A strong cold front combined with instability associated with an upper level low off the coast of California to generate severe convection in parts of Southeast Oregon and Southwest Idaho.
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 cold front combined with instability associated with an upper level low off the coast of California to generate severe convection in parts of Southeast Oregon and Southwest Idaho.
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 Aug 22, 1:09 PM MST, 6 hours 31 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE BOISE ID
209 PM MDT THU AUG 22 2013
.SHORT TERM...UPPER LOW WAS IN NORTHERN-MOST CALIFORNIA AT 19Z AND
MOVING NEWD. QUITE A CLUSTER OF THUNDERSTORMS JUST WEST OF SOUTHERN
HARNEY COUNTY WHERE NAM HAS MAXIMUM INSTABILITY. THAT MAXIMUM
MOVES TO SRN HARNEY COUNTY 21Z THEN FADES IN MALHEUR COUNTY 00Z.
THE INSTABILITY LOBE LOOKS LIKE IT IS JUST AHEAD OF A COLD FRONT
THAT WILL MAKE ITS WAY INTO SWRN IDAHO 00Z-03Z THIS EVENING WITH
SCATTERED THUNDERSTORMS AND GUSTY WINDS. ANOTHER AREA OF
INSTABILITY WILL TRACK NEWD INTO BAKER COUNTY 00Z AND THE WEST
CENTRAL IDAHO MOUNTAINS 03Z-06Z...AGAIN WITH THUNDERSTORMS AND GUSTY
WINDS. HEAVY RAIN ALSO POSSIBLE AS PRECIPITABLE WATER REMAINS
HIGH. IT IS WORTH NOTING THAT LATEST MOS GUIDANCE HAS LOWERED
POPS AND QPF FROM PREVIOUS FORECASTS...PERHAPS TOO MUCH...BUT
VALUES ARE LESS THAN BEFORE IN ALL AREAS. CLEARING FROM THE
SOUTHWEST OVERNIGHT AFTER UPPER LOW EXITS NEWD PAST OUR OREGON
ZONES. SOME LINGERING SHOWERS AND THUNDERSTORMS WILL CONTINUE IN
CENTRAL IDAHO MOUNTAIN ZONES FRIDAY BUT THE REST OF OUR CWA SHOULD
BE SUNNY AND 8 TO 10 DEGREES COOLER THAN TODAY. ON SATURDAY THE
LONG WAVE TROUGH OFF THE NW COAST WILL COME CLOSER AND A CHANCE OF
THUNDERSTORMS WILL DEVELOP IN THE BLUE MOUNTAINS OF WESTERN BAKER
COUNTY. ALSO...MONSOON MOISTURE IN THE SOUTHERN GREAT BASIN WILL
SURGE NORTH AND CLIP TWIN FALLS COUNTY FOR A CHANCE OF THUNDERSTORMS
THERE SATURDAY AFTERNOON. THE REST OF OUR CWA WILL BE SUNNY AND
DRY SATURDAY AND A LITTLE WARMER THAN FRIDAY.
.LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...LITTLE CHANGE IN THE
WEATHER PATTERN AS MODELS CONTINUE THE DRY SOUTHWEST FLOW OVER THE
FORECAST AREA. MODELS ALSO CONTINUE TO SHOW TWO MOISTURE STREAMS
THAT ARE CLOSE TO THE FORECAST AREA. GFS SHOWING A WEAK WAVE MOVING
THROUGH THE FLOW ON SUNDAY THAT MAY BRING SOME OF THE NORTHERN
STREAM OF MOISTURE TO BAKER COUNTY AND THE NORTHERN SECTION OF
HARNEY COUNTY. THE OTHER SOURCE OF MOISTURE THAT IS TO THE SOUTH
AND EAST IS MONSOON MOISTURE MOVING NORTH ALONG THE NEVADA/UTAH
LINE. GFS CONTINUES TO SHOW MORE OF THIS MOISTURE MOVING NORTH
COMPARED TO THE ECMWF BUT STILL THINK THIS MOISTURE WILL REMAIN TO
THE EAST OF THE FORECAST AREA. TEMPERATURES THROUGH THE EXTENDED
PERIOD WILL BE 4 TO 6 DEGREES ABOVE NORMAL.
