A strong cold front moving in from the northwest late in the afternoon on the 21st caused wind damage to parts of Southwest Idaho.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 moving in from the northwest late in the afternoon on the 21st caused wind damage to parts of 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 May 21, 1:29 PM MST, 26 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 229 PM MDT TUE MAY 21 2013 .SHORT TERM...TONIGHT THROUGH THURSDAY...LARGE STRONG CUT OFF LOW JUST OFF THE COAST OF WASHINGTON THIS AFTERNOON WILL DRIFT SE TOWARD THE AREA OVERNIGHT BUT THEN STALL GENERALLY OVER WASHINGTON AND OREGON TOMORROW. A POTENT COLD FRONT WILL RACE THROUGH SE OREGON THIS AFTERNOON AND SW IDAHO LATE THIS AFTERNOON AND THIS EVENING. WINDS WILL GUST 30 TO 40 MPH ALONG AND A FEW HOURS BEHIND THE FRONT. SHOWERS AND STORMS HAVE FORMED ALONG AND JUST AHEAD OF THE FRONT...AND THESE ARE EXPECTED TO REMAIN MOSTLY NORTH OF A LINE FROM BURNS TO ONTARIO TO FAIRFIELD. SHOWERS ARE EXPECTED TO ALSO CONTINUE BEHIND THE FRONT THIS EVENING...MAINLY IN THE HIGHER TERRAIN. THE COLD FRONT WILL BRING MUCH COOLER AIR INTO THE REGION...LOWERING HIGH TEMPS BY 20 TO 25 DEGREES FOR WEDNESDAY. SHOWERS WILL REMAIN POSSIBLE OVER THE HIGHER TERRAIN THROUGH THU AS THE LOW REMAINS NEARLY STATIONARY. TEMPS WILL RECOVER BY 5 TO 8 DEGREES ON THU...COMPARED TO WED/S HIGHS. .LONG TERM...THURSDAY NIGHT THROUGH TUESDAY...THE CLOSED UPPER LEVEL LOW PRESSURE SYSTEM WILL CONTINUE TO BE ANCHORED OVER THE PACIFIC NORTHWEST THROUGH SATURDAY. A SERIES OF SHORTWAVE TROUGHS EMBEDDED IN THE SW FLOW OVER THE AREA WILL BRING PERIODS OF SHOWERS AND AFTERNOON THUNDERSTORMS TO SOUTHEAST OREGON AND THE WEST CENTRAL IDAHO MOUNTAINS. EXPECT TEMPERATURES TO BE NEAR NORMAL OR SEVERAL DEGREES BELOW NORMAL. BY SUNDAY THE LOW CENTER WILL MOVE OFF TO OUR NORTH AND EAST AS A SECONDARY TROUGH PUSHES INTO THE INTERMOUNTAIN WEST. MONDAY AND BEYOND THE FLOW WILL SHIFT TO ZONAL...WITH AMPLE MOISTURE FOR A CHANCE OF SHOWERS MAINLY OVER THE HIGHER TERRAIN. SLIGHTLY HIGHER HEIGHTS IN THE ZONAL FLOW WILL ALLOW TEMPERATURES TO INCREASE TO SEVERAL DEGREES ABOVE NORMAL BY TUESDAY. && .AVIATION...VFR TODAY WITH A COLD FRONT MOVING THROUGH THE AREA. AHEAD OF THE FRONT...GUSTY SE TO SW SURFACE WINDS AT 10-20 KTS WITH WINDS REACHING 20-30 KTS AT TIMES. AT 20Z...SHOWERS AND THUNDERSTORMS ARE SPREADING INTO SE OREGON AHEAD OF THE FRONT. THE FRONT WILL PASS THROUGH KBNO-KBKE BETWEEN 20-21Z AND THEN PUSH THROUGH SW IDAHO FROM 00Z-03Z. SURFACE WINDS BEHIND THE FRONT WILL BE NW AT 15-25 KTS. SHOWERS AND THUNDERSTORMS ARE POSSIBLE WITH THE FRONTAL PASSAGE...MAINLY OVER EAST CENTRAL OREGON AND THE WEST CENTRAL IDAHO MOUNTAINS. SW WINDS ALOFT AVERAGING 25 KTS UP TO 10K FEET MSL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && WEATHER.GOV/BOISE SHORT TERM...SP LONG TERM....CB/JA AVIATION.....CB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 533 AM MDT TUE MAY 21 2013 IDZ011>016-028>030-033-ORZ061>064-221200- 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- 533 AM MDT TUE MAY 21 2013 /433 AM PDT TUE MAY 21 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 NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The national radar mosaic for the moment the first event began.
3 strong wind. Local standard time, as filed.
The local newspaper in Weiser reported a large, metal shed was thrown 30 to 40 feet in the air and displaced about 100 feet from it's original location.
A trained spotter reported trees down on a power box in McCall near Forest Road. At 215 MST, Idaho Power reported 575 customers around McCall were without power.
Wind damage was reported in Garden Valley with trees down and damage to homes.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2013Every state in 2013This day in weather historyWarnings in Idaho, May 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: 451824, 451826, 451829.