EXTREME PRECIPITATION IN NEW YORK & NEW ENGLAND

An Interactive Web Tool for Extreme Precipitation Analysis

& Monitoring

David NelsonAsst. State Conservation EngineerUSDA – Natural Resources Conservation Service

Who is updating the analysis?

Northeast Regional Climate Center (NRCC), Cornell University Arthur DeGaetano Dan Zarrow

What does this study do?

Updates rainfall analysis Rainfall Frequency Atlas of the US, TP-40, National

Weather Bureau, 1961 (≈ 20 years of record, 1938 – 1958 )

Also: 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. New study includes rainfall events through 2008 NOAA’s National Weather Service Atlas 14

updates not yet available for New England and New York

2-year - 24 hour Design Storm Comparison

County TP-40(inches)

NRCC(inches)

PercentChange

Barnstable 3.5 3.3 -5 %Berkshire 2.9 2.9 0 %Bristol 3.4 3.3 -3 %Dukes 3.6 3.3 -8 %Essex 3.1 3.2 3 %Franklin 2.8 3.0 5 %Hampden 3.0 3.1 2 %Hampshire 2.9 3.0 3 %Middlesex 3.1 3.1 1 %Plymouth 3.4 3.4 -1 %Worcester 3.0 3.1 2 %

100-year - 24 hour Design Storm Comparison

County TP-40 Rainfall(inches)

NRCC Rainfall(inches)

PercentChange

Barnstable 7.1 8.2 16 %Berkshire 6.4 7.6 19 %Bristol 7.0 8.6 22 %Dukes 7.2 8.3 15 %Essex 6.4 8.8 38 %Franklin 6.2 7.4 19 %Hampden 6.5 8.0 23 %Hampshire 6.4 7.6 19 %Middlesex 6.4 8.5 33 %Plymouth 6.9 8.7 26 %Worcester 6.4 8.2 29 %

What does this study do?

Updates rainfall analysis

Provides interactive web tool for easy access

www.precip.net

What does this study do?

Updates rainfall analysis

Provides interactive web tool for easy access

Offers real-time monitoring of rain events

What does this study do?

Updates rainfall analysis

Provides interactive web tool for easy access

Offers real-time monitoring of rain events

Provides a method to update the analysis in the future

Sample Changing Climate Product:Percent Difference Maps

Sample Changing Climate Product:Comparison Chart

www.precip.net