Difference between TP-40, TP-49, and HYDRO-35 and NRCC Data

Publications Technical Paper 40, 1961. 30-minute to 24-hour for 1-year to 100-year return periods. NWS HYDRO-35, 1977. 5- to 60- Minute Precipitation Frequency for the Eastern and Central United States. Technical Paper 49, 1964. Two- to Ten- Day Precipitation for Return Periods of 2 to 100 years. TP-40 vs NRCC October 2010

This picture is taken from NOAA Atlas 14 Volume 2 This picture is taken from NOAA Atlas 14 Volume 2. The areas colored in green have higher precipitation than TP-40. TP-40 vs NRCC October 2010

NRCC – TP40 10-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – TP40 10-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – TP40 25-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – TP40 25-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – TP40 100-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – TP40 100-year 24-hour, percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 10-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 10-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 25-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 25-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 100-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – Hydro35 100-year 60-min percent more or less TP-40 vs NRCC October 2010

NRCC – TP-49 100-year 10-day percent more or less TP-40 vs NRCC October 2010

NRCC – TP-49 100-year 10-day percent more or less TP-40 vs NRCC October 2010

Summary Not all durations and return periods were compared. NRCC data shows general increase as return period gets larger for 60-minute and 24-hour durations. NRCC 100-year 10-day precipitation trend is lower on average. NRCC RF Distribution October 2010

NRCC RF Distribution October 2010