A mid level short wave trough combined with an unstable atmosphere to produce severe thunderstorms with large hail and damaging winds across parts of Union and Wallowa counties during the evening.
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 PDT wrote it up.
A mid level short wave trough combined with an unstable atmosphere to produce severe thunderstorms with large hail and damaging winds across parts of Union and Wallowa counties during the evening.
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 Pendleton, OR wrote its last area forecast discussion before the first event at Jun 28, 7:30 PM PST, 2 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE PENDLETON OR 830 PM PDT MON JUN 28 2010 .SHORT TERM...UPDATE...A MID LEVEL SHORT WAVE WHICH IS MOVING ACROSS NORTHEAST OREGON THIS EVENING IS INTERACTING WITH AN UNSTABLE ATMOSPHERE AND TRIGGERING A CLUSTER OF STRONG THUNDERSTORMS WHICH HAVE MOVED INTO UNION AND WALLOWA COUNTIES. THESE STORMS WILL CONTINUE FOR THE NEXT HOUR OR TWO. THE THUNDERSTORMS HAVE A HISTORY OF PRODUCING HIGH WINDS AND SOME HAIL IN NORTHERN MALHEUR COUNTY. WE ARE MONITORING THE THUNDERSTORMS FOR POSSIBLE ISSUANCE OF A SEVERE THUNDERSTORM WARNING. I HAVE INCREASED THE POPS IN UNION AND WALLOWA COUNTIES FOR THIS EVENING DUE TO THESE THUNDERSTORMS AND WILL UPDATE THE ZONE FORECAST PACKAGE SHORTLY. POLAN && .PREV DISCUSSION... /ISSUED 230 PM PDT MON JUN 28 2010/ SHORT TERM...TONIGHT THROUGH WEDNESDAY NIGHT...THE AREA REMAINS UNDER THE INFLUENCE OF A RIDGE CENTERED OVER WESTERN MONTANA WITH A TROUGH DEVELOPING OUT IN THE EASTERN PACIFIC. VISIBLE SATELLITE IMAGERY SHOWS A WAVE MOVING UP FROM THE CALIFORNIA BORDER AND THIS WAVE MAY BRUSH THE EASTERN PART OF THE AREA LATE THIS AFTERNOON AND EARLY THIS EVENING. HAVE KEPT ISOLATED THUNDERSTORMS OVER THE EASTERN OREGON MOUNTAINS BUT IT REMAINS TO BE SEEN IF THE WAVE WILL PASS THROUGH THE AREA OR TO OUR EAST. ALSO EXPECTING A LATE AFTERNOON AND EARLY EVENING MARINE PUSH WITH WINDS REACHING 20 TO 30 MPH IN THE COLUMBIA GORGE AND KITTITAS VALLEY AND 10 TO 20 MPH IN THE COLUMBIA BASIN AND CENTRAL OREGON. MODELS ARE ALSO INDICATING SOME ELEVATED CONVECTION OVERNIGHT SO HAVE KEPT ISOLATED THUNDERSTORMS IN THE EASTERN MOUNTAINS THROUGH THE NIGHT. THE NAM WANTS TO BRING THE THUNDERSTORMS INTO THE BLUE MOUNTAIN FOOTHILLS AND FAR EASTERN COLUMBIA BASIN. I BELIEVE THIS IS OVERDONE AND DO NOT SEE SUPPORT FOR THIS IN OTHER MODELS. ALSO...THE MARINE PUSH SHOULD HELP STABILIZE THE ATMOSPHERE IN THE COLUMBIA BASIN AND WOULD WORK AGAINST THUNDERSTORMS. WOULD NOT BE SHOCKED TO SEE A FEW LIGHTNING STRIKES WEST OF THE BLUE MOUNTAINS OVERNIGHT BUT