In the early morning hours of Saturday, August 11th, severe thunderstorms were diminishing and pushing east across North Dakota. As this occurred, an outflow boundary with winds of 60 mph, moved across parts of north central North Dakota.
Every event with a place to put it; 3 filed by county or forecast zone are drawn at its center, in a lighter ring. 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 BIS wrote it up.
In the early morning hours of Saturday, August 11th, severe thunderstorms were diminishing and pushing east across North Dakota. As this occurred, an outflow boundary with winds of 60 mph, moved across parts of north central North Dakota. The high wind occurred away from convection, with no thunderstorms in progress at the location of these high winds.
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 Bismarck, ND wrote its last area forecast discussion before the first event at Aug 9, 1:42 PM CST, 10 hours 33 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE BISMARCK ND 242 PM CDT THU AUG 9 2007 .SHORT TERM...TONIGHT THROUGH SUNDAY NIGHT A TYPICAL MID TO LATE SUMMER PATTERN WILL REMAIN ESSENTIALLY UNCHANGED FOR THE NEXT 3 TO 6 DAYS WITH TROUGHS ON THE TWO COASTS AND RIDGING ACROSS THE CENTRAL U.S. ... AND THE WESTERLIES NEAR THE INTERNATIONAL BORDER WITH AN UPPER HIGH OVER THE SOUTH CENTRAL PART OF THE NATION. THIS PATTERN WILL BRING OUR FORECAST AREA ABOVE NORMAL TEMPERATURES. THE PATTERN ALSO FEATURES PASSING SHORT WAVES EVERY 24 TO 48 HOURS. THESE WILL BE ABLE TO TAP INTO A FAVORABLE THERMODYNAMIC PROFILE TO BRING US THE THREAT OF THUNDERSTORMS. THE ONLY REMAINING DETAILS OF THE FORECAST IS TO PROPERLY IDENTIFY THE TIMING OF THE IMPULSES. THE 12Z NAM INDICATES A SHORT WAVE ENTERING WESTERN NORTH DAKOTA AT MAX HEATING THIS AFTERNOON. THE 4KM WRF IS IN AGREEMENT AND GENERATES A LINE OF THUNDERSTORMS IN THE WEST CENTRAL AND SOUTHWEST PARTS OF THE STATE AROUND 22Z. THESE STORMS DIE OUT BY 06Z AS THEY MOVE INTO CENTRAL NORTH DAKOTA...HOWEVER THE NAM AND GFS STILL INDICATE A STRONG LLJ AT 06Z...SO THERE IS A REASONABLE CHANCE THAT THE CONVECTION WILL BECOME ELEVATED AND SURVIVE THROUGH DAYBREAK. FRIDAY EVENING WILL ALSO PRESENT A CHANCE OF THUNDERSTORMS...AS ANOTHER SHORT WAVE CROSSES THE REGION. BETTER MOISTURE WILL BE IN PLACE FOR THIS EPISODE AND SPC HAS PUT OUT A SLIGHT RISK FOR SEVERE THUNDERSTORMS FOR THE TIME FRAME. INCREASING H5 HEIGHTS WILL MAKE SATURDAY THE LIKELY CANDIDATE FOR A QUIET AFTERNOON AND NIGHT. ANOTHER SHORT WAVE SUNDAY NIGHT WILL BRING A CHANCE OF RENEWED ACTIVITY. .LONG TERM...MONDAY THROUGH THURSDAY NIGHT... A SPRAWLING MIDSUMMER RIDGE WILL REMAIN IN PLACE IN THE EXTENDED WITH NO SYNOPTIC-SCALE PATTERN SHIFT TO CAUSE ITS WEAKENING. BY THE END OF THE PERIOD...THE 06Z GFS WAS AGGRESSIVE IN BRINGING THE PACIFIC TROUGH EASTWARD...AND THE 12Z GFS THE EXACT OPPOSITE...BUT THE PERSISTENCE OF THE HOT RIDGE ALONE ARGUES AGAINST BOTH SOLUTIONS BEYOND DAY 5. THUS A BLEND OF THE 00Z GFS...ITS ENSEMBLE MEAN...AND THE 00Z ECMWF IS THE PROXY FOR OUR FCST DATABASE TODAY. IN THIS PATTERN THE CHALLENGE IS FINDING SOME CONSISTENCY IN S/WS IN ORDER TO ADD VALUE TO THE FCST. THE ENSEMBLE MEAN ITSELF WOULD SUGGEST NEAR CLIMATOLOGY /20 TO 30/ POPS FOR THE ENTIRE PERIOD. THE 12Z GFS CONFIRMED THAT THE BEST THREAT OF THUNDER MAY BE MON AND WED...AND WE WENT WITH THIS WHILE RECOGNIZING TIMING WILL