A strong, spring season cold front moved through Central Oregon on the afternoon of the 20th creating severe thunderstorms with damaging winds in Harney and Malheur counties.
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 BOI wrote it up.
A strong, spring season cold front moved through Central Oregon on the afternoon of the 20th creating severe thunderstorms with damaging winds in Harney and Malheur counties.
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 Boise, ID wrote its last area forecast discussion before the first event at Apr 20, 1:05 PM PST, 1 hour 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 305 PM MDT TUE APR 20 2010 .SHORT TERM...TONIGHT THROUGH THURSDAY...COLD FRONT FROM WESTERN NV THROUGH CENTRAL OREGON AT 2 PM MDT WILL SHIFT THROUGH SE OREGON TONIGHT AND SW IDAHO WEDNESDAY. THE PARENT UPPER LOW WILL CONTINUE ITS TREK TOWARDS THE SE ACROSS CA TONIGHT WHILE SPREADING THE NOSE OF AN UPPER LEVEL JET ALONG THE NV BORDER TONIGHT. THE STRONGEST THUNDERSTORMS ARE EXPECTED TO BE NEAR THE NOSE OF THE JET AND ALONG THE FRONT ACROSS HARNEY COUNTY THIS AFTERNOON... JORDAN VALLEY AND OWYHEE COUNTY LATE AFTERNOON INTO TONIGHT. ON THE NORTHERN SIDE OF THE UPPER LOW...BANDS OF SHOWERS ARE EXPECTED TO SPIRAL NORTH OVER OREGON TONIGHT AND IDAHO EARLY WEDNESDAY...WITH SNOW LEVELS LOWEST ACROSS HARNEY COUNTY. SHOWER BANDS ARE EXPECTED TO PERSIST OVER SE OREGON THROUGH THURSDAY EVENING AND SW IDAHO WEDNESDAY THROUGH THURSDAY NIGHT AS THE UPPER LOW RESIDES OVER NEVADA. AN UPPER LEVEL RIDGE IS EXPECTED TO GRADUALLY FOLD OVER THE LOW AS IT EXITS INTO THE FOUR CORNERS REGION THURSDAY NIGHT. BUT THIS KEEP BANDS OF SHOWERS AND LIFT GOING ACROSS SOUTHWEST TO SOUTH CENTRAL IDAHO THROUGH THURSDAY NIGHT FOR A WET AND UNSETTLED PERIOD. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...UPPER LEVEL LOW THAT WILL HAVE BEEN OVER SOUTHERN NEVADA FOR A FEW DAYS WILL FINALLY PUSH TO THE EAST THURSDAY NIGHT AS AN UPPER LEVEL RIDGE BUILDS INTO THE PACIFIC NORTHWEST. MODELS INDICATE A WEAK SHORT WAVE TROUGH RIDING OVER THE TOP OF THE RIDGE SO WILL KEEP CHANCE POPS OVER THE HIGHER TERRAIN OF SOUTHWEST IDAHO FOR THURSDAY NIGHT AND THEN DECREASE TO SLIGHT CHANCE FOR FRIDAY. DRY CONDITIONS FOR MOST AREAS ON FRIDAY AS THE RIDGE MOVES OVER THE REGION. FOR SATURDAY AND SUNDAY MODELS BEGIN TO DIFFER ON THE PLACEMENT OF THE NEXT SHORTWAVE TROUGH THAT WILL MOVE INTO THE PACIFIC NORTHWEST. THE LAST FEW MODEL RUNS HAVE CONTINUED THE TREND OF THIS SYSTEM COMING INTO THE PACIFIC NORTHWEST A LITTLE WEAKER AND ALSO A BIT FURTHER TO THE NORTH. IF THE MODELS CONTINUE THE TREND OF THIS TROUGH MOVING FURTHER TO THE NORTH THIS WILL BRING DRIER CONDITIONS TO THE REGION AND WARMER TEMPERATURES. WITH UNCERTAINTY AS TO HOW FAR NORTH THIS SHORT WAVE