NOAA/USAF Report of Solar-Geophysical Activity 26 Apr 2000

:Product: Report of Solar-Geophysical Activity

:Issued: 2000 Apr 26 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 117 ISSUED AT 2200Z ON 26 APR 2000

IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  25/2100Z

TO 26/2100Z:  SOLAR ACTIVITY CONTINUED AT THE LOW LEVEL. A C6/SF

FLARE FROM REGION 8970 (S15E04) AT 0923Z WAS THE DAY’S LARGEST

EVENT. THAT SPOT GROUP MEASURES OVER 1,000 MILLIONTHS IN WHITE LIGHT

AREA, BUT HAS A FAIRLY SIMPLE MAGNETIC STRUCTURE. NEARBY REGION 8971

(N18E16), STILL IMPOSING IN WHITE LIGHT,  WAS STABLE.

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

TO MODERATE. AN ISOLATED LOW-LEVEL M-CLASS EVENT MAY OCCUR FROM

REGION 8970 OR 8971.

IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 25/2100Z TO 26/2100Z:

THE GEOMAGNETIC FIELD WAS QUIET.

IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS

EXPECTED TO BE QUIET TO UNSETTLED THROUGHOUT THE PERIOD.

III.  EVENT PROBABILITIES 27 APR-29 APR

CLASS M    30/30/30

CLASS X    01/01/01

PROTON     01/01/01

PCAF       GREEN

IV.  PENTICTON 10.7 CM FLUX

OBSERVED           26 APR 190

PREDICTED   27 APR-29 APR  185/180/175

90 DAY MEAN        26 APR 187

V.  GEOMAGNETIC A INDICES

OBSERVED AFR/AP 25 APR  007/006

ESTIMATED AFR/AP 26 APR  003/007

PREDICTED AFR/AP 27 APR-29 APR  010/015-010/015-010/012

VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 27 APR-29 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