WAFFLE SOME. IN THE FIRST CASE 850MB THERMAL RIDGING /TEMPS 24-28 C/ WILL MAKE FOR A HOT MONDAY...AND ADD TO THE MUCAPE / WHICH THE 12Z GFS PROGS AT 3000 J/KG / AHEAD OF A SFC TROUGH. THE SCENARIO LOOKS SIMILAR TO THOSE OF THIS WEEK WHERE THE HIGHEST POPS MAY BE OVER CENT ND. THERMAL FIELDS DO COOL SOME IN THE WAKE OF THIS S/W...THOUGH WITH STEADY 500MB HEIGHTS THIS MAY NOT BE COMPLETELY TRUE. THUS FOR TUE-THU A BLEND OF CLIMO AND GFS ENSEMBLE TEMPS WERE USED MORE THAN ANYTHING...YIELDING LITTLE CHANGE TO THE GOING FCST. && .AVIATION... VFR CONDITIONS WILL CONTINUE INTO THE EVE FOR MOST AREAS. THE THREAT OF TSRA IN WESTERN ND IS NOT ZERO AFT 21Z...BUT INSTABILITY IS QUESTIONABLE SO WE WILL ONLY INCLUDE A CB AT DIK/ISN FOR THIS. A GREATER CHANCE OF THUNDER IS ACROSS CENTRAL ND BETWEEN 07-16Z...BUT STILL NOT EVERYONE WILL SEE STORMS. IMPACT IN THE TAFS MAY BE INCREASED AT SOME SITES ONCE CONFIDENCE IN TIMING/LOCATION OF TSRA CLUSTERS INCREASES. AT THE LEAST...MVFR CIGS/VIS WOULD ACCOMPANY ANY STORMS AT BIS/MOT AND ESPECIALLY JMS DURING THIS TIME. && .BIS WATCHES/WARNINGS/ADVISORIES... NONE. && RSL/CJS
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE BISMARCK ND 348 PM CDT THU AUG 9 2007 NDZ001>005-009>013-017>023-025-031>037-040>048-050-051-102100- DIVIDE-BURKE-RENVILLE-BOTTINEAU-ROLETTE-WILLIAMS-MOUNTRAIL-WARD- MCHENRY-PIERCE-MCKENZIE-DUNN-MERCER-OLIVER-MCLEAN-SHERIDAN-WELLS- FOSTER-GOLDEN VALLEY-BILLINGS-STARK-MORTON-BURLEIGH-KIDDER- STUTSMAN-SLOPE-HETTINGER-GRANT-BOWMAN-ADAMS-SIOUX-EMMONS-LOGAN- LA MOURE-MCINTOSH-DICKEY- 348 PM CDT THU AUG 9 2007 /248 PM MDT THU AUG 9 2007/ THIS HAZARDOUS WEATHER OUTLOOK IS FOR PORTIONS OF NORTH CENTRAL NORTH DAKOTA...NORTHWEST NORTH DAKOTA...SOUTH CENTRAL NORTH DAKOTA...SOUTHEAST NORTH DAKOTA AND SOUTHWEST NORTH DAKOTA. .DAY ONE...THIS AFTERNOON AND TONIGHT A FEW SEVERE THUNDERSTORMS ARE POSSIBLE TONIGHT. THE PRIMARY THREAT WILL BE IN THE FORM OF LARGE HAIL ACROSS CENTRAL NORTH DAKOTA. HEAVY RAINFALL AND DANGEROUS LIGHTNING WILL ALSO ACCOMPANY ANY STORMS. THE GREATEST CHANCE OF STORMS IS AFTER MIDNIGHT. .DAYS TWO THROUGH SEVEN...FRIDAY THROUGH WEDNESDAY THE POTENTIAL FOR SEVERE THUNDERSTORMS WILL INCREASE ON FRIDAY AND FRIDAY NIGHT. THE THREAT MAY COME IN TWO WAVES...THE FIRST IN SOUTH CENTRAL NORTH DAKOTA IN THE EARLY MORNING HOURS...AND THE SECOND...GREATER THREAT OVER A LARGE PART OF WESTERN AND CENTRAL NORTH DAKOTA FROM FRIDAY AFTERNOON INTO FRIDAY NIGHT. LARGE HAIL AND DAMAGING WINDS ARE THE PRIMARY THREAT...BUT ISOLATED TORNADOES ARE ALSO POSSIBLE FRIDAY AFTERNOON AND EVENING. A SLIGHT CHANCE OF THUNDERSTORMS EXISTS MONDAY THROUGH WEDNESDAY. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION MAY BE REQUIRED TONIGHT...BUT IS MORE LIKELY FRIDAY AFTERNOON AND FRIDAY NIGHT. CJS/RSL
The national radar mosaic for the moment the first event began.
4 high wind. Local standard time, as filed.
Wind estimated at 60 mph reported.
Wind estimated at 60 mph reported in Renville County. Public report to media. No thunderstorm in progress.
Minot ASOS reported peak wind gust at 0548Z of 52 knots.
Wind estimated at 60 mph reported in McHenry County.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in North Dakota in 2007Every state in 2007This day in weather historyWarnings in North Dakota, August 2007
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: 58402, 57161, 57160, 58400.