&&
.AVIATION...MOSTLY VFR. SCATTERED SHOWERS AND THUNDERSTORMS ALONG
THE NEVADA BORDER AT 20Z WILL CONTINUE TO DEVELOP AND MOVE NORTH
THROUGH THE EVENING HOURS. STRONGEST STORMS WILL BE NORTH AND WEST
OF A KREO-KBOI-KSMN LINE WITH SCATTERED MVFR CONDITIONS IN HEAVY
RAIN ALONG WITH MOUNTAIN OBSCURATION. THESE STORMS WILL DECREASE
FROM SOUTH TO NORTH AFTER 06Z BUT COULD SEE THESE STORMS LINGER OVER
NORTHERN ZONES INTO FRIDAY MORNING. SURFACE WINDS WILL BE LIGHT
EXCEPT WESTERLY 10-15 KNOTS OVER SOUTHEAST OREGON. WINDS ALOFT WILL
BE SOUTHERLY AROUND 20 KNOTS UP THROUGH 10K FEET MSL.
&&
.BOI WATCHES/WARNINGS/ADVISORIES...
ID...RED FLAG WARNING UNTIL 6 AM MDT FRIDAY IDZ424.
RED FLAG WARNING UNTIL 6 AM MDT FRIDAY IDZ423-426.
RED FLAG WARNING UNTIL 6 AM MDT FRIDAY IDZ400>403-420 421.
OR...RED FLAG WARNING UNTIL 6 AM MDT /5 AM PDT/ FRIDAY ORZ636-637.
&&
WEATHER.GOV/BOISE
SHORT TERM...LC
LONG TERM....JA/KA
AVIATION.....JAHAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 552 AM MDT THU AUG 22 2013 IDZ011>016-028>030-033-ORZ061>064-231200- 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-HARNEY COUNTY-BAKER COUNTY-MALHEUR COUNTY- LOWER TREASURE VALLEY OR- 552 AM MDT THU AUG 22 2013 /452 AM PDT THU AUG 22 2013/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTH CENTRAL IDAHO...SOUTHWEST IDAHO...WEST CENTRAL IDAHO...NORTHEAST OREGON AND SOUTHEAST OREGON. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS WILL DEVELOP LATER TODAY ACROSS THE AREA...AND CONTINUE INTO THE OVERNIGHT PERIOD. ABUNDANT LIGHTNING FROM THESE STORMS COULD EASILY START NEW WILDFIRES...AND RED FLAG WARNINGS ARE IN EFFECT. THESE THUNDERSTORMS COULD ALSO PRODUCE STRONG GUSTY WINDS AND LOCALLY HEAVY RAINFALL. PERSONS NEAR RECENT BURN SCARS SHOULD REMAIN ESPECIALLY WATCHFUL FOR HEAVY RAIN CAUSING FLASH FLOODING OR DEBRIS FLOWS OVER RECENTLY BURNED TERRAIN...AND BE PREPARED TO MOVE TO HIGHER GROUND IF FLASH FLOODING THREATENS. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT...
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BOISE ID 142 PM PDT THU AUG 22 2013 ORZ061-222130- HARNEY OR- 142 PM PDT THU AUG 22 2013 THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... EAST CENTRAL HARNEY COUNTY IN SOUTHEAST OREGON... UNTIL 230 PM PDT. AT 139 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 9 MILES SOUTH OF NEW PRINCETON...MOVING NORTH AT 20 MPH. HAIL UP TO THE SIZE OF NICKELS HAIL IS EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. A TRAINED WEATHER SPOTTER REPORTED .33 INCH OF RAIN IN 9 MINUTES FROM THIS STORM. THE THUNDERSTORM WILL BE NEAR... BARTON LAKE RESERVOIR AND RIDDLE MOUNTAIN AROUND 140 PM PDT. LIGHTNING IS ONE OF NATURES NUMBER ONE KILLERS. TAKE SHELTER INSIDE A BUILDING OR VEHICLE WHEN THUNDERSTORMS APPROACH. LIGHTNING CAN OCCUR 15 MILES OR MORE AWAY FROM THE CENTER OF A STORM. IF YOU CAN HEAR THUNDER...YOU ARE CLOSE ENOUGH TO BE STRUCK BY LIGHTNING. LAT...LON 4329 11866 4326 11842 4305 11846 4310 11866 TIME...MOT...LOC 2041Z 192DEG 17KT 4317 11855 LRC
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE BOISE ID
638 PM MDT THU AUG 22 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0508 PM TSTM WND GST 9 S BOISE 43.48N 116.23W
08/22/2013 M51.00 MPH ADA ID TRAINED SPOTTER
0514 PM TSTM WND GST BOISE 43.61N 116.23W
08/22/2013 M60.00 MPH ADA ID ASOS
KBOI ASOS
&&
KANDERSOThe Boise radar (KCBX), 97 km away, was scanning. The volume nearest the first event began at 02:39 UTC.
1 thunderstorm wind. Local standard time, as filed.
Malheur County Sheriff dispatch reported several large trees and power lines down in Vale, Oregon and power outages in Ontario, Oregon.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Oregon in 2013Every state in 2013This day in weather historyWarnings in Oregon, August 2013
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: 473973.