Two fronts combined with an usually cold air mass already in place to bring heavy snow to many portions of northern California. This storm had an unusually severe impact due to the low snow levels, all the way down into the deepest valleys.
Every event with a place to put it; 6 filed by county or forecast zone are drawn at its center, in a lighter ring. Tap one for its entry below.
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.
The episode as NWS MFR wrote it up.
Two fronts combined with an usually cold air mass already in place to bring heavy snow to many portions of northern California. This storm had an unusually severe impact due to the low snow levels, all the way down into the deepest valleys. Some areas that usually only get a few inches of snow in a season got as much as two feet over several days. There were numerous reports of power outages and tree damage. Traffic along major highways, including Interstate 5, was shut down at times, and there were numerous traffic accidents. Many people were stranded on the roads or in their homes. There were widespread school closures, many closed for the entire week.
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 Medford, OR wrote its last area forecast discussion before the first event at Jan 3, 10:00 AM PST, 0 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
1000 AM PST Tue Jan 3 2017
.DISCUSSION...Precipitation is already overspreading the area
this morning with temperatures near or just a tad below freezing.
Given the cloud sheild and precip are already here. Temperatures
will probably not move much if at all today. Therefore whatever
falls will be in the form of snow. Because of this have made
adjustments to the winter weather headlines which will include
Jackson, Josephine and southern portion of Douglas county. Please
see WSWMFR for details. The models are in good agreement tracking
the surface low in northern California. This will keep us in a
east to northeast flow into this evening which means relatively
warmer air will probably not make it into our area. There is a
chance for warmer air aloft to move into southwest Oregon later
this evening and tonight which could result in at least a slight
chance of freezing rain for some of westside valleys. Meanwhile
snow will be moderate to heavy along and east of the Cascades
this afternoon through at least early Wednesday morning, then
should gradually taper off. Weather should dry out Wednesday
night, but it will be cold, especially with a fresh snowpack.
-Petrucelli
&&
.AVIATION...03/12Z TAF CYCLE...Areas of MVFR and IFR cigs/vsbys in
snow showers (rain at sea level) will initially affect Douglas,
Jackson, Josephine, Curry, and Siskiyou Counties with higher terrain
obscured. Conditions will improve late this morning and early this
afternoon, but widespread MVFR/IFR cigs vsbys will spread up from
the south and affect the entire area later this afternoon and
evening. -JRS
&&
.MARINE...MARINE...Updated 230 AM PST Tuesday 3 January 2017...Weak low
pressure will bring gusty northeast winds north of Cape Blanco this
afternoon and evening. The low will move inland Wednesday and weak
high pressure will then move over the waters. The next significant
weather front will move in Saturday and it may bring south gale
force winds to the area. -JRS
&&
.PREV DISCUSSION... /Issued 321 AM PST Tue Jan 3 2017/
DISCUSSION...There is much on the forecaster's plate today, with
ongoing winter weather through tomorrow morning, the possibility
for light freezing rain in the valleys tonight, cold temperatures
later this week, and the chances for warmer, but wet and windy,
weather late in the term. There have been some minor changes to
the forecast in the short term, but no major changes to the
current winter weather headlines. It should be noted that there
still remains a fair amount of uncertainty regarding
precipitation, as type and amounts in the valleys will vary
greatly due to only a one or two degree difference in temperature.
Have adjusted the near term forecast towards current observations,
and this should help bring the forecast more in line with reality,
and increase confidence for the next 24 hours or so.
An upper level trough overhead will assist in swinging a surface
low through the area later today. The surface low center will
track along the coast of California, then occlude and become
vertically stacked under the upper level low just off Cape Blanco
by late tonight. This has forced some changes to the forecast,
namely some higher snow levels tonight into Wednesday as slightly
warmer air is pulled up into our area. However, precipitation
chances and amounts have not changed much, with the focus for
heavier precipitation remaining over the coastal ranges, along and
south of the Siskiyous, and along and East of the Cascades. Winter
Weather warnings remain in place for these locations, and details
can be found in the winter weather message, PDXWSWMFR.
Unfortunately, with the warmer air aloft, cold air trapped in the
valleys at the surface could result in light freezing rain
tonight and into early Wednesday morning. Confidence is very low,
but should freezing rain occur, amounts should be light and timing
should be brief, and it would not take much for roads and other
surfacers to become slick. We will continue to monitor this
situation through today and tonight, and update the forecast if
necessary.
The models this morning have been quicker in bringing and end to
precipitation Wednesday evening, even though the upper level low
will still remain overhead as it slides slowly to the East. This
appears to be at least partially the result of surface high
pressure nosing into the region from the north. Have dried the
forecast beginning Wednesday night, and kept it dry through
Friday, as high pressure remains in control, and the upper level
low gives way to broad ridging over the Pacific Northwest. With
clearer skies and plenty of snow on the ground, expect cold
temperatures to settle in for the latter half of the week.
overnight lows are not expected to be bitterly cold, but should be
well below normal. The development of freezing fog in the West
Side valleys may limit cooling overnight.
The models are in good agreement this weekend through the
remainder of the term, depicting the development of southwest flow
over our area as a deep trough sets up over the Eastern Pacific.
