NOAA/USAF Report of Solar-Geophysical Activity 12 June 2000

Report of Solar-Geophysical Activity

:Issued: 2000 Jun 12 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 164 ISSUED AT 2200Z ON 12 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  11/2100Z

TO 12/2100Z:  SOLAR ACTIVITY WAS LOW. THE LARGEST EVENT OF THE PERIOD

WAS A C6/1B FLARE AT 12/1226Z FROM NEW REGION 9042 (N21E77). THIS

REGION IS BRIGHT IN SOFT X-RAYS BUT ONLY SMALL SUNSPOTS ARE VISIBLE

AT THIS TIME.  MORE SPOTS ARE LIKELY TO ROTATE OVER THE LIMB. MOSTLY

STABLE REGION 9036 (S22E28) GENERATED A C6/SF AT 12/0138Z. REGION

9033 (N23W09) CREATED ONLY INFREQUENT SUBFLARES. NEARBY REGION 9041

(N17W22) EMERGED AT A MODERATE PACE AND APPEARED TO BE IMPINGING

UPON THE LEADER FIELDS OF REGION 9033. REGION 9026 (N22W63) WAS

MOSTLY QUIET.

IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY SHOULD BECOME MODERATE

FOR THE NEXT THREE DAYS. REGIONS 9026 AND 9033 REMAIN CAPABLE OF

M-CLASS FLARES AND ISOLATED X-CLASS EVENTS. CONTINUED EMERGENCE OF

NEARBY REGION 9041 COULD RESULT IN AN INCREASE IN FREQUENCY OF

M-CLASS EVENTS FROM THE 9033/9041 COMPLEX. FORESHORTENING OF NEW

REGION 9042 PREVENTS ACCURATE ASSESSMENT OF ITS FLARE POTENTIAL.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 11/2100Z TO 12/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET TO ACTIVE. SOLAR WIND VELOCITY WAS

BETWEEN ABOUT 450-600 KM/S. ACE ENERGETIC PARTICLE FLUXES INCREASED

DURING THE PERIOD, POSSIBLY INDICATING A SHOCK/CME IS APPROACHING

THE EARTH. GOES GT 10 MEV FLUXES REMAIN ENHANCED BUT BELOW EVENT

THRESHOLD.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  A GEOMAGNETIC STORM IS EXPECTED

TO BEGIN ON 13 JUN. GENERALLY, ACTIVE TO MINOR STORM LEVELS ARE

PREDICTED FOR THAT DAY AND ISOLATED MAJOR STORM PERIODS ARE

PROBABLE. THIS DISTURBANCE SHOULD CONTINUE INTO 14 JUN WHEN

UNSETTLED TO ACTIVE CONDITIONS ARE FORECAST. QUIET TO UNSETTLED

LEVELS ARE PREDICTED FOR 15 JUN. A SLIGHT POSSIBILITY EXISTS FOR AN

ENERGETIC SOLAR PROTON EVENT DURING THE NEXT THREE DAYS.

III.  EVENT PROBABILITIES 13 JUN-15 JUN

CLASS M    70/70/65

CLASS X    15/15/15

PROTON     20/20/20

PCAF       YELLOW

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           12 JUN 193

PREDICTED   13 JUN-15 JUN  205/210/205

90 DAY MEAN        12 JUN 188

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 11 JUN  022/032

ESTIMATED AFR/AP 12 JUN  014/015

PREDICTED AFR/AP 13 JUN-15 JUN  040/046-020/020-010/012

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 13 JUN-15 JUN

A.  MIDDLE LATITUDES

ACTIVE                20/30/25

MINOR STORM           40/30/15

MAJOR-SEVERE STORM    30/15/05

B.  HIGH LATITUDES

ACTIVE                20/30/25

MINOR STORM           40/30/15

MAJOR-SEVERE STORM    30/15/05