With the region under a slow moving trough, a series of snow bands impacted the region for the start of April. While most locations in Eastern Washington received one to three inches, a few locations reached six to ten inches.
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 OTX wrote it up.
With the region under a slow moving trough, a series of snow bands impacted the region for the start of April. While most locations in Eastern Washington received one to three inches, a few locations reached six to ten inches. The trough exited the region by April 4 and the snow shower threat diminished.
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 Spokane, WA wrote its last area forecast discussion before the first event at Apr 2, 9:40 AM PST, 3 hours 5 minutes earlier.
Area Forecast Discussion National Weather Service Spokane WA 1040 AM PDT Sun Apr 2 2023 .SYNOPSIS... Showers and thunderstorms will continue across the Inland Northwest on today. Sunday night snow could impact the Monday morning commute. A cooler and wetter patter will continue into the middle of the week. Temperatures will warm into the 50s by the end of the week with a chance of rain. Next weekend looks mild with temperatures warming into the 60s. && .DISCUSSION... Morning update: Showers are already beginning to develop in the Palouse this morning. Expect coverage to increase markedly into early afternoon, with another round of scattered snow/rain/graupel showers in eastern Washington and the Idaho Panhandle this afternoon and early evening, with isolated lightning strikes anticipated as well. Forecast for tonight into Monday morning remains quite uncertain, but latest guidance has trended just a tad to the south, with probabilities higher of impactful snow in the Palouse versus the Spokane and Coeur d'Alene areas. High confidence (>80 percent probabilities) that there will be a narrow corridor (nearly west-east) of 2-4 inches of snow by late Monday morning somewhere between I-90 and the northeast Blues eastward into the Idaho Panhandle, but this corridor will be quite small (roughly 20 miles or less), with highly variable (and quickly diminishing) totals within small distances of the main corridor. Tough forecast, to say the least... /CMS Today through Monday night: Very cold air aloft keeps the atmosphere very unstable throughout this forecast period, with 700-500mb lapse rates of -8 to -9 C/km. Saturday's graupel and thunder show should be repeated again this afternoon. There does appear to be some very small scale disturbance that swings through the area today, and that will favor the Palouse for the best odds of showers. But everyone has at least a 20 percent chance of some sort of precipitation. Precipitation type should be snow or graupel as dew points are very dry, around 20F. Forecast gets a little more complex and tricky for Sunday night and Monday. A closed low moves across the area during this period. Just about every forecast model shows it, but with slightly different tracks. The consensus has about an 80% chance of snow for Spokane, the Palouse, and the Panhandle. Given the unstable atmosphere and closed-low forcing, amounts are nearly impossible to forecast. Most folks in this region should see around an inch of snow, but amounts exceeding 4" by the Monday morning commute have about a 20% chance of occurring. Roads will be cold enough to accumulate snow, so the Monday morning commute has an 80% chance of being impacted. The alternate scenario is that this upper low tracks a little farther to the south, impacting the Palouse with snow, but leaving Spokane and CdA dry. If the morning snow lingers long enough, temperatures may struggle to reach 40F by the afternoon. Elsewhere, more graupel showers and thunderstorms are expected for Monday afternoon and evening. RJ Tuesday and Wednesday: Trough will continue its push across the southern Rocky Mountains and into the northern Plains. The back edge of the trough will slowly move across the Inland Northwest as the ridge noses onto the west coast. The atmosphere will remain unstable for showers to develop each late morning through the early evening. The deterministics are showing small pieces of energy swirling around the region. This will bring a threat of light snow to the valleys Tuesday morning. NBM has a 20% chance of a tenth of an inch or more of snow for Spokane, Deer Park, Coeur d'Alene, Bonners Ferry and Republic. A 30-40% for Pullman, Sandpoint and Kellogg, and about a 10% chance for Colville. As far as the mountain passes go Tuesday morning, the probabilities of more than a half