GREAT FALLS — While Saturday afternoon brought pea-sized hail and dangerous flash flooding to portions of central, north-central and southwest Montana, an even stronger chance of similar conditions is possible moving through Sunday.
The National Weather Service (NWS) in Great Falls issued a Flash Flood Watch early Sunday morning for portions of central and north-central Montana from noon until 10 p.m. Unexpectedly severe flash flooding caused by heavy rain and thunderstorms inundated Great Falls on Saturday, leaving the Fourth and Fifth blocks of Central Avenue nearly impassable and some cars stranded underneath the First Avenue North underpass.
ALERT: Flash Flood Watch for parts of Montana until 10:00pm Sunday. More Info: https://bit.ly/2RiUicx #mtwx
According to a social media post from NWS Great Falls, rapid rainfall rates and heavy rain could result in “flooding of fields, low land areas, streets, and underpasses due to poor drainage or runoff from saturated soils.” NWS has advised that roads and intersections could become impassable, and both fields and basements could be susceptible to flooding.
“It may be a good idea to move farm implements to higher ground today, and be prepared to move items from your basement if it starts to flood,” wrote NWS Great Falls on Facebook Sunday morning.
Lewis and Clark County saw hailstones Saturday reaching up to half an inch in diameter as well as approximately half an inch of rainfall. Helena is currently straddling the “marginal” to “slight” severe weather outlook. NWS officials have warned of the possibility of damaging winds up to 60 miles per hour and lightning into the afternoon and evening.
A Flash Flood Watch is also in effect for southwest Montana, which saw up to quarter-sized hail from Saturday’s thunderstorms in White Sulphur Springs and Meagher County.
NWS Great Falls has cautioned those in areas prone to flooding: “Turn around, don’t drown!”
Follow our STORMTracker Weather page for continuous updates on changing weather conditions in and around central and north-central Montana.
You can also download the STORMTracker Weather app, available on Google Play and the App Store.
Montana Department of Transportation resources:
- Road conditions map
- MDT webcams across Montana
- Non-MDT webcams across Montana
- Road conditions mobile app
- Reported crashes/slide-offs
STORMTracker Weather resources: