An Interactive Web Tool
for Extreme Precipitation Analysis
& Monitoring
David Nelson
Asst. State Conservation Engineer
USDA – Natural Resources Conservation Service

Northeast Regional Climate Center (NRCC),
Cornell University
Arthur DeGaetano
 Dan Zarrow


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
County
Barnstable
Berkshire
Bristol
Dukes
Essex
Franklin
Hampden
Hampshire
Middlesex
Plymouth
Worcester
TP-40
(inches)
3.5
2.9
3.4
3.6
3.1
2.8
3.0
2.9
3.1
3.4
3.0
NRCC
(inches)
3.3
2.9
3.3
3.3
3.2
3.0
3.1
3.0
3.1
3.4
3.1
Percent
Change
-5 %
0%
-3 %
-8 %
3%
5%
2%
3%
1%
-1 %
2%
County
Barnstable
Berkshire
Bristol
Dukes
Essex
Franklin
Hampden
Hampshire
Middlesex
Plymouth
Worcester
TP-40 Rainfall
(inches)
7.1
6.4
7.0
7.2
6.4
6.2
6.5
6.4
6.4
6.9
6.4
NRCC Rainfall
(inches)
8.2
7.6
8.6
8.3
8.8
7.4
8.0
7.6
8.5
8.7
8.2
Percent
Change
16 %
19 %
22 %
15 %
38 %
19 %
23 %
19 %
33 %
26 %
29 %


Provides interactive web tool for easy access



Offers real-time monitoring of rain events




Provides a method to update the analysis in the
future