Alert archive / Oregon / Winter Storm Warnings in 2017

Winter Storm Warning 13, NWS Pendleton, OR

December 22, 20175 counties in Oregon

NWS Pendleton, OR issued this winter storm warning at Dec 22, 2017, 7:48 PM PST for 5 counties in Oregon. It was in force for 11 hr. 17 reports came from inside the area while it was in force.

The area

The counties it named, with what was reported inside it.

The facts

Issued
Dec 22, 2017, 7:48 PM PST (03:48 UTC)
Expired
Dec 23, 2017, 6:48 AM PST
In force
11 hr
Issued by
NWS Pendleton, OR

Counties Gilliam County, OR, Morrow County, OR, Umatilla County, OR, Union County, OR, Wheeler County, OR

The radar

The Pendleton radar (KPDT), 58 km from the middle of the area, began a volume at 03:47 UTC, the scan nearest the moment this went out.

Open the radar archive at this moment

The archived warnings, watches and discussions in force at that minute are drawn over the scan, this one among them.

What was reported inside it

TimeReportWhereRemark
Dec 22, 8:50 PM PSTSNOW 4Nnw Meacham, OR4 INCHES OF NEW SNOW SINCE 10 AM. ELEVATION 3740 FEET.
Dec 22, 9:44 PM PSTSNOW 3.21 Nnw Pendleton, OR3.2 INCHES OF NEW SNOW SINCE 1 PM. ELEVATION 1492 FEET.
Dec 23, 2:00 AM PSTSNOW 3Milton-Freewater, OR
Dec 23, 2:00 AM PSTHEAVY SNOW 4Athena, ORODOT REPORTED 4 INCHES OF SNOW IN THE LAST 4 HOURS ALONG HIGHWAY 11 NEAR ATHENA
Dec 23, 2:00 AM PSTHEAVY SNOW 5Condon, ORCO-OP OBSERVER REPORTED 5 INCHES IN NEW SNOW, WITH SOME ARES OF DRIFTING. LARGEST DRIFTS WERE AROUND 2 FEET.
Dec 23, 3:00 AM PSTHEAVY SNOW 41 Ne Pendleton, ORMEMBER OF THE PUBLIC REPORTED 4 INCHES OF NEW SNOW IN PENDLETON, VIA FACEBOOK.
Dec 23, 3:00 AM PSTHEAVY SNOW 5.5Cove, OR5-6 INCHES IN COVE.
Dec 23, 3:00 AM PSTSNOW 6Island City, ORA MEMBER OF THE PUBLIC REPORTED AN ESTIMATED 6 INCHES OF NEW ACCUMULATION IN ISLAND CITY, VIA FACEBOOK.
Dec 23, 3:00 AM PSTHEAVY SNOW 6La Grande, ORA MEMBER OF THE PUBLIC REPORTED 6 INCHES OF SNOW ACCUMULATION IN LA GRANDE, VIA FACEBOOK.
Dec 23, 3:00 AM PSTHEAVY SNOW 75 W La Grande, OR
Dec 23, 3:30 AM PSTSNOW 3.5Hermiston, OR
Dec 23, 3:51 AM PSTHEAVY SNOW 4.81 Nnw Pendleton, OR4.8 INCHES OF SNOW AT NWS PENDLETON SINCE SNOW STARTED MIDDAY FRIDAY.
Dec 23, 4:00 AM PSTHEAVY SLEET 6Weston, ORA MEMBER OF THE PUBLIC REPORTED MEASURING 6 INCHES OF NEW SNOW IN WESTON, VIA FACEBOOK.
Dec 23, 4:00 AM PSTHEAVY SNOW 55 Ne La Grande, ORA MEMBER OF THE PUBLIC REPORTED 5 INCHES OF SNOW ACCUMULATION ON THE NE SIDE OF LA GRANDE, VIA FACEBOOK.
Dec 23, 4:00 AM PSTHEAVY SNOW 6Pilot Rock, ORA MEMBER OF THE PUBLIC REPORTED A MEASUREMENT OF 6 NEW INCHES OF SNOW ACCUMULATION AT PILOT ROCK, VIA FACEBOOK.
Dec 23, 4:30 AM PSTHEAVY SNOW 5.5Heppner, ORMEASURING STICK ON PICNIC TABLE.
Dec 23, 5:00 AM PSTHEAVY SNOW 186 Sse Hardman, ORA MEMBER OF THE PUBLIC ESTIMATED A FOOT AND A HALF NEW ACCUMULATION AT AINSON WRIGHT STATE PARK TO THE SOUTH OF HARDMAN, OR VIA FACEBOOK.

