A line of strong thunderstorms resulting from a Pacific cold frontal passage caused damage as it moved East from Canyon and Ada Counties through Boise, Owyhee, and Camas County to the Eastern edge of the county warning area. Mudslides also occurred on Highway 17 East of Banks in Boise County.
Every event with a place to put it; 1 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 BOI wrote it up.
A line of strong thunderstorms resulting from a Pacific cold frontal passage caused damage as it moved East from Canyon and Ada Counties through Boise, Owyhee, and Camas County to the Eastern edge of the county warning area. Mudslides also occurred on Highway 17 East of Banks in Boise County. These mudslides occurred near steep terrain in an area undermined by previous mudslides.
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 Apr 14, 8:10 AM MST, 2 hours 20 minutes earlier.
SOUTHWEST IDAHO/SOUTHEAST OREGON AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BOISE IDAHO 910 AM MDT SUN APR 14 2002 MORNING SATELLITE PICS SHOWING COLD FRONT ALG A MSO-S80-BNO LINE AT THIS TIME. EXPECT NORTHERN PORTION OF FRONT TO SCREAM E-WARD WITH TAIL END TO HANG UP ACROSS SE ID BY LATE THIS AFTERNOOON/EARLY EVENING. RADAR AND IR PICS CONTINUE TO SHOW PRECIP DEVELOPING ALONG TAIL END OF FRONT INTO SE OREGON. DRY SLOT SEEN ON WATER VAPOR PIC SHOULD SLOWLY MOVE INTO THE REGION LATER THIS AFTERNOON GIVING SOME CLEARING TO AREA...BUT FOR THE MOST PART MOSTLY CLOUDY SKIES SUFFICE. MAIN FORECAST PROBLEM WILL BE STRONG WINDS ACROSS THE REGION WITH STRONGEST WINDS EXPECTED TO BE IN THE MAGIC VALLEY WHERE WIND ADVISORIES ARE POSTED. 700MB WINDS DECREASE LATER THIS AFTERNOON...BUT STRONG JET CONTINUE TO RIDES OVER THE REGION...SO EXPECT WINDS THRU SUNSET...THEN DECREASE. 12Z MDLS CONT TREND OF LIFTED INDCIES AROUND 0/-1 AND CAPE AROUND 2-300...SO CHC TSRA LOOKS GOOD IN MAGIC VALLEY. NO UPDATED AT THIS TIME. .BOI...WIND ADVISORY TODAY FOR IDAHO ZONE 16. REDMAN
The national radar mosaic for the moment the first event began.
4 thunderstorm wind, 1 flood. Local standard time, as filed.
A strong pacific cold frontal system generated thunderstorms from the Idaho-Oregon state line Eastward across Southwest Idaho. Trees were blown down 7 miles South of Mc Call in Valley County.
Heavy rain and snowmelt near Donnelly in Valley County caused small stream flooding which washed out West Rockberry Road and Mud Creek Bridge. A sewer line and several culverts were also destroyed and a 50-mile detour resulted from the damage.
A severe thunderstorm wind gust of 54 knots destroyed a carport 10 miles South of Nampa in Canyon County.
A trained storm spotter reported 50 to 60 MPH thunderstorm winds and minor street flooding in Glenns Ferry, Elmore County.
A trained storm spotter reported that severe thunderstorm winds destroyed a 20-foot tall by 15-foot wide granary in Gooding.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Idaho in 2002Every state in 2002This day in weather historyWarnings in Idaho, April 2002
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: 5292393, 5292391, 5292394, 5292395, 5292392.