On April 17 an 18, an upper level trough moved across North Central Idaho producing heavy snowfall in the higher terrain.
Every event with a place to put it; 2 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 MSO wrote it up.
On April 17 an 18, an upper level trough moved across North Central Idaho producing heavy snowfall in the higher terrain.
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 Missoula, MT wrote its last area forecast discussion before the first event at Apr 17, 8:34 PM MST, 1 hour 26 minutes earlier.
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE MISSOULA MT
934 PM MDT TUE APR 17 2007
.UPDATE...JUST ISSUED A ZONE UPDATE TO KEEP THE MENTION OF
THUNDERSTORMS IN THE FORECAST UNTIL MIDNIGHT. RIGHT NOW...APPEARS
THAT THE SEVERE CONCERNS WITH THE CONVECTION ARE OVER. SEVERAL
NEAR-SEVERE HAIL AND WIND REPORTS WERE RECEIVED ACROSS SW MONTANA
THIS EVENING...WITH ONE SEVERE (3/4 INCH HAIL) REPORT RECEIVED
FROM PHILIPSBURG. WITH THE MID LEVEL LAPSE RATES CONTINUING TO
WEAKEN AND THE SURFACE INSTABILITY DIMINISHING...THE LINGERING
STORM ACTIVITY SHOULD END AROUND MIDNIGHT.
ALSO...HAVE RAISED THE OVERNIGHT LOWS ACROSS THE MISSOULA AND
BITTERROOT VALLEYS. WITH WINDS EXPECTED TO STAY UP ALL NIGHT AND
WITH DEW POINTS NOW HIGHER THAN WHAT THEY WERE THIS
AFTERNOON...THINKING THAT LOWS WILL ONLY BOTTOM OUT IN THE MIDDLE
TO UPPER 30S TONIGHT. ANTICIPATED TEMPERATURES ELSEWHERE APPEAR TO
BE RIGHT ON TRACK. PLANNING ON NO ADDITIONAL UPDATES TONIGHT.
&&
AVIATION...RAIN AND SNOW SHOWERS WILL CONTINUE TO IMPACT AIRFIELD
OPERATIONS OVER THE NEXT 24 HOURS...ESPECIALLY AT KBTM WHERE
SIGNIFICANT SNOWFALL IS EXPECTED ON WEDNESDAY. PLEASE SEE
APPROPRIATE TAFS AND TWEBS.
&&
.MSO WATCHES/WARNINGS/ADVISORIES...
MT...HEAVY SNOW WARNING FROM 3 AM TO 6 PM MDT WEDNESDAY FOR
BUTTE/BLACKFOOT REGION-POTOMAC/SEELEY LAKE REGION.
HEAVY SNOW WARNING UNTIL 6 PM MDT WEDNESDAY FOR
BITTERROOT/SAPPHIRE MOUNTAINS.
HEAVY SNOW WARNING FROM 3 AM WEDNESDAY TO MIDNIGHT MDT WEDNESDAY
NIGHT FOR WEST GLACIER REGION.
ID...HEAVY SNOW WARNING UNTIL 5 PM PDT WEDNESDAY FOR SOUTHERN
CLEARWATER MOUNTAINS.
HEAVY SNOW WARNING UNTIL 6 AM MDT WEDNESDAY ABOVE 6000 FEET FOR
EASTERN LEMHI COUNTY-WESTERN LEMHI COUNTY.
&&
SHORT TERM...HENRY
LONG TERM....99
AVIATION...99PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE MISSOULA MT
855 PM MDT TUE APR 17 2007
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0748 PM HAIL 1 SSW PHILIPSBURG 46.31N 113.30W
04/17/2007 M0.75 INCH GRANITE MT TRAINED SPOTTER
STORM SPOTTER REPORTED PENNY SIZED HAIL IN PHILLIPSBURG
AT 748 PM.
&&
HENRYThe national radar mosaic for the moment the first event began.
2 heavy snow. Local standard time, as filed.
Moose Creek and Lost Trail Pass received 8 inches of snow during this event.
Seven to eight inches of heavy snow was received at the Savage Pass and Mountain Meadows Snotel sites during this event.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2007Every state in 2007This day in weather historyWarnings in Idaho, April 2007
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: 22727, 22722.