Storm Events Database

Event Details

Event Thunderstorm Wind
Magnitude 52 kts.
State IDAHO
County/Area NEZ PERCE
WFO OTX
Begin Date 07/20/2012 11:45:00 PST-8
Begin Range 4
Begin Azimuth S
Begin Location WEBB
Begin Lat/Lon 46.29/-116.84
End Date 07/20/2012 11:45:00 PST-8
Deaths Direct/Indirect 0/0 (fatality details below, when available...)
Injuries Direct/Indirect 0/0
Property Damage 8.00K
Crop Damage 0.00K
Episode Narrative One of the largest and most widespread severe weather events occurred across the Spokane County Warning Area on July 20th. Several days prior to the day of the event, a deep upper-level low slowly sagged down the Pacific Northwest Coastline. Southerly flow ahead of the low pumped moist, unstable air into the Inland Northwest. The combination of afternoon heating and smaller impulses ejecting from the offshore low kept the region very unsettled with several rounds of severe thunderstorms from the 15th through the 19th. On the morning of the 20th, the remnants of Tropical Storm Fabio became ingested into the southerly flow and transported toward the region. Meanwhile, a shortwave dropping into the Gulf of Alaska acted to kick the upper-low off the southwestern Oregon Coast inland. The upper-level wave took on a strong negative tilt, driven northeastward by a 75kt jet streak, crossing through Eastern Washington and Northern Idaho during the early to late afternoon on July 20th. The combination of strong dynamic forcing along the shortwave, presence of an abnormally moist, unstable air mass, highly diffluent flow aloft, and jet streak dynamics led to numerous severe thunderstorms across Northern Idaho. Severe hail and winds were observed with storms during the early afternoon across lower portions of the Idaho Panhandle. The threat transitioned to severe winds by the mid to late afternoon as storms migrated into northern sections of the Panhandle with hundreds of downed trees and one fatality.
Event Narrative Thunderstorm winds knocked down several trees. There was also roof damage to an outbuilding.


All events for this episode:

Location County/Zone St. Date Time T.Z. Type Mag Dth Inj PrD CrD
Totals: 0 0 76.00K 0.00K
WEBB NEZ PERCE CO. ID 07/20/2012 11:45 PST-8 Thunderstorm Wind 52 kts. EG 0 0 8.00K 0.00K
LEWISTON ORCHARDS NEZ PERCE CO. ID 07/20/2012 11:48 PST-8 Hail 0.75 in. 0 0 0.00K 0.00K
LAPWAI NEZ PERCE CO. ID 07/20/2012 11:48 PST-8 Hail 1.50 in. 0 0 0.00K 0.00K
LAPWAI NEZ PERCE CO. ID 07/20/2012 11:48 PST-8 Hail 1.50 in. 0 0 0.00K 0.00K
LEWISTON ORCHARDS NEZ PERCE CO. ID 07/20/2012 11:48 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
JULIAETTA LATAH CO. ID 07/20/2012 11:48 PST-8 Hail 1.75 in. 0 0 0.00K 0.00K
SUMMIT NEZ PERCE CO. ID 07/20/2012 12:00 PST-8 Hail 2.75 in. 0 0 2.00K 0.00K
MYRTLE NEZ PERCE CO. ID 07/20/2012 12:00 PST-8 Hail 2.50 in. 0 0 2.00K 0.00K
JULIAETTA LATAH CO. ID 07/20/2012 12:15 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
SUMMIT NEZ PERCE CO. ID 07/20/2012 12:15 PST-8 Hail 2.50 in. 0 0 2.00K 0.00K
BRADLEY SHOSHONE CO. ID 07/20/2012 12:35 PST-8 Thunderstorm Wind 56 kts. EG 0 0 6.00K 0.00K
BOVARD LATAH CO. ID 07/20/2012 12:40 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
CONKLING PARK KOOTENAI CO. ID 07/20/2012 13:03 PST-8 Thunderstorm Wind 54 kts. EG 0 0 2.00K 0.00K
CALDER SHOSHONE CO. ID 07/20/2012 13:30 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
ROSE LAKE KOOTENAI CO. ID 07/20/2012 13:36 PST-8 Thunderstorm Wind 52 kts. EG 0 0 1.00K 0.00K
DUDLEY KOOTENAI CO. ID 07/20/2012 13:59 PST-8 Thunderstorm Wind 54 kts. EG 0 0 1.00K 0.00K
CEDAR CREEK BONNER CO. ID 07/20/2012 14:10 PST-8 Thunderstorm Wind 50 kts. MG 0 0 0.00K 0.00K
POLARIS SHOSHONE CO. ID 07/20/2012 14:11 PST-8 Thunderstorm Wind 52 kts. EG 0 0 2.00K 0.00K
PRICHARD SHOSHONE CO. ID 07/20/2012 14:15 PST-8 Thunderstorm Wind 55 kts. EG 0 0 1.00K 0.00K
PRICHARD SHOSHONE CO. ID 07/20/2012 14:16 PST-8 Thunderstorm Wind 52 kts. EG 0 0 1.00K 0.00K
KINGSTON SHOSHONE CO. ID 07/20/2012 14:21 PST-8 Thunderstorm Wind 52 kts. EG 0 0 1.00K 0.00K
FALCON SHOSHONE CO. ID 07/20/2012 14:25 PST-8 Thunderstorm Wind 52 kts. EG 0 0 1.00K 0.00K
NORDMAN BONNER CO. ID 07/20/2012 14:53 PST-8 Thunderstorm Wind 52 kts. EG 0 0 6.00K 0.00K
NORDMAN BONNER CO. ID 07/20/2012 15:00 PST-8 Thunderstorm Wind 52 kts. EG 0 0 40.00K 0.00K
Totals: 0 0 76.00K 0.00K