:Product: Report of Solar-Geophysical Activity
:Issued: 2000 Feb 24 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 055 ISSUED AT 2200Z ON 24 FEB 2000
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  23/2100Z
TO 24/2100Z:  SOLAR ACTIVITY WAS MODERATE. AN OPTICALLY UNCORRELATED
M1 FLARE OCCURRED AT 24/0111Z. THERE ARE SOME TENTATIVE INDICATIONS
THAT THIS EVENT ORIGINATED FROM NEW REGION 8889 NEAR N19E67. THIS
REGION IS A MODERATE SIZE D CLASS GROUP BUT FORESHORTENING MAY BE
MASKING ITS TRUE SIZE. A TOTAL OF THREE OTHER REGIONS IN THE EASTERN
HEMISPHERE BECAME VISIBLE BUT, AT THIS TIME, NONE APPEARED LARGE OR
COMPLEX. THERE MAY BE ONE OR MORE REGIONS STILL BEHIND THE EAST
LIMB.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BE PREDOMINANTLY
MODERATE FOR THE NEXT THREE DAYS. THE POSSIBILITY OF A MAJOR FLARE
FROM NEAR EAST LIMB REGIONS IS A POSSIBILITY. ONCE THESE LONGITUDES
BECOME VISIBLE, A BETTER ASSESSMENT WILL BE POSSIBLE.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 23/2100Z TO 24/2100Z:
THE GEOMAGNETIC FIELD BEGAN THE PERIOD AT QUIET LEVELS AND WAS AT
ACTIVE TO MINOR STORM LEVELS AFTER 24/0300Z. SOLAR WIND VELOCITY
INCREASED TO SLIGHTLY OVER 800 KM/S AND DENSITY DECLINED TO LOW
LEVELS INDICATING THE EARTH IS IMMERSED IN THE PREVIOUSLY FORECAST
CORONAL HOLE STREAM. THE SOURCE HOLE ON THE SUN IS SLIGHTLY MORE
ELONGATED THAN LAST SOLAR ROTATION.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD BE
PREDOMINANTLY UNSETTLED TO ACTIVE FOR 25-26 FEB. OCCASIONAL PERIODS
OF MINOR STORMING ARE LIKELY DURING THAT PERIOD. THIS CORONAL HOLE
RELATED DISTURBANCE SHOULD BEGIN TO EBB ON 27 FEB WHEN QUIET TO
SLIGHTLY ACTIVE CONDITIONS ARE EXPECTED. ENERGETIC ELECTRON FLUXES
AT GEOSYNCHRONOUS ORBIT SHOULD BECOME ELEVATED TO HIGH LEVELS ON 25
FEB.
III.  EVENT PROBABILITIES 25 FEB-27 FEB
CLASS M    75/75/75
CLASS X    10/10/10
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           24 FEB 192
PREDICTED   25 FEB-27 FEB  195/197/200
90 DAY MEAN        24 FEB 164
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 23 FEB  008/009
ESTIMATED AFR/AP 24 FEB  024/023
PREDICTED AFR/AP 25 FEB-27 FEB  025/020-018/018-012/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 25 FEB-27 FEB
A.  MIDDLE LATITUDES
ACTIVE                40/50/30
MINOR STORM           35/25/15
MAJOR-SEVERE STORM    05/05/01
B.  HIGH LATITUDES
ACTIVE                40/50/30
MINOR STORM           40/25/15
MAJOR-SEVERE STORM    10/05/01