WILL MOVE FOR SATURDAY AND SUNDAY WILL KEEP SLIGHT CHANCE TO CHANCE POPS OVER NORTHERN ZONES BUT DID INCREASE MAX TEMPERATURES BETWEEN 5 AND 7 DEGREES. MONDAY AND TUESDAY MODELS DIFFER ON THE TIMING OF ANOTHER WEAK RIDGE MOVING OVER THE AREA AND THE NEXT UPPER LEVEL TROUGH THAT WILL MOVE INTO THE PACIFIC NORTHWEST. WITH LOW CONFIDENCE IN THE MODELS AND UNCERTAINTY AS TO IF THERE WILL BE A RIDGE OR A TROUGH WILL KEEP POPS NEAR CLIMATOLOGY AND TEMPERATURES NEAR NORMAL. && .AVIATION...SOUTHEAST OREGON...AS OF 20Z SURFACE COLD FRONT STALLED ON A LINE FROM KMFR-KAAT WITH SCATTERED SHOWERS AND THUNDERSTORMS AROUND 70 MILES TO THE EAST OF THIS LINE. SHOWERS AND THUNDERSTORMS WILL MOVE INTO THE KBNO AREA AFTER 23Z AND KBKE AFTER 02Z. THIS ACTIVITY WILL LEAD TO AREAS OF MVFR/LOCAL IFR CONDITIONS ALONG WITH MOUNTAINS BECOMING OBSCURED. SURFACE WINDS WILL BE LIGHT TO LOCALLY MODERATE TONIGHT WITH GUSTY WINDS NEAR THUNDERSTORMS. MODERATE SOUTH WINDS ALOFT. SOUTHWEST IDAHO...AS OF 20Z CONVECTIVE ACTIVITY WAS DEVELOPING OVER THE OWYHEE MOUNTAINS SOUTH INTO NEVADA. THESE SHOWERS AND THUNDERSTORMS WILL CONTINUE TO DEVELOP INTO THIS EVENING AND SPREAD TO THE NORTH AND WEST. THUNDERSTORMS AREA POSSIBLE AT KBOI AFTER 00Z BUT DO NOT EXPECT ANY AT KTWF/KJER. LOCAL MVFR CONDITIONS AND GUSTY WINDS/SMALL HAIL WILL ACCOMPANY SOME OF THE THUNDERSTORMS. SURFACE WINDS WILL BE LIGHT TO LOCALLY MODERATE WITH MODERATE SOUTH WINDS ALOFT. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && WEATHER.GOV/BOISE SHORT TERM...VM LONG TERM....JA/LH AVIATION.....JA
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 617 AM MDT TUE APR 20 2010 ORZ061>064-211215- HARNEY COUNTY-BAKER COUNTY-MALHEUR COUNTY- LOWER TREASURE VALLEY OR- 617 AM MDT TUE APR 20 2010 /517 AM PDT TUE APR 20 2010/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTHEAST OREGON AND SOUTHEAST OREGON. .DAY ONE...TODAY AND TONIGHT A STRONG LOW PRESSURE SYSTEM A COLD FRONT WILL MOVE INTO SOUTHEAST OREGON. RAIN AND HIGH ELEVATION SNOW WILL DEVELOP THIS MORNING AND BECOME WIDESPREAD DURING THE AFTERNOON. SNOW LEVELS WILL REMAIN ABOVE 7500 FEET. COLDER AIR WILL MOVE IN BEHIND THE FRONT TONIGHT WITH SNOW LEVELS DROPPING TO BETWEEN 4000 AND 4500 FEET ACROSS HARNEY AND SOUTHERN MAHLER COUNTIES. IN THESE AREAS...SNOW ACCUMULATIONS OF 1 TO 4 INCHES ARE POSSIBLE ON NON-PAVED SURFACES WITH 1 TO 2 FEET POSSIBLE IN THE STEENS MOUNTAIN. SNOW LEVELS WILL REMAIN ABOVE 7500 FEET ACROSS THE REMAINDER OF SOUTHEAST OREGON. THOSE PLANNING TRAVEL TONIGHT...ESPECIALLY IN HARNEY COUNTY AND SOUTHERN MALHEUR COUNTY...SHOULD BE PREPARED FOR WINTER-LIKE CONDITIONS. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY WET WEATHER WILL CONTINUE WEDNESDAY AND THURSDAY BEFORE DRIER AIR MOVES IN ON FRIDAY. ADDITIONAL SNOW ACCUMULATIONS ARE POSSIBLE...ESPECIALLY IN THE STEENS. