Rainfall breaks record in 2018
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| Kovacs’ rain gauge |
By Bob Kovacs
Yes, it has been incredibly wet in 2018.
At my home in the Columbia Pines neighborhood in Annandale,
we measured 72.92 inches of rain as of 11:59 p.m. on Dec. 31. Compare that to
the average annual precipitation in Annandale (according to Intellicast)
of 45.11 inches.
we measured 72.92 inches of rain as of 11:59 p.m. on Dec. 31. Compare that to
the average annual precipitation in Annandale (according to Intellicast)
of 45.11 inches.
I do not know what the previous record was for Annandale, but
the record for rainfall in Washington, D.C., was 61.33 inches in 1889.
the record for rainfall in Washington, D.C., was 61.33 inches in 1889.
What made 2018 so much wetter than previous years were
multiple days of unusually heavy rain that flooded streets and basements. There
were 26 days with more than an inch of rain, and several storms dumped nearly
biblical amounts of water.
For example, more than three inches of rain fell on April
15-16. Nearly five inches of rain fell on July 21, followed by another 3+
inches of rain on July 23-24.
15-16. Nearly five inches of rain fell on July 21, followed by another 3+
inches of rain on July 23-24.
The heavy rain on July 21 happened to be during the
overnight stay of my only house guests in 2018. The 18-month old sump pump in
my basement failed and part of my basement flooded. Fortunately, my guests
helped out with bailing water, as I ran to Home Depot for a new pump.
overnight stay of my only house guests in 2018. The 18-month old sump pump in
my basement failed and part of my basement flooded. Fortunately, my guests
helped out with bailing water, as I ran to Home Depot for a new pump.
Other heavy rainfall days included June 4 (2.57 inches) and
Dec. 15-16 (3.66 inches).
Dec. 15-16 (3.66 inches).
To measure rainfall, we use a Stratus rain gauge built to
U.S. Weather Bureau standards that measures accurately to 0.01 inches and holds
up to 11 inches of water. We collect snow in the main tube of the rain gauge,
melt it, then measure it in the measurement tube.
U.S. Weather Bureau standards that measures accurately to 0.01 inches and holds
up to 11 inches of water. We collect snow in the main tube of the rain gauge,
melt it, then measure it in the measurement tube.
The design of the gauge is such that it minimizes
evaporation if the sun comes out immediately after a shower, although it does
not completely eliminate the possibility of evaporation. So there actually
could have been an extra couple hundredths of an inch of rain that evaporated
from the gauge.
evaporation if the sun comes out immediately after a shower, although it does
not completely eliminate the possibility of evaporation. So there actually
could have been an extra couple hundredths of an inch of rain that evaporated
from the gauge.
The most fortunate thing about all the precipitation in 2018
is that very little of it fell as snow, sleet, or some other frozen form. We
did have some frozen stuff in January, February, and March (and a wet fall snow
on Nov. 15!), but it was mostly washed away with rain immediately afterward.
is that very little of it fell as snow, sleet, or some other frozen form. We
did have some frozen stuff in January, February, and March (and a wet fall snow
on Nov. 15!), but it was mostly washed away with rain immediately afterward.
Considering the precipitation totals for a couple of those
winter storms (1.17 inches on Feb. 5 and 0.83 on Feb. 10), it could easily have
been crippling snowfall.
winter storms (1.17 inches on Feb. 5 and 0.83 on Feb. 10), it could easily have
been crippling snowfall.
My seat-of-the-pants impression of our weather is that it
has been unusual in the past few years. We had a pleasantly mild winter in
2010-2011, a bitterly cold February that was far below normal in 2015, and now
a thoroughly drenched 2018.
has been unusual in the past few years. We had a pleasantly mild winter in
2010-2011, a bitterly cold February that was far below normal in 2015, and now
a thoroughly drenched 2018.
I have no idea what will happen next, but my gauge is already
collecting rainfall.
collecting rainfall.
One response to “Rainfall breaks record in 2018”
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Thanks Bob.