Local storm reports filed while the alert was in force, from inside its polygon or its counties.

The nearest sounding before it

Salem/Mcnary, OR (KSLE), launched 00:00Z, 3.8 hours before the alert went out and 292 km from the middle of its area. This is the routine balloon launch nearest before it, the air the forecaster had in hand, not a measurement taken for the alert.

Skew-T log-pSkew-T log-p diagram, Salem/Mcnary, OR at 00:00Z on 2017-12-23Temperature and dew point through the depth of the atmosphere, with the mixed-layer parcel. CAPE 0 joules per kilogram.LCL10008507005003002001001 km2 km3 km6 km9 km12 km15 km-30°-20°-10°0°10°20°30°40°
Temperature in red, dew point in green, the mixed-layer parcel dashed.
HodographHodograph, Salem/Mcnary, OR at 00:00Z on 2017-12-23The wind through the lowest 10 kilometers. Zero to 1 km storm-relative helicity 215 square meters per square second.1939587897117136Sfc1 km3 km6 km9 kmRMLM
The wind turning with height, colored by layer: ground to 1 km, 1 to 3 km, 3 to 6 km, 6 to 10 km.
Mixed-layer CAPE
0 J/kg
Mixed-layer CIN
No buoyant parcel
Mixed-layer LCL
725 m above ground
0-6 km bulk shear
69 kt
0-1 km storm-relative helicity
215 m²/s²
0-3 km storm-relative helicity
227 m²/s²
Significant tornado parameter
0.0
Supercell composite
0.0

Open this sounding in Storm Lab

The text

As transmitted.

666 
WWUS46 KPDT 230348
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
748 PM PST Fri Dec 22 2017

...SIGNIFICANT SNOW...

.A cold front will drop south and stall over northern Oregon
producing snow through Saturday morning.

ORZ049-231200-
/O.NEW.KPDT.WS.W.0013.171223T0348Z-171223T1200Z/
Grande Ronde Valley-
Including the cities of Cove, Elgin, and La Grande
748 PM PST Fri Dec 22 2017

...WINTER STORM WARNING IN EFFECT UNTIL 4 AM PST SATURDAY...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. Additional snow accumulations of 2 to 4 inches 
  with a total of 4 to 7 inches expected.

* WHERE...Cove, Elgin, and La Grande.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ044-507-WAZ029-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
Lower Columbia Basin of Oregon-
Foothills of the Northern Blue Mountains of Oregon-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Pendleton, 
Pilot Rock, Dayton, Waitsburg, and Walla Walla
748 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of 1 to 3 inches with a total of 2
  to 4 inches expected .

* WHERE...Boardman, Hermiston, Ione, Pendleton, Pilot Rock, 
  Dayton, Waitsburg, and Walla Walla.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ508-510-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Foothills of the Southern Blue Mountains of Oregon-
North Central Oregon-
Including the cities of Heppner, Condon, Fossil, Dufur, 
and Maupin
748 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of 1 to 3 inches with a total of 2
  to 4 inches expected.

* WHERE...Heppner, Condon, Fossil, Dufur, and Maupin.

* WHEN...Until noon Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
6 follow-up statements
449 
WWUS46 KPDT 230512
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
912 PM PST Fri Dec 22 2017

...SIGNIFICANT SNOW...

.A cold front will drop south and stall over northern Oregon
producing snow through Saturday morning.

ORZ049-231200-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1200Z/
Grande Ronde Valley-
Including the cities of Cove, Elgin, and La Grande
912 PM PST Fri Dec 22 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST
SATURDAY...

* WHAT...Heavy snow occurring. Plan on difficult travel 
  conditions. Additional snow accumulations of 2 to 4 inches 
  with a total of 4 to 7 inches expected.

