A negatively tilted shortwave trough lifted through the Inland Northwest during the late evening hours of July 2nd. As the forcing interacted with an axis of moist, unstable air already in place, a line of thunderstorms developed across the central Idaho Panhandle.
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 OTX wrote it up.
A negatively tilted shortwave trough lifted through the Inland Northwest during the late evening hours of July 2nd. As the forcing interacted with an axis of moist, unstable air already in place, a line of thunderstorms developed across the central Idaho Panhandle. A few of these storms matured into severe storms producing large hail.
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 Spokane, WA wrote its last area forecast discussion before the first event at Jul 2, 4:08 PM PST, 4 hours 27 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE SPOKANE WA 508 PM PDT Mon Jul 2 2012 .SYNOPSIS... A strong Pacific system will move into the Inland Northwest tonight into Tuesday, bringing a chance for showers and thunderstorms along with breezy gusty winds. High pressure will begin to strengthen over the region by this weekend into next week bringing the potential for summer-like heat and mostly dry conditions. && .DISCUSSION... Tonight through Tuesday night: Unsettled early summer weather for the Inland Northwest. The region will be under the influence of a Pacific upper level trough that is expected to roll through the region during the next 24-30 hours. High level moisture will continue to stream in ahead of the feature early this evening. Meanwhile, instability will be on the rise across northeast Oregon and into southeast Washington as seen in the 850mb thetae values. The models show this area to remain capped through the afternoon, but as the trough approaches and a mid level disturbance acts like a cold front will interact with a swath of instability and lead to a band of elevated convection that will develop over the Blue mountains of Washington and expand northeast, over the Palouse, the Coeur d'Alene area and into north Idaho. Embedded thunderstorms are possible with the convection along with heavy rainfall especially over north Idaho. This convection will press into north Idaho by early Tuesday morning, but the cold pool aloft associated with the upper level low will cross the Cascades and track across the Canadian border. This will provide the instability for another region of thunderstorms by mid morning and through the day on Tuesday. Again areas of moderate to heavy rainfall are possible with the track of the upper low, but it appears the main area of concern will be north of the border from Metaline and Bonners Ferry. This may cause concern with the current high water flows moving through the Kootenai River in Bonners Ferry. In the wake of the cold front, surface winds will steadily increase from the lee of the Cascades, across the Columbia Basin and into the Spokane and Pullman areas with sustained speeds of 20-30 mph and gusts in the 30s. This would be below any wind advisory criteria, but still windy. Temperatures will drop 5 to 12 degrees over today's highs while RH increase slightly. Fine fuels across the Columbia Basin have cured. Despite the gusty winds, the RH levels are NOT sufficient to raise red flags at this time. The winds and convection will gradually decrease early Tuesday evening as high pressure moves into the region. /rfox. Wednesday through Saturday...Slight retrogression westward of the long-wave trof which has kept Eastern Washington and Northern Idaho continued cool and generally unsettled is expected during this time interval. This in turn will allow the ridging that has been keeping the Central United States hot and dry to move a bit to the west and show some slight amplification. Still the general pattern change continues to allow for prolonged southwest flow at lower and mid levels. Additionally the lower level thermal features show some amplification of their ridge axises into Eastern Oregon and Northwest Montana with time. So...essentially a dry forecast with a warming trend remains appropriate. /Pelatti Saturday afternoon through Monday: The Inland Northwest will remain under an amplifying ridge through the weekend, before it begins to shift slightly east. Average 500mb height rise to between 585-590 dam much of the period, which around the Spokane area is 10-15 dam above climatology. Average 850mb temperatures rise to between 25 and 28 C. Mean 1000-500mb relative humidity values range between 25 and 35% through Sunday, then increase slightly Sunday night into Monday as some monsoonal moisture creeps in from the south as the ridge axis edges east. Such conditions translate to dry and mostly clear weather, with above normal temperatures much of the period. The aforementioned 850mb temperatures support afternoon highs some 8-13 degrees above normal, which pushes many areas toward the upper 80s to mid-90s. This meant I raised temperatures from the previous forecast. The primary kink in the dry forecast is the moisture creeping in toward the end of the forecast period. With a thermal trough developing over the