inch are as follows: Sherman Pass 10%, Stevens Pass 25% and Lookout Pass 30%. Temperatures Tuesday will continue to be about 8 to 10 degrees below average for the beginning of April. Highs will be in the 40s, with lower 50s for parts of central WA. We will begin to see some warming starting Wednesday with populated lowland temps in the mid 40s to mid 50s, but it will still be about 4 to 6 degrees below average. Thursday and Friday: Cluster analysis agrees on the ridge moving into the Pacific Northwest Thursday. They are split about 50/50 as far as a drier more amplified ridge vs a wetter broad ridge. Both EC and GFS Ensembles suggest an increase in precipitable water values and precipitation moving into central WA midday and eastern WA/north ID by later afternoon or evening. Temperatures continue to warm, so threat of snow will be confined to the mountains during the late night and early morning. Accumulations currently look to be generally 1-3 inches, but if the wetter EC Ensemble were to verify, it could be more. Daytime temps will finally be around average by Thur/Fri - in the 50s to around 60. The one exception will be the adjacent Cascade valleys where they will still be in the upper 40s to mid 50s, which is about 4-6 degrees below average. Chances of precipitation continues through Friday, tho amounts look to be lighter than what we will see Thursday Night. Saturday and Sunday: Shower chances decrease Saturday to mainly the Cascade crest and ID Panhandle, and by Sunday as the ridge really amplifies over the region, we dry out and warm up. Saturday will be our first chance of seeing 60 degrees for many locations across the region. Statistics of 60 degrees or higher are: Spokane 65-75%, Coeur d'Alene 40%, Pullman 30%, Colville 65%, Omak 85%, Lewiston, Moses Lake and Wenatchee 95% or higher. Sunday probabilities are 90% or higher with all locations but Pullman (85%) and Sandpoint (55%) of seeing 60 degrees. /Nisbet && .AVIATION... 18z TAFs: Very challenging 24-hour forecast. Expect one or more snow/rain/graupel showers through 03z at most of the TAF sites, with very brief sub-VFR conditions if a shower directly impacts a terminal. After 03z, the showers should diminish in coverage; however, a steadier band of snow is forecast to develop in portions of eastern/southeastern Washington and adjacent portions of the Idaho Panhandle (>90 percent probability). The exact location of this band is uncertain, and because of its anticipated narrow size, this leads to a low-confidence forecast for GEG/SFF/COE/PUW/LWS overnight into Monday morning. Probabilities of IFR snow are around 50 percent at GEG/SFF/COE to around 75 percent at PUW (less than 25 percent at LWS), with timing generally between 06z and 15z. If the band sets up directly over a terminal, quick and impactful accumulation is probable (>80 percent). However, if the band is displaced by more than 15-25 miles, little impactful snow may be observed. There is higher confidence that sub-VFR CIGs will develop with time after 06z, lingering through Monday morning. Winds at the TAF sites will primarily be southerly or southwesterly around 10 kt this afternoon, becoming lighter and more terrain-driven or variable overnight. /CMS && .PRELIMINARY POINT TEMPS/POPS... Spokane 44 28 45 27 46 29 / 50 70 60 20 30 10 Coeur d'Alene 42 27 42 26 44 25 / 60 70 80 20 50 10 Pullman 42 27 41 26 42 26 / 90 70 80 30 30 20 Lewiston 49 32 47 32 49 31 / 30 30 40 30 20 20 Colville 46 23 48 25 49 25 / 40 60 40 20 40 0 Sandpoint 41 26 42 28 44 27 / 70 70 70 30 70 20 Kellogg 38 27 39 26 41 26 / 90 90 90 30 70 20 Moses Lake 51 28 53 29 53 29 / 20 10 20 10 10 0 Wenatchee 47 29 50 30 50 30 / 30 10 20 10 20 0 Omak 48 28 50 28 51 28 / 10 20 20 10 20 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
The national radar mosaic for the moment the first event began.
3 heavy snow. Local standard time, as filed.
Observer estimated ten inches of snow four miles East of Sprague. WSDOT reported six inches in Sprague.
Observer reported six inches of snow. Other six plus inch reports occurred in the Cheney, Spangle, and Marshall. A ten inch report was estimated in Spangle. Other reports of one to four inches were observed around Spokane.
Observer estimated eight inches of snow in Waverly. Another report of six inches was estimated in Latah. Whitman County snow amounts ranged from one to four inches.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2023Every state in 2023This day in weather historyWarnings in Washington, April 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: 1096399, 1096429, 1096405.