High Wind in Oregon, December 14, 2018

Name: High Wind in Oregon, December 14, 2018
Start: 2018-12-14T06:30
End: 2018-12-14T15:00
Location: Oregon

December 14, 2018 · NWS PDT · 2 events in 2 counties and zones

Where it happened

Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.

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Wind
Hail
Winter weather
Heat and drought
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The toll

Deaths: 0
Injuries: 0
Property damage: None recorded
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 PDT wrote it up.

A combination of a strong thermal gradient between the lower Treasure Valley and the Columbia Basin and significant momentum transfer of strong winds aloft created localized areas of significant damaging winds in the foothills of the Blue Mountains and Grande Ronde Valley. Interstate 84 was closed for several hours between Pendleton and La Grande after a tractor trailer was blown over coming off the Blue Mountains toward Pendleton. A mesonet station in close proximity to this blow over reported a gust of 78 knots (90 mph) around the time of the accident. Portions of Highway 11 between Pendleton and Milton-Freewater were also closed briefly as a precaution with crosswind gusts estimated at 61 knots (70 mph). Winds decreased rapidly away from the foot of the mountains.

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 Pendleton, OR wrote its last area forecast discussion before the first event at Dec 14, 2:13 AM PST, 4 hours 17 minutes earlier.

Area forecast discussion, Dec 14, 2:13 AM PST, 4 hours 17 minutes before

Area Forecast Discussion
National Weather Service Pendleton OR
213 AM PST Fri Dec 14 2018

.SHORT TERM...Today through Sunday...An active short term period is
expected with significant concerns for today. A deep upper trough
off the coast and high pressure aloft with cold air inland is
causing very tight thermal pressure gradients over the eastern and
southeast third of the forecast area. Pressure gradients are
expected to reach a peak at between 15Z-18Z this morning. There are
a number of wind advisories in effect for the Blue Mountain
Foothills and Wallowa county, and a High Wind Warning for the Grande
Ronde Valley all until 4 PM this afternoon. Winds are increasing in
these areas. A cold front with the weather system and trough is
expected to move across the CWA today and will reach the eastern
third of the CWA this afternoon. Winds will be strong ahead of the
front and then once the front passes by gradients will weaken by
tonight. There will also be precipitation with this front, mainly
over the eastern mountains and the Cascade east slopes with the
lower elevations remaining mostly dry. Precipitation amounts will
not be too significant and snow levels are fairly high so there is
not a concern with winter weather precipitation with this system
today. There will be a break in the weather late tonight and on
Saturday. After that there will be another weather system moving
into the region Saturday night into Sunday with more abundant
moisture. However, snow levels will remain fairly high for this time
of year and precipitation type will be mostly rain for Saturday
night and Sunday. Pressure gradients over the Blue Mountains
eastward will tighten up again Saturday night into Sunday, but they
should not be nearly as strong as today. The strongest winds for
Saturday night into Sunday will be over the Grande Ronde Valley, but
wind speeds at this time are not expected to reach advisory criteria
again. This second system in the short term will be more of a
precipitation producer with all areas receiving mainly rain, except
for the higher mountains. As mentioned, snow levels will be fairly
high so snow should not be much of a concern Saturday night and
Sunday either. The progressive pattern with frequent weather systems
will continue into the extended period. Maximum temperatures will be
mainly in the upper 40s to mid 50s in the lower elevations and mid
30s to mid 40s in the mountains which will also continue into the
extended period. 88.

.LONG TERM...Sunday night through Friday.  Active weather
continues through the extended with system moving into the area
Sunday night and early Monday, with another system for Monday night
and Tuesday.  Snow levels for these systems remain fairly high, 4000-
5000 feet Sunday night and Monday and 5000 to 7000 for Tuesday and
it will be breezy to windy ahead and along these systems as well.
The next system get pushed north into mainly Washington for
Wednesday and Thursday before moving across the region on Friday. 93

&&

.AVIATION...12z Tafs.  Patchy fog affecting KDLS through this
morning with MFR conditions, otherwise VFR with increasing mid and
high clouds.  Strong winds will continue along the Blue Mountain
foothills with gusts to 25-30 kts through the day at PDT/ALW and
gusts to 20kt other sites except DLS/YKM. Light rain will spread
east of the Cascades overnight with some MVFR cigs and vsby in the
heavier showers. 93

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  50  32  46  34 /  10  30   0  20
ALW  50  34  46  36 /  10  40   0  20
PSC  49  34  46  35 /  10  10   0  20
YKM  43  28  41  31 /  20  20   0  40
HRI  48  33  47  34 /  10  10   0  20
ELN  39  28  39  31 /  10  20  10  50
RDM  52  26  45  35 /  40  30   0  30
LGD  40  28  39  35 /  10  50   0  20
GCD  43  28  41  35 /  20  60  10  20
DLS  46  34  44  36 /  30  50   0  40

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Wind Advisory until 4 PM PST this afternoon for ORZ507-508.

     High Wind Warning until 4 PM PST this afternoon for ORZ049.

     Wind Advisory until 4 PM PST this afternoon for ORZ050.

WA...Wind Advisory until 4 PM PST this afternoon for WAZ029.

&&

88/93/93

The radar

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

Open the radar archive at this moment

Event by event

2 high wind. Local standard time, as filed.

High Wind, Grand Ronde Valley

When: December 14, 6:30 AM PST to 1:00 PM PST
Where: Grand Ronde Valley forecast zone
Measured: 53 kt (61 mph) measured gust
Reported by: AWOS
Coordinates: 45.310, -118.009 (the zone’s center; the record gives no point)

High Wind, Foothills of the Northern Blue Mountains of Oregon

When: December 14, 10:00 AM PST to 3:00 PM PST
Where: Foothills of the Northern Blue Mountains of Oregon forecast zone
Measured: 78 kt (90 mph) measured gust
Reported by: Department of Highways
Coordinates: 45.592, -118.737 (the zone’s center; the record gives no point)

A tractor trailer was blown over on Interstate 84 going up Cabbage Hill east of Pendleton. The Interstate was closed for several hours in both directions due to high winds. A mesonet station near the scene reported a gust to 90 mph around the time of the accident.

What these are

High Wind: Sustained non-thunderstorm winds of 40 mph or more for an hour, or gusts of 58 mph or more.

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

The same day elsewhere

Every storm in Oregon in 2018 Every state in 2018 This day in weather history Warnings in Oregon, December 2018

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: 789236, 789237.