Severe thunderstorm wind thresholds were reached on the evening of the 24th at Atomic City and INL sites and Gas Caves in Fremont County.
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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 PIH wrote it up.
Severe thunderstorm wind thresholds were reached on the evening of the 24th at Atomic City and INL sites and Gas Caves in Fremont County.
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 Pocatello, ID wrote its last area forecast discussion before the first event at Apr 24, 1:01 PM MST, 2 hours 22 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE POCATELLO ID 201 PM MDT TUE APR 24 2012 .SHORT TERM...TONIGHT THROUGH FRIDAY. SOME THUNDERSTORMS HAVE DEVELOPED IN THE CENTRAL MOUNTAINS AND UPPER SNAKE HIGHLANDS THIS AFTERNOON FORMING IN LINES. NOTHING SEVERE REPORTED AS OF 2 PM BUT EXPECT GUSTY WINDS NEAR ANY THUNDERSTORM ACTIVITY. UPPER RIDGE HAS MOVED EAST AND A STEADY SOUTHWEST FLOW ALOFT CONTINUES TO KEEP VERY WARM AIR OVER SOUTHEAST IDAHO AS WELL AS CONTINUING TO PUMP MOISTURE NORTHWARD. KEPT ISOLATED TO SCATTERED SHOWER AND THUNDERSTORM ACTIVITY THROUGH 11 PM THEN JUST HAVE SHOWERS AFTER THAT POINT. EXPECT SAME TREND WEDNESDAY AS REMAIN IN WARM UNSTABLE AIR MASS WITH CONTINUE SHOWER AND THUNDERSTORM ACTIVITY. EXPECT MORE SUSTAINED PRECIPITATION WEDNESDAY NIGHT THROUGH THURSDAY AS STRONG COLD FRONT MOVES THROUGH EARLY THURSDAY WITH PRECIPITATION BEHIND THE FRONT. SNOW LEVELS BEGIN TO DROP RAPIDLY THURSDAY NIGHT DOWN TO NEAR THE 5 THOUSAND FOOT LEVEL BY FRIDAY MORNING. SHOULD SEE SOME LIGHT SNOW ACCUMULATIONS IN THE MOUNTAINS THURSDAY AFTERNOON THROUGH FRIDAY IN THE 1 TO 6 INCH RANGE. HIGH TEMPERATURES WILL CONTINUE TO FALL THROUGH THE PERIOD AFTER THE 70S AND 80S THE LAST COUPLE DAYS BY FRIDAY HIGHS WILL BE IN THE 30S IN THE MOUNTAINS TO NEAR 50 IN THE SNAKE RIVER PLAIN. EXPECT BREEZY CONDITIONS BEHIND THE FRONT THURSDAY AND FRIDAY AS WELL. GK .LONG TERM...FRI NIGHT THROUGH NEXT TUE NIGHT. LARGE DIFFERENCES FROM MODEL RUN TO MODEL RUN ARE EVIDENT...MAKING THIS PERIOD A LOW CONFIDENCE FORECAST. THE 500MB LONG WAVE PATTERN INDICATES A SIGNIFICANT RIDGE OVER THE NORTHERN GREAT BASIN THAT TRANSITION BY THE MON TO NEARLY ZONAL FLOW. THE FACT THAT THE 24/00Z GUIDANCE BROUGHT IN A SHORTWAVE THAT COMPLETELY OBLITERATED THE HIGH AND LINGERED AN ACTUAL CLOSED LOW OVER THE GREAT BASIN HAS BECOME A DRY NORTHWESTERLY FLOW ON THE 24/12Z GUIDANCE. HAVE PUSHED WEEKEND FORECAST CLOSER TO CLIMATOLOGY. THE ZONAL FLOW FOR THE END OF THE PERIOD MEANS THAT WEATHER WILL BE DRIVEN BY SHORTWAVE TIMING...THUS THE SECOND HALF OF THE TIME WILL ALSO BE SHOWING LARGE RUN-TO-RUN CHANGES. OVERALL...THERE DOES NOT APPEAR TO BE ANY MAJOR STORM AT LEAST DURING ANY POINT IN THIS MEDIUM RANGE FORECAST. DID NOT MAKE ANY CHANGES TO THE