FROM SPACE ENVIRONMENT SERVICES CENTER, BOULDER, COLORADO
SDF NUMBER 351
JOINT USAF/NOAA REPORT OF SOLAR AND GEOPHYSICAL ACTIVITY.
ISSUED 2200Z 16 DEC 1988
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM 15/2100Z
TO 16/2100Z:  SOLAR ACTIVITY WAS HIGH. REGION 5278 (N27E30)
PRODUCED AN X4/1B FLARE AT 0846Z WHICH LASTED ABOUT 3 HOURS,
HAD A TOTAL INTEGRATED FLUX OF 1.1 JOULES/SQUARE-METER, WAS
ASSOCIATED WITH VERY STRONG DISCRETE RADIO BURSTS AND A STRONG
TYPE IV SWEEP. SUPRISINGLY, THIS WAS THE ONLY FLARE THE REGION
PRODUCED DURING THE 24 HOUR PERIOD THAT WAS M-CLASS OR GREATER.
THE REGION CONTINUES TO BE IMPRESSIVE WITH A MAGNETIC DELTA
CONFIGURATION IN THE LARGE LEADER SPOT. REGION 5279 (N23W03)
PRODUCED AN M1/1B FLARE AT 15/2132Z AND CONTINUED TO FLUCTUATE
TO SUB-FLARE LEVEL THROUGHOUT THE DAY. A SURGE REGION ON THE
EAST LIMB AT N17 PRODUCED SUBFLARE LEVEL ACTIVITY DURING THE
DAY AND WAS ASSIGNED SESC REGION NUMBER 5283. A NEW REGION
5282 (S23E43) EMERGED ON THE DISK. THE REMAINDER OF THE SOLAR
DISK AND LIMBS WERE ESSENTIALLY STABLE ALTHOUGH REGIONS 5280,
5273 PRODUCED NUMEROUS SUBFLARE FLUCTUATIONS DURING THE PERIOD.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH. REGION 5278 IS EXPECTED TO CONTINUE AS THE
PRIMARY THREAT FOR M-CLASS AND GREATER FLARES. REGIONS 5273,
5279, AND 5280 ARE ALSO CAPABLE OF PRODUCING MODERATE LEVELS
OF ACTIVITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 15/2100Z TO 16/2100Z:
THE GEOMAGNETIC FIELD WAS MOSTLY QUIET UNTIL 0900Z WHEN ACTIVE
TO MINOR STORM LEVEL CONDITIONS BEGAN. THE GREATER THAN 10MEV
PARTICLE FLUX LEVELS ROSE DURING THE PERIOD AND APPEAR TO BE
COUNTINUING ON AN UPWARD TREND AT THIS TIME: THE PEAK PARTICLE
FLUX SO FAR HAS BEEN 8 PFU. THESE EFFECTS ARE PROBABLY THE
RESULT OF THE X1/1N FLARE THAT OCCURRED AT 15/0509Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO CONTINUE AT MOSTLY MINOR STORM CONDITIONS OVER THE
NEXT THREE DAYS. THIS ACTIVITY IS EXPECTED AS CONSEQUENCE OF
CONTINUED EFFECTS FROM THE X1 FLARE THAT OCCURRED ON THE 15TH
AND IS EXPECTED TO CONTINUE THROUGH THE SECOND AND THIRD DAY
AS A RESULT OF TODAY'S X4 FLARE. A PROTON EVENT IS EXPECTED
TO BEGIN AND PEAK AT ABOUT 130 PFU SOMETIME IN THE NEXT 24
HOURS.
III.  EVENT PROBABILITIES 17 DEC-19 DEC
CLASS M    85/85/85
CLASS X    30/30/30
PROTON     30/30/30
PCAF       RED
IV.  OTTAWA 10.7 CM FLUX
OBSERVED           16 DEC  239
PREDICTED   17 DEC-19 DEC  240/240/240
90 DAY MEAN        16 DEC  166
V.  GEOMAGNETIC A INDICES
OBSERVED  AFR/AP 15 DEC  007/010
ESTIMATED AFR/AP 16 DEC  020/018
PREDICTED AFR/AP 17 DEC-19 DEC  040/040-040/040-035/030