DO NOT THINK THE CHANCE IS STRONG ENOUGH TO ADD TO THE FORECAST. CLOUD COVER SHOULD BE A LITTLE LIGHTER TONIGHT AND THE AIR MASS IS COOLING AS THE RIDGE MOVES EAST SO HAVE LOWERED TEMPERATURES A FEW DEGREES TONIGHT. TOMORROW SHOULD BE ANOTHER MOSTLY SUNNY DAY BUT WITH THE RIDGE CONTINUING TO MOVE EAST AND THE TROUGH OFFSHORE MOVING CLOSER...A COOLER DAY IS EXPECTED WITH TEMPERATURES DOWN 5 TO 10 DEGREES FROM TODAY. ONCE AGAIN A FEW THUNDERSTORMS SHOULD DEVELOP MAINLY IN UNION AND WALLOWA COUNTIES BUT ALSO ALONG THE HIGHER TERRAIN DOWN TO JOHN DAY AND SENECA. WINDS SHOULD PICK UP AGAIN TOMORROW AFTERNOON SIMILAR TO TODAY WITH 20 TO 30 MPH IN THE COLUMBIA GORGE AND KITTITAS VALLEY AND 10 TO 20 MPH IN THE COLUMBIA BASIN AND CENTRAL OREGON. ELEVATED CONVECTION IS INDICATED IN THE MODELS AGAIN OVERNIGHT AND HAVE KEPT A SLIGHT CHANCE OF THUNDERSTORMS IN THE NORTHERN BLUE MOUNTAINS AND WALLOWA COUNTY AFTER MIDNIGHT. OVERNIGHT TEMPERATURES WILL DROP A FEW MORE DEGREES TO THE MID 40S TO MID 50S WITH UPPER 30S TO UPPER 40S IN THE MOUNTAINS. BY WEDNESDAY THE TROUGH WILL BE OVER THE AREA AND TEMPERATURES WILL BE IN THE 70S WITH MID 60S TO LOWER 70S IN THE MOUNTAINS. INSTABILITY IS LIMITED SO THUNDERSTORMS WILL BE CONFINED TO WALLOWA COUNTY WITH A FEW SHOWERS POSSIBLE ALONG THE WASHINGTON CASCADE CREST. WEDNESDAY NIGHT LOOKS DRY AND CONTINUED COOL. PERRY LONG TERM...THURSDAY THROUGH SATURDAY...MODELS OVER THE PAST COUPLE OF DAYS HAVE CONSISTENTLY SHOWN A LONG WAVE TROUGH OVER THE PACIFIC NORTHWEST FROM THURSDAY THROUGH FRIDAY NIGHT. THE LONG WAVE TROUGH AXIS FINALLY MOVES EAST INTO IDAHO/MONTANA ON SATURDAY WITH THE 12Z GFS RUN BEING FASTER IN THE TROUGH AXIS EXITING THE FORECAST AREA FRIDAY EVENING. AS SUCH I WILL KEEP A LOW CHANCE OF MEASURABLE RAINFALL FROM DIURNALLY DRIVEN OROGRAPHIC SHOWERS OVER THE MOUNTAINS FROM THURSDAY THROUGH FRIDAY NIGHT. SUBSIDENCE KICKS IN ON SATURDAY AS A FLAT MID/UPPER LEVEL RIDGE OF HIGH PRESSURE OVER THE NORTHEAST PACIFIC BEGINS MOVING INTO THE REGION SO I WILL FORECAST ONLY A SLIGHT CHANCE OF OROGRAPHIC SHOWERS OVER MOUNTAINS ON SATURDAY. OTHERWISE...THE FORECAST AREA WILL BE DRY IN THIS PERIOD. POLAN SATURDAY NIGHT THROUGH MONDAY...A WEAK WAVE WILL MOVE THROUGH THE BROAD TROUGH. THIS MAY TRIGGER A FEW SHOWERS ALONG THE CASCADES AND IN NORTHEAST OREGON MOUNTAINS. BY 18Z SUNDAY THE GFS AND ECMWF HAVE COMPLETELY DIFFERENT SOLUTIONS WITH THE 12Z GFS DEVELOPING A CLOSED LOW IN BRITISH COLUMBIA MOVING SOUTH AND THE 12Z ECMWF DEVELOPING A RIDGE SLIGHTLY WEST OVER VANCOUVER ISLAND. WITH OPPOSITE SOLUTIONS DECIDED TO KEEP SLIGHT CHANCE POPS IN THE MOUNTAINS SINCE EVEN A WEAK WAVE AHEAD OF