Showers and thunderstorms, both slow moving and moving over the same locations, resulted in some flash flooding and debris flows in Eastern Washington.
Every event with a place to put it. 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.
Showers and thunderstorms, both slow moving and moving over the same locations, resulted in some flash flooding and debris flows in Eastern Washington.
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 May 16, 3:35 PM PST, 2 hours 15 minutes earlier.
Area Forecast Discussion National Weather Service Spokane WA 435 PM PDT SAT MAY 16 2015 .SYNOPSIS... Showers with embedded thunderstorms are expected tonight especially over Northeast Washington into the Idaho Panhandle. Seasonably mild conditions will continue through the next week, with showers possible over the higher terrain. && .DISCUSSION... Tonight and Sunday...Satellite shows a rather complex pattern with a blocking high over northern British Columbia...a large closed low over NW Wyoming...and a smaller low over southern BC. This places eastern Washington and north Idaho in the middle of these features. However for tonight there will be a weak forcing mechanism as a surface high dropping south into Montana brings a push of NE winds down the Purcell Trench into North Idaho with a boundary noted along this leading push. This combined with uncapped CAPE values over NE Washington and North Idaho around 500-800 J/KG will result in increasing showers and isolated thunderstorms. This boundary will shift west into North Central Washington overnight as the low over southern BC swings west into Vancouver Island. Models show mid level instability as well as thus areas such as Omak, Winthrop, and Chelan have the best chance for showers during the overnight hours. Models show a wide range of qpf totals in these areas and confidence in the degree of overnight shower activity is low. However given no strong forcing in place forecast leads towards lighter qpf amounts of less than a tenth. On Sunday another large closed low drops to near the Central CA coast with a southerly flow aloft over the area. However mostly cloudy skies and northeast boundary layer winds ushering in some drier low level air will result in less instability compared to today. The GFS and ECMWF show the best chance for showers on Sunday over North Central Washington (especially the higher terrain), Blue Mountains, and Camas Prairie. Thunder chances on Sunday are marginal, and have restricted this to a slight chance over just the mountains near the Cascade crest, Blue Mountains, and Camas Prairie. JW Wednesday night through Saturday: The Inland NW remains under a mild and unstable atmosphere, with the continued opportunity for showers each afternoon for at least a few areas. The long-wave pattern shows a ridge of western Canada and trough over the Southwest U.S., leaving the Pacific Northwest in a weak flow pattern. A weak mid-level low cut-off from the main flow bobbles somewhere around the Pacific NW. However in the weak flow pattern models diverge over its placement. Between the surface to 700mb, however, models generally hold a trough of low pressure/theta-e around eastern WA and north ID. With expanding instability (CAPE) each afternoon this will result in some expanding shower and thunderstorm chances during the afternoon. Thursday chances will be best across the Cascades, southeast WA and the lower ID Panhandle. Friday into Saturday the chances gradually expand into northeast WA and north ID. /J. Cote' && .AVIATION... 00Z TAFS: Thunderstorms with gusty wind and heavy rainfall moving through the KGEG, KSFF, and KCOE vicinity and they area all working their way down to the south at about 15 mph. After 6Z tonight most of the thunderstorm activity will subside however showers may linger at times through the night and into tomorrow as the atmosphere still remains somewhat unstable. /Pelatti && .PRELIMINARY POINT TEMPS/POPS... Spokane 51 69 49 73 49 76 / 60 10 10 10 10 10 Coeur d'Alene 48 69 45 73 46 75 / 60 10 10 10 10 10 Pullman 49 67 44 72 47 75 / 60 30 20 20 20 30 Lewiston 54 73 51 77 52 79 / 60 30 30 30 20 30 Colville 52 72 48 75 47 78 / 60 20 10 10 10 0 Sandpoint 48 69 40 71 42 74 / 50 10 10 10 10 0 Kellogg 46 68 43 71 43 74 / 60 10 10 10 10 10 Moses Lake 53 73 50 79 55 81 / 30 30 20 10 10 10 Wenatchee 55 72 54 79 54 81 / 50 50 20 10 10 10 Omak 52 72 50 77 47 81 / 60 50 20 10 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SPOKANE WA 630 AM PDT SAT MAY 16 2015 IDZ001>004-026-027-WAZ031>038-041>044-171330- 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- 630 AM PDT SAT MAY 16 2015 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...SUNDAY THROUGH FRIDAY No hazardous weather is expected at this time.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SPOKANE WA 550 PM PDT SAT MAY 16 2015 IDZ003-WAZ033-170145- IDAHO PALOUSE ID-WASHINGTON PALOUSE WA- 550 PM PDT SAT MAY 16 2015 AT 547 PM PDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 17 MILES NORTHEAST OF COLFAX...OR 25 MILES NORTH OF PULLMAN. THIS STORM WAS MOVING SOUTH AT 10 MPH OR LESS. BRIEF HEAVY RAIN...SMALL HAIL...AND GUSTY WIND FROM THIS STORM. SOME ROTATION HAS BEEN DETECTED IN THIS STORM SO THERE IS THE POSSIBILITY OF A BRIEF FUNNEL CLOUD ASSOCIATED WITH THIS THUNDERSTORM. LOCATIONS IMPACTED INCLUDE... TEKOA...GARFIELD...OAKESDALE...FARMINGTON AND BELMONT. LAT...LON 4716 11732 4723 11707 4697 11694 4693 11733 TIME...MOT...LOC 0047Z 351DEG 2KT 4711 11717 RP
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
628 PM PDT SAT MAY 16 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0550 PM FLASH FLOOD 3 NE OAKESDALE 47.16N 117.20W
05/16/2015 WHITMAN WA LAW ENFORCEMENT
WHITMAN COUNTY SHERIFF DISPATCH REPOTED FLASH FLOODING
BETWEEN OAKSDALE AND TEKOA. NUMEROUS REPORTS RECIEVED OF
CARS STRANDED ON AREA ROADS. FIRST REPORT ARRIVED AROUND
550 PM.
&&PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE SPOKANE WA
640 PM PDT SAT MAY 16 2015
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0615 PM FLASH FLOOD 7 NE OAKESDALE 47.20N 117.14W
05/16/2015 WHITMAN WA PUBLIC
HEAVY RAINS CREATED WATER ON ROADWAYS UP TO TOP OF TIRE
ON CARS.
&&
JCLEVThe national radar mosaic for the moment the first event began.
2 flash flood. Local standard time, as filed.
Whitman County Sheriff dispatch reported flash flooding between Oaksdale and Teknoa. The water damaged some nearby spring wheat crops and damaged county roads.
A Facebook post from public reported .92 inches of rain in Oaksedale and Flash Flooding east of Oakesdale and included a photo of flooding over a roadway.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Washington in 2015Every state in 2015This day in weather historyWarnings in Washington, May 2015
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: 566435, 566436.