SATELLITE RAINFALL ESTIMATES IN SAB

1. SATELLITE RAINFALL ESTIMATES IN SAB MOVING FROM IFFA ESTIMATES TO THE AUTOMATIC ESTIMATOR Richard Borneman- SATELLITE ANALYSIS BRANCH NESDIS/SATELLITE SERVICES DIVISION richard.borneman@noaa.gov http://www.ssd.noaa.gov

2. PART 1 BACKGROUND ON SAB PRECIPITATION OPERATIONS

3. HISTORY OF IFFA/QPE OPERATION • 1979FirstEstimates • 1983 - Fully Operational • using McIDAS system • SPENES messages on AFOS • 1990 - IFFA to Mainframe • much more data • 1993 - Collocated with HPC into NPPU • better QPF support • 1995 - Move to OS/2 • faster operations • 1996 - Estimate Graphics to WWW • SSD homepage • 1997 - Orographic Correction added • for short-term estimates • 1999 - Moved to Solaris Operating System • Y2K compliant • 2000 - Combined IFFA/Auto-Estimator Operation

4. SPRING 2000 SAB begins using the automatic rainfall estimator (AE) for precipitation operations

5. SatelliteAnalysisBranchPrecipitationProducts/Services 1. SPENES Flash Flood Guidance 2. Satellite Rainfall Estimates 3. Support HPC/NCEP

6. SPENES Contents 1. IFFA Estimates or Auto-Estimates (hourly rates 3-6 hour totals 24 hour totals) 2. Satellite Analysis (satellite interpretation - SIM) 3. Nowcast and Satellite Trends 4. Additional Satellite Data In addition to GOES IR & Vis: -Microwave: SSM/I &AMSU (Rain Rate/PW) -GOES Sounder and Imager (PW & LI) -GOES Water Vapor Imagery * Issued as needed - Using FF guidance and meteorological judgement

7. EXAMPLE OF SPENES WITH AUTO-ESTIMATES

8. PART 2 BACKGROUND ON AUTO-ESTIMATOR AND EXAMPLES

9. Cloud Top Temperature/Rain Rate Curve for Auto-Estimator

10. ADDITONAL AE CORRECTIONS/ADJUSTMENTS • 15 min imagery • Parallax (satellite viewing angle) • Cloud growth/cloud top cooling and warming • Moisture correction • Orographic correction • Warm cloud tops/ equilibrium level • Radar reflectivity/ rain- no rain

11. AUTO-ESTIMATOR PRODUCTS • Every Half Hour: • Instantaneous Rate • 1 hour totals • 3 hour totals • Hourly: • 6 hour totals • Daily (12Z): • 24 hour totals

12. WEB SITES FOR SATELLITE ESTIMATES • SSD HOME PAGE • SAB OPERATIONAL PRODUCTS • http://www.ssd.noaa.gov/SSD/ML/pcpn-ndx.html • SPENES guidance message • Very high resolution estimate graphics- accompany SPENES’s • ORA FLASH FLOOD HOME PAGE • AUTO-ESTIMATOR PRODUCTS • http://orbit-net.nesdis.noaa.gov/arad/ht/ff/index.html • National products in real-time • Higher resolution by U.S. quadrants

13. HOW TO USE AE FOR HEAVY RAIN AND FLASH FLOOD POTENTIAL • Short term maximums (1 to 6 hours) • For moderate/heavy convection (not for light rains) • Use instantaneous product for very short term heavy rains (1 hour or less) • Location may be off by 1 or 2 counties with strong vertical wind shear (check against radar) • Looping of 1 and 3 hour totals good for trends and movement

