NOAA/USAF Report of Solar-Geophysical Activity 25 June 2000

Report of Solar-Geophysical Activity

:Issued: 2000 Jun 25 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 177 ISSUED AT 2200Z ON 25 JUN 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  24/2100Z

TO 25/2100Z:  SOLAR ACTIVITY INCREASED TO MODERATE LEVELS DUE TO A

PAIR OF M-CLASS FLARES. THE FIRST WAS AN M2/SF AT 25/0114Z WITH AN

ASSOCIATED LOOP PROMINENCE SYSTEM FROM REGION 9042, NOW ABOUT A DAY

BEYOND THE WEST LIMB. THE SECOND WAS AN M1/2N AT 25/0752Z FROM

REGION 9046 (N21W61). THIS REGION SHOWED NO SIGNIFICANT CHANGES

DURING THE PERIOD AND REMAINED A SMALL, MIXED-POLARITY SPOT GROUP.

MINOR GROWTH WAS REPORTED IN REGIONS 9054 (N12W04) AND 9058

(S14W41). THE REMAINING REGIONS WERE STABLE AND SIMPLY-STRUCTURED.

AN ERUPTIVE PROMINENCE WAS OBSERVED AT NE26 AROUND 25/1200Z. NEW

REGION 9062 (S19E72) WAS NUMBERED.

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

MODERATE LEVELS. ISOLATED M-CLASS FLARES ARE POSSIBLE DURING THE

PERIOD.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 24/2100Z TO 25/2100Z:

GEOMAGNETIC FIELD ACTIVITY DECREASED TO QUIET TO UNSETTLED LEVELS. A

GREATER THAN 10 MEV PROTON FLUX ENHANCEMENT AT GEOSYNCHRONOUS ORBIT

BEGAN AROUND 25/1300Z, LIKELY ASSOCIATED WITH THE M1/SF LIMB-FLARE

FROM OLD REGION 9042.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  GEOMAGNETIC FIELD ACTIVITY IS

EXPECTED TO INCREASE TO UNSETTLED TO ACTIVE LEVELS DURING 26 – 27

JUNE DUE TO CORONAL HOLE EFFECTS. BRIEF MINOR STORM CONDITIONS MAY

ALSO OCCUR DURING THIS PERIOD. FIELD ACTIVITY IS EXPECTED TO

DECREASE TO QUIET TO UNSETTLED LEVELS ON THE FINAL DAY OF THE

FORECAST PERIOD. THE GREATER THAN 10 MEV PROTON FLUX AT

GEOSYNCHRONOUS ORBIT IS EXPECTED TO RETURN TO BACKGROUND LEVELS

EARLY TOMORROW. THE GREATER THAN 2 MEV ELECTRON FLUX AT

GEOSYNCHRONOUS ORBIT IS EXPECTED TO REACH MODERATE TO HIGH LEVELS

LATE IN THE PERIOD.

III.  EVENT PROBABILITIES 26 JUN-28 JUN

CLASS M    30/30/35

CLASS X    05/05/05

PROTON     05/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           25 JUN 175

PREDICTED   26 JUN-28 JUN  160/155/155

90 DAY MEAN        25 JUN 185

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 24 JUN  010/017

ESTIMATED AFR/AP 25 JUN  006/010

PREDICTED AFR/AP 26 JUN-28 JUN  018/030-015/020-012/012

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 JUN-28 JUN

A.  MIDDLE LATITUDES

ACTIVE                35/35/25

MINOR STORM           20/20/15

MAJOR-SEVERE STORM    05/05/01

B.  HIGH LATITUDES

ACTIVE                40/40/30

MINOR STORM           25/25/20

MAJOR-SEVERE STORM    10/10/01