:Product: 19990310RSGA.txt
:Issued: 1999 Mar 10 2200 UTC
# 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 069 ISSUED AT 2200Z ON 10 MAR 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  09/2100Z
TO 10/2100Z:  SOLAR ACTIVITY WAS LOW. REGION 8484 (S23E54) PRODUCED A
C3/1F FLARE AT 09/2257UT. THREE ADDITIONAL OPTICALLY UNCORRELATED C1
CLASS FLARES WERE OBSERVED DURING THE PERIOD. REGION 8485 (N22E40)
IS NOW THE LARGEST REGION ON THE DISK AND SHOWED FLUCTUATIONS AND
WEAK SUBFLARE ACTIVITY DURING THE PERIOD. REGION 8477 (S28W46)
INCREASED SIZE TODAY, BUT APPEARED TO BE STABLE. A 45-DEGREE
FILAMENT NEAR S53E06 DISAPPEARED SOMETIME BETWEEN 10/0021Z AND
10/1423Z.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.
THERE IS A SLIGHT CHANCE, HOWEVER, FOR AN ISOLATED M-CLASS EVENT
FROM REGION 8485, 8484 OR 8477.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 09/2100Z TO 10/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO MAJOR STORM LEVELS. A WEAK
SHOCK WAS OBSERVED AT ACE AT 10/0040Z AND WAS FOLLOWED BY A SUDDEN
IMPULSE AT 10/0130Z (MEASURED AS 13 NT ON THE BOULDER MAGNETOMETER).
THE SUDDEN IMPULSE WAS FOLLOWED BY ABOUT 12 HOURS OF MINOR TO MAJOR
STORM ACTIVITY, WITH THE MOST INTENSE PART OF THE DISTURBANCE FROM
0300-0600Z. ACE SIGNATURES WERE CONSISTENT WITH A SHORT LIVED BUT
GEOEFFECTIVE TRANSIENT (DURATION OF PREDOMINANTLY NEGATIVE BZ WAS
ABOUT 10 HOURS). CONDITIONS GRADUALLY SUBSIDED FOR THE REMAINDER OF
THE DAY WITH QUIET TO UNSETTLED PREVAILING FOR THE LAST THREE HOURS.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED WITH OCCASIONAL ACTIVE PERIODS FOR THE NEXT
24 HOURS. UNSETTLED CONDITIONS ARE EXPECTED TO DOMINATE FOR THE
SECOND AND THIRD DAYS. THERE IS A POSSIBILITY, HOWEVER, FOR AN
INCREASE IN ACTIVITY FROM TODAY'S FILAMENT ERUPTION LATE ON THE
THIRD DAY OR PERHAPS THE FOURTH DAY.
III.  EVENT PROBABILITIES 11 MAR-13 MAR
CLASS M    20/20/20
CLASS X    05/05/05
PROTON     01/01/01
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           10 MAR 135
PREDICTED   11 MAR-13 MAR  145/150/155
90 DAY MEAN        10 MAR 142
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 09 MAR  019/023
ESTIMATED AFR/AP 10 MAR  030/030
PREDICTED AFR/AP 11 MAR-13 MAR  015/015-010/008-015/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 11 MAR-13 MAR
A.  MIDDLE LATITUDES
ACTIVE                30/15/25
MINOR STORM           05/05/10
MAJOR-SEVERE STORM    01/01/05
B.  HIGH LATITUDES
ACTIVE                30/15/35
MINOR STORM           10/05/15
MAJOR-SEVERE STORM    01/01/05