Thunderstorm outflows merged in the Treasure Valley and caused wind damage 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.
Thunderstorm outflows merged in the Treasure Valley and caused wind damage 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 21, 1:49 PM MST, 3 hours 41 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE ID 249 PM MDT WED MAY 21 2014 .SHORT TERM...TONIGHT THROUGH FRIDAY...SHOWERS AND THUNDERSTORMS CONTINUE TO FIRE OVER THE SOUTHEAST PORTION OF THE CWA AND THEN MOVE W AND NW THROUGH THE AREA. WE EXPECT ADDITIONAL STORMS TO DEVELOP AND MOVE W INTO THE BOISE MOUNTAINS...AND MOVE NW INTO OWYHEE COUNTY...THE WESTERN MAGIC VALLEY...AND THE UPPER TREASURE VALLEY...THIS AFTERNOON AND THIS EVENING. HIGH-RESOLUTION MODEL DATA INDICATES THE POTENTIAL FOR STRONG WINDS CREATED BY MERGING STORM OUTFLOWS TO MOVE NW FROM THE WESTERN MAGIC VALLEY INTO THE TREASURE VALLEY LATE THIS AFTERNOON AND EARLY THIS EVENING. THE UPPER LOW MOVES AWAY FROM THE AREA...INTO SRN CA AND THEN TOWARDS THE FOUR-CORNERS REGION...TONIGHT AND TOMORROW. AS THIS OCCURS...THE CHANCE FOR SHOWERS AND STORMS OVER OUR AREA WILL DECREASE. POPS ARE CONSIDERABLY LOWER THU AND THU NIGHT THAN THEY ARE TODAY AND TONIGHT. ON FRIDAY...THE NEXT SYSTEM WILL BEGIN TO INFLUENCE SE OREGON...SPREADING AN INCREASING CHANCE OF SHOWERS AND STORMS INTO MAINLY BAKER AND HARNEY COUNTIES. SW IDAHO WILL STAY DRY. TEMPS WILL CONTINUE TO TREND UPWARD TOMORROW AND FRIDAY...WITH HIGHS FRI AROUND 10 DEGREES ABOVE NORMAL. LOWS WILL BE 5 TO 10 DEGREES ABOVE NORMAL. .LONG TERM...FRIDAY NIGHT THROUGH WEDNESDAY...MODEL CONSISTENCY AND AND RUN TO RUN CONTINUITY CONTINUE ABOVE AVERAGE. THE UPPER LEVEL LOW WHICH HAS BEEN GENERATING AFTERNOON AND EVENING SHOWERS AND THUNDERSTORMS WILL BE TOO FAR SOUTH TO AFFECT SOUTHEAST OREGON AND SOUTHWEST IDAHO OVER THE MEMORIAL DAY WEEKEND. HOWEVER...INCREASING UPPER LEVEL FLOW FROM THE NORTH PACIFIC WILL BRING CHANGING CONDITIONS DURING THE COMING WEEK. FRIDAY NIGHT AND SATURDAY A SHALLOW SHORTWAVE TROUGH WILL BRING A CHANCE OF SHOWERS MAINLY OVER THE MOUNTAINS OF BAKER COUNTY OREGON AND CENTRAL IDAHO. A SHORTWAVE RIDGE WILL FOLLOW...ENDING THE SHOWERS SATURDAY NIGHT. UPSTREAM A MUCH DEEPER UPPER LEVEL TROUGH APPROACHING THE NORTHWEST COAST ON SUNDAY WILL BE CENTERED OVER VANCOUVER ISLAND ON MONDAY...PUTTING SOUTHEAST OREGON AND SOUTHWEST IDAHO UNDER INCREASINGLY MOIST SOUTHWEST FLOW ALOFT. AHEAD OF THE TROUGH SCATTERED SHOWERS WILL DEVELOP ACROSS EASTERN OREGON AND THE CENTRAL IDAHO MOUNTAINS SUNDAY NIGHT AND MONDAY. BY MONDAY EVENING ISOLATED SHOWERS COULD SPREAD AS FAR SOUTH AS NORTHERN HARNEY AND MALHEUR COUNTIES AND THE TREASURE VALLEY. THE TROUGH IS EXPECTED TO REMAIN CENTERED OVER THE NORTHWEST COAST THROUGH TUESDAY. TEMPERATURES WILL STAY ABOVE NORMAL THROUGH MONDAY...THEN COOL TO NEAR NORMAL ON TUESDAY. && .AVIATION...VFR. EXPECT SCATTERED SHOWERS AND ISOLATED THUNDERSTORMS TO CONTINUE THROUGH THIS EVENING OVER OVER THE MOUNTAINS ON BOTH SIDES OF THE SNAKE RIVER VALLEY...WITH ONLY ISOLATED CONVECTION IN THE LOWER VALLEYS. SURFACE WINDS...LIGHT AND VARIABLE EXCEPT GUSTS TO 40 KTS POSSIBLE NEAR ANY THUNDERSTORMS. WINDS ALOFT...EASTERLY 10- 15 KTS UP THROUGH 10K FT MSL. && .BOI WATCHES/WARNINGS/ADVISORIES... ID...NONE. OR...NONE. && WEATHER.GOV/BOISE SHORT TERM...SP LONG TERM....JT/WH AVIATION.....JT
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BOISE ID 535 AM MDT WED MAY 21 2014 IDZ011>016-028>030-033-ORZ061>064-221145- 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- 535 AM MDT WED MAY 21 2014 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.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE BOISE ID
214 PM MDT WED MAY 21 2014
IDZ030-212100-
SOUTHERN TWIN FALLS COUNTY ID-
214 PM MDT WED MAY 21 2014
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHWESTERN TWIN FALLS COUNTY
UNTIL 300 PM MDT...
AT 211 PM MDT...DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM
ABOUT 10 MILES SOUTH OF ROGERSON...OR JUST NORTH OF JACKPOT...MOVING
NORTHWEST AT 20 MPH.
DIME SIZE HAIL AND WINDS IN EXCESS OF 40 MPH WILL BE POSSIBLE WITH
THIS STORM.
THIS STRONG THUNDERSTORM WILL BE NEAR...
ROGERSON AROUND 235 PM MDT.
OTHER LOCATIONS IMPACTED BY THIS STORM INCLUDE SALMON FALLS DAM...
SALMON FALLS RESERVOIR...CEDAR CREEK RESERVOIR...WINTER SPRING AND
NORTON BAY.
LAT...LON 4223 11499 4240 11471 4233 11465 4207 11444
4200 11457 4200 11468
TIME...MOT...LOC 2011Z 142DEG 17KT 4208 11460
SPThe Boise radar (KCBX), 86 km away, was scanning. The volume nearest the first event began at 00:32 UTC.
2 thunderstorm wind. Local standard time, as filed.
The Emergency Manager command post reported wind damage and power outages across Payette County due to thunderstorm outflow winds out of the southeast.
A trained spotter reported trees down around the Weiser area due to thunderstorm outflow winds.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2014Every state in 2014This day in weather historyWarnings in Idaho, May 2014
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: 522473, 522476.