A low pressure system moved into the Pacific Northwest coast bringing a more moist, unstable, and southwesterly flow to the region. This helped generate showers and|thunderstorms over the higher terrain of these areas.
Every event with a place to put it. Tap one for its entry below.
Deaths and injuries are direct and indirect together, as the offices filed them. Damage is property and crops in the dollars of the year, not adjusted for inflation, and only where an office estimated it.
The episode as NWS TFX wrote it up.
A low pressure system moved into the Pacific Northwest coast bringing a more moist, unstable, and southwesterly flow to the region. This helped generate showers and|thunderstorms over the higher terrain of these areas. The frontal boundary associated with this system moved into western Montana later in the day bringing the chance of severe thunderstorms, damaging winds, large hail, and heavy rainfall to the area. Thunderstorm activity decreased overnight.
The local office's own words before the first event, as it sent them, from the Iowa Environmental Mesonet's archive of National Weather Service text.
NWS Great Falls, MT wrote its last area forecast discussion before the first event at Jun 17, 4:43 PM MST, 1 hour 7 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 543 PM MDT Mon Jun 17 2013 Aviation Section Updated .DISCUSSION... Tonight through Wednesday...The high pressure ridge will continue to keep the airmass relatively dry and shower/thunderstorm activity will diminish this evening. The ridge will move east of the zones Tuesday and a low pressure system over the Eastern Pacific will move over the West Coast. This will put central Montana underneath moist, unsettled southwest flow aloft. The airmass will become unstable during the day and a cold front will be crossing the Rockies late afternoon and evening. Scattered thunderstorms are expected across most of the region with numerous storms over the Rockies and adjacent slopes. Convection may last well into Tuesday evening along the eastern zones due to the slow eastward movement of the cold front. The low pressure system will continue to approach the region and heights aloft will continue to fall. and thunderstorm activity will increase Wednesday as the airmass becomes very moist and unstable. Heavy rain is possible across the central and northern portions of the region, and large hail possible over the northeastern zones. Wednesday night through Monday...A somewhat unsettled pattern will characterize the long term forecast. A low pressure system will push slowly drift across the Pacific Northwest through the long term. Shortwave energy will continue to rotate out from the main trough and move across the area from the southwest. Scattered showers and thunderstorms will continue to develop over Southwest Montana and then move northeast across Central Montana. The system will reach Northwest Montana Thursday morning before stalling and slowly weakening. The low will lift out over southern Saskatchewan Sunday. The models develop differences in their solutions by Monday with the ECMWF building a ridge and the GFS maintaining weak cyclonic flow over Montana. Uncertainty with the timing and placement of convective activity has led to a broad-brushed approach with regards to POP grids during the period. Due to cloud cover and periodic advection of cooler air following shortwaves, temperatures will remain generally below seasonal averages through Saturday. Highs should climb above seasonal averages to start the week. && .AVIATION... Updated 2343Z. VFR conditions will prevail through the period. Existing late afternoon showers will dissipate by 03Z, with light winds and few clouds overnight. Southwest flow aloft will destabilize after 18Z Tuesday with showers and thunderstorms probable KBZN/KHLN/KCTB/KGTF after 20Z. This activity will develop first over higher terrain and move east to northeast. Showers will push further east to affect KHVR/KLWT around 19/00Z. MVFR conditions may be possible in the vicinity of showers and thunderstorms. Nutter && .HYDROLOGY... A stronger period of