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000
FXXX10 KWNP 231230
DAYTDF

:Product: 3-Day Forecast
:Issued: 2013 May 23 1230 UTC
# Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center
# Product description and SWPC contact on the Web
# http://www.swpc.noaa.gov/wwire.html
#
#             3-Day Forecast
#
A. NOAA Geomagnetic Activity Observation and Forecast

The greatest observed 3 hr Kp over the past 24 hours was 3 (below NOAA
Scale levels).
The greatest expected 3 hr Kp for May 23-May 25 2013 is 4 (below NOAA
Scale levels).

NOAA Kp index breakdown May 23-May 25 2013

            May 23     May 24     May 25
00-03UT        2          3          3
03-06UT        3          2          4
06-09UT        1          1          4
09-12UT        2          1          3
12-15UT        2          2          3
15-18UT        3          2          3
18-21UT        3          3          3
21-00UT        4          3          2

Rationale: Geomagnetic field activity is expected to remain mostly below
NOAA Scale threshold levels on 23 May, with a slight chance for (G1)
Minor storm levels, due to recurrent coronal hole high-speed stream (CH
HSS) effects. Activity is expected to decrease for the first part of 24
May as CH HSS effects diminish, then expected to increase, starting
midday on 24 May through 25 May, with a slight chance for (G1) minor
storm levels due an expected glancing blow from the 22 May partial halo
CME.


B. NOAA Solar Radiation Activity Observation and Forecast

Solar radiation, as observed by NOAA GOES-15 over the past 24 hours, was
above S-scale storm level thresholds.

Solar Radiation Storm Forecast for May 23-May 25 2013

              May 23  May 24  May 25
S1 or greater   99%     99%     70%

Rationale: The greater than 10 MeV proton flux at geosynchronous orbit
is expected to remain at event (S2 to S3 - Moderate to Strong) levels on
23 May as a result of the 22 May M5/3n flare, then decrease to S1 to S2
- Minor to Moderate levels by 24 May. S1 - Minor levels are likely on 25
May.

C. NOAA Radio Blackout Activity and Forecast

Radio blackouts reaching the R2 levels were observed over the past 24
hours. The largest was at May 22 2013 1332 UTC

Radio Blackout Forecast for May 23-May 25 2013

              May 23        May 24        May 25
R1-R2           50%           50%           50%
R3 or greater   15%           15%           15%

Rationale: Solar activity is expected to be below NOAA Scale thresholds
during the period (23 - 25 May). There is, however, a chance for an
M-class (R1 - Minor) flare and a slight chance for an X-class (R3 -
Strong) flare throughout the period.