Weather Briefing for The 2013 Presidential Inauguration

1. Weather BriefingforThe 2013 Presidential Inauguration NOAA/ National Weather Service Baltimore/Washington Weather Forecast Office January 21, 2013 0800 UTC/3:00 AM EST Christopher Strong Warning Coordination Meteorologist

2. Outline • Weather Hazards • Forecast Overview • Forecast Tables and Graphs • Reagan and Dulles METAR & TAF • Illumination Data • Space Weather • Dispersion Modeling • Summary of Weather Hazards • Briefing Schedule NWS Baltimore/Washington Weather Forecast Office

3. Weather Hazards0800 UTC 21 Jan – 0000 UTC 22 Jan 2013for Washington, D.C. 30% chance of a snow squall sometime between 5:00 PM and 09:00 PM today (Monday) • Arctic cold front may produce a snow squall that could produce up to 1 inch of snow. Gusty Winds (30 mph tonight, 35 mph Tuesday) • Small Craft Advisory for the Potomac starts at Noon today. • Wind chills will drop below 20 by midnight, and will fall to the upper single numbers by dawn Tuesday. NWS Baltimore/Washington Weather Forecast Office

4. Forecast Overviewfor Washington, D.C. Normals: Hi: 43F Lo: 28F NWS Baltimore/Washington Weather Forecast Office

5. Weather Element Forecastfor Washington, D.C. NWS Baltimore/Washington Weather Forecast Office

6. KDCA METAR & TAFRonald Reagan National Airport METAR KDCA 210652Z 01009KT 10SM SCT250 03/M11 A3011 RMK AO2 SLP195 T00281106 TAF KDCA 210529Z 2106/2206 35005KT P6SM SCT250 FM211400 14004KT P6SM BKN100 FM211700 18008KT P6SM BKN090 FM212200 23011KT P6SM BKN050 FM212300 28012G20KT P6SM BKN050 FM220500 30014G23KT P6SM SCT250 NWS Baltimore/Washington Weather Forecast Office

7. KIAD METAR & TAFDulles International Airport METAR KIAD 210652Z 36007KT 10SM FEW250 01/M10 A3009 RMK AO2 SLP191 T00061100 TAF KIAD 210529Z 2106/2212 36005KT P6SM SCT250 FM210900 03004KT P6SM BKN090 FM211400 15005KT P6SM BKN090 FM211700 19009KT P6SM BKN090 FM212200 24010KT P6SM BKN050 FM212300 28012G20KT P6SM BKN050 FM220500 30015G23KT P6SM SCT250 NWS Baltimore/Washington Weather Forecast Office

8. Illumination Data Washington, D.C. NWS Baltimore/Washington Weather Forecast Office

9. Space Weather Summary/Forecast 1640 1660 1660 1644 1654 1654 1638 1641 1658 1658 • Summary/Forecast Details: • Region 1654 continues to decay and will begin to rotate off the disk on 21 January. • Currently quiet across S and G scales • Overall threat of significant space weather activity is low 1642 Geomagnetic Storms Solar Flare Radio Blackouts Joint NOAA/USAF Space Weather Briefing Jan. 21, 2013 - 0800 UTC

10. Phenomena Reference/Impacts • Solar Flare Radio Blackout (R Scale): • No advance warning • Effects lasts for 10’s of minutes to several hours • Impacts High Frequency (HF) communication on the sunlit side of the Earth • First indication significant S and G scale activity may be possible • Solar Radiation Storm (S Scale): • Warnings possible on the minutes to hours time scale • Elevated levels can persist for several days • Impacts to the health and operation of satellites and International Space Station operations and crew • Impacts High Frequency communication in the polar regions, affecting commercial airline operations • Geomagnetic Storm (G Scale): • Advance notice possible given coronal mass ejection (CME) transit times from Sun to Earth range from just under a day to several days (CMEs being the main driver of significant storms) • In extreme storms, impacts to power grid operations and stability • Impacts to Global Positioning System (GPS) accuracy and availability • Driver of aurora; severe to extreme storms may cause aurora to be visible over most of the lower 48 Joint NOAA/USAF Space Weather Briefing Jan. 21, 2013 - 0800 UTC Complete NOAA Space Weather Scale information available online at: http://www.swpc.noaa.gov/NOAAscales/

11. HYSPLIT DISPERSION MODEL 1/21/13 Release at 2300Z 21 Jan 2013 (NAM) Release at 1700Z 21 Jan 2013 (NAM) NWS Baltimore/Washington Weather Forecast Office

12. NOAA/NWSBaltimore/Washington http://www.erh.noaa.gov/washington Always Up-to-date NWS Baltimore/Washington Weather Forecast Office

13. Summary • Mostly clear skies overnight. • Inauguration Day: Mostly cloudy and cooler, turning cold late. A chance of a snow squall between 5-10 P.M. • This could produce a quick accumulation of snow from a dusting to an inch. • Monday Night: Chance of a snow squall until 10 P.M., then becoming mostly clear and cold with lows in the lower 20s and gusty northwest winds to 30 mph; wind chills in the upper single numbers by dawn. NWS Baltimore/Washington Weather Forecast Office

14. Briefing Schedule • T-7 days: Tue Jan 15 1500 EST • T-6 days: Wed Jan 16 1500 EST • T-4 days: Thu Jan 17 1500 EST • T-3 days: Fri Jan 18 1500 EST • T-2 days: Sat Jan 19 1500 EST • T-1.5 Day: Sat Jan 19 2200 EST • T-1 Day: Sun Jan 20 1500 EST • T-14 hours: Sun Jan 20 2200 EST • T-12 hours: Mon Jan 21 0000 EST • T-9 hours: Mon Jan 21 0300 EST (if needed) • T-6 hours: Mon Jan 21 0600 EST • T-3 hours: Mon Jan 21 0900 EST • T-1 hour: Mon Jan 21 1100 EST • T+2 hour: Mon Jan 21 1400 EST • T+5 hour: Mon Jan 21 1700 EST • Other times / dates as needed or requested NWS Baltimore/Washington Weather Forecast Office

15. Next Scheduled Briefing 1100 UTC/6:00 AM EST Mon 21 Jan 2013 Thank you for your participation! NWS Baltimore/Washington Weather Forecast Office