* WHERE...Cove, Elgin, and La Grande.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ502-503-231315-
/O.EXA.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Northern Blue Mountains of Oregon-
Southern Blue Mountains of Oregon-
Including the cities of Meacham, Tollgate, Long Creek, 
North Powder, and Ukiah
912 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY IN EFFECT UNTIL NOON PST SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions. For the
  Northern Blue Mountains an additional snow accumulations of 3 
  to 6 inches with a total of 6 to 12 inches expected. For the 
  Southern Blue Mountains an additional snow accumulations of 2 to
  5 inches with a total of 4 to 8 inches expected.

* WHERE...Meacham, Tollgate, Long Creek, North Powder, and Ukiah.

* WHEN...Until noon Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ044-507-WAZ029-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
Lower Columbia Basin of Oregon-
Foothills of the Northern Blue Mountains of Oregon-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Pendleton, 
Pilot Rock, Dayton, Waitsburg, and Walla Walla
912 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of 1 to 3 inches with a total of 
  2 to 4 inches expected .

* WHERE...Boardman, Hermiston, Ione, Pendleton, Pilot Rock, 
  Dayton, Waitsburg, and Walla Walla.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ508-510-231315-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Foothills of the Southern Blue Mountains of Oregon-
North Central Oregon-
Including the cities of Heppner, Condon, Fossil, Dufur, 
and Maupin
912 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of 1 to 3 inches with a total of 
  2 to 4 inches expected.

* WHERE...Heppner, Condon, Fossil, Dufur, and Maupin.

* WHEN...Until noon Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
034 
WWUS46 KPDT 230730
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
1130 PM PST Fri Dec 22 2017

...SIGNIFICANT SNOW...

.A cold front will drop south and stall over northern Oregon
producing snow through Saturday morning.

ORZ507-231200-
/O.UPG.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
/O.EXB.KPDT.WS.W.0013.000000T0000Z-171223T1500Z/
Foothills of the Northern Blue Mountains of Oregon-
Including the cities of Pendleton and Pilot Rock
1130 PM PST Fri Dec 22 2017

...WINTER STORM WARNING IN EFFECT UNTIL 7 AM PST SATURDAY...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. Additional snow accumulations of 1 to 3 inches with
  a total of 4 to 6 inches expected.

* WHERE...Pendleton and Pilot Rock.

* WHEN...Until 7 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ049-231200-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1200Z/
Grande Ronde Valley-
Including the cities of Cove, Elgin, and La Grande
1130 PM PST Fri Dec 22 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST
SATURDAY...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. Additional snow accumulations of 1 to 3 inches with
  a total of 4 to 7 inches expected.

* WHERE...Cove, Elgin, and La Grande.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ044-WAZ029-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
Lower Columbia Basin of Oregon-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Dayton, 
Waitsburg, and Walla Walla
1130 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of around an inch with a total of
  3 to 4 inches expected .

* WHERE...Boardman, Hermiston, Ione, Pendleton, Pilot Rock, 
  Dayton, Waitsburg, and Walla Walla.

* WHEN...Until 4 AM Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ508-510-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Foothills of the Southern Blue Mountains of Oregon-
North Central Oregon-
Including the cities of Heppner, Condon, Fossil, Dufur, 
and Maupin
1130 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of 1 to 3 inches with a total of 3
  to 5 inches expected.

* WHERE...Heppner, Condon, Fossil, Dufur, and Maupin.

* WHEN...Until noon Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ502-503-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Northern Blue Mountains of Oregon-
Southern Blue Mountains of Oregon-
Including the cities of Meacham, Tollgate, Long Creek, 
North Powder, and Ukiah
1130 PM PST Fri Dec 22 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
SATURDAY...

* WHAT...Snow occurring. Plan on slippery road conditions. For 
  the Northern Blue Mountains an additional snow accumulations 
  of 3 to 6 inches with a total of 6 to 12 inches expected. For 
  the Southern Blue Mountains an additional snow accumulations 
  of 2 to 5 inches with a total of 4 to 8 inches expected.

* WHERE...Meacham, Tollgate, Long Creek, North Powder, and Ukiah.

* WHEN...Until noon Saturday.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
770 
WWUS46 KPDT 230858
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
1258 AM PST Sat Dec 23 2017

...SIGNIFICANT SNOW TONIGHT AND SATURDAY MORNING...

.A cold front will drop south and stall over northern Oregon
producing snow through Saturday morning.

