:Product: 19980429RSGA.txt
:Issued: 1998 Apr 29 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 119 ISSUED AT 2200Z ON 29 APR 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  28/2100Z
TO 29/2100Z:  SOLAR ACTIVITY BECAME MODERATE. REGION 8210 (S16E19)
PRODUCED A MODERATE DURATION M6/3B FLARE AT 29/1637Z. THIS EVENT WAS
ACCOMPANIED BY SMALL CENTIMETRIC RADIO BURSTS AND A STRONG TYPE IV
SWEPT FREQUENCY BURST THAT REMAINED IN PROGRESS AT THE END OF THE
PERIOD. A MODERATE SIZE FILAMENT IN THE REGION FADED WITH THE FLARE
AND A LARGE HALO CORONAL MASS EJECTION WAS OBSERVED FOLLOWING THIS
EVENT. ACCORDING TO ANALYSIS BY SOHO/LASCO SCIENTISTS, THIS HALO
APPEARED TO PROPAGATE MORE DIRECTLY AT THE EARTH THAN THE HALO
OBSERVED ON 27 APR. PRIOR TO THIS FLARE, REGION 8210 HAD PRODUCED
SEVERAL SMALL C-CLASS EVENTS. THE DELTA CONFIGURATION IN REGION 8210
FADED DURING THE PERIOD BUT SOME MIXED POLARITIES REMAINED. WHITE
LIGHT AREA REMAINED CONSTANT IN THIS SMALL REGION. A SMALL REGION
EMERGED NEAR N27E60 AND WAS NUMBERED AS NEW REGION 8214.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
PREDOMINANTLY LOW. REGION 8210 APPEARS TO BE ON A DOWNWARD TREND BUT
MAINTAINS THE CAPABILITY OF PRODUCING ISOLATED M AND SMALL X-CLASS
EVENTS. OLD REGION 8194 IS RETURNING TO THE SOUTHEAST LIMB DURING
THE PERIOD, BUT AT THIS EARLY TIME IT DOES NOT APPEAR TO BE A POTENT
FLARE PRODUCING REGION.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 28/2100Z TO 29/2100Z:
THE GEOMAGNETIC FIELD WAS QUIET. AT PRESS TIME, THE EXPECTED SHOCK
FROM THE X1/HALO CME OF 27 APR HAD NOT ARRIVED. ENERGETIC ELECTRON
FLUXES AT GEOSYNCHRONOUS ORBIT WERE PREDOMINANTLY HIGH.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD SHOULD
BECOME DISTURBED ON 30 APR IN RESPONSE TO THE HALO CME OBSERVED ON
27 APR. THE CME MENTIONED ABOVE SHOULD IMPACT THE EARTH ON 01-02
MAY. THUS, ACTIVE TO MINOR STORM CONDITIONS ARE EXPECTED FOR THE
NEXT THREE DAYS. ISOLATED PERIODS OF MAJOR STORMING ARE POSSIBLE
DURING THIS INTERVAL.
III.  EVENT PROBABILITIES 30 APR-02 MAY
CLASS M    25/25/25
CLASS X    15/15/15
PROTON     15/15/15
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           29 APR 101
PREDICTED   30 APR-02 MAY  101/104/108
90 DAY MEAN        29 APR 104
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 28 APR  007/010
ESTIMATED AFR/AP 29 APR  006/005
PREDICTED AFR/AP 30 APR-02 MAY  020/020-020/020-018/018
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 30 APR-02 MAY
A.  MIDDLE LATITUDES
ACTIVE                30/30/30
MINOR STORM           30/30/30
MAJOR-SEVERE STORM    15/15/15
B.  HIGH LATITUDES
ACTIVE                30/30/30
MINOR STORM           40/40/40
MAJOR-SEVERE STORM    15/15/15