region Sunday into Monday and guidance showing some increasing surface-based and elevated instability, any minor shortwave or vorticity max that slides up from the south could trigger some showers or thunderstorms near the Cascades and over the Blues to central Panhandle mountains. Details of such triggers are difficult to pinpoint at such a distance, however it is enough to have a slight chance of thunderstorms around these mountain areas. The threat will mainly be confined to the Blues and Camas Prairie Saturday, but expand into the Cascades and central Panhandle Mountains by late Sunday and Monday. Whether any develop or any can survive moving off the higher terrain is less certain, so I will hold precipitation chances in nearby lowlands (including the Palouse and L-C valley). /J. Cote' && .AVIATION... 00z TAFS: A Pacific storm system spinning offshore the Pac NW will begin to impact the region late this evening into the overnight hours. This system will interact with some elevated instability and moisture moving northeastward into eastern WA and the Idaho Panhandle from northeast Oregon after 03Z. We are expecting showers and thunderstorms to develop across this area, affecting KLWS first between 03-05Z and progressing northward into KPUW, KGEG, KSFF and KCOE through tonight. Moderately confident that we will see thunder in the vicinity of KLWS and KPUW, but low confidence at KCOE, KSFF and KGEG as most of the activity will be to their east. A cold front will swing across the region from west to east during the overnight hours, reaching KEAT by 03Z and then into the Idaho Panhandle between 09-12Z. This will create some weak low level wind shear as the front reaches each TAF site and then winds will become gusty with cold air advection behind the front bringing down the stronger winds. Gusty conditions will carry on into Tuesday afternoon with the best possibility of showers north of the Spokane/Coeur d'Alene area after frontal passage. /SVH && .PRELIMINARY POINT TEMPS/POPS... Spokane 55 70 46 76 52 81 / 50 30 0 0 0 0 Coeur d'Alene 55 68 43 74 50 79 / 80 30 10 0 0 0 Pullman 53 67 40 75 48 80 / 80 20 10 0 0 0 Lewiston 61 77 51 84 57 89 / 70 10 0 0 0 0 Colville 54 71 46 77 49 82 / 20 70 10 0 0 0 Sandpoint 55 66 43 73 44 78 / 80 80 10 10 10 10 Kellogg 53 67 46 74 50 79 / 90 60 10 10 10 10 Moses Lake 57 77 46 82 53 86 / 10 10 0 0 0 0 Wenatchee 58 73 51 79 56 84 / 10 10 0 0 0 0 Omak 55 75 44 80 51 85 / 20 20 10 0 10 10 && .OTX WATCHES/WARNINGS/ADVISORIES... ID...None. WA...None. &&
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE SPOKANE WA 547 AM PDT MON JUL 2 2012 WAZ033>036-041-044-031300- WASHINGTON PALOUSE-MOSES LAKE AREA-UPPER COLUMBIA BASIN- SPOKANE AREA-WENATCHEE AREA-WATERVILLE PLATEAU- 547 AM PDT MON JUL 2 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL WASHINGTON...EAST CENTRAL WASHINGTON...NORTH CENTRAL WASHINGTON... NORTHEAST WASHINGTON AND SOUTHEAST WASHINGTON. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY GUSTY WINDS AND DRY CONDITIONS ON TUESDAY WILL HAVE THE POTENTIAL TO QUICKLY SPREAD FIRES THROUGH FINE FUELS SUCH AS GRASS...HAY...AND SAGEBRUSH. THOSE PARTAKING IN OUTDOOR ACTIVITIES INVOLVING CAMPFIRES AND FIREWORKS ARE URGED TO BE RESPONSIBLE. IDZ001>004-026-027-WAZ031-032-037-038-042-043-031300- NORTHERN PANHANDLE-COEUR D'ALENE AREA-IDAHO PALOUSE- CENTRAL PANHANDLE MOUNTAINS-LEWISTON AREA- LEWIS AND SOUTHERN NEZ PERCE COUNTIES-NORTHEAST BLUE MOUNTAINS- LOWER GARFIELD AND ASOTIN COUNTIES-NORTHEAST MOUNTAINS- OKANOGAN HIGHLANDS-EAST SLOPES NORTHERN CASCADES-OKANOGAN VALLEY- 547 AM PDT MON JUL 2 2012 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH IDAHO... NORTH CENTRAL IDAHO...NORTH CENTRAL WASHINGTON...NORTHEAST WASHINGTON AND SOUTHEAST WASHINGTON. .DAY ONE...TODAY AND TONIGHT NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY NO HAZARDOUS WEATHER IS EXPECTED AT THIS TIME.
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE SPOKANE WA 921 PM PDT MON JUL 2 2012 IDZ002>004-030500- BENEWAH ID-KOOTENAI ID- 921 PM PDT MON JUL 2 2012 THE NATIONAL WEATHER SERVICE IN SPOKANE HAS ISSUED A SIGNIFICANT WEATHER ADVISORY FOR... SOUTHEASTERN KOOTENAI COUNTY IN THE PANHANDLE OF IDAHO NORTHWESTERN BENEWAH COUNTY IN THE PANHANDLE OF IDAHO UNTIL 1000 PM PDT AT 921 PM PDT...NATIONAL WEATHER SERVICE DOPPLER RADAR INDICATED A STRONG THUNDERSTORM 5 MILES SOUTH OF PLUMMER. THIS STORM WAS MOVING NORTHEAST AT 40 MPH. HAIL UP TO THE SIZE OF PENNIES IS EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN...AND FREQUENT CLOUD TO GROUND LIGHTNING. LOCATIONS IMPACTED INCLUDE... HARRISON... ST. MARIES... THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. LAT...LON 4761 11663 4740 11633 4718 11690 4728 11703 TIME...MOT...LOC 0421Z 230DEG 35KT 4727 11684 KOCH
The Spokane radar (KOTX), 77 km away, was scanning. The volume nearest the first event began at 04:35 UTC.
4 hail. Local standard time, as filed.
Hail sizes were generally between pea to dime but a few nickel to quarter size hailstones were observed.
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, July 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: 386811, 386812, 386813, 386814.