This will produce an extended period of moist onshore flow into
early next week, along with higher snow levels and warmer
temperatures. With the colder air in place as the first round of
precipitation enters the region Saturday, precipitation could fall
as freezing rain or sleet before transitioning to all rain. Models
solutions are also showing the possibility for a potent wind and
rain storm as the trough finally pushes inland by the end of the
term. Will need to keep an eye on this pattern as it develops,
especially in regards to ice, and hydro concerns due to heavy rain
on any remaining lower level snow. -BPN
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...Winter Storm Warning until 10 AM PST Wednesday for ORZ029>031.
Winter Storm Warning until 4 AM PST Wednesday ABOVE 2000 FEET
for for ORZ024.
Winter Weather Advisory until 10 AM PST Wednesday for
ORZ021-023.
Winter Storm Warning until 10 AM PST Wednesday for ORZ027-028.
Winter Weather Advisory until 4 AM PST Wednesday for ORZ026.
CA...Winter Storm Warning until 10 AM PST Wednesday for CAZ084-085.
Winter Weather Advisory until 10 AM PST this morning for
CAZ082-083.
Winter Storm Warning until 10 AM PST Wednesday for CAZ082-083.
Winter Weather Advisory until 10 AM PST this morning for CAZ080.
Winter Storm Warning until 10 AM PST Wednesday ABOVE 3000 FEET
for for CAZ080.
Winter Weather Advisory until 4 AM PST Wednesday for CAZ081.
Pacific Coastal Waters...None.PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
849 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0805 AM HEAVY SNOW SELMA 42.28N 123.62W
01/03/2017 M7.5 INCH JOSEPHINE OR TRAINED SPOTTER
24 HOUR SNOW ACCUMULATION FROM WEST SELMA.
17 INCH 2 DAY STORM TOTAL. POWER CURRENTLY
OUT. COCORAHS #JS21. THE DURATION OF THE
HEAVY SNOW EVENT WAS 24 HOURS.
&&
NWS MEDFORD OR
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
918 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0900 AM SNOW 1 W WILLIAMS 42.22N 123.29W
01/03/2017 M14.5 INCH JOSEPHINE OR TRAINED SPOTTER
STORM TOTAL SNOWFALL SO FAR. THERE IS A 12"
SNOW DEPTH. STILL SNOWING MODERATELY. THE
DURATION OF THE SNOW EVENT WAS 48 HOURS.
&&
BSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
919 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0918 AM SNOW 5 NNE SELMA 42.35N 123.57W
01/03/2017 M20.0 INCH JOSEPHINE OR TRAINED SPOTTER
STORM TOTAL SNOW SO FAR. THERE IS STILL
LIGHT SNOW FALLING. THE DURATION OF THE SNOW
EVENT WAS 48 HOURS.
&&
BSPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
952 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0949 AM SNOW 7 NNW ROGUE RIVER 42.53N 123.20W
01/03/2017 E7.0 INCH JACKSON OR TRAINED SPOTTER
SPOTTER REPORTED 6 TO 8 INCHES OF NEW SNOW
SINCE ONSET YESTERDAY EVENING... ALSO GOT 3
INCHES OF SNOW YESTERDAY DURING THE DAY.
SNOW DEPTH OF A FOOT IN SOME PLACES. .
&&
NWS MEDFORD OR
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
954 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM SNOW 4 SW WEED 41.37N 122.43W
01/03/2017 M5.5 INCH SISKIYOU CA TRAINED SPOTTER
5.5 INCHES OF NEW SNOW FROM 8:00 AM TO 8:00
AM, WATER EQUIVALENT IS 0.29 INCH.
&&
NWS MEDFORD OR
IRIS SYSTEMPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
955 AM PST TUE JAN 3 2017
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0954 AM SNOW 2 SSW WEED 41.38N 122.39W
01/03/2017 M5.0 INCH SISKIYOU CA TRAINED SPOTTER
.
&&
NWS MEDFORD OR
IRIS SYSTEMThe national radar mosaic for the moment the first event began.
6 winter storm. Local standard time, as filed.
Public Reports: Canby got 11.0 inches of snow as of 03/1700 PST.
A spotter 2S Greenview reported 13.0 inches of snow as of 03/2100 PST. He later reported 8.0 inches of snow in 12 hours ending at 04/0800 PST. The cooperative observer at Copco Dam #1 reported 8.0 inches of snow in 24 hours as of 04/0800 PST. The cooperative observer in Fort Jones reported 14.2 inches of snow in 24 hours as of 04/0800 PST.
Public Report: 3SSE Mount Shasta, 16.0 inches of snow as of 03/2300 PST.
Spotter Report: 2SSW Weed, 18-20 inches of snow in 24 hours as of 04/0630 PST.
The cooperative observer at McCloud reported 10.2 inches of snow in 24 hours as of 04/0800 PST. The Mount Shasta Avalanche Center reported 10.0 inches of snow in 24 hours as of 04/0900 PST.
A spotter in Tennant reported 14.0 inches of snow in 24 hours as of 04/0800 PST.
Public Reports: 7SSE Hilt got 8.5 inches of snow as of 03/2000 PST; Yreka got 13.0 inches of snow as of 03/2100 PST.
Spotter Reports: 1WNW Yreka got 15.0 inches of snow in 18 hours as of 04/0600 PST.
The cooperative observer at Yreka reported 15.0 inches of snow in 24 hours as of 04/0800 PST.
The cooperative observer at Tulelake reported 12.0 inches of snow in 24 hours as of 04/1900 PST.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in California in 2017Every state in 2017This day in weather historyWarnings in California, January 2017
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: 666293, 666295, 666296, 666297, 666292, 666300.