An upper low moving through the Intermountain West kicked off showers and isolated severe thunderstorms across parts of 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.
An upper low moving through the Intermountain West kicked off showers and isolated severe thunderstorms across 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 26, 8:38 AM MST, 4 hours 32 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 938 AM MDT SUN MAY 26 2013 .DISCUSSION...INCREASED POPS THIS MORNING AND AFTERNOON ACROSS MUCH OF THE AREA WITH PASSAGE OF A POTENT SHORTWAVE. 15Z SATELLITE IMAGERY SHOWING THE SHORTWAVE OVER CENTRAL OREGON AND IS FORECAST TO MOVE E-NE OVER REACHING LEWISTON IDAHO THIS EVENING. ALREADY SCATTERED RAIN SHOWERS DEVELOPING ACROSS THE AREA THIS MORNING. EXPECT THUNDERSTORMS TO DEVELOP EARLY THIS AFTERNOON ACROSS OUR SOUTHERN ZONES WITH STORMS MOVING N-NE INTO THE VALLEYS AND NORTHERN ZONES LATER THIS AFTERNOON. CLOUDY SKIES WILL LIMIT SURFACE BASED INSTABILITY THIS AFTERNOON. HOWEVER...DO EXPECT 300-500 J/KG OF CAPE AND BEST DYNAMIC SUPPORT ACROSS NORTHERN ZONES /BAKER COUNTY-WEST CENTRAL MOUNTAINS/ BETWEEN 21-03Z TODAY. SHEARS IS MARGINAL AT BEST...BUT LOW FREEZING LEVELS /9500 FEET MSL/ FOR WOULD SUGGEST SMALL HAIL WITH THE STRONGER STORMS. UPDATED ZONES WILL BE SENT OUT SHORTLY. && .AVIATION...WIDESPREAD SHOWERS WITH SCATTERED THUNDERSTORMS IN THE MTNS AND ISOLATED THUNDERSTORMS IN THE LOWER VALLEYS TODAY. HEAVIER SHOWERS AND THUNDERSTORMS WILL BRIEFLY PRODUCE MVFR CONDITIONS... OBSCURING HIGHER TERRAIN. THUNDERSTORMS COULD ALSO PRODUCE SMALL HAIL ACROSS SE OREGON AND THE MTNS OF SW IDAHO THIS AFTERNOON. WINDS TO 20 KTS SURFACE THROUGH 10K FEET MSL. LOWER CEILINGS AND RAIN LINGER OVERNIGHT IN THE WEST CENTRAL AND BOISE MTNS. VFR ON MONDAY WITH LOWERING CEILINGS AND SHOWERS DEVELOPING ACROSS SE OREGON IN THE AFTERNOON. && .PREV DISCUSSION... SHORT TERM...TODAY THROUGH MONDAY...A MODERATE SHORT WAVE TROUGH SEEN JUST COMING ONSHORE ON THE OREGON COAST AS OF 2 AM MDT WILL MOVE THROUGH THE AREA TODAY AND EARLY TONIGHT...BRINGING WITH IT A WEAK COLD FRONT...SHOWERS...AND THUNDERSTORMS. MOST OF THE PRECIPITATION WILL BE IN THE MOUNTAINS...BUT SOME IS EXPECTED IN THE VALLEYS AS WELL. AFTER A BRIEF BREAK LATE SUNDAY NIGHT INTO EARLY MONDAY...ANOTHER SYSTEM WILL APPROACH LATE MONDAY. THIS WILL SPREAD SHOWERS AND STORMS INTO EASTERN OREGON LATE IN THE DAY. HIGH TEMPS WILL BE HELD IN CHECK BY THE CLOUD COVER AND PRECIPITATION BOTH DAYS...WHILE LOWS WILL NEAR NORMAL. THE SYSTEM TODAY WILL BE WETTER THAN THE ONE YDAY...AND THE ONE COMING IN LATE MONDAY WILL BE WETTER STILL. LONG TERM...MONDAY NIGHT THROUGH SATURDAY...BROAD CYCLONIC FLOW WILL CONTINUE OVER THE PACIFIC NORTHWEST. FORECAST STILL ON TRACK FOR A RELATIVELY MOIST SHORTWAVE TROUGH TO MOVE INTO SOUTHEAST OREGON LATE MONDAY NIGHT...AND THROUGH SOUTHWEST IDAHO ON TUESDAY. EXPECT WIDESPREAD SHOWERS AND A CHANCE OF AFTERNOON/EVENING THUNDERSTORMS. THIS TROUGH WILL ALSO DROP TEMPS TO AROUND 10 DEGREES BELOW NORMAL. THERE WILL BE A BRIEF BREAK IN PRECIP ON WEDNESDAY...BEFORE A SECOND SHORTWAVE TRAVERSES ACROSS THE NORTHERN ZONES OF THE CWA. JET STREAM ACTIVITY AND MOST OF THE ENERGY IN THE PATTERN WILL THEN SHIFT FURTHER NORTH INTO BRITISH COLUMBIA FOR THE WEEKEND...BRINGING HIGHER HEIGHTS OVER THE INTERMOUNTAIN WEST AND A RETURN TO NEAR NORMAL TEMPERATURES FOR THE WEEKEND. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && WEATHER.GOV/BOISE DISCUSSION...JDS AVIATION.....DG PREV SHORT TERM...SP PREV LONG TERM....CB
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 550 AM MDT SUN MAY 26 2013 IDZ011>016-028>030-033-ORZ061>064-271200- 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- 550 AM MDT SUN MAY 26 2013 /450 AM PDT SUN MAY 26 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...MONDAY THROUGH SATURDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The Boise radar (KCBX), 44 km away, was scanning. The volume nearest the first event began at 20:09 UTC.
1 tornado. Local standard time, as filed.
Two photographs submitted by the public on Facebook show an EF-0 tornado about 10 miles northwest of Mountain Home. No damage was reported.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2013Every state in 2013This day in weather historyThe tornado archive for Idaho, 2013Warnings 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: 451830.