ORZ508-231200-
/O.UPG.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
/O.EXB.KPDT.WS.W.0013.000000T0000Z-171223T1800Z/
Foothills of the Southern Blue Mountains of Oregon-
Including the cities of Heppner, Condon, and Fossil
1258 AM PST Sat Dec 23 2017

...WINTER STORM WARNING IN EFFECT UNTIL 10 AM PST THIS MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. Additional snow accumulations of up to two inches
  are expected. Total snow accumulation of 4 to 6 inches.

* WHERE...Heppner, Condon, and Fossil.

* WHEN...Until 10 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ049-231200-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1200Z/
Grande Ronde Valley-
Including the cities of Cove, Elgin, and La Grande
1258 AM PST Sat Dec 23 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 4 AM PST EARLY
THIS MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel 
  conditions. Additional snow accumulations of up to two inches 
  are expected.

* WHERE...Cove, Elgin, and La Grande.

* WHEN...Until 4 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ507-231200-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1500Z/
Foothills of the Northern Blue Mountains of Oregon-
Including the cities of Pendleton and Pilot Rock
1258 AM PST Sat Dec 23 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM PST THIS
MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. Additional snow accumulations of 1 to 2 inches are 
  expected.

* WHERE...Pendleton and Pilot Rock.

* WHEN...Until 7 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ044-WAZ029-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
Lower Columbia Basin of Oregon-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Dayton, 
Waitsburg, and Walla Walla
1258 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL 4 AM PST EARLY
THIS MORNING...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of up to one inch are expected.

* WHERE...Boardman, Hermiston, Ione, Dayton, Waitsburg, and 
  Walla Walla.

* WHEN...Until 4 AM today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ510-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
North Central Oregon-
Including the cities of Dufur and Maupin
1258 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of up to two inches are expected.

* WHERE...Dufur and Maupin.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ502-503-231200-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Northern Blue Mountains of Oregon-
Southern Blue Mountains of Oregon-
Including the cities of Meacham, Tollgate, Long Creek, 
North Powder, and Ukiah
1258 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of 1 to 3 inches are expected.

* WHERE...Meacham, Tollgate, Long Creek, North Powder, and Ukiah.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
862 
WWUS46 KPDT 231149
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
349 AM PST Sat Dec 23 2017

...SNOW WILL TAPER OFF THIS MORNING...

.A cold front will drop south and dissipate over central Oregon
this morning. 

ORZ049-231300-
/O.EXP.KPDT.WS.W.0013.000000T0000Z-171223T1200Z/
Grande Ronde Valley-
Including the cities of Cove, Elgin, and La Grande
349 AM PST Sat Dec 23 2017

...WINTER STORM WARNING WILL EXPIRE AT 4 AM PST EARLY THIS
MORNING...

A little light snow may continue this morning but no significant
additional accumulation is expected. 

$$

ORZ044-WAZ029-231300-
/O.EXP.KPDT.WW.Y.0031.000000T0000Z-171223T1200Z/
Lower Columbia Basin of Oregon-
Foothills of the Blue Mountains of Washington-
Including the cities of Boardman, Hermiston, Ione, Dayton, 
Waitsburg, and Walla Walla
349 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY WILL EXPIRE AT 4 AM PST EARLY THIS
MORNING...

Light snow may continue this morning but little additional
accumulation is expected. 

$$

ORZ507-231500-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1500Z/
Foothills of the Northern Blue Mountains of Oregon-
Including the cities of Pendleton and Pilot Rock
349 AM PST Sat Dec 23 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 7 AM PST THIS
MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel
  conditions. An additional inch or so of snow mainly south of
  Pendleton before snow tapers off. 

* WHERE...Pendleton and Pilot Rock.

* WHEN...Until 7 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ508-231500-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1800Z/
Foothills of the Southern Blue Mountains of Oregon-
Including the cities of Heppner, Condon, and Fossil
349 AM PST Sat Dec 23 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST THIS
MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel 
  conditions. Additional snow accumulations of up to two inches 
  are expected.

* WHERE...Heppner, Condon, and Fossil.

* WHEN...Until 10 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ510-231500-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
North Central Oregon-
Including the cities of Dufur and Maupin
349 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of 1 to 2 inches.

