Status Report

NOAA/USAF Report of Solar-Geophysical Activity 12 Apr 2000

By SpaceRef Editor
April 12, 2000
Filed under

:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Apr 12 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 103 ISSUED AT 2200Z ON 12 APR 2000
IA. ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 11/2100Z
TO 12/2100Z: SOLAR ACTIVITY REMAINED AT MODERATE LEVELS. REGION 8948
(S16W37) APPEARED TO STABILIZE AS A MODERATE-SIZED, MIXED-POLARITY
REGION FOLLOWING TWO DAYS OF GRADUAL DECAY. IT PRODUCED TWO M-CLASS
FLARES DURING THE PERIOD: AN M1/1N AT 11/2337Z AND AN M1/SF AT
12/0335Z. REGION 8948 ALSO PRODUCED A C2/SN FLARE AT 12/0630Z WITH
AN ASSOCIATED TYPE II RADIO SWEEP. NEW REGION 8959 (S19E29) EMERGED
JUST SOUTH OF REGION 8953 (S16E31).
IB. SOLAR ACTIVITY FORECAST: ACTIVITY IS EXPECTED TO BE AT LOW TO
MODERATE LEVELS. THERE IS A FAIR TO GOOD CHANCE FOR ISOLATED M-CLASS
FLARES FROM REGION 8948.
IIA. GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z:
GEOMAGNETIC FIELD ACTIVITY WAS AT QUIET TO UNSETTLED LEVELS. THE
GREATER THAN 2 MEV ELECTRON FLUX AT GEOSYNCHRNOUS ORBIT WAS AT
MODERATE TO HIGH LEVELS.
IIB. GEOPHYSICAL ACTIVITY FORECAST: GEOMAGNETIC FIELD ACTIVITY IS
EXPECTED TO REMAIN AT QUIET TO UNSETTLED LEVELS. AT THIS POINT, IT
APPEARS UNLIKELY THAT WE WILL SEE ANY SIGNIFICANT EFFECTS FROM THE
FAINT HALO-CME OBSERVED EARLY ON 10 APRIL. THE GREATER THAN 2 MEV
ELECTRON FLUX AT GEOSYNCHRONOUS ORBIT IS EXPECTED TO DECLINE TO
NORMAL TO MODERATE LEVELS EARLY IN THE PERIOD.
III. EVENT PROBABILITIES 13 APR-15 APR
CLASS M 50/45/40
CLASS X 05/05/05
PROTON 05/05/05
PCAF GREEN
IV. PENTICTON 10.7 CM FLUX
OBSERVED 12 APR 173
PREDICTED 13 APR-15 APR 175/175/170
90 DAY MEAN 12 APR 185
V. GEOMAGNETIC A INDICES
OBSERVED AFR/AP 11 APR 008/010
ESTIMATED AFR/AP 12 APR 008/005
PREDICTED AFR/AP 13 APR-15 APR 012/012-010/010-012/012
VI. GEOMAGNETIC ACTIVITY PROBABILITIES 13 APR-15 APR
A. MIDDLE LATITUDES
ACTIVE 20/15/20
MINOR STORM 10/05/10
MAJOR-SEVERE STORM 05/01/05
B. HIGH LATITUDES
ACTIVE 25/20/25
MINOR STORM 15/10/15
MAJOR-SEVERE STORM 15/10/15

SpaceRef staff editor.