SECOND HALF EXCEPT FOR COORDINATION ISSUES. MESSICK && .AVIATION...UNSTABLE ATMOSPHERE WITH EVEN THE GFS INDICATING WIDESPREAD CAPE OVER 300 J/KG AND NEGATIVE LIFTED INDICES FOR THE BOUNDARY LAYER WELL BELOW MINUS 1 MEANS THAT -TSRA ARE STRONG POSSIBILITY. SPC HAS ALSO ISSUED A MESOSCALE DISCUSSION ABOUT THE HELICITY AND THE ENHANCED INSTABILITY DUE TO THE EXTREMELY DRY SURFACE LAYER. STRONGEST PROBABILITY WAS KIDA SO PUT IN TEMPORARY CONDITION OF -TSRA. AT THIS TIME A BAND OF -SHRA DEVELOPED INTO A LINE OF -TSRA AND PASSED JUST TO THE NORTH OF THIS AIRDROME. MORE -SHRA/-TSRA ARE DEVELOPING IN NORTHERN NEVADA WITH STEERING FLOW INTO THE MAGIC VALLEY AND SNAKE RIVER PLAIN AND MAY HAVE TO DO THE SAME WITH KBYI. -TSRA SHOULD WRAP UP PRIOR TO 25/03Z WITH SOME VIRGA OR -SHRA POSSIBLE UNTIL 25/06Z-25/09Z. MESSICK && .HYDROLOGY... THE HENRYS FORK AT REXBURG AND SAINT ANTHONY IS STILL FORECAST TO REACH FLOOD STAGE LATE IN THE DAY ON THURSDAY. FLOOD WATCHES AND OR WARNINGS MAY NEED TO BE ISSUED BEGINNING WEDNESDAY FOR THOSE FORECAST POINTS. GK && .PIH WATCHES/WARNINGS/ADVISORIES... NONE. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE POCATELLO ID 314 AM MDT TUE APR 24 2012 IDZ017>025-031-032-250915- EASTERN MAGIC VALLEY-SAWTOOTH MOUNTAINS-UPPER SNAKE HIGHLANDS- UPPER SNAKE RIVER PLAIN-LOWER SNAKE RIVER PLAIN- SOUTH CENTRAL HIGHLANDS-CARIBOU HIGHLANDS- CACHE VALLEY/IDAHO PORTION-WASATCH MOUNTAINS/IDAHO PORTION- BIG AND LITTLE WOOD RIVER REGION-LOST RIVER/PAHSIMEROI- 314 AM MDT TUE APR 24 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR EASTERN IDAHO. .DAY ONE...TODAY AND TONIGHT SHOWERS AND THUNDERSTORMS WILL CONTINUE THROUGH TONIGHT. THE MAIN THREATS WILL BE BRIEF RAINFALL...GUSTY WINDS IN EXCESS OF 40 MPH AND BLOWING DUST. THE THREAT OF SEVERE THUNDERSTORMS IS MINIMAL. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY SHOWERS AND THUNDERSTORMS CONTINUE WEDNESDAY WITH A THREAT OF BRIEF DOWNPOURS...GUSTY WINDS AND SMALL HAIL. A GOOD CHANCE OF RAIN AND MOUNTAIN SNOW SHOWERS ARRIVES WEDNESDAY NIGHT AND CONTINUES THROUGH FRIDAY. SNOW LEVELS BY FRIDAY AFTERNOON WILL DROP TO AROUND 5000-5500 FEET AS TEMPERATURES WILL 25-35 DEGREES COOLER THAN WHAT WAS EXPERIENCED EARLIER IN THE WEEK. LINGERING SHOWERS WILL REMAIN PLACE THROUGH MONDAY. RECORD BREAKING HEAT FOLLOWED UP BY MODERATE PRECIPITATION IN SOME SPOTS WILL CONTRIBUTE TO RISING WATER LEVELS ACROSS PORTIONS OF EASTERN IDAHO. THE HENRY'S FORK AT REXBURG AND ST. ANTHONY ARE FORECAST TO GO INTO FLOOD BY THURSDAY AND FRIDAY...RESPECTIVELY. THE BIG WOOD RIVER IN HAILEY COULD REACH BANKFULL BY THE END OF THE WEEK AS WELL. .SPOTTER INFORMATION STATEMENT... WE ASK TRAINED SPOTTERS AND CITIZENS TO REPORT SIGNIFICANT WEATHER CONDITIONS WHEN IT IS SAFE TO DO SO. THESE CONDITIONS MAY INCLUDE HAIL...TORNADOES...STRONG WIND...DUST STORMS...SNOWFALL... EXTREME COLD TEMPERATURES...FREEZING RAIN OR HEAVY RAIN...DENSE FOG...AND FLOODING OR ICE JAMS. INFORMATION ABOUT THESE HAZARDOUS CONDITIONS SHOULD BE CALLED INTO YOUR NATIONAL WEATHER SERVICE OFFICE IN POCATELLO USING THE 1-800 SEVERE WEATHER HOTLINE...OR 208-233-0834.