* WHERE...Dufur and Maupin.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ502-503-231500-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Northern Blue Mountains of Oregon-
Southern Blue Mountains of Oregon-
Including the cities of Meacham, Tollgate, Long Creek, 
North Powder, and Ukiah
349 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions.
  Additional snow accumulations of 1 to 3 inches are expected
  mainly south of Meacham.

* WHERE...Meacham, Tollgate, Long Creek, North Powder, and Ukiah.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
395 
WWUS46 KPDT 231254
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
454 AM PST Sat Dec 23 2017

...SNOW WILL TAPER OFF THIS MORNING...

.A cold front will drop south and dissipate over central Oregon
this morning.

ORZ507-231400-
/O.CAN.KPDT.WS.W.0013.000000T0000Z-171223T1500Z/
Foothills of the Northern Blue Mountains of Oregon-
454 AM PST Sat Dec 23 2017

...WINTER STORM WARNING IS CANCELLED...

The band of steady light to moderate snow has pushed south of the
region. A little light snow or flurries are still possible this
morning with no significant accumulation.  

$$

ORZ502-231400-
/O.CAN.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Northern Blue Mountains of Oregon-
454 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY IS CANCELLED...

The heavier snow has pushed south of the region. a little light
snow or flurries are still possible this morning with no
significant accumulation. 

$$

ORZ508-231800-
/O.CON.KPDT.WS.W.0013.000000T0000Z-171223T1800Z/
Foothills of the Southern Blue Mountains of Oregon-
Including the cities of Heppner, Condon, and Fossil
454 AM PST Sat Dec 23 2017

...WINTER STORM WARNING REMAINS IN EFFECT UNTIL 10 AM PST THIS
MORNING...

* WHAT...Heavy snow occurring. Plan on difficult travel 
  conditions. Additional snow accumulations of up to one inch 
  are expected.

* WHERE...Heppner, Condon, and Fossil.

* WHEN...Until 10 AM today.

* ADDITIONAL DETAILS...Be prepared for significant reductions in 
  visibility at times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Storm Warning for snow means severe winter weather
conditions are occurring. If you must travel, keep an extra
flashlight, food and water in your vehicle in case of an
emergency. The latest road conditions for the state you are
calling from can be obtained by calling 5 1 1.

$$

ORZ510-231800-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
North Central Oregon-
Including the cities of Dufur and Maupin
454 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of up to one inch are expected.

* WHERE...Dufur and Maupin.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$

ORZ503-231800-
/O.CON.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Southern Blue Mountains of Oregon-
Including the cities of Long Creek, North Powder, and Ukiah
454 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY REMAINS IN EFFECT UNTIL NOON PST
TODAY...

* WHAT...Snow occurring. Plan on slippery road conditions. 
  Additional snow accumulations of up to one inch are expected.

* WHERE...Long Creek, North Powder, and Ukiah.

* WHEN...Until noon today.

* ADDITIONAL DETAILS...Be prepared for reduced visibilities at 
  times.

PRECAUTIONARY/PREPAREDNESS ACTIONS...

A Winter Weather Advisory for snow means periods of snow will
cause primarily travel difficulties. Be prepared for snow covered
roads and limited visibilities, and use caution while driving.
The latest road conditions for the state you are calling from can
be obtained by calling 5 1 1.

$$
177 
WWUS46 KPDT 231448
WSWPDT

URGENT - WINTER WEATHER MESSAGE
National Weather Service Pendleton OR
648 AM PST Sat Dec 23 2017


ORZ508-231600-
/O.CAN.KPDT.WS.W.0013.000000T0000Z-171223T1800Z/
Foothills of the Southern Blue Mountains of Oregon-
648 AM PST Sat Dec 23 2017

...WINTER STORM WARNING IS CANCELLED...

Heavy snow has ended. Light snow or flurries may continue early
this morning. 

$$

ORZ503-510-231600-
/O.CAN.KPDT.WW.Y.0031.000000T0000Z-171223T2000Z/
Southern Blue Mountains of Oregon-North Central Oregon-
648 AM PST Sat Dec 23 2017

...WINTER WEATHER ADVISORY IS CANCELLED...

