Late evening thunderstorms developed over Judith Basin County. Wind gusts in excess of 60 mph were reported.
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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.
Late evening thunderstorms developed over Judith Basin County. Wind gusts in excess of 60 mph were reported.
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 Aug 10, 7:28 PM MST, 43 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE GREAT FALLS MT 828 PM MDT TUE AUG 10 2010 .UPDATE... TONIGHT...THUNDERSTORM ACTIVITY WILL CONTINUE TO WEAKEN THROUGH THE EVENING BUT GUSTY WINDS AND HEAVY RAIN WILL CONTINUE NEAR THUNDERSTORMS. WILL INCREASE POPS ACROSS THE NORTHEAST ZONES AFTER MIDNIGHT DUE TO WEAK DISTURBANCES CONTINUING TO MOVE THROUGH FLOW ALOFT. OTHERWISE...UPDATE TO FRESHEN FIRST PERIOD POPS...WX...AND WINDS. ZELZER && .AVIATION... UPDATED 0000Z. AN UPPER LEVEL TROUGH OF LOW PRESSURE OVER THE PACIFIC NW WILL CONTINUE TO PROVIDE A MOIST AND UNSTABLE SW FLOW ALOFT OVER THE REGION THROUGH THE NEXT 24 HRS. SCATTERED THUNDERSTORMS DEVELOPING OVER CENTRAL ID AND SW/WESTERN MT THIS AFTERNOON WILL SPREAD NE ACROSS NORTH CENTRAL AND SW MT THROUGH THE REMAINDER OF THIS AFTERNOON AND EVENING. SOME STORMS WILL PRODUCE STRONG GUSTY WINDS AND HAIL WITH LOCAL MVFR CONDITIONS IN THE IMMEDIATE VICINITY OVER STRONGER CELLS. CONVECTION WILL GRADUALLY DIMINISH AFTER SUNSET WITH A FEW SHOWERS/TSTORMS LINGERING LATER IN THE NIGHT OVER PORTIONS OF NORTH CENTRAL MT. HOENISCH && .PREV DISCUSSION... /ISSUED 530 PM MDT TUE AUG 10 2010/ TONIGHT THROUGH THURSDAY...UPPER TROF REMAINS OVER THE PACIFIC NORTHWEST WITH MOISTURE CONTINUING TO ADVECT OVER THE AREA. MODELS INDICATE A SHORT WAVE EJECTING FROM THE TROF BASE EARLY THIS EVENING WHICH WILL AID IN FOCUSING THUNDERSTORM ACTIVITY. THE COUNTY WARNING AREA REMAINS UNDER A SLIGHT RISK CATEGORY FROM SPC AND SOME STORMS COULD BECOME SEVERE LATE THIS AFTERNOON OR EARLY EVENING. BIGGEST THREAT WILL BE HEAVY RAIN AND DAMAGING WINDS THOUGH LARGE HAIL COULD ALSO OCCUR. BY WEDNESDAY AFTERNOON THE UPPER TROF APPROACHES WESTERN MONTANA WITH SCATTERED THUNDERSTORMS DEVELOPING AGAIN DURING THE AFTERNOON. MORE OF THE SAME ON THURSDAY AS THE UPPER TROF BEGINS TO LIFT OUT OVER THE AREA. TEMPERATURES WILL BE NEAR TO SLIGHTLY BELOW SEASONAL AVERAGES. EMANUEL THURSDAY NIGHT THROUGH TUESDAY...A RATHER ACTIVE WEATHER PATTERN WILL BEGIN THE PERIOD ON THURSDAY NIGHT...AS AN UPPER LEVEL TROF DIVES SOUTH OUT OF ALBERTA INTO NORTH CENTRAL MONTANA. AS A RESULT...THERE IS A GOOD CHANCE FOR PRECIPITATION OVER CENTRAL AND NORTH CENTRAL MONTANA LATE THURSDAY NIGHT AND INTO FRIDAY MORNING...WITH RAINFALL AMOUNTS OF 0.25 TO 0.50 INCHES POSSIBLE OVER PORTIONS OF NORTH CENTRAL MONTANA. THUS THE CHANCES FOR PRECIPITATION HAVE BEEN RAISED A BIT...ESPECIALLY OVER THE ROCKY MOUNTAIN FRONT AND FOR AREAS BETWEEN GREAT FALLS AND LEWISTOWN. WITH A CLOUD COVER AND PRECIP ON FRIDAY...EXPECT A RATHER COOL DAY OVER NORTH CENTRAL MONTANA...WITH A BIT WARMER TEMPERATURES OVER SOUTHWEST MONTANA...AS AFTERNOON HIGHS WILL BE JUST A FEW DEGREES BELOW NORMAL OVER THE SOUTHWEST. THIS