An upper level trough combined with aftenoon heating leading to the development of strong to severe thunderstorms over parts of South Central Idaho on the 4th.
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 level trough combined with aftenoon heating leading to the development of strong to severe thunderstorms over parts of South Central Idaho on the 4th.
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 Jul 4, 1:50 PM MST, 4 hours earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 250 PM MDT THU JUL 4 2013 .SHORT TERM...TONIGHT THROUGH SATURDAY...A SMALL AREA OF THUNDERSTORMS OVER FAR NORTHWEST NEVADA HAS BEEN MOVING E-NE AND WILL BE MOVING INTO EXTREME SOUTHERN HARNEY COUNTY BY 3 PM MDT. THIS COMPLEX OF STORMS WAS ASSOCIATED WITH A SHORT WAVE AS SEEN IN WATER VAPOR IMAGERY. MODELS CONTINUE TO SHOW SHOWERS/STORMS INITIATING ACROSS SOUTHERN HARNEY/SOUTHERN MALHEUR COUNTIES INTO OWYHEE COUNTY ASSOCIATED WITH THIS FEATURE THROUGH THIS EVENING. NORTHWEST WINDS BROUGHT DRIER AIR INTO THE REMAINDER OF THE CWA AS DEWPOINTS ARE CONSIDERABLY LOWER THAN YESTERDAY. CONVECTION WILL WEAKEN AFTER SUNSET BUT MAY LINGER ALONG THE NEVADA BORDER THROUGH FRIDAY MORNING. ON FRIDAY...AN UPPER LEVEL TROUGH WILL SHARPEN BUT REMAIN TO OUR WEST. THE AIR MASS WILL BE SOMEWHAT DRIER AND LESS FAVORABLE FOR THUNDERSTORMS. HOWEVER...SOUTHWEST WINDS ALOFT WILL BECOME MORE FAVORABLE AND LEND A LITTLE MORE SUPPORT FOR THUNDERSTORMS OVER THE SOUTHWEST HIGHLANDS...SOUTHERN TWIN FALLS COUNTY...AND THE EASTERN SIDES OF THE BOISE/WEST CENTRAL MTNS FRIDAY AFT-EVE. THE UPPER TROUGH AXIS WILL REMAIN TO OUR WEST ON SATURDAY. DRIER AIR WILL CONTINUE TO MOVE INTO THE AREA SUCH THAT THE ONLY AREA THAT WILL HAVE ENOUGH MOISTURE/INSTABILITY FOR CONVECTION WILL BE FROM ABOUT TWIN FALLS SOUTH. TEMPERATURES WILL BE A LITTLE LOWER BOTH DAYS ALTHOUGH HIGHS WILL STILL BE A FEW DEGREES ABOVE NORMAL. .LONG TERM...SATURDAY NIGHT THROUGH THURSDAY...WITH A WEAK UPPER LEVEL TROUGH TO OUR WEST...WEAK SW FLOW ALOFT WILL CONTINUE THROUGH MONDAY. THE FLOW FLATTENS TO WESTERLY MONDAY EVENING THROUGH LATE TUE BEFORE GOING BACK INTO SW FLOW WED AND THU AS ANOTHER TROUGH SETS UP OFF THE PAC COAST OF CANADA AND EXTENDS DOWN ALONG THE U.S. COAST. UNLIKE RECENT DAYS...MOISTURE WILL BE HARD TO COME BY IN THIS FLOW AND WE REDUCED POPS SAT NIGHT THROUGH TUE. TEMPS WILL BE AROUND 5 DEGREES ABOVE NORMAL THROUGH THE PERIOD. WINDS WILL BE LIGHT. WEDNESDAY A SHORTWAVE RIDGE BUILDS OVER THE CWA AND TEMPERATURES WARM TO AROUND 5-10 DEGREES ABOVE NORMAL. THURSDAY THE RIDGE MOVES EAST AND ALLOWS FOR A CHANCE OF INCREASED POPS IN THE NORTHERN ZONES. && .AVIATION...VFR...WITH ISOLATED TO SCATTERED THUNDERSTORMS SOUTH OF LINE FROM 70 MILES SW OF KBNO TO KREO TO 50 MILES SW OF KBOI TO KTWF...FROM 21Z TO 08Z. STORMS MAY CONTAIN GUSTS TO 50 MPH AND BRIEF MVFR CONDITIONS. SURFACE WINDS WILL OTHERWISE BE LIGHT WEST TO NORTHWEST. WINDS ALOFT AT 10K FT WILL BE WESTERN AT 15 TO 20 KTS. WEEKEND OUTLOOK...VFR WITH A DECREASING CHANCE OF STORMS AND LIGHT WINDS SFC AND ALOFT. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...RED FLAG WARNING FROM 9 AM TO 9 PM FRIDAY IDZ423-426. OR...NONE. && WEATHER.GOV/BOISE SHORT TERM...BW LONG TERM....SP/KA AVIATION.....SP