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT ANY SIGNIFICANT WEATHER IN ACCORDANCE WITH STANDARD OPERATING PROCEDURES. IDZ011>016-028>030-033-211215- WEST CENTRAL MOUNTAINS-LOWER TREASURE VALLEY ID-BOISE MOUNTAINS- UPPER TREASURE VALLEY-SOUTHWEST HIGHLANDS-WESTERN MAGIC VALLEY- CAMAS PRAIRIE-OWYHEE MOUNTAINS-SOUTHERN TWIN FALLS COUNTY- UPPER WEISER RIVER- 617 AM MDT TUE APR 20 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL IDAHO...SOUTHWEST IDAHO AND WEST CENTRAL IDAHO. .DAY ONE...TODAY AND TONIGHT SCATTERED SHOWERS AND THUNDERSTORMS WILL DEVELOP THIS AFTERNOON THROUGH THIS EVENING AHEAD OF A STRONG PACIFIC SYSTEM AND COLD FRONT. THE THUNDERSTORMS COULD PRODUCE GUSTY WINDS AND SMALL HAIL. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY EXPECT COOLER...BREEZY...AND SHOWERY WEATHER WEDNESDAY AND THURSDAY BEFORE DRIER AIR MOVES IN ON FRIDAY. SNOW LEVELS WILL REMAIN ABOVE 7000 FEET ACROSS MOST OF SOUTHWEST IDAHO...EXCEPT IN THE OWYHEE MOUNTAINS...SOUTHWEST HIGHLANDS...AND SOUTHERN TWIN FALLS COUNTY WHERE SNOW LEVELS COULD DROP DOWN TO NEAR 5000 FEET. SOME SNOW ACCUMULATIONS ARE LIKELY ABOVE 5000 FEET WITH UP TO A FOOT OF SNOW POSSIBLE ABOVE 6000 FEET. .SPOTTER INFORMATION STATEMENT... SPOTTERS SHOULD REPORT ANY SIGNIFICANT WEATHER IN ACCORDANCE WITH STANDARD OPERATING PROCEDURES.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BOISE ID 414 PM MDT TUE APR 20 2010 ORZ061-063-202300- HARNEY OR-MALHEUR OR- 314 PM PDT TUE APR 20 2010 THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... EASTERN HARNEY COUNTY IN SOUTHEAST OREGON... AND SOUTHWESTERN MALHEUR COUNTY IN SOUTHEAST OREGON... UNTIL 400 PM PDT/500 PM MDT/. AT 308 PM PDT...STORM SPOTTERS REPORTED A STRONG THUNDERSTORM 18 MILES SOUTHEAST OF FRENCHGLEN...MOVING NORTH AT 40 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER IS EXPECTED WITH THIS STORM. WIND GUSTS TO 40 MPH AND RAPIDLY FALLING TEMPERATURES ARE ALSO EXPECTED. LOCATIONS IMPACTED INCLUDE... FISH LAKE CAMPGROUND... MOON HILL... DIAMOND... DIAMOND CRATERS... AND BARTON LAKE RESERVOIR. LAT...LON 4348 11930 4364 11880 4204 11782 4205 11827 TIME...MOT...LOC 2212Z 169DEG 35KT 4275 11860 !LRC!
The Boise radar (KCBX), 195 km away, was scanning. The volume nearest the first event began at 22:31 UTC.
2 thunderstorm wind. Local standard time, as filed.
Harney County Sheriff Department reported 52 broken or downed power poles along state highway 78, damaged roofs, several outbuildings partially destroyed, and a mobile home blown 3 feet off the foundation.
The Rome ASOS measured a wind gust of 62 MPH from the southwest.
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, April 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: 228002, 228003.