showers and thunderstorms are possible on Wednesday, which may produce brief heavy rainfall. In fact, this situation will likely need to be monitored for possible areal flood/flash flood highlights across portions of north central and central Montana that still have moist soil that would not be able to absorb much rapid rainfall. && .PRELIMINARY POINT TEMPS/POPS... GTF 51 84 53 74 / 20 40 40 80 CTB 48 82 50 70 / 20 50 60 90 HLN 51 84 51 73 / 30 50 30 70 BZN 45 85 45 76 / 20 50 30 60 WEY 38 77 37 69 / 20 40 10 60 DLN 47 82 47 68 / 20 40 30 70 HVR 54 87 57 80 / 10 30 30 90 LWT 49 82 53 79 / 20 40 50 70 && .TFX WATCHES/WARNINGS/ADVISORIES... Flood warning continues for Big Sandy Creek near Havre until further notice. && weather.gov/greatfalls
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 515 AM MDT MON JUN 17 2013 MTZ011-181200- HILL- 515 AM MDT MON JUN 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT THE FLOOD WARNING FOR BIG SANDY CREEK NEAR HAVRE IN HILL COUNTY CONTINUES UNTIL FURTHER NOTICE. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN INCREASINGLY MOIST AND UNSTABLE SOUTHWESTERLY FLOW ALOFT WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY THROUGH WEDNESDAY. ACROSS NORTH CENTRAL AND CENTRAL MONTANA...SOME STORMS COULD BECOME STRONG ON TUESDAY...AND POSSIBLY SEVERE ON WEDNESDAY...ESPECIALLY EAST OF INTERSTATE 15. THREATS FROM SUCH STORMS MAY INCLUDE STRONG GUSTY WINDS AND HAIL...BUT BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE...ESPECIALLY ON WEDNESDAY. WE WILL CONTINUE TO MONITOR THIS SITUATION AS IT DEVELOPS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS REQUESTED FOR ANY REPORTS OF SIGNIFICANT FLOODING. MTZ009-010-012>014-044>051-053-054-181200- NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-CASCADE-CHOUTEAU- CENTRAL AND SOUTHERN LEWIS AND CLARK-TOOLE-LIBERTY- EASTERN PONDERA-BLAINE-SOUTHERN ROCKY MOUNTAIN FRONT- EASTERN TETON-JUDITH BASIN-FERGUS-BROADWATER-MEAGHER- 515 AM MDT MON JUN 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER TODAY AND TONIGHT IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN INCREASINGLY MOIST AND UNSTABLE SOUTHWESTERLY FLOW ALOFT WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY THROUGH WEDNESDAY. ACROSS NORTH CENTRAL AND CENTRAL MONTANA...SOME STORMS COULD BECOME STRONG ON TUESDAY...AND POSSIBLY SEVERE ON WEDNESDAY...ESPECIALLY EAST OF INTERSTATE 15. THREATS FROM SUCH STORMS MAY INCLUDE STRONG GUSTY WINDS AND HAIL...BUT BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE...ESPECIALLY ON WEDNESDAY. WE WILL CONTINUE TO MONITOR THIS SITUATION AS IT DEVELOPS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME. MTZ008-015-052-055-181200- BEAVERHEAD-MADISON-JEFFERSON-GALLATIN- 515 AM MDT MON JUN 17 2013 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER TODAY AND TONIGHT IS LOW. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN INCREASINGLY MOIST AND UNSTABLE SOUTHWESTERLY FLOW ALOFT WILL BRING A GOOD CHANCE FOR SHOWERS AND THUNDERSTORMS TO THE AREA TUESDAY THROUGH WEDNESDAY. ACROSS SOUTHWEST MONTANA...SOME STORMS COULD BECOME STRONG. THREATS FROM SUCH STORMS MAY INCLUDE STRONG GUSTY WINDS AND HAIL...BUT BRIEF HEAVY RAINFALL WILL ALSO BE POSSIBLE ON WEDNESDAY. WE WILL CONTINUE TO MONITOR THIS SITUATION AS IT DEVELOPS. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION IS NOT EXPECTED AT THIS TIME.
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
336 PM MDT MON JUN 17 2013
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0307 PM HAIL 13 SW DUPUYER 48.05N 112.69W
06/17/2013 E0.25 INCH TETON MT TRAINED SPOTTER
PEA SIZE HAIL WITH 0.15 RAIN IN 15 MINUTES. SPOTTER
REPORTED ONLY LIGHT WINDS.
&&
PNSPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
345 PM MDT MON JUN 17 2013
MTZ009-046-048-172215-
EASTERN PONDERA MT-NORTHERN ROCKY MOUNTAIN FRONT MT-SOUTHERN ROCKY
MOUNTAIN FRONT MT-
345 PM MDT MON JUN 17 2013
...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL PONDERA AND NORTHERN
TETON COUNTIES UNTIL 415 PM MDT...
AT 340 PM MDT...STORM SPOTTERS REPORTED A THUNDERSTORM 18 MILES
SOUTHWEST OF VALIER...MOVING NORTHEAST AT 15 MPH.