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 555 AM MDT THU JUL 4 2013 IDZ011>016-028>030-033-ORZ061>064-051200- 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- 555 AM MDT THU JUL 4 2013 /455 AM PDT THU JUL 4 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...FRIDAY THROUGH WEDNESDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BOISE ID 358 PM MDT THU JUL 4 2013 ORZ063-042245- MALHEUR OR- 258 PM PDT THU JUL 4 2013 THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... SOUTH CENTRAL MALHEUR COUNTY IN SOUTHEAST OREGON... UNTIL 345 PM PDT/445 PM MDT/. AT 248 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 22 MILES NORTHWEST OF MCDERMITT...MOVING NORTHEAST AT 15 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER...WIND GUSTS UP TO 50 MPH AND BRIEF HEAVY RAIN ARE EXPECTED WITH THIS STORM. THE STORM WILL CROSS HIGHWAY 95 BETWEEN MILE MARKERS 88 AND 105 BETWEEN 315 PM PDT AND 345 PM PDT. THE THUNDERSTORM WILL BE NEAR... SCHOOLHOUSE HILL AND TWIN PEAKS AROUND 255 PM PDT... BLUE MOUNTAIN PASS AROUND 320 PM PDT... BASQUE STATION AROUND 430 PM MDT... OVERSHOE PASS AROUND 445 PM MDT. LAT...LON 4257 11777 4239 11753 4213 11794 4226 11812 TIME...MOT...LOC 2155Z 225DEG 15KT 4226 11794
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE BOISE ID 644 PM MDT THU JUL 4 2013 IDZ012>014-029-050130- ADA ID-CANYON ID-BOISE ID-OWYHEE ID-ELMORE ID- 644 PM MDT THU JUL 4 2013 THE NATIONAL WEATHER SERVICE IN BOISE HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... ADA COUNTY IN SOUTHWEST IDAHO... SOUTHEASTERN CANYON COUNTY IN SOUTHWEST IDAHO... CENTRAL ELMORE COUNTY IN SOUTHWEST IDAHO... NORTHWESTERN OWYHEE COUNTY IN SOUTHWEST IDAHO... AND SOUTHWESTERN BOISE COUNTY IN WEST CENTRAL IDAHO... UNTIL 730 PM MDT. AT 639 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A LINE OF OUTFLOW WIND EXTENDING FROM MARSING TO 12 MILES NORTHWEST OF MOUNTAIN HOME AFB...AND MOVING NORTHEAST AT 35 MPH. WIND GUSTS UP TO 45 MPH ARE EXPECTED WITH PASSAGE OF THIS OUTFLOW. THE OUTFLOW WIND WILL BE NEAR... MELBA AROUND 640 PM MDT... INITIAL POINT AROUND 645 PM MDT... CINDER CONE BUTTE AROUND 650 PM MDT... NAMPA AND KUNA AROUND 700 PM MDT... BLACKS CREEK RESERVOIR AND BOISE STAGE STOP AROUND 710 PM MDT... MERIDIAN AND BOISE AROUND 715 PM MDT. LAT...LON 4378 11615 4335 11521 4308 11602 4350 11696 TIME...MOT...LOC 0042Z 245DEG 31KT 4349 11674 4317 11601
The Boise radar (KCBX), 57 km away, was scanning. The volume nearest the first event began at 00:48 UTC.
3 thunderstorm wind. Local standard time, as filed.
A wind gust of 59 MPH was reported at the Mountain Home ASOS.
A wind gust of 60 MPH was reported at the Jerome ASOS.
A wind gust of 60 MPH was reported at the Twin Falls ASOS.
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, July 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: 455696, 455697, 455698.