Funnel Cloud — Flathead, Montana

2014-05-05 · near Whitefish, Flathead, Montana

Event narrative

An official observer at the Glacier Park International Airport observed a funnel cloud approximately 8 miles to the northwest. They reported that it didn't seem to reach the ground and only lasted for a minute. Radar and lightning data confirmed that the funnel cloud was attached to a cumulonimbus cloud(thunderstorm). Due to strong deep layer southwest wind shear ranging between 40 and 45 knots and with the relative location of the precipitation shaft to the base of the storm, the thunderstorm could have been supercellular. The Glacier National Park ASOS observed high relative humidities and south to south-southeast winds between 13 and 17 knots which added low-level wind shear. The appearance of the thunderstorm cloud base was relatively low which is another favorable atmospheric condition for funnel cloud development. Thanks to James LaDue from the NWS Warning Decision Training Branch for his added contribution to this report.

Wider weather episode

Very unstable conditions contributed to thunderstorm development northwest of Kalispell which allowed for a funnel cloud to develop.

View location on OpenStreetMap → (48.3688, -114.4071)

Source: NOAA Storm Events Database, event_id 510873. Narrative written by the NWS forecast office that issued the report.