Heavy snow has ended. Light snow or flurries may continue early
this morning. 

$$

What forecasters said that day

The local office's own words before this winter storm warning went out, 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 this winter storm warning went out at Dec 22, 7:05 PM PST, 43 minutes earlier.

Area forecast discussion, Dec 22, 7:05 PM PST, 43 minutes before
Area Forecast Discussion
National Weather Service Pendleton OR
705 PM PST Fri Dec 22 2017

.SHORT TERM...Tonight and Saturday...A cold front continues to stall
over northern Oregon and southern Washington this evening. All
precipitation has now turned to snow even in the eastern Columbia
River Gorge. A steady light snow will continue over northern Oregon
and extreme southern Washington overnight with accumulations ranging
from around an inch to possible 4 to 6 inches. A surface north winds
is aiding in enhancing precipitation along the Foothills of the Blue
Mountains and north central Oregon were winter weather advisories
are in effect. The front will weaken and fall apart Saturday morning
with precipitation coming to an end by noon over most of the area.
With snow on the ground, high temperatures on Saturday will only
reach the upper 20s and lower 30s in the lower elevations.

&&

.PREV DISCUSSION... /issued 352 PM PST Fri Dec 22 2017/

SHORT TERM...Tonight through Sunday Night...The Winter Weather
Advisories currently in effect for the Blue Mountain Foothills
(WA/OR), the Lower Columbia Basin of Oregon, and North Central
Oregon are on track with minor changes. The quasi-stationary cold
front south of the WA/OR border will remain a little longer than
previously expected, and the southern Blue Mtn Foothills and north
central Oregon will observe steady light snow through mid-morning on
Saturday. This includes Heppner, Condon, Fossil, Maupin and Shaniko.
The advisory for these areas will be extended until noon. Snow
accumulations will be around 4 inches in some locations--just shy of
Winter Storm Warning criteria. The other forecast zones under the
advisory will remain through 4 AM. The WA portion of the Blue Mtn
Foothills may only observe an inch or less, and the evening shift
may decide to cancel the advisory if amounts are less than one inch.
 Little change was made to the snow forecast for the remainder of
the forecast area.  That is, 2-5 inches over the Blue Mountains, 1-3
inches over central Oregon and areas east-southeast of the Blue
Mountains as well as the Simcoe Highlands and the east slopes of the
WA Cascades, with one inch or less for areas north of Prosser.

Precipitation will end Saturday afternoon as the front exits the
region followed by a drier northwest flow aloft. It will be cold and
dry Saturday and Saturday evening with subfreezing temperatures
in most areas during the day and single digits and teens Saturday
night. The increasing cloud cover Saturday night will prevent
overnight lows from plummeting even lower. The ground will be snow-
covered for most of the forecast area.

Winter highlights are possible with the next system on Christmas
Eve. There have been several forecast challenges for Sunday and
Sunday night, namely the amount of QPF and snow as well as
precipitation type for central Oregon. Deep cold air will remain in
place throughout eastern Washington and northeast Oregon, therefore
precipitation will fall as snow in these areas. Weak warm air
advection aloft over central Oregon may result in sleet or freezing
rain mixed with the snow. The warmer air overriding the cold air is
not significant, and only a slight chance of freezing precipitation
will be added to central and north central Oregon and the east
slopes of the OR Cascades. Based on model QPF, the forecast area
should see accumulating snow on Sunday and Sunday night with 1-3
inches possible areawide. This may warrant advisories in some of the
lower elevation zones. Will wait until this first system exits the
region before deciding if any highlights are needed for the next
one.  Wister

LONG TERM...Monday through Wednesday night...There is fair
agreement among the mid range models that the region will be under a
northwesterly upper level flow Monday and Monday night. Thus will
continue to indicate some chances of snow showers across the area
during this period, with the higher chances over the mountains.
Confidence in the forecast weather pattern declines during the
Tuesday through Wednesday night period. There may some sort of
ridging, though it could be of low amplitude. Thus will keep some
mention of precip through this period, though it will be a limited
mention on Tuesday (ridge potentially at it's strongest). The one
area where there is some confidence is temperatures, which will be
below seasonal. Thus any precip will be in the form of snow. 90

