Press Release

Report of Solar-Geophysical Activity 20 Feb

By SpaceRef Editor
February 20, 2000
Filed under

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Feb 20 2210 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 051 ISSUED AT 2200Z ON 20 FEB 2000
IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 19/2100Z
TO 20/2100Z: SOLAR ACTIVITY WAS LOW. NUMEROUS C-CLASS X-RAY EVENTS
WERE OBSERVED WITH THE LARGEST BEING A C8/1N FROM REGION 8869
(S20W61). REGIONS 8875 (S22W13) AND 8869 BOTH DISPLAYED SOME GROWTH
DURING THE PERIOD. REGION 8869 MAINTAINED A BETA-GAMMA MAGNETIC
CLASSIFICATION WITH APPROXIMATELY 41 SUNSPOTS. NEW REGION 8880
(S08W69) WAS NUMBERED TODAY AND IS CURRENTLY A BETA GROUP WITH 3
SPOTS.
IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO BE LOW
TO MODERATE WITH THE POSSIBILITY OF AN ISOLATED M-CLASS EVENT FROM
REGION 8869.
IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET.
IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS
EXPECTED TO REACH UNSETTLED TO MINOR STORM LEVELS DURING THE FIRST
DAY OF THE PERIOD WITH POSSIBLE MAJOR STORM CONDITIONS AT HIGHER
LATITUDES. THESE CONDITIONS WILL BE DUE TO A FULL-HALO CME PRODUCED
BY AN EVENT ON 17 FEBRUARY. THE SECOND AND THIRD DAY OF THE PERIOD
ARE EXPECTED TO BE QUIET TO UNSETTLED.
III. EVENT PROBABILITIES 21 FEB-23 FEB
CLASS M 35/35/35
CLASS X 05/05/05
PROTON 01/01/01
PCAF GREEN
IV. PENTICTON 10.7 CM FLUX
OBSERVED 20 FEB 153
PREDICTED 21 FEB-23 FEB 150/145/135
90 DAY MEAN 20 FEB 165
V. GEOMAGNETIC A INDICES
OBSERVED AFR/AP 19 FEB 003/004
ESTIMATED AFR/AP 20 FEB 010/010
PREDICTED AFR/AP 21 FEB-23 FEB 030/050-015/030-010/010
VI. GEOMAGNETIC ACTIVITY PROBABILITIES 21 FEB-23 FEB
A. MIDDLE LATITUDES
ACTIVE 50/35/25
MINOR STORM 30/15/05
MAJOR-SEVERE STORM 15/05/01
B. HIGH LATITUDES
ACTIVE 20/40/30
MINOR STORM 60/25/15
MAJOR-SEVERE STORM 15/10/05

SpaceRef staff editor.