A cool and unstable air mass residing over Central Washington beneath a -34 Celsius cold pool resulted in widely scattered convective showers and isolated thunderstorms during the afternoon hours of April 5th. One cell between Wenatchee and Cashmere produced a cold core funnel cloud which was observed by a trained spotter.
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The episode as NWS OTX wrote it up.
A cool and unstable air mass residing over Central Washington beneath a -34 Celsius cold pool resulted in widely scattered convective showers and isolated thunderstorms during the afternoon hours of April 5th. One cell between Wenatchee and Cashmere produced a cold core funnel cloud which was observed by a trained spotter.
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 5, 3:31 PM PST, 39 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 431 PM PDT Thu Apr 5 2012 .SYNOPSIS... The Inland Northwest will remain under a cool and unstable air mass which will promote scattered showers and possibly a few thunderstorms through Friday. A break in the active weather pattern will occur this weekend and early next week...before more unsettled weather returns by the middle of the week. && .DISCUSSION... This evening and tonight: A cool upper-level trough centered directly overhead with 500mb temperatures on the order of -35 C will keep widely scattered showers of rain, snow, and graupel in the forecast through sunset. The distinct circulation organizing showers across the western Basin and Palouse is showing signs of weakening per warming cloud tops and this bodes well with the latest NAM/RUC progs. The forecast still carries a slight chance for thunder mainly until early evening with the highest threat north of highway 2, and south of Interstate 90 based on latest visible satellite imagery however with the midlevel circulation weakening, we may see a bit more sun then expected along the highway 2 corridor leading to one last gasp of deeper, surface based instability prior to dark. Showers will quickly diminish this evening and we should see appreciable clearing across the north overnight and likelihood for patchy fog mainly across the sheltered valleys of Kettle Falls eastward and potentially into the Spokane Area. Drier air filtering down the Okanogan Valley and Northern Cascades should keep the fog threat low but enhance the potential for unseasonably cold overnight temperatures. Further south and east, cyclogenesis taking shape over Wyoming will lead to light N/NW gradients with lingering light upsloping showers expected to persist into the night across the Camas Prairie and Blue Mtns. The persistent cloud shield is expected to keep temperatures a bit warmer but overall trends for the region will be for near to below freezing temperatures and possibility for slick conditions during the Friday commute given showers falls across any given location this afternoon. /sb Friday through Sunday...One more day of fairly active weather is expected on Friday before a benign break period set up for the weekend. Satellite indicates a broad and cool trough is slowly migrating across the region. Models are in good agreement in continuing to move this trough through the region on Friday...with the added twist of an embedded short wave traveling from south to north roughly along the Idaho/Montana border during the day Friday. Similar in character to yesterdays wave...but displaced a hundred miles east of yesterday's track. This suggests the main precipitation shield will just brush the forecast area and focus the really inclement weather over the Idaho Panhandle with moderate mountain snow accumulations and valley light snow or non- accumulating snow/rain mix. The eastern third of Washington will likely be under the fringe of this moisture shield...no doubt subject to occasional brief showers but with no significant accumulation potential. The air mass over the region will continue to be unstable especially during the afternoon as the inter-trough cold pool remains aloft. Thus...like today...shallow convective showers featuring rain or snow or graupel or a mix of all of them will probably make an appearance once again. Every zone is subject to a shower on Friday...but concentration will likely be densest over the mountains of the north and over the east basin rising terrain. High temperatures on Friday will be a few degrees warmer than today...especially in the dryer deep basin area away from the eastern precipitation area. Friday night will be a transition period from a generally troffy pattern to a short wave ridge pattern. Most of the forecast area will dry out on Friday night except for lingering showers over the northeast caused by the remnants of the exiting storm system. By Saturday and through Sunday