THE RIDGE (ECMWF AND 06Z GFS) WOULD GENERATE SOME POPS. IF 12Z GFS IS CORRECT THERE WOULD BE HIGHER POPS AND COOLER TEMPERATURES SUNDAY AND MONDAY...BUT THERE IS NOT ENOUGH CONTINUITY TO HAVE ANY CONFIDENCE IN THE STRONGER SOLUTION. COONFIELD AVIATION...00Z TAFS...VFR CONDITIONS WILL CONTINUE FOR THE NEXT 24 HOURS. SUBSIDENCE ASSOCIATED WITH AN AMPLIFYING MID/UPPER LEVEL RIDGE OF HIGH PRESSURE ACROSS THE REGION WILL SUPPRESS CUMULUS DEVELOPMENT THIS AFTERNOON OVER THE MOUNTAINS. A WEAK WAVE AROUND 10000 FT WILL BACK WINDS AT THAT LEVEL FROM SOUTHWEST TO SOUTH THIS AFTERNOON AND TONIGHT AND TRANSPORT INCREASING MID LEVEL MOISTURE AND CLOUDS INTO CENTRAL OREGON THIS AFTERNOON. THE CLOUD BASES WILL BE AROUND 7000 TO 10000 FT AGL. THIS CLOUD COVER WILL MOVE NORTHWARD ACROSS THE LOWER COLUMBIA TONIGHT AND THEN EXIT INTO NORTHEAST WASHINGTON BY 29/16Z ON TUESDAY MORNING. WIND OF 5 TO 10 MPH THIS AFTERNOON WILL DECREASE THIS EVENING AND OVERNIGHT. POLAN && .PRELIMINARY POINT TEMPS/POPS... PDT 55 78 49 76 / 10 10 10 10 ALW 58 80 54 77 / 10 10 10 10 PSC 57 83 51 80 / 10 0 0 0 YKM 52 78 45 76 / 0 0 0 0 HRI 57 81 50 79 / 10 0 0 0 ELN 54 74 49 75 / 0 0 0 10 RDM 44 76 37 75 / 0 0 0 10 LGD 53 79 47 74 / 30 20 20 10 GCD 52 79 48 75 / 30 20 20 10 DLS 55 74 50 78 / 0 0 0 10 && .PDT WATCHES/WARNINGS/ADVISORIES... OR...NONE. WA...NONE. && THREAT INDEX TUESDAY : GREEN WEDNESDAY : GREEN THURSDAY : GREEN GREEN: NONE OR LIMITED NEED FOR WATCHES, WARNINGS, OR ADVISORIES. YELLOW: A FEW WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. RED: NUMEROUS WATCHES, WARNINGS, OR ADVISORIES POSSIBLE OR IN EFFECT. FOR ADDITIONAL WEATHER INFORMATION, CHECK OUR WEB SITE AT... WWW.WEATHER.GOV/PENDLETON 83/99/99
HAZARDOUS WEATHER OUTLOOK
NATIONAL WEATHER SERVICE PENDLETON OR
515 AM PDT MON JUN 28 2010
ORZ041>044-049-050-501>506-WAZ024-026>030-501-502-291215-
EASTERN COLUMBIA RIVER GORGE OF OREGON-NORTH CENTRAL OREGON-
CENTRAL OREGON-LOWER COLUMBIA BASIN OF OREGON-GRANDE RONDE VALLEY-
WALLOWA COUNTY-FOOTHILLS OF THE BLUE MOUNTAINS OF OREGON-
NORTHERN BLUE MOUNTAINS OF OREGON-
SOUTHERN BLUE MOUNTAINS OF OREGON-
NORTHERN WHEELER AND SOUTHERN GILLIAM COUNTIES-JOHN DAY BASIN-
OCHOCO-JOHN DAY HIGHLANDS-
EASTERN COLUMBIA RIVER GORGE OF WASHINGTON-KITTITAS VALLEY-
YAKIMA VALLEY-LOWER COLUMBIA BASIN OF WASHINGTON-
FOOTHILLS OF THE BLUE MOUNTAINS OF WASHINGTON-
NORTHWEST BLUE MOUNTAINS OF WASHINGTON-
EAST SLOPES OF THE CENTRAL CASCADES OF WASHINGTON-
EAST SLOPES OF THE SOUTHERN CASCADES OF WASHINGTON-
515 AM PDT MON JUN 28 2010
THIS HAZARDOUS WEATHER OUTLOOK IS FOR CENTRAL AND NORTHEAST OREGON
AS WELL AS SOUTH CENTRAL AND SOUTHEAST WASHINGTON.
