Another very cold area of low pressure moved south along the Oregon coast and produced significant snow from the coast to the Coast Range and into the Illinois Valley. Snow levels |were down to sea level at the coast and to valley floors in Josephine County.
Every event with a place to put it; 3 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.
Another very cold area of low pressure moved south along the Oregon coast and produced significant snow from the coast to the Coast Range and into the Illinois Valley. Snow levels |were down to sea level at the coast and to valley floors in Josephine County.
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 Feb 22, 2:38 PM PST, 1 hour 22 minutes earlier.
Area Forecast Discussion
National Weather Service Medford OR
238 PM PST Wed Feb 22 2023
.DISCUSSION...The latest satellite image shows plenty of "popcorn"
configuration of clouds over the waters and are moving southeast
into our area. In the lower elevations, especially below 1500 feet,
snow showers that do occur the rest of the afternoon will melt on
the roads. The exception will be in heavier showers where they
could result in brief slushy roads, then once the heavier showers
let up in intensity or move away with sun breaks, any snow on the
roads will once again melt.
Models continue to show surface low pressure just off the NW Oregon
Coast this evening, and a closed upper low moving southward just
offshore tonight into Thursday. The cold air mass is already in
place, and we expect a continuation of showers to develop
surrounding the low, and will likely be focused along the coast. It
is pretty difficult to predict, because, there just aren't that many
times in the historical record of accumulating snow at the beaches.
However, all signs among the operational and convective allowing
models (CAM for short) are pointing towards an enhanced area of
moderate to heavy showers moving to the coast early this evening,
then pushing inland west of the Cascades later this evening and
tonight. Once again precipitation will be in showery form and will
vary in intensity (light, moderate or heavy). Because of this,
snowfall amounts tonight could very quite a bit. For example if your
in a locations below 1500 feet and heavier showers passes by, it
could result in a couple of inches of accumulation. In the flip side
if you don't see much in the overnight period, snowfall amounts
could end up less than an inch. Given the above mentioned reasoning,
existing cold air in place that could get even colder tonight as the
the next shortwave comes in, Winter storm warnings and Winter
Weather Advisories were issued for areas along and west of the
Cascades, except for the ongoing Winter Storm Warning for the coast.
Please see WSWMFR for details on the locations of Warning and
Advisory areas.
One thing to note: The extreme forecast indices and shift of tails
data from the ECMWF continue to show decent values along the coast,
which indicates that this could be a rare event with respect to the
climatological record.
Cold low pressure continues to drop south along the Oregon coast
Thursday with plenty of showers rotating around the low just about
everywhere, along and west of the Cascades. However like today, once
we get past around the mid to late morning hours. Snow showers will
melt on the roads, except for brief road slush in areas that get
caught under a heavier shower. Even then it will be brief with any
road snow or slush melting once again once the shower moves away or
is less intense.
The low will move south into northern California Thursday evening
and night at which point the focus for moderate to heavy snow will
be in northern California, specifically around the Mount Shasta
Area, and eastern through southeast Siskiyou County However, the
lift and upslope flow will develop from about Weed south to the
Mount Shasta Area, including Mount Shasta City, the Mount Shasta ski
area, and areas northeast of Mount Shasta towards Tennant. Moderate
to heavy snow is possible in these areas with snowfall rates pushing
into the 1 to 2 inch per hour range south of Weed, along highway 89
Thursday night. Therefore the Winter Storm Watch has been upgraded
to a Winter Storm Warning for the areas noted above.
Meanwhile a colder air mass will be moving into the area and there
could be several locations that could break record lows Thursday
night into Friday morning, including the coast. This despite ample
cloud cover over most of the area.
Friday, the upper and surface low will slowly move south along the
California coast. Upslope flow precipitation will persist in the
Mount Shasta area with moderate to heavy snow lingering into the
morning hours, then precipitation should gradually diminish during
the afternoon hours Friday.
Friday night, any precipitation in northern California will end with
increasing clearing from north to south. Friday night into Saturday
morning could even be colder, especially where is fresh snowpack
with numerous record lows being broken once again. -Petrucelli
.LONG TERM...Saturday 2/25 through Wednesday 3/01...With such an
active and unusually cold period of late-winter weather in the short
term, it seems natural to expect a return to more seasonable
conditions. But, there is, in fact, higher than normal confidence in
a continuation of the current large scale pattern. In not only the
long term /Day 3 to Day 7/, but also in the Day 8 to Day 14 time
frame into early March, we will likely see little change in the
character of our weather. Though both will be of significance, low
snow levels will be more noteworthy than snow amounts.
Though not far off from the previous couple of morning's lows, most
sites in southern Oregon and northern California are expected to
start off Saturday with the coldest morning low temperatures of this
lengthy episode. This will be partially due to easterly flow in our
area as the southward-tracking closed upper low reaches the central
California coast, and also due to a significant decrease in cloud
cover. For the first time in several days, clear skies are expected
over most of our area Saturday morning. The exception will be
areas of inland west side valley low clouds and fog.
Saturday will be a break between systems with ridging extending into
Oregon from offshore of northern California, producing light winds
and mostly clear afternoon skies. The first signs of model
disagreement in the long term relate to the timing of the next
front. The majority of ensemble members indicate rain reaching the
southern Oregon coast late Saturday evening, around midnight, then
precipitation reaching the Cascades by sunrise Sunday with a snow
level around 1800 to 2500 feet msl. Precipitation is likely to be
focused upon Sunday morning, with the front weakening as it moves
east of the Cascades later in the day. 1 to 4 inches of snow are
forecast for the Umpqua Divide Sunday morning including highway 227
between Tiller and Trail, and 3 to 6 inches for the southern Oregon
Cascades, and up to 2 inches for Siskiyou County and northern
Klamath County.
