A large area of low pressure situated over the Great Basin created favorable conditions for isolated severe convection across the region, including parts of southern 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 large area of low pressure situated over the Great Basin created favorable conditions for isolated severe convection across the region, including parts of southern 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 8, 1:45 PM MST, 2 hours 35 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 245 PM MDT WED MAY 8 2013 .SHORT TERM...GRADUAL WARMING AND DRYING THROUGH FRIDAY BUT ENOUGH MOISTURE AND INSTABILITY REMAINING FOR AFTERNOON/EVENING SHOWERS AND THUNDERSTORMS. ON THE LARGER SCALE...UPPER LOW NEAR FOUR CORNERS IS STRETCHING ENE-WSW WHILE UPPER HIGH COMES INLAND ACROSS WA/OR. THIS WILL MAINTAIN AN EASTERLY WIND COMPONENT ALOFT IN OUR AREA WITH SHOWERS/STORMS CONTINUING TO TRACK FROM ENE TO WSW. SHOWERS WILL BE MAINLY ON THE IDAHO SIDE NORTH OF THE SNAKE BASIN AND AS THEY MOVE INTO THE SNAKE BASIN THEY WILL WEAKEN WITH LITTLE IF ANY RAIN FOR THE AG AREAS. GREATEST INSTABILITY FOR THUNDERSTORMS WILL BE IN AN ARC FROM CENTRAL IDAHO THROUGH BAKER COUNTY THEN SWD THROUGH HARNEY COUNTY. LESS INSTABILITY ELSEWHERE INCLUDING THE SNAKE BASIN ...BUT ENOUGH EVEN THERE FOR A CHANCE OF WEAK THUNDERSTORMS. WARMING TREND WILL CONTINUE AS BEFORE IN THE FORECASTS...NO CHANGES THERE. LIGHT WINDS EXCEPT GUSTS TO 35 MPH NEAR LATE-DAY THUNDERSTORMS. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...UPPER RIDGE THIS WEEKEND WILL BRING TEMPERATURES WELL ABOVE NORMAL. HOWEVER... DEPENDING ON HOW QUICKLY THE NEXT TROUGH REACHES THE AREA WILL DETERMINE HOW WARM WE GET. COULD BE CLOSE TO RECORD TEMPERATURES ON SUNDAY IN SW IDAHO. HOWEVER...CLOUD COVER AND WESTERLY SURFACE WINDS COULD LIMIT TEMPERATURE POTENTIAL TO UPPER 80S IN THE VALLEY. STILL NO MODEL AGREEMENT WITH THE TROUGH APPROACHING THE AREA ON SUNDAY. 12Z GFS IS STILL HAS THE COLD FRONT REACHING THE REGION ON MONDAY. 12Z EC REMAINS THE SAME AS BEFORE WEAKENING THE TROUGH AS IT MOVES INLAND AND ESSENTIALLY KEEPING THE FRONT AND PRECIPITATION NORTH OF THE REGION SUNDAY AND MONDAY. BOTH MODELS SHOWING A TAP OF TROPICAL MOISTURE ASSOCIATED WITH THIS SYSTEM WITH DECENT UPPER LEVEL SUPPORT FOR THUNDERSTORMS SUNDAY AND MONDAY AFTERNOON. MUCH MORE UNCERTAINTY ASSOCIATED WITH THE CUTOFF LOW FOR THE MIDDLE OF THE WEEK BUT GIVEN THE MOISTURE IN PLACE AND ABOVE NORMAL TEMPERATURES THROUGH MID WEEK WILL CONTINUE CLIMO POPS DURING THE AFTERNOON PERIODS TUESDAY AND WEDNESDAY. && .AVIATION...VFR. SCATTERED SHOWERS AND THUNDERSTORMS ACROSS THE HIGHER TERRAIN THIS AFTERNOON SHOULD DRIFT TO THE WEST-SOUTHWEST OVER LOWER VALLEYS. SURFACE WINDS GENERALLY LIGHT AROUND 10 KTS BUT WITH HIGHER GUSTS NEAR THUNDERSTORMS. WINDS ALOFT NORTHEAST AT 15 KTS OR LESS THROUGH 10K FT MSL. EXPECT THUNDERSTORMS TO DIMINISH AFTER SUNSET. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && WEATHER.GOV/BOISE SHORT TERM...LC LONG TERM....JDS AVIATION.....JDS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 528 AM MDT WED MAY 8 2013 IDZ011>016-028>030-033-ORZ061>064-091200- 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- 528 AM MDT WED MAY 8 2013 /428 AM PDT WED MAY 8 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...THURSDAY THROUGH TUESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
The Pocatello radar (KSFX), 144 km away, was scanning. The volume nearest the first event began at 23:20 UTC.
1 tornado. Local standard time, as filed.
A Jerome County deputy reported a brief tornado touchdown. 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: 451821.