.DAY ONE...TODAY AND TONIGHT
THUNDERSTORMS
NORTHWEST BLUE MOUNTAINS OF WASHINGTON, GRANDE RONDE VALLEY,
WALLOWA COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN
BLUE MOUNTAINS OF OREGON, JOHN DAY BASIN, OCHOCO-JOHN DAY
HIGHLANDS
AN UPPER TROUGH APPROACHING THE WEST COAST WILL KEEP A SOUTHWEST
FLOW ALOFT OVER THE REGION TODAY AND TONIGHT. THIS WILL CAUSE THE
ATMOSPHERE TO BECOME MORE UNSTABLE THIS AFTERNOON AND TONIGHT AS
SURFACE HEATING COMBINES WITH INCREASING MOISTURE AND INSTABILITY
FROM THE SOUTHWEST. AS A RESULT ISOLATED THUNDERSTORMS ARE EXPECTED
THIS AFTERNOON AND TONIGHT...MAINLY FROM THE BLUE MOUNTAINS EASTWARD
AND SOUTHWARD. AS OF THIS TIME ANY THUNDERSTORMS THAT DO FORM ARE
NOT EXPECTED TO BECOME SEVERE.
.DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY
THUNDERSTORMS TUESDAY
NORTHWEST BLUE MOUNTAINS OF WASHINGTON, GRANDE RONDE VALLEY,
WALLOWA COUNTY, NORTHERN BLUE MOUNTAINS OF OREGON, SOUTHERN
BLUE MOUNTAINS OF OREGON, JOHN DAY BASIN, OCHOCO-JOHN DAY
HIGHLANDS
AFTERNOON AND EVENING THUNDERSTORMS ARE EXPECTED AGAIN ON TUESDAY AS
THE SOUTHWEST FLOW ALOFT PERSISTS. HOWEVER COOLER AND MORE STABLE
MARINE AIR WILL BEGIN TO FILTER EAST OF THE CASCADES AS THE LOW
LEVEL WINDS BECOME MORE WESTERLY AND THEN NORTHWEST BY TUESDAY
NIGHT. EVEN THOUGH IT WILL BECOME COOLER AND MORE STABLE ISOLATED TO
SCATTERED SHOWERS WILL REMAIN A THREAT EACH DAY...MAINLY OVER THE
MOUNTAINS...FOR THE REMAINDER OF THE WEEK INTO THE WEEKEND ALONG
WITH THE COOLER TEMPERATURES.
.SPOTTER INFORMATION STATEMENT...
SPOTTER ACTIVATION MAY BE REQUIRED.
WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER
CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
GRAPHICAL FORECASTS OF WEATHER HAZARDS OUT TO SEVEN DAYS
ARE DISPLAYED ON THE WORLD WIDE WEB AT:
WWW.WRH.NOAA.GOV/PDT/CURRENTHAZARDS/HWO.HTML
ALL LETTERS IN THE ABOVE URL ARE LOWER CASE.SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PENDLETON OR
655 PM PDT MON JUN 28 2010
ORZ505-506-290300-
JOHN DAY BASIN OR-OCHOCO-JOHN DAY HIGHLANDS OR-
655 PM PDT MON JUN 28 2010
...SIGNIFICANT WEATHER ADVISORY FOR EASTERN GRANT COUNTY IN EAST
CENTRAL OREGON UNTIL 800 PM PDT...
