Storm Events Database

Event Details

Event Hail
Magnitude 1.25 in.
State WASHINGTON
County/Area GRANT
WFO OTX
Begin Date 07/20/2012 13:07:00 PST-8
Begin Range 7
Begin Azimuth SE
Begin Location ADRIAN
Begin Lat/Lon 47.3/-119.29
End Date 07/20/2012 13:12:00 PST-8
Deaths Direct/Indirect 0/0 (fatality details below, when available...)
Injuries Direct/Indirect 0/0
Property Damage 0.00K
Crop Damage 0.00K
Episode Narrative One of the 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 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, time of day, highly diffluent flow aloft, and jet streak dynamics led to numerous severe thunderstorms across Eastern Washington. Severe hail, winds, and flash flooding were observed with storms during the early afternoon but the threat transitioned to severe winds by the mid to late afternoon as storms migrated into the Northeastern Mountains. These storms blew down hundreds of trees causing one fatality. Ferry and Okanogan Counties were the hardest hit counties and experienced power outages in some remote communities in excess of one week. Consequently, state and federal assistance was necessary. Preliminary damage figures for Ferry County estimated 2.6 million in debris removal, 1.6 million in emergency protective measures, 128 thousand for road and bridge repair, 570 thousand to building and equipment, 3.2 million for utility repair, and 163 thousand for parks and recreation. 7000 people lost power in Ferry County and three major roads were closed for sometime due to downed trees. These roads included Highway 21, 97, and 155. Utility companies estimated 200 downed power poles and 40 miles of line needed restoration. In Okanogan County, estimations of 82 thousand in debris removal, 36 thousand in emergency protective measures, 180 thousand for road and bridge repair, 419 thousand to building and equipment, 364 thousand for utility repair, and 25 thousand for parks and recreation. Cumulative figures indicated a total of 8.4 million for Ferry and 1.1 million for Okanogan. Due to the complexity and magnitude of this event, Appendix B was utilized to estimate individual costs for each event. Cumulative figures listed in the Episode narrative would be more representative of the actual event. Some reports stated that private weather instruments at residents' houses recorded winds between 80 and 100 mph.
Event Narrative


All events for this episode:

Location County/Zone St. Date Time T.Z. Type Mag Dth Inj PrD CrD
Totals: 0 0 1.072M 9.00K
ANATONE ASOTIN CO. WA 07/20/2012 11:35 PST-8 Flash Flood 0 0 1.00K 0.00K
BEVERLY GRANT CO. WA 07/20/2012 11:55 PST-8 Thunderstorm Wind 57 kts. MG 0 0 0.00K 0.00K
CORFU GRANT CO. WA 07/20/2012 12:10 PST-8 Flash Flood 0 0 15.00K 0.00K
MAE GRANT CO. WA 07/20/2012 12:15 PST-8 Hail 1.25 in. 0 0 1.00K 5.00K
MOODY ADAMS CO. WA 07/20/2012 12:15 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
MAE GRANT CO. WA 07/20/2012 12:35 PST-8 Hail 1.75 in. 0 0 0.00K 0.00K
(MWH)GRANT CO ARPT M GRANT CO. WA 07/20/2012 12:50 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
ADRIAN GRANT CO. WA 07/20/2012 13:07 PST-8 Hail 1.25 in. 0 0 0.00K 0.00K
STEHEKIN CHELAN CO. WA 07/20/2012 13:15 PST-8 Debris Flow 0 0 0.00K 0.00K
SPOKANE SPOKANE CO. WA 07/20/2012 13:30 PST-8 Thunderstorm Wind 43 kts. EG 0 0 1.00K 0.00K
COLUMBIA CENTER GARFIELD CO. WA 07/20/2012 13:35 PST-8 Hail 1.00 in. 0 0 0.00K 0.00K
COLUMBIA CENTER GARFIELD CO. WA 07/20/2012 13:35 PST-8 Hail 0.88 in. 0 0 0.00K 0.00K
OMAK OKANOGAN CO. WA 07/20/2012 14:00 PST-8 Flash Flood 0 0 2.00K 0.00K
OMAK OKANOGAN CO. WA 07/20/2012 14:00 PST-8 Thunderstorm Wind 52 kts. EG 0 0 1.50K 0.00K
ELECTRIC CITY GRANT CO. WA 07/20/2012 14:25 PST-8 Thunderstorm Wind 60 kts. EG 0 0 2.00K 0.00K
DISAUTEL OKANOGAN CO. WA 07/20/2012 14:30 PST-8 Thunderstorm Wind 56 kts. EG 0 0 1.00K 0.00K
KELLER FERRY CO. WA 07/20/2012 14:30 PST-8 Thunderstorm Wind 56 kts. EG 0 0 1.00K 0.00K
KELLER FERRY CO. WA 07/20/2012 14:30 PST-8 Thunderstorm Wind 61 kts. EG 0 0 500.00K 0.00K
DISAUTEL OKANOGAN CO. WA 07/20/2012 14:30 PST-8 Flash Flood 0 0 6.00K 0.00K
KELLER FERRY CO. WA 07/20/2012 14:30 PST-8 Thunderstorm Wind 61 kts. EG 0 0 400.00K 0.00K
NESPELEM OKANOGAN CO. WA 07/20/2012 14:30 PST-8 Thunderstorm Wind 56 kts. EG 0 0 0.50K 0.00K
KELLER FERRY CO. WA 07/20/2012 14:35 PST-8 Thunderstorm Wind 56 kts. EG 0 0 0.00K 2.00K
NESPELEM OKANOGAN CO. WA 07/20/2012 14:40 PST-8 Thunderstorm Wind 56 kts. EG 0 0 8.00K 0.00K
KELLER POOLER ARPT FERRY CO. WA 07/20/2012 14:42 PST-8 Thunderstorm Wind 57 kts. EG 0 0 0.00K 2.00K
KELLER POOLER ARPT FERRY CO. WA 07/20/2012 14:46 PST-8 Thunderstorm Wind 56 kts. EG 0 0 2.00K 0.00K
REPUBLIC FERRY CO. WA 07/20/2012 15:00 PST-8 Thunderstorm Wind 61 kts. EG 0 0 5.00K 0.00K
REPUBLIC FERRY CO. WA 07/20/2012 15:15 PST-8 Thunderstorm Wind 61 kts. EG 0 0 0.00K 0.00K
MATNEYS SPUR FERRY CO. WA 07/20/2012 15:26 PST-8 Thunderstorm Wind 56 kts. EG 0 0 2.00K 0.00K
MARCUS STEVENS CO. WA 07/20/2012 15:26 PST-8 Thunderstorm Wind 56 kts. EG 0 0 1.00K 0.00K
BOYDS FERRY CO. WA 07/20/2012 15:30 PST-8 Thunderstorm Wind 56 kts. EG 0 0 1.00K 0.00K
MALO FERRY CO. WA 07/20/2012 15:32 PST-8 Thunderstorm Wind 56 kts. EG 0 0 1.00K 0.00K
NIGHTHAWK OKANOGAN CO. WA 07/20/2012 15:45 PST-8 Thunderstorm Wind 57 kts. EG 0 0 120.00K 0.00K
Totals: 0 0 1.072M 9.00K