NOAA/USAF Report of Solar-Geophysical Activity 20 June 2000

Report of Solar-Geophysical Activity

:Issued: 2000 Jun 20 2200 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 172 ISSUED AT 2200Z ON 20 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  19/2100Z

TO 20/2100Z:  SOLAR ACTIVITY HAS BEEN LOW. REGION 9042 (N24W24)

PRODUCED TODAY’S LARGEST EVENT, A C6/1N AT 1928Z WHICH WAS

ACCOMPANIED BY A WEAK TYPE II RADIO SWEEP. THE REGION APPEARED TO BE

DECLINING SLIGHTLY. REGION 9046 (N21E06) CONTINUES TO BE THE LARGEST

GROUP ON THE DISK BUT PRODUCED ONLY A SUBFLARE DURING THE PAST 24

HOURS. REGION 9052 (S26E29) EXHIBITED SLOW GROWTH BUT WAS STABLE.

NEW REGION 9054 (N09E64) ROTATED INTO VIEW TODAY AS A SMALL C-TYPE

GROUP.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE LOW.

THERE IS A CHANCE FOR AN ISOLATED M-CLASS EVENT FROM REGION 9042 OR

9046 OVER THE NEXT THREE DAYS.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 19/2100Z TO 20/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE PREDOMINANTLY UNSETTLED FOR THE NEXT THREE DAYS.

III.  EVENT PROBABILITIES 21 JUN-23 JUN

CLASS M    25/25/25

CLASS X    05/05/05

PROTON     05/05/05

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           20 JUN 184

PREDICTED   21 JUN-23 JUN  185/185/180

90 DAY MEAN        20 JUN 186

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 19 JUN  008/009

ESTIMATED AFR/AP 20 JUN  007/010

PREDICTED AFR/AP 21 JUN-23 JUN  010/012-010/015-010/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 21 JUN-23 JUN

A.  MIDDLE LATITUDES

ACTIVE                20/20/20

MINOR STORM           10/10/10

MAJOR-SEVERE STORM    05/05/05

B.  HIGH LATITUDES

ACTIVE                20/20/20

MINOR STORM           10/10/10

MAJOR-SEVERE STORM    05/05/05