Forest Fire Smoke

Smoke from area wildfires has been settling into the valleys of northwest Montana. These pictures were taken from the NEXRAD site at the top of a peak north of Missoula.

Smoke in the Missoula valley on Tuesday 9/22/09. Photo by LeeAnn Allegretto.

Smoke in the Missoula valley on Tuesday 9/22/09. Photo by LeeAnn Allegretto.

August Report

August was highlighted by periods of heavy rain and large hail events. The most active days for severe weather were August 6 and 21. On August 6, a Super Cell Thunderstorm moved through Lemhi and Silver Bow Counties, producing flash flooding on Fourth of July Creek and just east of Butte. Large hail reports ranging from 1.00 to 2.50 inches in diameter damaged vehicles and homes in the southern portions of Butte. Wind gusts up to 71 mph also accompanied the storm. On August 21, large hail ranging from 1.00 to 1.50 inches fell from Maxville to Drummond.

Missoula’s 3.08 inches of rain in August was the second wettest August on record.

Severe Weather Event August 6, 2009

On August 6, 2009 severe thunderstorms impacted North Central Idaho and Western Montana. The storms tracked from southwest to northeast across the area...producing large hail, flash flooding and damaging winds. Hail of 2 to 2.5 inches in diameter was observed in the Butte area. Debris flowed over the roadway near 4th of July creek north of Salmon, ID 8-12 feet deep and 50-75 yards wide. Severe Weather Reports 

Debris over roadway near 4th of July creek 18 miles north of Salmon, ID. Photo by Jay Davis.

Silver dollar size hail near Salmon, ID. Photo by Jay Davis.

Damage to a home near Butte, MT.

Radar imagry from the National Weather Service of the storms passing over Idaho and Montana.

A microburst can be seen at the base of this storm as it passed near Butte, MT. Photo by Seth Slatter.

Tennis ball sized hail fell near Butte, MT. Photo by Roger Ebner.

Another picture of large hail that fell near Butte, MT. Photo by Roger Ebner.

July Report

July saw convective activity increase with most storms producing heavy rain and hail. One inch diameter hail reports were received on July 6, 24 and 28. The largest hail report came from a weather spotter near Conner, MT on July 6, where golf ball size hail covered the ground. During the evening of July 28, heavy rain produced flood and debris flows near the Black Cat severely burned area northeast of Frenchtown, where flood waters 2 inches deep entered a basement of a home. Another residence had water and debris flow into their back yard and driveway, briefly cutting off access to the home.

Philipsburg Hail

On July 26th a low pressure system moved into the region creating an unstable environment that led to thunderstorms. In Philipsburg, MT hail one half to one inch in diameter fell to a depth of two inches covering the ground creating a scene that resembled winter.

Pea sized hail covering the ground near Philipsburg, MT. Photo by Anne Luthje

Pea sized hail covering the ground near Philipsburg, MT. Photo by Anne Luthje

Warm Weather

A strong ridge of high pressure dominated the Northern Rockies over the past weekend, bringing the warmest temperatures so far this year to portions of the region. Afternoon temperatures were well above normal for this time of year, as illustrated in the following graphs for Missoula, Kalispell and Butte.

Missoula (KMSO) high temperatures.

Kalispell (KGPI) high temperatures.

Butte (KBTM) high temperatures.

June Report

The threat of heavy rain and flooding was the dominate weather hazard our office had to deal with in June as we issued a number of Flash Flood Watches. On June 21, the southeast portion of Lemhi County experienced heavy rain where up to two inches of precipitation fell, causing local small streams to flood and the Lemhi River to rise above flood stage. Flood waters impacted the Lemhi Store and Post Office in Lemhi, as a foot of water covered and washed out Lemhi Back Road. In addition, three to four inches of water covered Highway 28, and McFarland BLM campground (approx. 10 miles north of Leadore) was completely under water. Quite a bit of low land flooding was reported between Tendoy and 5 miles north of Leadore. Staff coordinated effectively with DES and RFC on flood issues. A severe thunderstorm on June 5 blew down trees onto Highway 12, blocking traffic near Syringa in Idaho County.

Warm Springs Creek near Anaconda (May 2009)

Minor flooding occurred along Warm Springs Creek and along other small creeks in Anaconda on May 30th and 31st . Above normal snowpack melted and caused the flooding.

Homes just west of Anaconda being surrounded by water from Warm Springs Creek.

Homes just west of Anaconda being surrounded by water from Warm Springs Creek.

Bitterroott River Flooding (May 2009)

The Bitterroot River had minor flooding due to snowmelt from surrounding mountains in mid to late May of 2009. Most of the flooding that occurred affected county roads, ranch and agricultural land and a few homeowners had water on their property.

County road between Stevensville and Florence.

Low-lying areas between Stevensville and Florence.

May Report

May 2009 was dominated by non thunderstorm wind events, with damage occurring in southern Idaho County on the 19th. Several ranches along the Salmon River corridor reported trees blown down between Shoup and Riggins. Warm temperatures started the spring snowmelt and runoff in earnest bringing the Bitterroot, Clark Fork and South Fork Rivers near or above flood stage at the end of the month. Warm Springs Creek also rose above flood stage inundating some property near Anaconda with flood waters.

Lemhi County Storm Ready ceremony was held May 11 at the LEPC meeting with Michelle Mead and I attending. Pictures of the event were posted on the Storm Ready web site.