PEA SIZED HAIL HAS BEEN REPORTED WITH THIS STORM...ALONG WITH
LOCALLY HEAVY RAIN.
LOCATIONS NEAR THE PATH OF THIS STORM INCLUDE...DUPUYER AND PENDROY.
LAT...LON 4830 11220 4809 11212 4808 11217 4806 11214
4805 11215 4799 11279 4818 11270
TIME...MOT...LOC 2141Z 256DEG 11KT 4812 11252
PANSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 347 PM MDT MON JUN 17 2013 MTZ014-052-053-172230- BROADWATER MT-CENTRAL AND SOUTHERN LEWIS AND CLARK MT-JEFFERSON MT- 347 PM MDT MON JUN 17 2013 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LEWIS AND CLARK... NORTHERN JEFFERSON AND NORTHWESTERN BROADWATER COUNTIES UNTIL 430 PM MDT... AT 344 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR MONTANA CITY...OR 9 MILES SOUTHEAST OF HELENA...MOVING EAST AT 15 MPH. HAIL UP TO THE SIZE OF NICKELS AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. * LOCATIONS IMPACTED INCLUDE... EAST HELENA... WINSTON... LAT...LON 4672 11166 4644 11148 4637 11201 4654 11209 TIME...MOT...LOC 2147Z 253DEG 13KT 4648 11192 MPJ
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 602 PM MDT MON JUN 17 2013 MTZ012-180100- CASCADE MT- 602 PM MDT MON JUN 17 2013 ...SIGNIFICANT WEATHER ADVISORY FOR CENTRAL CASCADE COUNTY UNTIL 700 PM MDT... AT 559 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 18 MILES SOUTH OF GREAT FALLS...MOVING EAST AT 15 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 40 MPH ARE POSSIBLE WITH THIS STORM...ALONG WITH HEAVY RAIN. * LOCATIONS IMPACTED INCLUDE... STOCKETT... CENTERVILLE... SAND COULEE AND TRACY... IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. LAT...LON 4753 11093 4719 11080 4713 11134 4736 11159 TIME...MOT...LOC 0002Z 249DEG 12KT 4725 11126 MPJ
The Great Falls radar (KTFX), 101 km away, was scanning. The volume nearest the first event began at 00:50 UTC.
9 hail, 2 high wind, 1 flash flood. Local standard time, as filed.
Severe hail measuring 1.75 inches (approximately golf ball sized) was reported 17 miles WNW of Augusta, MT. Reports of vehicle and metal roof damage were also received.
Severe hail estimated at 1.00 inches (approximately quarter sized) was reported at Goose Bay Marina 8 miles ENE of Winston, MT.
Severe hail measuring 1.75 inches (approximately golf ball sized) was reported in Browning, MT.
Severe hail measuring 1.75 inches (approximately golf ball sized) was reported 1 mile S of Browning, MT.
Severe hail measuring 1.00 inches (approximately quarter sized) was reported 7 miles NNE of Browning, MT.
High winds estimated at 52KT (60MPH) were reported 2 miles W of Vaughn, MT.
Severe hail estimated at 1.00 inches (approximately quarter sized) was reported 4 miles SSE of Saint Mary, MT. A motorist on MT Highway 49 reported vehicle damage.
Severe hail measuring 1.00 inches (approximately quarter sized) was reported 2 miles W of Vaughn, MT.
High winds measuring 62KT (71MPH) were reported at Logan Pass. Thunderstorm activity was noted in the area on radar.
Severe hail measuring 1.50 inches (approximately ping pong ball sized) was reported 5 miles SSE of Brady, MT.
Multiple public calls about flash flooding due to thunderstorms in the area. Water was reported flowing over portions of Interstate 15 near Brady.
Heavy rain, pea sized hail, and a few severe hailstones measuring 1.00 inches (approximately quarter sized) were reported in Shelby, MT.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2013Every state in 2013This day in weather historyWarnings in Montana, June 2013
NOAA National Centers for Environmental Information, Storm Events Database, compiled from the National Weather Service’s monthly Storm Data. Complete through 2026-06; NCEI adds each month about 75 days after it ends and revises past years a few times a year. Rebuilt 2026-09-24. Each event’s entry at NCEI: 450492, 450493, 450497, 450498, 450499, 450504, 450500, 450503, 450494, 450505, 454456, 450506.