Post-frontal showers and snow showers are expected to be diminishing
Sunday night with a colder system following on Monday or Monday
night. It is with this Monday through Tuesday night system that
solutions more noticeably diverge with the GFS and a majority of its
ensemble members in line with its historical bias of being more
progressive in a westerly flow. Meantime, most of the ECMWF ensemble
members show a colder pattern resembling the cold closed low that is
impacting our area now into Thursday/tomorrow. As such the low would
track southward just offshore from far northern California.
Accounting for the model differences during Monday through Tuesday
night, there is a wide range of possible snow levels...likely around
500 feet to 2000 feet. The GFS pattern would favor snow for the
southern Oregon Cascades while the ECMWF would favor the Coast Range
and Mount Shasta region.
In a majority of ensemble members, the divergent early week patterns
come back into phase for Day 7, next Wednesday. Weak ridging is most
likely (a break between systems similar to what is expected for this
Saturday). There is the possibility of a weak system moving over the
top of the ridge with the highest probability of light precipitation
for Coos and Douglas counties northward.
-DW
&&
.AVIATION...22/18Z TAFs...Isolated to numerous snow showers through
Thursday will be most frequent from the coastal waters to the
Cascades. Conditions will mainly be a mix of VFR and MVFR with
mountain obscuration and lower conditions accompanying snow showers.
There is also a slight chance of thunderstorms from the coastal
waters to the Coast Range.
VFR will be most frequent east of the Cascades as downsloping air
keeps ceilings high, or nonexistent in some spots. -DW
&&
.MARINE...Updated 200 PM Wednesday, February 22, 2023...A very
strong northwest swell mixed with northwest wind waves is at its
peak this afternoon. Buoy 229 has reports wave height of 24 feet
with lower wave heights (17-19 ft) farther to the south near Buoy
27. Buoys off the northern Oregon coast are reporting wave heights
from 22 to 26 feet but Washington buoys are reporting much lower
wave heights from 15 to 17 feet.
These very high and very steep waves are will gradually lower
overnight and then lower more rapidly on Thursday with seas
diminishing to 13 to 15 feet by Thursday night. Friday morning, with
high pressure offshore, gusty north to northeast winds will develop
and keep the waves hazardous to smaller crafts, especially beyond 10
nm from shore into Saturday. Unsettled weather returns Saturday
night into next week.
-Sargeant
&&
.MFR WATCHES/WARNINGS/ADVISORIES...
OR...High Surf Advisory until 4 AM PST Thursday for ORZ021-022.
Winter Storm Warning from 7 PM this evening to 10 AM PST
Thursday for ORZ021-022.
Winter Storm Warning from 7 PM this evening to 10 AM PST
Thursday above 1500 feet for ORZ023-024-026.
Winter Weather Advisory from 7 PM this evening to 10 AM PST
Thursday below 1500 feet for ORZ023-024-026.
Winter Storm Warning from 7 PM this evening to 10 AM PST
Thursday for ORZ025.
Winter Weather Advisory from 7 PM this evening to 10 AM PST
Thursday for ORZ027-028.
CA...Winter Storm Warning until 10 AM PST Friday above 2000 feet for
CAZ080.
Winter Weather Advisory until 10 AM PST Friday for CAZ080.
Winter Storm Warning from 4 PM Thursday to 10 AM PST Friday for
CAZ081>083.
Winter Weather Advisory from 4 PM Thursday to 10 AM PST Friday
for CAZ081-083.
PACIFIC COASTAL WATERS...Hazardous Seas Warning until 4 AM PST
Thursday for PZZ350-356.
Small Craft Advisory from 4 AM Thursday to 4 AM PST Saturday for
PZZ350-356.
Gale Warning until 4 PM PST this afternoon for PZZ370-376.
Hazardous Seas Warning until 10 AM PST Thursday for PZZ370-376.
Small Craft Advisory from 10 AM Thursday to 4 AM PST Saturday
for PZZ370.
Hazardous Seas Watch from Friday morning through late Friday
night for PZZ370-376.
Small Craft Advisory from 10 AM Thursday to 10 AM PST Friday for
PZZ376.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
1007 AM PST WED FEB 22 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM HEAVY SNOW WIMER 42.53N 123.16W
02/22/2023 M2.3 INCH JACKSON OR CO-OP OBSERVER
&&
WRIGHTPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MEDFORD OR
339 PM PST WED FEB 22 2023
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0800 AM SNOW 2 WSW OBRIEN 42.06N 123.73W
02/22/2023 M0.5 INCH JOSEPHINE OR TRAINED SPOTTER
1600 FEET ELEVATION.
&&
CZSThe national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
The national gridded snowfall analysis indicated 1 to 5 inches of snow across the zone.
The national gridded snowfall analysis indicated 2 to 8 inches of snow across the zone, with the highest amounts in the Coast Range.
The national gridded snowfall analysis indicated 2 to 8 inches of snow across the zone. Amounts were highest in the Kalmiopsis Wilderness.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2023Every state in 2023This day in weather historyWarnings in Oregon, February 2023
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: 1084076, 1084077, 1084078.