Press Release

NOAA/USAF Report of Solar-Geophysical Activity 27 Apr 2000

By SpaceRef Editor
April 27, 2000
Filed under

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Apr 27 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 118 ISSUED AT 2200Z ON 27 APR 2000
IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 26/2100Z
TO 27/2100Z: SOLAR ACTIVITY WAS LOW. INTERMITTENT C-CLASS EVENTS
OCCURRED, WITH REGIONS 8967 (N23W42) AND 8970 (S14W10) THE PRIMARY
CONTRIBUTORS. ALL REGIONS ON THE DISK WERE, IN GENERAL, EITHER
STABLE OR DECAYING. A PROMINENCE ERUPTED FROM THE NW LIMB AT
APPROXIMATELY 1500Z.
IB. SOLAR ACTIVITY FORECAST: SOLAR ACTIVITY IS EXPECTED TO PERSIST
AT THE LOW LEVEL.
IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 26/2100Z TO 27/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.
IIB. GEOPHYSICAL ACTIVITY FORECAST: THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE ON 28 APRIL, AS A HIGH SPEED
STREAM MAY HAVE A MINIMAL IMPACT ON THE FIELD. UNSETTLED CONDITIONS
SHOULD PREVAIL FOR THE FINAL TWO DAYS OF THE INTERVAL.
III. EVENT PROBABILITIES 28 APR-30 APR
CLASS M 30/30/30
CLASS X 01/01/01
PROTON 01/01/01
PCAF GREEN
IV. PENTICTON 10.7 CM FLUX
OBSERVED 27 APR 184
PREDICTED 28 APR-30 APR 180/175/175
90 DAY MEAN 27 APR 188
V. GEOMAGNETIC A INDICES
OBSERVED AFR/AP 26 APR 003/004
ESTIMATED AFR/AP 27 APR 010/011
PREDICTED AFR/AP 28 APR-30 APR 010/018-010/012-010/010
VI. GEOMAGNETIC ACTIVITY PROBABILITIES 28 APR-30 APR
A. MIDDLE LATITUDES
ACTIVE 20/20/20
MINOR STORM 05/05/05
MAJOR-SEVERE STORM 01/01/01
B. HIGH LATITUDES
ACTIVE 30/30/30
MINOR STORM 05/05/05
MAJOR-SEVERE STORM 01/01/01

SpaceRef staff editor.