFT RADIOMETER HAS ALSO DETECTED A FAST
INTERPLANETARY TYPE II BURST.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE FIELD IS FORECAST TO BE
QUIET UNTIL MIDDAY ON 23 MAY WHEN THE SHOCK FROM THE EARTH DIRECTED
CME IS EXPECTED TO ARRIVE. ACTIVE TO MINOR STORM CONDITIONS SHOULD
OCCUR DURING THE LATTER HALF OF 23 MAY AND ON 24 MAY. QUIET TO
ACTIVE LEVELS ARE EXPECTED ON 25 MAY AS THE DISTURBANCE PASSES THE
EARTH. ENERGETIC ELECTRON FLUXES AT GEOSYNCHRONOUS ORBIT SHOULD
DECAY WITHIN 24 HOURS.
III.  EVENT PROBABILITIES 23 MAY-25 MAY
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           22 MAY 081
PREDICTED   23 MAY-25 MAY  081/081/080
90 DAY MEAN        22 MAY 074
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 21 MAY  006/005
ESTIMATED AFR/AP 22 MAY  003/008
PREDICTED AFR/AP 23 MAY-25 MAY  015/025-025/025-010/005
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 23 MAY-25 MAY
A.  MIDDLE LATITUDES
ACTIVE                30/35/20
MINOR STORM           20/25/05
MAJOR-SEVERE STORM    05/15/01
B.  HIGH LATITUDES
ACTIVE                30/35/20
MINOR STORM           20/25/05
MAJOR-SEVERE STORM    05/15/01