14. EXAMPLE Auto-Estimates for July 8 – 9, 2000 Northwest Wisconsin/Eastern Minnesota

17. 6 hour Auto-Estimates

18. ZCZC NFDSPENES ALL DDHHMM;470,0960 470,0890 440,0890 440,0960; TTAA00 KNFD DDHHMM . SATELLITE PRECIPITATION ESTIMATES..DATE/TIME 7/9/00 0447Z THE SATELLITE ANALYSIS BRANCH/NESDIS‑‑‑NPPU‑‑‑TEL.301‑763‑8678 VALUES ARE MAX OR SGFNT EST. NO OROGRAPHIC CORRECTION UNLESS NOTED... ....EST'S FM:/GOES8‑CNTRL AND E. U.S./GOES10‑W. U.S... LATEST DATA USED: GOES‑8 0432Z CK AUTOESTIMATOR 0400Z . LOCATION...MINNESOTA WISCONSIN . EVENT...LATEST CNVCTV TRENDS THRU 0432Z . REMARKS...BACK EDGE OF CNVTN HAS BEEN SLIPPING S OVER OTTER TAIL COUNTY/MN.. BUT REMAINS INTENSE WITH SOME BUILDING TWD THE SW. FURTHER EAST..CELL MERGERS CONTINUE OVER TODD AND MORRISON COUNTIES. NO LET‑UP YET FOR PINE COUNTY. INTENSE CELLS OVER S AITKIN/MILLE LAC/KANNEBEC COUNTIES ARE DIRFTING S. OVR WI INTENSE CELL S OF EAU MOVG S. . AUTOESTIMATES... 6 HR TOTALS MN COUNTIES... 22‑04Z OTTER TAIL/TODD 2" (TOO LIGHT) CROW WING/AITKIN 2.5" MN/WI CONTIES... PINE TO SAWYER 4‑5" MAX AMOUNTS WI COUNTIES... CHIPPEWA (N OF EAU) 2.5" PRICE (W OF RHI) 2.7" . SEE GRAPHIC AT ADDRESS BELOW..NOTE..SOME OF THE AMOUNTS MAY BE ON THE LIGHT SIDE. ... ...SEE HPC QPF GRAPHICS AND DISCUSSIONS FOR FCST... . http://www.ssd.noaa.gov/SSD/ML/pcpn‑ndx.html [ONLINE SSD PRECIPITATION PRODUCT INDEX] . NNNN SPENES Message that Was sent

19. 24 hour Reports

20. CASESTUDY EASTERN IOWA/NORTHWEST ILLINOIS May 31, 2000 AUTO ESTIMATES Vs. IFFA ESTIMATES

30. SPENES WHICH WAS SENT----BEFORE AE WAS OPERATIONAL

32. IFFA 24hr. Totals

33. AE 24hr. Totals

34. 24 HOUR REPORTS

35. PART 3 USING AUTOMATIC SATELLITE RAINFALL ESTIMATES FOR HEAVY CONVECTIVE RAINFALL

36. BENEFITS OF USING AE FOR BOTH RAINFALL ESTIMATES AND SAB SPENES GUIDANCE • More timely • Greater coverage for whole U.S. • Continuous coverage • More frequent SPENES flash flood guidance

37. EXAMPLE OF IMPROVED SAB PRECIPITATION OPERATIONS USING AUTO-ESTIMATOR(for first week-started June 12, 2000) • MORE SPENES MESSAGES- 110 messages; second highest total in 10 years • BETTER COVERAGE- 54 heavy rain systems for which messages were sent; highest weekly total • INCREASED TIMELINESS- 21 minutes average time between satellite data and SPENES transmission (compared to 30 min for IFFA)

38. DEFICIENCIES OF AE ESTIMATES • Heavy estimates cover too large of an area • Mislocation for shearing cold tops • Overestimates for longer term totals (mostly 24 hour) • Initial estimates low (first hour) • Overestimates for very cold cloud tops with much cirrus debris • Not good for light amounts • Misses very small short-lived events • Despite auto-adjustment, warm tops often underestimated.

40. PART 4 THE FUTURE

41. FUTURE AUTO-ESTIMATOR IMPROVEMENTS • Available on AWIPS • Visible Imagery-mostly location of heaviest rains • AMSU/SSMI Microwave-calibrate rain rates • Rain Burst- increase amounts in first hour • Screen Out Lighter Amounts- decrease long-term overestimates • GOES Multi-Spectral- rain/no-rain; better amounts