Thursday and Friday...Unsettled weather continues through the end of
the week with the models continuing to be in disagreement on timing
position and strength of systems so there continues to be some
chance of snow and or rain through the period. They are however in
better agreement on warmer air returning to the area and have
trended temperatures and snow levels to show this change. If this
trend continues more adjustments will be necessary as numerical
guidance showing near to above normal temperature by Friday. 93

AVIATION...00Z TAFs...A cold front will continue to move gradually
south across the region through the next 24 hours. This front will
bring decent chances of snow to most TAF sites during the next 18
hours. KDLS will see rain initially before changing to snow around
mid evening. Expect snow at KYKM and KPSC to decrease through the
evening and largely be done after 06 UTC. VLIFR/LIFR conditions at
KALW are as much due to fog as snow. Expect to see some improvement
this evening as slightly drier near surface air moves into KALW.
Snow should persist for a while at KPDT. KRDM and KBDN should see a
period of persistent snow and upslope fog/low clouds after midnight
as the cold front finally reaches these two sites. Winds will
generally be 10 kts or less, though KBDN will see southwest winds of
10-15 kts at times this evening. 90

&&

.PRELIMINARY POINT TEMPS/POPS...
PDT  24  27  15  25 / 100  60  10  40
ALW  23  29  18  28 /  80  20   0  40
PSC  25  32  19  27 /  50  10   0  50
YKM  21  30  18  25 /  60  10   0  40
HRI  25  31  17  26 /  90  40  10  50
ELN  18  27  14  23 /  20  10   0  30
RDM  21  29  16  32 /  40  50  20  50
LGD  21  25  14  27 /  90  50  10  40
GCD  25  30  17  33 /  80  60  20  40
DLS  33  35  25  30 /  90  60  10  50

&&

.PDT WATCHES/WARNINGS/ADVISORIES...
OR...Winter Weather Advisory until noon PST Saturday for ORZ508-510.

     Winter Weather Advisory until 4 AM PST Saturday for ORZ044-507.

WA...Winter Weather Advisory until 4 AM PST Saturday for WAZ029.

&&

91/91/91

In the hours before

Local storm report, Dec 22, 5:20 PM PST, 2 hours 28 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
520 PM PST FRI DEC 22 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0400 PM     SNOW             5 ENE YAKIMA            46.61N 120.43W
12/22/2017  M0.6 INCH        YAKIMA             WA   PUBLIC

            0.6 INCHES OF NEW SNOW FROM NOON THROUGH 4PM. ELEVATION
            1306 FEET.

0400 PM     SNOW             1 NNW PENDLETON         45.69N 118.83W
12/22/2017  M0.5 INCH        UMATILLA           OR   OFFICIAL NWS OBS

            0.5 INCHES OF NEW SNOW FROM 1PM THROUGH 4PM. ELEVATION
            1492 FEET.

&&

JAS
Local storm report, Dec 22, 7:38 PM PST, 10 minutes before
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
738 PM PST FRI DEC 22 2017

..TIME...   ...EVENT...      ...CITY LOCATION...     ...LAT.LON...
..DATE...   ....MAG....      ..COUNTY LOCATION..ST.. ...SOURCE....
            ..REMARKS..

0736 PM     HEAVY SNOW       E LA GRANDE             45.32N 118.08W
12/22/2017  E5.0 INCH        UNION              OR   TRAINED SPOTTER

            5 INCHES OF NEW SNOW SINCE 1PM. ELEVATION 2800 FEET.

0736 PM     SNOW             1 WSW LA GRANDE         45.32N 118.10W
12/22/2017  M4.5 INCH        UNION              OR   TRAINED SPOTTER

            4.5 INCHES OF NEW SNOW SINCE 1PM. ELEVATION 2825 FEET.

&&

JAS

The office that day

Everything else NWS Pendleton, OR issued on the same UTC day.

IssuedProductOfficeCountiesLasted
Dec 23, 2:52 PM PSTWinter Weather AdvisoryPDTGilliam, Grant, Jefferson, Morrow, Sherman, Umatilla and 4 more49 hr

Nearby

Winter Storm Warnings in Oregon, 2017Every winter storm warning in 2017

Sources

The product and its follow-ups from the Iowa Environmental Mesonet's archive of National Weather Service and Storm Prediction Center text; local storm reports from the same archive; the sounding from the Mesonet's radiosonde archive; radar from the NEXRAD Level II archive.