STORM SYSTEM WILL BE A FAST MOVING SYSTEM...AS BY FRIDAY NIGHT...MOST OF THE PRECIPITATION SHOULD HAVE EXITED THE REGION...AS WARMER...MORE SUMMER-LIKE AIR STARTS TO MAKE ITS RETURN. FOR THE WEEKEND...FORECAST MODELS STILL PROG A DRY AND WARM WEATHER PATTERN OVER THE REGION...AS AFTERNOON TEMPERATURES RISE BACK UP TO NEAR SEASONAL READINGS...ALONG WITH DRY CONDITIONS. FOR MONDAY AND INTO TUESDAY...A NEW UPPER LEVEL LOW WILL BE DEVELOPING OVER THE PACIFIC NORTHWEST...RESULTING IN AN UNSTABLE SOUTHERLY FLOW ALOFT DEVELOPING OVER THE REGION. THUS...THE CHANCES FOR AFTERNOON/EVENING THUNDERSTORMS WILL START TO INCREASE OVER THE AREA FOR MONDAY AND TUESDAY...AS AFTERNOON TEMPERATURES REMAIN NEAR SEASONAL NORMALS. BRUSDA && .PRELIMINARY POINT TEMPS/POPS... GTF 53 81 53 79 / 50 30 30 30 CTB 50 77 50 76 / 40 30 20 30 HLN 53 79 54 78 / 60 30 30 30 BZN 49 85 49 81 / 50 30 30 40 WEY 37 76 37 69 / 30 20 30 30 DLN 48 74 47 75 / 60 30 30 20 HVR 54 89 55 81 / 40 30 30 30 LWT 51 81 51 73 / 50 30 20 30 && .TFX WATCHES/WARNINGS/ADVISORIES... NONE. && WEATHER.GOV/GREATFALLS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE GREAT FALLS MT 941 AM MDT TUE AUG 10 2010 MTZ008>015-044>046-048>055-111545- BEAVERHEAD-NORTHERN ROCKY MOUNTAIN FRONT-EASTERN GLACIER-HILL- CASCADE-CHOUTEAU-CENTRAL AND SOUTHERN LEWIS AND CLARK-MADISON- TOOLE-LIBERTY-EASTERN PONDERA-SOUTHERN ROCKY MOUNTAIN FRONT- EASTERN TETON-JUDITH BASIN-FERGUS-JEFFERSON-BROADWATER-MEAGHER- GALLATIN- 941 AM MDT TUE AUG 10 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF CENTRAL MONTANA...NORTH CENTRAL MONTANA AND SOUTHWEST MONTANA. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS WILL DEVELOP DURING THE AFTERNOON AND EVENING HOURS. SOME STORMS MAY BECOME SEVERE WITH HEAVY RAIN...DAMAGING WINDS AND LARGE HAIL. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES. MTZ047-111545- BLAINE- 941 AM MDT TUE AUG 10 2010 THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL MONTANA. .DAY ONE...TODAY AND TONIGHT SCATTERED THUNDERSTORMS ARE POSSIBLE DURING THE AFTERNOON AND EVENING HOURS. SOME STORMS MAY BECOME STRONG WITH GUSTY WINDS AND HEAVY RAIN. .DAYS TWO THROUGH SEVEN...WEDNESDAY THROUGH MONDAY THE PROBABILITY FOR WIDESPREAD HAZARDOUS WEATHER IS LOW. .SPOTTER INFORMATION STATEMENT... WEATHER SPOTTERS ARE ENCOURAGED TO REPORT SIGNIFICANT WEATHER CONDITIONS ACCORDING TO STANDARD OPERATING PROCEDURES.
SPECIAL WEATHER STATEMENT
NATIONAL WEATHER SERVICE GREAT FALLS MT
608 PM MDT TUE AUG 10 2010
MTZ014-052-053-110045-
BROADWATER MT-CENTRAL AND SOUTHERN LEWIS AND CLARK MT-JEFFERSON MT-
608 PM MDT TUE AUG 10 2010
...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LEWIS AND CLARK...
NORTHERN JEFFERSON AND NORTHWESTERN BROADWATER COUNTIES UNTIL 645 PM
MDT...
AT 600 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A
STRONG THUNDERSTORM 9 MILES NORTHWEST OF BASIN...OR 16 MILES
NORTHWEST OF BOULDER...MOVING NORTHEAST AT 25 MPH.
HAIL UP TO ONE-HALF INCH IN DIAMETER AND HEAVY RAIN ARE EXPECTED
WITH THIS STORM. WIND GUSTS UP TO 50 MPH ARE POSSIBLE.
* LOCATIONS IMPACTED INCLUDE...
MONTANA CITY... HELENA AND EAST HELENA...
