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

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Apr 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 116 ISSUED AT 2200Z ON 25 APR 2000

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

TO 25/2100Z:  SOLAR ACTIVITY CONTINUED LOW. MOST OF THE ACTIVITY

ORIGINATED IN REGION 8972 (N34W47). REGIONS 8970 (S15E18) AND 8971

(N18E16) REMAIN IMPRESSIVE IN WHITE LIGHT AND H-ALPHA, BUT AS YET

HAVE BEEN LARGELY UNPRODUCTIVE. LITTLE ELSE OF SIGNIFICANCE

OCCURRED.

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

TO MODERATE. AN ISOLATED M-CLASS EVENT MAY ORIGINATE FROM EITHER

REGION 8970, 8971 OR 8972.

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

THE GEOMAGNETIC FIELD WAS QUIET TO UNSETTLED.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE UNSETTLED THROUGHOUT THE PERIOD.

III.  EVENT PROBABILITIES 26 APR-28 APR

CLASS M    30/30/30

CLASS X    01/01/01

PROTON     01/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           25 APR 203

PREDICTED   26 APR-28 APR  205/205/200

90 DAY MEAN        25 APR 186

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 24 APR  014/021

ESTIMATED AFR/AP 25 APR  005/009

PREDICTED AFR/AP 26 APR-28 APR  010/015-010/012-010/010

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 26 APR-28 APR

A.  MIDDLE LATITUDES

ACTIVE                20/20/20

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    01/01/01

B.  HIGH LATITUDES

ACTIVE                30/30/30

MINOR STORM           05/05/05

MAJOR-SEVERE STORM    01/01/01