the upper level ridge will take hold and surface high pressure will become established over the basin. This bodes for a dry weekend...but with some periods of thick high clouds hiding the moon and sun from time to time. Temperatures will also climb each day Saturday and Sunday as southwest flow in the mid levels advects warm air into the region...subject to being mixed adiabatically down to the surface during the afternoon mixing periods. Indeed by Sunday afternoon high temperatures may approach or even exceed climatological normals for a comfortably mild spring day for outdoor activities. /Fugazzi Sunday night through Thursday...The work week will start out warm and dry, then the chance of precipitation will increase by Wednesday. On Sunday night the region will be positioned between low pressure systems, one over the upper Great Lakes to the east and the other in the eastern Pacific. The upper ridge axis will be over Idaho then drift to the northern Great Plains by Wednesday. The Inland Northwest will come under increasingly warm and moist southwest flow on Monday. The jet stream rounding the base of the Pacific trough will become more north-south oriented as the upper low starts to approach the coast. This should keep precipitation close to the Cascades with little advancement toward the eastern half of the forecast area through Tuesday. The surface low off the coast will induce an easterly pressure gradient which will also keep the focus on the east slopes of the Cascades until the cold front arrives. Model solutions diverge on the evolution of the upper trough but the best bet for widespread precipitation appears to be on Wednesday. Temperatures will be seasonably warm Monday then follow a gradual cooling trend as clouds increase and precipitation spreads east. Expect temperatures slightly below normal by Thursday behind the cold front. /Kelch && .AVIATION... 18z TAFS: A cold unstable upper level trough will remain over the area through Friday. This will promote scattered rain or snow showers and isolated thunderstorms with small hail from 00-02Z tonight...and again from 18Z to 24Z Friday. All TAF sites will likely experience VFR conditions during day and evening unstable periods...with brief MVFR conditions if any shower cores move across any particular TAF site. Light winds and clearing skies aft 03z will bring the potential for bcfg along the KGEG- KCOE corridor with MVFR ceiling stratus expected to develop across SE WA and advect into KPUW. The northern periphery of the stratus shield will extend toward KGEG but confidence is low if we will see restrictions and opted to include sct decks at this time. /MJF && .PRELIMINARY POINT TEMPS/POPS... Spokane 30 46 31 51 33 60 / 30 40 20 10 0 0 Coeur d'Alene 29 42 31 51 31 60 / 30 50 30 10 0 0 Pullman 29 43 30 50 32 62 / 30 50 30 0 0 0 Lewiston 34 46 33 57 37 67 / 30 40 20 0 0 0 Colville 28 48 31 54 32 60 / 20 50 30 10 0 0 Sandpoint 28 41 30 49 29 57 / 30 50 40 10 0 0 Kellogg 27 38 28 48 29 58 / 40 80 60 10 0 0 Moses Lake 28 53 29 57 35 65 / 20 20 10 0 0 0 Wenatchee 33 52 32 54 36 61 / 20 20 10 0 0 0 Omak 30 53 30 55 33 61 / 20 20 10 0 0 0 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SPOKANE WA 625 AM PDT THU APR 5 2012 IDZ001>004-026-027-WAZ031>038-041>044-061330- NORTHERN PANHANDLE-COEUR D'ALENE AREA-IDAHO PALOUSE- CENTRAL PANHANDLE MOUNTAINS-LEWISTON AREA- LEWIS AND SOUTHERN NEZ PERCE COUNTIES-NORTHEAST BLUE MOUNTAINS- LOWER GARFIELD AND ASOTIN COUNTIES-WASHINGTON PALOUSE- MOSES LAKE AREA-UPPER COLUMBIA BASIN-SPOKANE AREA- NORTHEAST MOUNTAINS-OKANOGAN HIGHLANDS-WENATCHEE AREA- EAST SLOPES NORTHERN CASCADES-OKANOGAN VALLEY-WATERVILLE PLATEAU- 625 AM PDT THU APR 5 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO... NORTH CENTRAL IDAHO...CENTRAL WASHINGTON...EAST CENTRAL WASHINGTON...NORTH CENTRAL WASHINGTON...NORTHEAST WASHINGTON AND SOUTHEAST WASHINGTON. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
443 PM PDT THU APR 05 2012
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0415 PM FUNNEL CLOUD 4 SE CASHMERE 47.48N 120.41W
04/05/2012 CHELAN WA TRAINED SPOTTER
SPOTTER REPORTED A FUNNEL CLOUD TO THE NORTHWEST OF
WENATCHEE TOWARD CASHMERE. THE FUNNEL CLOUD LASTED A FEW
MINUTES BEFORE RETRACTING BACK UP INTO THE CLOUD.
&&
VAN HORNThe Seattle radar (KATX), 175 km away, was scanning. The volume nearest the first event began at 00:10 UTC.
1 funnel cloud. Local standard time, as filed.
A trained spotter observed a funnel cloud to the northwest of Wenatchee toward Cashmere. The funnel cloud lasted a few minutes before dissipating.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2012Every state in 2012This day in weather historyWarnings in Washington, April 2012
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: 370110.