:Product: 19970501RSGA.txt
:Issued: 1997 May 01 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 121 ISSUED AT 2200Z ON 01 MAY 1997
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  30/2100Z
TO 01/2100Z:  SOLAR ACTIVITY REMAINED VERY LOW. A SMALL REGION IS
ROTATING ONTO THE DISK NEAR S28E90 BUT NO SPOTS WERE VISIBLE DURING
THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD REMAIN AT A VERY
LOW LEVEL FOR THE NEXT THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 30/2100Z TO 01/2100Z:
THE GEOMAGNETIC FIELD WAS ACTIVE LATE ON 30 APR, THEN BECAME QUIET TO
UNSETTLED UNTIL 01/1500Z. ACTIVE CONDITIONS BEGAN ANEW AFTER THAT
TIME. RECENT SOLAR WIND DATA INDICATE AN INCREASE IN VELOCITY (TO
APPROXIMATELY 475 KM/S) AND DENSITY (47 P/CC) AT ABOUT 01/1200Z. NO
MAGNETIC CLOUD SIGNATURE WAS PRESENT IN BZ. THE SOLAR WIND
PARAMETERS ABOVE POINT TO A CME CAUSE OF THE DISTURBANCE LATE IN THE
PERIOD.  A CME WAS OBSERVED BY A SPACE-BASED CORONAGRAPH EARLY ON 27
APR.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE AT UNSETTLED TO MINOR STORM LEVELS FOR THE REST OF 01
MAY AND THE FIRST HALF OF 02 MAY AS THE CME FINISHES ITS TRANSIT BY
THE EARTH. QUIET TO UNSETTLED CONDITIONS ARE EXPECTED FOR THE
REMAINDER OF THE FORECAST PERIOD.
III.  EVENT PROBABILITIES 02 MAY-04 MAY
CLASS M    01/01/01
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           01 MAY 072
PREDICTED   02 MAY-04 MAY  073/075/076
90 DAY MEAN        01 MAY 074
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 30 APR  013/011
ESTIMATED AFR/AP 01 MAY  015/012
PREDICTED AFR/AP 02 MAY-04 MAY  015/012-010/008-008/008
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 02 MAY-04 MAY
A.  MIDDLE LATITUDES
ACTIVE                25/20/10
MINOR STORM           10/05/05
MAJOR-SEVERE STORM    05/01/01
B.  HIGH LATITUDES
ACTIVE                25/25/15
MINOR STORM           10/05/01
MAJOR-SEVERE STORM    05/01/01