:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Apr 20 2200 UT
# 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 111 ISSUED AT 2200Z ON 20 APR 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z
TO 20/2100Z:  SOLAR ACTIVITY WAS LOW. NEW REGION 8969 (N13E62)
PRODUCED THE LARGEST FLARE OF THE DAY, A C8/SF AT 20/1033UT. REGION
8963 (N16W18) ALSO PRODUCED C-CLASS ACTIVITY, THE LARGEST BEING A
C4/SF AT 20/1937UT. NEW REGION 8970 (S14E77) IS ROTATING AROUND THE
EAST LIMB. SO FAR A LARGE H-TYPE SPOT IS VISIBLE AND TRAILER SPOTS
ARE EXPECTED TO APPEAR BY TOMORROW.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE. C-CLASS ACTIVITY IS EXPECTED TO CONTINUE IN REGION
8963. AN ISOLATED M-CLASS FLARE IS ALSO POSSIBLE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE PREDOMINATELY QUIET TO UNSETTLED WITH THE POSSIBILITY
OF ISOLATED ACTIVE PERIODS.
III.  EVENT PROBABILITIES 21 APR-23 APR
CLASS M    40/40/40
CLASS X    01/01/01
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           20 APR 181
PREDICTED   21 APR-23 APR  185/190/200
90 DAY MEAN        20 APR 183
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 APR  009/012
ESTIMATED AFR/AP 20 APR  018/015
PREDICTED AFR/AP 21 APR-23 APR  015/012-010/005-010/005
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 APR-23 APR
A.  MIDDLE LATITUDES
ACTIVE                15/15/15
MINOR STORM           15/10/10
MAJOR-SEVERE STORM    05/02/02
B.  HIGH LATITUDES
ACTIVE                15/15/15
MINOR STORM           15/10/10
MAJOR-SEVERE STORM    05/05/05