Public Information Statement...Updated
National Weather Service Baltimore MD/Washington DC
1252 PM EDT Tue Aug 2 2016

...Historic heavy rainfall Saturday in Ellicott City...

Extremely heavy rain fell Saturday evening in Ellicott City,
Maryland. Thanks to rain gauge data from Ellicott City, which is
provided by Howard County to the National Weather Service, we have
detailed information on how quickly the heavy rain fell.

The NWS obtained data with more precise (to the second) timestamps
on August 2nd, which slightly alters some of the values previously
reported in this statement.

The following table lists the rain that was recorded by this gauge.
Note that the gauge reports in increments of 0.04 inch, so the
times are when the 0.04 inch increments were recorded:

DURATION    AMOUNT   TIMEFRAME
----------------------------------------
1 minute  ..0.20 from 7:52pm-7:53pm
5 minutes ..0.80 from 7:50pm-7:55pm
10 minutes..1.44 from 7:50pm-8:00pm
15 minutes..2.04 from 7:46pm-8:01pm
20 minutes..2.44 from 7:44pm-8:04pm
30 minutes..3.20 from 7:36pm-8:06pm
60 minutes..4.56 from 7:30pm-8:30pm
90 minutes..5.48 from 7:00pm-8:30pm
2 hours.....5.96 from 6:50pm-8:50pm

The storm total at Ellicott City was recorded as 6.60 inches.

This data is preliminary and is subject to correction.

For additional information and perspective on the heavy rain and
flooding, visit our website at http://weather.gov/washington and
click on the link at the top of the page for the Ellicott City flood.

$$

JE