####018002313#### FXXX12 KWNP 121231 DAYDIS :Product: Forecast Discussion :Issued: 2026 Mar 12 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 # # Forecast Discussion # Solar Activity .24 hr Summary... Solar activity was low. Region 4384 (N08W61, Cso/beta) produced a C4.0 flare at 12/1046 UTC, the largest of the period. Growth was observed in 4384, 4391 (N05E27, Dro/beta), and 4393 (N13E40, Cro/beta). Only minor changes were observed in the remaining spotted regions. No Earth-directed CMEs were observed in available coronagraph imagery. .Forecast... Solar activity is expected to be at low levels, with a slight chance for M-class (R1-R2/Minor-Moderate) flares through 14 Mar. Energetic Particle .24 hr Summary... The greater than 2 MeV electron flux reached high levels with a peak flux of 2,076 pfu observed at 11/1825 UTC. The greater than 10 MeV proton flux was at background levels. .Forecast... The greater than 2 MeV electron flux is expected to reach high levels on 12-13 Mar. A decrease to normal to moderate levels is likely on 14 Mar due to CH HSS onset. The greater than 10 MeV proton flux is expected to continue at background levels through 14 Mar. Solar Wind .24 hr Summary... Solar wind parameters were slightly elevated. Total magnetic field strength was between 5-6 nT. The Bz component reached as far south as -5 nT. Solar wind speeds varied from ~400-450 km/s. Phi angle was predominantly oriented in the negative sector. .Forecast... Near nominal levels are expected over 12 Mar. On 13 Mar, solar wind enhancements are likely due to the anticipated onset if influence from a negative polarity coronal hole. Elevated solar parameters are expected to persist through 14 Mar. Geospace .24 hr Summary... The geomagnetic field was at quiet to unsettled levels. .Forecast... The geomagnetic field is expected to be quiet to unsettled on 12 Mar. The onset of a CIR/CH HSS is expected around midday on 13 Mar causing causing conditions to increase up to G1 (Minor) storm conditions. G1 (Minor) conditions are remain likely through 14 Mar. ####018002097#### FXXX10 KWNP 121231 DAYTDF :Product: 3-Day Forecast :Issued: 2026 Mar 12 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 Mar 12-Mar 14 2026 is 5.00 (NOAA Scale G1). NOAA Kp index breakdown Mar 12-Mar 14 2026 Mar 12 Mar 13 Mar 14 00-03UT 2.67 1.67 4.67 (G1) 03-06UT 2.33 1.33 4.00 06-09UT 2.00 1.33 4.00 09-12UT 1.33 2.67 3.00 12-15UT 1.33 3.33 2.67 15-18UT 1.67 5.00 (G1) 2.33 18-21UT 1.33 4.33 2.33 21-00UT 1.67 4.33 3.67 Rationale: G1 (Minor) geomagnetic storms are likely over 13-14 Mar due to influence from a positive polarity coronal hole. B. NOAA Solar Radiation Activity Observation and Forecast Solar radiation, as observed by NOAA GOES-18 over the past 24 hours, was below S-scale storm level thresholds. Solar Radiation Storm Forecast for Mar 12-Mar 14 2026 Mar 12 Mar 13 Mar 14 S1 or greater 1% 1% 1% Rationale: No S1 (Minor) or greater solar radiation storms are expected. No significant active region activity favorable for radiation storm production is forecast. C. NOAA Radio Blackout Activity and Forecast No radio blackouts were observed over the past 24 hours. Radio Blackout Forecast for Mar 12-Mar 14 2026 Mar 12 Mar 13 Mar 14 R1-R2 20% 20% 20% R3 or greater 1% 1% 1% Rationale: There exists a slight chance for R1-R2 (Minor-Moderate) radio blackouts over 12-14 Mar.