####018002272#### FXXX10 KWNP 271231 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Mar 27 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 27-Mar 29 2024 is 3.00 (below NOAA Scale levels). NOAA Kp index breakdown Mar 27-Mar 29 2024 Mar 27 Mar 28 Mar 29 00-03UT 3.00 1.67 2.67 03-06UT 1.33 1.67 2.00 06-09UT 2.00 1.67 2.33 09-12UT 1.67 1.33 2.33 12-15UT 1.33 1.33 2.33 15-18UT 2.00 1.33 2.33 18-21UT 2.00 1.33 2.33 21-00UT 2.33 1.33 2.67 Rationale: No G1 (Minor) or greater geomagnetic storms are expected. No significant transient or recurrent solar wind features are forecast. 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 27-Mar 29 2024 Mar 27 Mar 28 Mar 29 S1 or greater 30% 30% 30% Rationale: There is a chance for S1 (Minor) or greater solar radiation storms over the next three days due primarily to the flare potential of Region 3615. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Mar 26 2024 1330 UTC. Radio Blackout Forecast for Mar 27-Mar 29 2024 Mar 27 Mar 28 Mar 29 R1-R2 75% 75% 75% R3 or greater 25% 25% 25% Rationale: R1-R2 (Minor-Moderate) radio blackouts are expected over the next three days with a chance for an isolated R3 (Strong) event due primarily to the flare potential of Region 3615. ####018003194#### FXXX12 KWNP 271231 DAYDIS :Product: Forecast Discussion :Issued: 2024 Mar 27 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 reached high levels. Region 3615 (S13W48, Fkc/beta-gamma-delta) was responsible for five M-class flares the largest of which was a M1.9 flare at 26/1330 UTC. This AR continued to be the largest, most complex region on the visible disk, and was responsible for the majority of the activity. New spots were observed trailing AR 3619 (N18W18, Dso/beta), but remain unnumbered at this time as we await additional observatory reports. Region 3617 (S14W18, Hsx/alpha) exhibited signs of decay, and Region 3623 (S19W55, L=223) decayed to plage. At approximately 26/1405 UTC a filament eruption just north of AR 3620 (S09E11, Hrx/alpha) was observed in GOES SUVI 304 angstroms. Seemingly, a subsequent easterly, faint, narrow CME can first be seen in LASCO C2 coronagraph imagery around 26/1524 UTC. Modeling efforts suggest that a weak, glancing blow at Earth may be possible by early 31 Mar. Additionally, a more impressive, westerly CME was observed in LASCO C2 coronagraph imagery beginning near 27/0125 UTC. However, this event appears to have originated from beyond the western limb and is therefore not Earth-directed. .Forecast... Solar activity is expected to continue at moderate (R1-R2/Minor-Moderate) levels, with a chance for an X-class flares (R3/Strong), over 27-29 Mar due primarily to the flare potential of Region 3615. Energetic Particle .24 hr Summary... The greater than 10 MeV proton flux remained elevated, but below the 10 pfu threshold. The greater than 2 MeV electron flux was at normal to moderate levels. .Forecast... A chance for S1 (Minor) solar radiation storms will persist through 29 Mar primarily due to the potential and location of AR 3615. The greater than 2 MeV electron flux is expected to be at normal to moderate levels on 27 Mar, with a chance to reach high levels beginning on 28 Mar. Solar Wind .24 hr Summary... Solar wind parameters reflected waning influence of a coronal mass ejection (CME) that left the Sun on 23 Mar. Total field was between 4-5 nT, and the Bz component was mostly northward or near neutral. Solar wind speeds gradually decreased from ~650 km/s to just above 500 km/s by the end of the period. Phi was predominantly positive while taking a few brief excursions into a negative solar sector. .Forecast... Ambient-like solar wind conditions are expected to return by 28 Mar. Geospace .24 hr Summary... The geomagnetic field was quiet to unsettled. .Forecast... Quiet to unsettled periods are expected to continue for the remainder of 27 Mar as CME effects continue to wane. Mostly quiet conditions are expected to prevail on 28 Mar with a return of isolated unsettled periods by late on 29 Mar under negative polarity CH HSS effects.