Overview of the Hydrometeorological Prediction Center Precipitation/Flash Flood Products/Services hpc.ncep.noaa

1. Overview of the Hydrometeorological Prediction Center Precipitation/Flash Flood Products/Serviceswww.hpc.ncep.noaa.gov Michael Eckert michael.eckert@noaa.gov National Flood Workshop

2. NCEP Headquarters @ height of the 02/10/10 Blizzard NCEP HQ Hydrometeorological Prediction Center Climate Prediction Center Ocean Prediction Center Environmental Modeling Center NCEP Central Operations Space Weather Prediction Center Aviation Weather Center Nat’l Hurricane Center Storm Prediction Center

3. Hydrometeorological Prediction Center • Mission:HPC delivers weather forecast guidance and services in support of the daily activities of the National Weather Service and its users. • NWS ROLES: • Starting point • Second opinion • Catalyst for Collaboration • Historical Record • Emergency Backup Camp Springs, MD

4. HPC Responsibilities • Hydrometeorological guidance for: • NWS Field Offices • Other NCEP Centers • Federal/State Agencies • Media • Private Sector • International Partners • Academia • General Public • Mitigation of: • Loss of life & Injuries • Loss of property QPF Medium Range Winter Weather Short Term Weather Model Diagnostics Surface Analysis Tropical Alaska Med. Range Daily Weather Map

5. Precipitation Area of Responsibility Runoff into Columbia River Runoff into Rio Grande River

6. HPC Quantitative Precipitation Forecast Products • Deterministic QPF Graphics • Probabilistic QPF Graphics • Excessive Rainfall Graphics • Flood Outlook Graphics • Storm/Tropical Summaries • Written Discussions • Verification

7. Deterministic QPF • Provided as: • Graphics • Web • AWIPS • GRIB 2 format • Web only • ftp.hpc.ncep.noaa.gov • GIS format • Web only • KML for Google Maps

8. Deterministic Quantitative Precipitation ForecastHPC QPF = Most likely areal-averaged QPF • 6 hour QPF through Day 3.5 • Day 1 & 2 – 06, 10, 18 & 22 • Day 3 – 10 & 22z • 24 hour QPF through Day 3 • Day 1 & 2 – 06, 10, 18 & 22z • Day 3 – 10 & 22z • 48 hour QPF Days 4-5 • 00z & 12z • 6-h disaggregation via GEFS • Day 1-5 QPF total accumulation • 00z & 12z • Fuel for RFC hydrologic models, NDFD & many other uses

9. QPF Desk HPC WFO RFC

10. Available QPF Forecast periods 6 hour QPF 24 Hour QPF 48 hour QPF 72 Hour QPF 120 Hour QPF

11. QPF in Google Earth

12. Probabilistic QPFwww.hpc.ncep.noaa.gov/pqpf_6hr/conus_hpc_pqpf_6hr.php • Experimental • Binormal probability distribution (density) function (PDF) • HPC QPF is mode • Variance is ensemble of: • GFS • NAM • SREF • ECMWF

13. Probabilistic QPF(Probability of exceeding a particular QPF amount) • Probability of a particular QPF amount • ≥ 0.01”…≥ 3.00” • Select amount • Select time period

14. Probabilistic QPF(Percentile of a particular QPF) • Percentile Accumulations • Select percentile • Select time period Conversely…75% chance precipitation will exceed these amounts

15. HPC Excessive Rainfall • Categorical probability of Rainfall Exceeding RFC FFG at a point • Day 1, Day 2, and Day 3 products RFC 5km FFG • Day 1 updated: • 03, 06, 15, 18 UTC • OR as Necessary! • Day 2 & 3 updated: 06 and 18 UTC Rainfall SLGT = 5-10% MOD = 10-15% HIGH = >15% www.hpc.ncep.noaa.gov/qpf/excess_rain.shtml

16. SPC Mesoscale Discussion(0-6 hour discussion guidance) QUASI STATIONARY MCS REMAINS ELONGATED IN AN E-W FASHION ACROSS MUCH OF WRN/MIDDLE TN. ALTHOUGH LLJ MAY RELAX A BIT OVER THE NEXT FEW HOURS...SIGNIFICANT STRENGTHENING IS EXPECTED LATER THIS AFTERNOON…THIS STRENGTHENING SHOULD RESULT IN CONTINUED THUNDERSTORM DEVELOPMENT ALONG WRN/SRN FRINGE OF MCS WITHIN A VERY MOIST AIRMASS...PWAT APPROACHING 2 INCHES. NET RESULT APPEARS TO BE A CONTINUED HEAVY RAIN THREAT ACROSS MUCH OF WRN/MIDDLE TN. www.spc.ncep.noaa.gov/products/md

17. Flood Outlook Product (FOP) Summary of expected river flood conditions over the U.S. during the next 5 days Data submitted by RFCs Pieced together at HPC www.hpc.ncep.noaa.gov/nationalfloodoutlook/index.html

18. QPF Verificationwww.hpc.ncep.noaa.gov/html/hpcverif.shtml • Threat/Bias • Improvement over models • Record threat scores • Monthly • Yearly • Seasonal • Specific Values Verified

19. Storm Summaries • Issued 4 times per day • (03Z, 09Z, 15Z & 21Z) • Expansive organized heavy snow/heavy rainfall events • Heavily used by Media • Summaries include: • Headline – Describing the Event • General overview of Watches, Warnings & Advisories • Table of accumulations (snow or rain) & magnitude of wind • Future expectations of storm

20. Tropical Summaries • Issued 4 times per day • (03Z, 09Z, 15Z & 21Z) • Starts when NHC Drops Advisories, but heavy rainfall remains a threat • Format is exactly like NHC Tropical Public Advisories • Summaries include: • Location • Watches, Warnings & Advisories • Discussion & 48 hour outlook • Hazards • Rainfall accumulations

21. Hydrometeorological Prediction Center • Forecast and Guidance on a National Scale • Experts focused on one particular forecast entity • Wide variety of Precipitation related products • Mitigation of: • Loss of Life • Injuries • Property Damage

22. Questions?