LAT...LON 4700 11215 4677 11162 4633 11145 4615 11232
4634 11246 4639 11241 4641 11233 4660 11230
4664 11233 4665 11242 4669 11243 4669 11251
TIME...MOT...LOC 0007Z 241DEG 23KT 4641 11231
13PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
619 PM MDT TUE AUG 10 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0600 PM HAIL 2 NW MELROSE 45.65N 112.71W
08/10/2010 M0.50 INCH BEAVERHEAD MT TRAINED SPOTTER
0.25 OF AN INCH OF RAIN FELL IN 15 MIN.
&&
WILLIAMSON DCSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 647 PM MDT TUE AUG 10 2010 MTZ014-052-053-110130- BROADWATER MT-CENTRAL AND SOUTHERN LEWIS AND CLARK MT-JEFFERSON MT- 647 PM MDT TUE AUG 10 2010 ...SIGNIFICANT WEATHER ADVISORY FOR SOUTHEASTERN LEWIS AND CLARK... NORTHEASTERN JEFFERSON AND NORTHWESTERN BROADWATER COUNTIES UNTIL 730 PM MDT... AT 640 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM NEAR HELENA...MOVING NORTHEAST AT 35 MPH. THIS STORM HAS ALREADY PRODUCED WIND GUSTS TO AROUND 50 MPH IN THE HELENA AREA. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 55 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN AND FREQUENT DANGEROUS LIGHTNING. * LOCATIONS IMPACTED INCLUDE... EAST HELENA... YORK... MONTANA CITY... WINSTON... IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. LAT...LON 4684 11167 4642 11144 4634 11202 4666 11212 TIME...MOT...LOC 0045Z 234DEG 36KT 4662 11192 HOENISCH
SPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 650 PM MDT TUE AUG 10 2010 MTZ012-014-054-110130- CASCADE MT-CENTRAL AND SOUTHERN LEWIS AND CLARK MT-MEAGHER MT- 650 PM MDT TUE AUG 10 2010 ...SIGNIFICANT WEATHER ADVISORY FOR EASTERN LEWIS AND CLARK...EXTREME NORTHWESTERN MEAGHER AND SOUTHWESTERN CASCADE COUNTIES UNTIL 730 PM MDT... AT 645 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 7 MILES EAST OF WOLF CREEK...MOVING NORTHEAST AT 25 MPH. HAIL UP TO ONE-HALF INCH IN DIAMETER AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM. * LOCATIONS IMPACTED INCLUDE... HOLTER LAKE... CRAIG... IF THREATENING WEATHER APPROACHES YOUR AREA...TAKE SHELTER IN A STURDY BUILDING. LAT...LON 4724 11153 4684 11151 4674 11211 4721 11205 TIME...MOT...LOC 0049Z 242DEG 20KT 4700 11190 HOENISCH
PRELIMINARY LOCAL STORM REPORT
NATIONAL WEATHER SERVICE GREAT FALLS MT
654 PM MDT TUE AUG 10 2010
..TIME... ...EVENT... ...CITY LOCATION... ...LAT.LON...
..DATE... ....MAG.... ..COUNTY LOCATION..ST.. ...SOURCE....
..REMARKS..
0635 PM TSTM WND GST 3 NE HELENA 46.63N 111.98W
08/10/2010 M52 MPH LEWIS AND CLARK MT ASOS
52 MPH WIND GUST MEASURED AT HELENA REGIONAL AIRPORT.
&&
HOENISCHSPECIAL WEATHER STATEMENT NATIONAL WEATHER SERVICE GREAT FALLS MT 700 PM MDT TUE AUG 10 2010 MTZ015-052-055-110145- GALLATIN MT-JEFFERSON MT-MADISON MT- 700 PM MDT TUE AUG 10 2010 ...SIGNIFICANT WEATHER ADVISORY FOR EXTREME WESTERN GALLATIN... NORTHERN MADISON AND SOUTHEASTERN JEFFERSON COUNTIES UNTIL 745 PM MDT... AT 655 PM MDT...NATIONAL WEATHER SERVICE DOPPLER RADAR WAS TRACKING A STRONG THUNDERSTORM 10 MILES NORTHEAST OF SHERIDAN...MOVING NORTHEAST AT 40 MPH. HAIL UP TO THE SIZE OF PENNIES AND WIND GUSTS UP TO 50 MPH ARE EXPECTED WITH THIS STORM...ALONG WITH HEAVY RAIN. * LOCATIONS IMPACTED INCLUDE... PONY... NORRIS... HARRISON... THIS STORM MAY INTENSIFY...SO BE CERTAIN TO MONITOR LOCAL RADIO AND TV STATIONS...AS WELL AS LOCAL CABLE TV OUTLETS...FOR ADDITIONAL INFORMATION AND POSSIBLE WARNINGS FROM THE NATIONAL WEATHER SERVICE. LAT...LON 4593 11185 4560 11150 4543 11199 4556 11216 TIME...MOT...LOC 0100Z 226DEG 33KT 4557 11196 HOENISCH
The Great Falls radar (KTFX), 74 km away, was scanning. The volume nearest the first event began at 03:12 UTC.
1 thunderstorm wind. Local standard time, as filed.
A thunderstorm produced a wind gust to 65 mph at Geyser 2ESE.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Montana in 2010Every state in 2010This day in weather historyWarnings in Montana, August 2010
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: 253214.