:Product: 19990404RSGA.txt
:Issued: 1999 Apr 04 2200 UTC
# 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 094 ISSUED AT 2200Z ON 04 APR 1999
IA.  ANALYSIS OF SOLAR ACTIVE REGIONS AND ACTIVITY FROM  03/2100Z
TO 04/2100Z:  SOLAR ACTIVITY WAS HIGH.  REGION 8508 (N18E62) PRODUCED
AN M5/1F X-RAY EVENT AT 04/0528Z.  THIS EVENT HAD A 190 SFU RADIO
BURST AT 2695 MHZ.  ADDITIONAL DATA SHOW ACTIVITY OCCURRING AT THE
SAME TIME IN NEARBY REGION 8507 (N10E44).  REGION 8508 ALSO PRODUCED
AN M4/1F EVENT EARLIER DURING THE PERIOD WITH AN ASSOCIATED TYPE II
SWEEP AND A SPEED OF 500 KM/S AT 03/2310Z.  REGIONS 8504 (S28W03),
8506, (S26W15), 8507, AND 8508 ALL SHOWED MINOR TO MODERATE GROWTH.
ALL OF THESE REGIONS HAVE EXHIBITED NEAR CONTINUOUS SURGING AND
BRIGHTENING.
IB.  SOLAR ACTIVITY FORECAST:  SOLAR ACTIVITY IS EXPECTED TO BE
MODERATE TO HIGH.  SEVERAL REGIONS ARE NOW CAPABLE OF CONTINUED
M-CLASS EVENT PRODUCTION.  REGION 8506 APPEARS THE MOST POTENT WITH
AN INCREASE IN THE NUMBER OF SPOTS AND MAGNETIC COMPLEXITY.
IIA.  GEOPHYSICAL ACTIVITY SUMMARY FROM 03/2100Z TO 04/2100Z:
THE GEOMAGNETIC FIELD RANGED FROM QUIET TO ACTIVE.  THE GREATER THAN
2 MEV ENERGETIC  ELECTRONS AT GEOSYNCHRONOUS ORBIT REACHED HIGH
LEVELS AT 04/1420Z THEN DECREASED TO MODERATE LEVELS AFTER 04/1800Z.
IIB.  GEOPHYSICAL ACTIVITY FORECAST:  THE GEOMAGNETIC FIELD IS
EXPECTED TO BE QUIET TO UNSETTLED.  ISOLATED ACTIVE TO MINOR STORM
LEVELS ARE POSSIBLE DURING THE FIRST DAY OF THE PERIOD DUE TO AN
ELONGATED CORONAL HOLE IN THE SOLAR SOUTHWEST QUADRANT.
III.  EVENT PROBABILITIES 05 APR-07 APR
CLASS M    50/50/50
CLASS X    05/05/05
PROTON     05/05/05
PCAF       GREEN
IV.  PENTICTON 10.7 CM FLUX
OBSERVED           04 APR 116
PREDICTED   05 APR-07 APR  125/135/140
90 DAY MEAN        04 APR   134
V.  GEOMAGNETIC A INDICES
OBSERVED AFR/AP 03 APR  012/008
ESTIMATED AFR/AP 04 APR  014/012
PREDICTED AFR/AP 05 APR-07 APR  012/015-012/010-012/010
VI.  GEOMAGNETIC ACTIVITY PROBABILITIES 05 APR-07 APR
A.  MIDDLE LATITUDES
ACTIVE                30/30/25
MINOR STORM           10/10/05
MAJOR-SEVERE STORM    01/01/01
B.  HIGH LATITUDES
ACTIVE                35/35/30
MINOR STORM           15/15/10
MAJOR-SEVERE STORM    01/01/02