:Product: 04191230three_day_forecast.txt
:Issued: 2014 Apr 19 1230 UTC
# Prepared by the U.S. Dept. of Commerce, NOAA, Space Weather Prediction Center
#
A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 4 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for Apr 19-Apr 21 2014 is 5 (NOAA Scale
G1).

NOAA Kp index breakdown Apr 19-Apr 21 2014

            Apr 19     Apr 20     Apr 21
00-03UT        4          3          5 (G1)
03-06UT        4          5 (G1)     4     
06-09UT        3          4          3     
09-12UT        3          3          3     
12-15UT        2          2          2     
15-18UT        2          5 (G1)     2     
18-21UT        4          4          3     
21-00UT        4          4          4     

Rationale: The geomagnetic field is expected to be enhanced on day one
(19 Apr) with the passage of two weak CMEs from 15 and 16 Apr embedded
in the ambient solar wind, but remain below G1 - Minor levels. Early on
20 Apr, the arrival of another CME from 16 Apr is expected to bring G1 -
minor storm conditions before being reinforced by the midday arrival of
the CME from 18 Apr. The second impact will prolong minor storm
conditions and introduce a chance for major (G2) storm levels. G1 -
Minor (G1) storm conditions are expected to persist into the early hours
of day three (21 Apr) before diminishing to active or unsettled levels.

B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-13 over the past 24 hours, was
above S-scale storm level thresholds.

Solar Radiation Storm Forecast for Apr 19-Apr 21 2014

              Apr 19  Apr 20  Apr 21
S1 or greater   99%     75%     50%

Rationale: The greater than 10 MeV proton flux at geosynchronous orbit
is expected to remain above the 10 pfu threshold (S1-Minor) into day one
(19 Apr). S1 events remain likely on day two (20 Apr) with a continued
chance on day three (21 Apr), particularly with the passage of the
approaching CMEs.

C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R2 levels were observed over the past 24
hours. The largest was at Apr 18 2014 1303 UTC

Radio Blackout Forecast for Apr 19-Apr 21 2014

              Apr 19        Apr 20        Apr 21
R1-R2           60%           60%           60%
R3 or greater   10%           10%           10%

Rationale: Solar activity is likely to be at R1-Minor levels with a
slight chance for R3-Strong or greater for the next three days (19-21
Apr) due to the number of complex regions currently populating the disk.