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE POCATELLO ID 1228 PM MDT TUE APR 24 2012 IDZ018-031-032-241915- BUTTE ID-BLAINE ID-CUSTER ID- 1228 PM MDT TUE APR 24 2012 THE NATIONAL WEATHER SERVICE IN POCATELLO HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... SOUTHEASTERN CUSTER COUNTY IN CENTRAL IDAHO CENTRAL BLAINE COUNTY IN CENTRAL IDAHO NORTHWESTERN BUTTE COUNTY IN EAST CENTRAL IDAHO UNTIL 115 PM MDT AT 1220 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 28 MILES NORTHEAST OF DICKEY TO 13 MILES EAST OF SUN VALLEY..AND MOVING EAST AT 20 MPH. WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS. LOCATIONS IMPACTED INCLUDE... MACKAY... GROUSE... LAT...LON 4415 11327 4349 11363 4364 11418 4430 11383 TIME...MOT...LOC 1828Z 291DEG 17KT 4440 11345 4369 11402 GK
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE POCATELLO ID
140 PM MDT TUE APR 24 2012
IDZ019-020-032-242045-
CLARK ID-JEFFERSON ID-BUTTE ID-FREMONT ID-CUSTER ID-
140 PM MDT TUE APR 24 2012
THE NATIONAL WEATHER SERVICE IN POCATELLO HAS ISSUED A
SIGNIFICANT WEATHER ADVISORY FOR...
SOUTHEASTERN CUSTER COUNTY IN CENTRAL IDAHO
NORTHERN BUTTE COUNTY IN EAST CENTRAL IDAHO
EXTREME NORTH CENTRAL FREMONT COUNTY IN EASTERN IDAHO
CLARK COUNTY IN EASTERN IDAHO
NORTHWESTERN JEFFERSON COUNTY IN SOUTHEAST IDAHO
UNTIL 245 PM MDT
AT 134 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED
STRONG THUNDERSTORMS ALONG A LINE EXTENDING FROM 20 MILES NORTHEAST
OF MONIDA TO 7 MILES WEST OF DARLINGTON..AND MOVING EAST AT 15 MPH.
WIND GUSTS UP TO 40 MPH ARE EXPECTED WITH THESE STORMS.
LOCATIONS IMPACTED INCLUDE...
DARLINGTON...
HUMPHREY...
HOWE... KILGORE AND DUBOIS...
LAT...LON 4365 11295 4377 11372 4381 11370 4424 11296
4424 11283 4432 11282 4449 11254 4446 11239
4453 11236 4457 11229 4453 11210 4457 11187
4452 11182 4456 11166 4467 11149 4472 11149
4473 11139
TIME...MOT...LOC 1940Z 289DEG 15KT 4472 11195 4380 11353
GKThe Pocatello radar (KSFX), 130 km away, was scanning. The volume nearest the first event began at 22:21 UTC.
3 thunderstorm wind. Local standard time, as filed.
Fifty knot wind gust measured at the Gas Caves RAWS site from thunderstorm wind.
The INTEC/Grid 3 INL site measured a peak wind of 67 mph reaching severe criteria at 18:55 EST.
Fifty-nine mph wind gust measured at Atomic City.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2012Every state in 2012This day in weather historyWarnings in Idaho, April 2012
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: 379665, 379650, 379654.