####018002960#### FXXX12 KWNP 180031 DAYDIS :Product: Forecast Discussion :Issued: 2024 Apr 18 0030 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 at moderate levels. AR 3645 (S10E24, Cai/beta) produced an M1.6 flare at 17/2208 UTC. AR 3638 (S17E15, Cri/beta) a C9.0/Sn flare at 17/2004 UTC. Growth was observed in ARs 3633 (S07W78, Cso/beta), 3643 (S13E34, Fai/beta) and 3646 (N21E59, Cso/beta). The remaining numbered ARs on the visible disk were either mostly stable or in gradual decay. Other activity included a filament eruption observed around 17/0100 UTC in H-alpha imagery. The approximate 20 degree filament structure was centered near N40W00. An associated CME was observed off the NW limb at 17/0506 UTC in SOHO/LASCO C3 imagery. Analysis suggested an Earth-directed component was unlikely. A series of CMEs were observed off the SE starting around 17/1730 UTC in C2 imagery. These ejecta are possibly associated with flare activity from a cluster of regions in the SE quadrant. Analysis is ongoing for these events at the time of this summary. .Forecast... Solar activity is forecast to be moderate, with M-class flares (R1-R2/Minor-Moderate) likely and a slight chance for an X-class flare (R3/Strong) over 18-20 Apr. Energetic Particle .24 hr Summary... The greater than 10 MeV proton flux was at background levels. The greater than 2 MeV electron flux was at normal to moderate levels. .Forecast... There is a slight chance for a greater than 10 MeV proton event (S1/Minor) over 18-20 Apr. The greater than 2 MeV electron flux is expected to continue at normal to moderate levels through 20 Apr. Solar Wind .24 hr Summary... Solar wind parameters continued under the influence of a passing CME. Solar wind speeds remained low, with values observed from ~345-400 km/s. Total magnetic field strength was predominantly southward from ~17/0800 UTC to ~17/1730 UTC. The Bz component reached as far south as -8 nT. .Forecast... Solar wind enhancements from CMEs that left the Sun over 14-15 Apr are expected to pass Earth on 18 Apr and should wane over 19 Apr. 20 Apr is likely to see the onset of influence from a negative polarity CH HSS. Geospace .24 hr Summary... The geomagnetic field ranged from quiet unsettled levels. .Forecast... The geomagnetic field is likely to reach G1 (Minor) geomagnetic storm conditions on 18 Apr due to anticipated arrival of CMEs that left the Sun on 14 and 15 Apr. Quiet to unsettled conditions are likely over 19 Apr as CME influence wanes. Quiet to unsettled conditions are against likely on 20 Apr from the anticipated onset of a negative polarity CH HSS. ####018001284#### AXXX82 KWNP 180031 DAYOBS :Product: Summary of Space Weather Observations dayobs.txt :Issued: 2024 Apr 18 0030 UTC # Prepared by the US Dept. of Commerce, NOAA, Space Weather Prediction Center # Product description and SWPC contact on the Web # https://www.swpc.noaa.gov/content/subscription-services # # Summary of Space Weather Observations # :Solar_Region_Summary: 2024 Apr 17 # Region Location Sunspot Characteristics # Helio Spot Spot Mag. # Num Lat.,CMD Long. Area Extent class count class 3633 S07W78 322 80 4 CSO 3 B 3634 N27W70 314 290 11 EKI 8 B 3635 N22W42 286 10 4 AXX 3 A 3636 S20W05 249 70 3 CSO 4 B 3637 S13E13 231 20 4 CRO 4 B 3638 S17E15 228 30 7 CRI 5 B 3639 N29E22 222 320 11 EKI 16 BGD 3641 N12W28 272 60 8 DAO 3 B 3643 S13E34 210 130 16 FAI 20 B 3644 N12E60 184 80 4 DSO 2 B 3645 S10E24 220 30 5 CAI 8 BG 3646 N21E59 185 30 8 CSO 3 B ####018002241#### FXXX10 KWNP 180031 DAYTDF :Product: 3-Day Forecast :Issued: 2024 Apr 18 0030 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 Apr 18-Apr 20 2024 is 5.00 (NOAA Scale G1). NOAA Kp index breakdown Apr 18-Apr 20 2024 Apr 18 Apr 19 Apr 20 00-03UT 3.00 3.00 2.67 03-06UT 3.00 3.00 2.00 06-09UT 5.00 (G1) 2.67 2.00 09-12UT 4.00 2.33 2.33 12-15UT 3.00 2.00 2.67 15-18UT 2.33 2.00 3.00 18-21UT 2.33 2.00 2.67 21-00UT 3.33 2.00 2.33 Rationale: G1 (Minor) geomagnetic storms are likely on 18 Apr due to possible CME influences. 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 Apr 18-Apr 20 2024 Apr 18 Apr 19 Apr 20 S1 or greater 10% 10% 10% Rationale: There is a slight chance for S1 (Minor) or greater solar radiation storms all three days due to collective potential from numerous active regions. C. NOAA Radio Blackout Activity and Forecast Radio blackouts reaching the R1 levels were observed over the past 24 hours. The largest was at Apr 17 2024 2208 UTC. Radio Blackout Forecast for Apr 18-Apr 20 2024 Apr 18 Apr 19 Apr 20 R1-R2 65% 65% 65% R3 or greater 10% 10% 10% Rationale: R1-R2 (Minor-Moderate) radio blackouts are likely all three days. There is a slight chance for R3 (Strong) or greater radio blackouts all three days due to the flare potential from several regions.