Flooding in Idaho, April 1 to 30, 2017

Name: Flooding in Idaho, April 1 to 30, 2017
Start: 2017-04-01T00:00
End: 2017-04-30T23:59
Location: Idaho

April 1 to 30, 2017 · NWS BOI · 2 events in 2 counties and zones

S. Army Corps of Engineers.

Where it happened

Every event with a place to put it. Tap one for its entry below.

Tornadoes
Tropical storms and surge
Floods
Wind
Hail
Winter weather
Heat and drought
Cold
Fire, smoke and dust
Marine and coastal
Other

Open the live radar over this ground

The toll

Deaths: 0
Injuries: 0
Property damage: $1.5 million
Crop damage: None recorded
Events: 2

Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.

What happened

The episode as NWS BOI wrote it up.

Flooding continued for the entire month of April on the Boise River as a result of flood control efforts by the U.S. Army Corps of Engineers.

What forecasters said that day

The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.

NWS Boise, ID wrote its last area forecast discussion before the first event at Mar 31, 7:40 PM MST, 4 hours 20 minutes earlier.

Area forecast discussion, Mar 31, 7:40 PM MST, 4 hours 20 minutes before

Area Forecast Discussion
National Weather Service Boise ID
840 PM MDT Fri Mar 31 2017

.DISCUSSION...Dry conditions today will remain in place overnight
tonight. Most locations that saw gusty winds today are
experiencing a decrease in wind speeds as of 2030 mdt and all
locations should be under 15 kts by midnight. Ongoing flooding
concerns in the Camas Prairie, in Gooding County, along the Snake
River near Weiser, and along the Boise river in Ada and Canyon
counties remain unchanged. No update to the forecast is needed
this evening.

&&

.AVIATION...VFR. Wind across the region are diminishing and expected
to be become light and variable around midnight. Due to light
winds...patches of fog possible near KBKE and KMYL and in the higher
mtn valleys. Besides light surface winds...wind around  10kft expected to
be north to northeast 10-20 kts becoming northwest 10 kts aft
01/1200z.

&&

.PREV DISCUSSION...
SHORT TERM...Tonight through Sunday...High pressure building into
the PacNW along with a low pressure system in the Southwest U.S.
continues to induce a tight pressure gradient and gusty Northwest
winds. The winds will subside tonight as the surface high
pressure settles into the area. An upper ridge will fold into the
region on Saturday for dry weather, light winds and near-normal
temperatures. A weak and mostly dry cold front will slide across
the area Saturday night, bringing slightly cooler temperatures and
breezy Northwest Winds on Sunday. Moisture will be limited with
the front as it crosses the region, with a slight chance of
showers near the Nevada border and east of McCall.

LONG TERM...Sunday night through Friday...A fairly dry cold
front passes through the area Sunday night into Monday giving a
slight chance for some precipitation, mostly in northern portions
of the West Central Mountains. By Tuesday morning an upper level
ridge begins to build over the Pacific Northwest drying things out
and increasing snow levels. This ridge stays in place for much of
the long term forecast. Models have once again pushed back the
timing of the next system. On Thursday morning a wave out ahead of
the main frontal boundary begins to make its way into SE Oregon
increasing chances of precipitation through the day Thursday and
into Friday morning. It doesn't look like the main frontal
boundary will hit our CWA until after this time period.
Temperatures begin below normal Monday then climb back up above
normal for the rest of the period. Thursday looks to be the
warmest of the extended period with temperatures forecast to be
about 10 degrees above normal.

&&

.BOI WATCHES/WARNINGS/ADVISORIES...
ID...None.
OR...None.

&&

www.weather.gov/Boise
www.facebook.com/NWSBoise
www.twitter.com/NWSBoise

DISCUSSION...EP
AVIATION.....CR
PREV SHORT TERM...BW
PREV LONG TERM....JC/WH

The radar

The national radar mosaic for the moment the first event began.

Open the radar archive at this moment

Event by event

2 flood. Local standard time, as filed.

Flood, Ada

When: April 1, 12:00 AM MST to April 30, 11:59 PM MST
Where: Ada County, 4.12 mi SE of Barber to 1.85 mi SW of Star
Cause: Planned Dam Release
Property damage: $1.0 million
Reported by: Official NWS Observations
Coordinates: 43.532, -116.056

Planned releases from Lucky Peak Reservoir for flood control ranged from 7800 CFS to 8900 CFS during the month of April. The prolonged flood flows continued to cause extensive damage to the Greenbelt and Nature Trail paths. Flood waters inundated portions of Eagle Island, particularly along Artesian Road and Hatchery Road. Numerous homes in Riviera Estates were surrounded by water. Flood fight efforts continued to focus in the Eagle Island area with extensive sandbagging taking place. Additional flood fight efforts to mitigate a pit capture continued along the Eagle Island south channel of the river. Flood diversion tubes and muscle wall barriers were used to limit river encroachment on the sandpit. Large sections of Ann Morrison Park, Marianne Williams Park, and Barber Park were flooded. Some residential streets adjacent to the river had water on them, especially in the Garden City Warehouse District.

Flood, Canyon

When: April 1, 12:00 AM MST to April 30, 11:59 PM MST
Where: Canyon County, 1.75 mi ENE of Stoddard to 1.62 mi WSW of Apple Vly
Cause: Planned Dam Release
Property damage: $500,000
Reported by: Official NWS Observations
Coordinates: 43.685, -116.516

Planned releases from Lucky Peak Reservoir for flood control ranged from 7800 CFS to 8900 CFS during the month of April. The prolonged flood flows caused extensive damage along the river banks and widespread flooding of lowlands.

What these are

Flood: Flooding that develops more slowly than a flash flood: rivers leaving their banks, or water standing over land for an extended time.

After NWS Directive 10-1605, the rules offices file Storm Data by.

The same day elsewhere

Every storm in Idaho in 2017 Every state in 2017 This day in weather history Warnings in Idaho, April 2017

Sources

NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 697136, 697137.