AT 649 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 26 MILES NORTHWEST OF DREWSEY...OR 38 MILES
NORTHEAST OF BURNS...MOVING NORTHEAST AT 35 MPH.
HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
LAT...LON 4406 11889 4435 11896 4470 11847 4467 11851
4464 11835 4457 11830 4453 11836 4446 11836
4442 11842 4435 11841 4432 11847 4426 11849
4425 11823 4408 11821 4405 11825 4403 11863
4403 11880
TIME...MOT...LOC 0154Z 218DEG 30KT 4411 11869
MCJSPECIAL WEATHER STATEMENT...RETRANSMITTED
NATIONAL WEATHER SERVICE PENDLETON OR
702 PM PDT MON JUN 28 2010
ORZ505-506-290300-
JOHN DAY BASIN OR-OCHOCO-JOHN DAY HIGHLANDS OR-
702 PM PDT MON JUN 28 2010
...SIGNIFICANT WEATHER ADVISORY FOR EASTERN GRANT COUNTY IN EAST
CENTRAL OREGON UNTIL 800 PM PDT...
AT 649 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 26 MILES NORTHWEST OF DREWSEY...OR 38 MILES
NORTHEAST OF BURNS...MOVING NORTHEAST AT 35 MPH.
HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
LAT...LON 4406 11889 4435 11896 4470 11847 4467 11851
4464 11835 4457 11830 4453 11836 4446 11836
4442 11842 4435 11841 4432 11847 4426 11849
4425 11823 4408 11821 4405 11825 4403 11863
4403 11880
TIME...MOT...LOC 0154Z 218DEG 30KT 4411 11869
MCJSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE PENDLETON OR
745 PM PDT MON JUN 28 2010
ORZ049-050-503-290345-
GRANDE RONDE VALLEY OR-SOUTHERN BLUE MOUNTAINS OF OREGON OR-WALLOWA
COUNTY OR-
745 PM PDT MON JUN 28 2010
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN UNION AND SOUTHERN
WALLOWA COUNTIES UNTIL 845 PM PDT...
AT 738 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 13 MILES SOUTHEAST OF UNION...OR 23 MILES NORTH
OF BAKER...MOVING NORTHEAST AT 35 MPH.
HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE
EXPECTED WITH THIS STORM.
IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A
STURDY BUILDING.
LAT...LON 4506 11721 4507 11755 4498 11757 4499 11779
4504 11785 4504 11788 4499 11789 4500 11808
4502 11809 4501 11816 4501 11829 4540 11778
4534 11742 4510 11711
TIME...MOT...LOC 0244Z 209DEG 44KT 4515 11761
MCJPRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE PENDLETON OR
816 PM PDT MON JUN 28 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0741 PM HAIL 1 ENE NORTH POWDER 45.04N 117.90W
06/28/2010 E0.25 INCH UNION OR TRAINED SPOTTER
LIGHT RAIN CURRENTLY. PEA-SIZED HAIL STARTED WHILE ON THE
PHONE. WIND IS BLOWING HARD, AND SEEING BLOWING DUST.
LOOKING SOUTH AT APPROACHING STORM, LOOKS BLACK.
&&
DMHThe Pendleton radar (KPDT), 112 km away, was scanning. The volume nearest the first event began at 03:30 UTC.
2 thunderstorm wind, 2 hail. Local standard time, as filed.
Thunderstorm winds broke the 1.5 inch diameter top off a 10 year old maple tree. Winds accompanied by very heavy rainfall and hail.
Hail accompanied by 40-50 mph winds. Spotter also observed a wall cloud about 5 miles south of LaGrande.
Wallowa County dispatch reported a tree blown down on Highway 3 at milepost 30.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2010Every state in 2010This day in weather historyWarnings in Oregon, June 2010
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: 238387, 238388, 238389, 238391.