:Product: 19980508RSGA.txt
:Issued: 1998 May 08 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 128 ISSUED AT 2200Z ON 08 MAY 1998
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  07/2100Z
TO 08/2100Z:  SOLAR ACTIVITY WAS MODERATE. THREE M-CLASS EVENTS
OCCURRED OVER THE LAST 24 HOURS: AN M3 AT 0204Z (WITH TYPE II/IV
SWEEPS), AND M1 AT 0608Z (WITH TYPE II/IV), AND AN M1 AT 1415Z. NO
H-ALPHA FLARES WERE OBSERVED WITH THESE X-RAY EVENTS, BUT
SUPPLEMENTAL DATA (EIT AND LASCO) INDICATE THAT REGION 8210, WHICH
HAS ROTATED AROUND WEST LIMB, WAS THE MOST LIKELY SOURCE. REGION
8214 (N28W61) WAS ABLE TO MUSTER A C5/1N FLARE AT 1306Z. THE REGION
APPEARS TO BE DECAYING AND SIMPLIFYING, ALTHOUGH THE PROXIMITY TO
THE LIMB MAKES ANALYSIS MORE DIFFICULT. A NEW B-TYPE GROUP NEAR
N26E53 WAS ASSIGNED TODAY AS 8219. REGION 8218 (S20E48) APPEARS TO
BE GROWING, BUT WAS FAIRLY STABLE. X-RAY IMAGES INDICATE THAT THERE
IS A REGION BEHIND THE NORTHEAST LIMB WHICH SHOULD ROTATE INTO VIEW
SOMETIME IN THE NEXT FEW DAYS.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE. THERE IS A FAIR CHANCE FOR AN ISOLATED M-CLASS EVENT FROM
EITHER REGION 8214 OR 8218.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 07/2100Z TO 08/2100Z:
THE GEOMAGNETIC FIELD WAS PREDOMINANTLY ACTIVE DURING THE PAST 24
HOURS. THERE WERE SOME PERIODS OF MINOR STORM LEVELS AT HIGH
LATITUDES, PARTICULARLY AROUND 07/2100-08/0200Z AND FROM
08/1500-08/1700Z.THE DISTURBANCE BEGAN GRADUALLY: THERE WAS NO CLEAR
INDICATOR OF THE ARRIVAL OF A SHOCK AT L1 OR EARTH. THE GREATER THAN
2 MEV ELECTRON FLUXES WERE AT MODERATE TO HIGH LEVELS DURING THE
DAY.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE UNSETTLED TO ACTIVE FOR THE NEXT 24 HOURS.
PERSISTENCE FROM THE CURRENT DISTURBANCE MAY CAUSE SOME LOCAL
NIGHTTIME SUBSTORM EFFECTS. PREDOMINANTLY UNSETTLED LEVELS ARE
EXPECTED FOR THE SECOND AND THIRD DAYS.
III.  EVENT PROBABILITIES 09 MAY-11 MAY
CLASS M    55/55/55
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           08 MAY 118
PREDICTED   09 MAY-11 MAY  115/110/105
90 DAY MEAN        08 MAY 107
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 07 MAY  010/013
ESTIMATED AFR/AP 08 MAY  025/020
PREDICTED AFR/AP 09 MAY-11 MAY  015/015-010/015-010/015
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 09 MAY-11 MAY
A.  MIDDLE LATITUDES
ACTIVE                50/10/10
MINOR STORM           15/05/05
MAJOR-SEVERE STORM    05/05/05
B.  HIGH LATITUDES
ACTIVE                50/10/10
MINOR STORM           20/05/05
MAJOR-SEVERE STORM    15/05/05