:Product: 20000128RSGA.txt
:Issued: 2000 Jan 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 028 ISSUED AT 2200Z ON 28 JAN 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  27/2100Z
TO 28/2100Z:  SOLAR ACTIVITY WAS LOW. THERE WERE TWO C-CLASS FLARES
DURING THE PAST 24 HOURS. THE LARGEST OF THESE WAS A C4/SF AT 2009UT
FROM REGION 8841 (S30W22). THIS REGION HAS SHOWN A SLOW GROWTH TREND
BUT IS STILL MAGNETICALLY SIMPLE. REGION 8848 (S09E54) PRODUCED THE
OTHER C-FLARE; A C1/SF AT 0659Z. THE GROUP IS SMALL BUT EXHIBITED
RELATIVELY BRIGHT, OCCASIONALLY FLUCTUATING  PLAGE. NEW REGION 8849
EMERGED NEAR S16E19 AS A SMALL, B-TYPE SUNSPOT GROUP. (NOTE: TODAY'S
10.7 CM FLUX READING WAS TAKEN FROM THE PENTICTON OBSERVATORY
MORNING READING BECAUSE THE NOON TIME VALUE OF 152 WAS FLARE
ENHANCED)
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
THERE IS A SLIGHT CHANCE, HOWEVER, FOR AN ISOLATED M-CLASS EVENT
OVER THE NEXT THREE DAYS.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 27/2100Z TO 28/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM UNSETTLED TO MAJOR STORM LEVELS.
MOSTLY ACTIVE LEVELS HAVE DOMINATED THE MAJORITY OF THE PAST 24
HOURS, BUT A PERIOD OF MINOR TO MAJOR STORM LEVELS OCCURRED BETWEEN
0000-0300 UT AND A PERIOD OF MINOR STORM LEVELS OCCURRED BETWEEN
1200-1500 UT. TODAY'S SOLAR WIND OBSERVATIONS INDICATED THE ONSET OF
HIGH SPEED, LOW DENSITY CORONAL HOLE CONDITIONS AROUND 28/0000UT:
SPEEDS LEVELED TO 700-800 KM/S AND THE DENSITY FELL STEADILY DURING
THE UT DAY WITH INITIAL VALUES OF 10 P/CC DECLINING TO 1-2 P/CC BY
THE END OF THE REPORTING PERIOD.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE MOSTLY ACTIVE FOR THE NEXT 24 HOURS, AND IS EXPECTED
TO BE UNSETTLED TO ACTIVE FOR THE SECOND AND THIRD DAYS. THE
ENHANCED LEVEL OF ACTIVITY IS EXPECTED DUE TO CONTINUING CORONAL
HOLE EFFECTS.
III.  EVENT PROBABILITIES 29 JAN-31 JAN
CLASS M    15/15/15
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           28 JAN 126
PREDICTED   29 JAN-31 JAN  125/125/125
90 DAY MEAN        28 JAN 174
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 27 JAN  010/012
ESTIMATED AFR/AP 28 JAN  025/025
PREDICTED AFR/AP 29 JAN-31 JAN  020/020-015/025-015/020
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 29 JAN-31 JAN
A.  MIDDLE LATITUDES
ACTIVE                50/40/35
MINOR STORM           20/15/10
MAJOR-SEVERE STORM    10/05/05
B.  HIGH LATITUDES
ACTIVE                40/45/50
MINOR STORM           25/15/10
MAJOR-SEVERE STORM    10/05/05