A mountain wave wind event developed on the east side of the Wind River Mountain range causing strong mountaintop winds to descend the east slopes and into the adjacent Lander Foothills. m.
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The episode as NWS RIW wrote it up.
A mountain wave wind event developed on the east side of the Wind River Mountain range causing strong mountaintop winds to descend the east slopes and into the adjacent Lander Foothills. Gusts over 50 mph lasted for over three hours and a peak gust of 74 mph was measured at Hunt Field at 1:37 p.m. MDT. The strong wind downed several trees, damaged house roofs around Lander, and fanned a grass fire in the Baldwin Creek drainage. The grass fire engulfed one small barn as it made a one mile run to the east.
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 Riverton, WY wrote its last area forecast discussion before the first event at Oct 1, 8:35 AM MST, 1 hour 25 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 935 AM MDT MON OCT 1 2007 UPDATE...ADDED FIRE WEATHER ZONE 289 TO RED FLAG WARNING FOR WIND AND LOW RELATIVE HUMIDITIES. TREND OF SLOWING TROUGH DOWN CONTINUES WITH DELAY/DECREASE IN PRECIPITATION ACROSS THE WEST THIS AFTERNOON. .SHORT TERM...TODAY THROUGH WEDNESDAY NIGHT SURFACE LOW PRESSURE CURRENTLY DEEPENING OVER SOUTHEAST MONTANA EARLY THIS MORNING AS THE ASSOCIATED UPPER LEVEL TROUGH MOVES INTO NORTHWEST OREGON. WINDY AND WARM CONDITIONS EXPECTED FOR MOST AREAS IN WESTERN AND CENTRAL WYOMING TODAY AHEAD OF THE APPROACHING UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT. DECIDED TO CANCEL THE HIGH WIND WATCH FOR THE WIND RIVER MOUNTAINS GIVEN THE LATEST DATA SHOWING THE CRITICAL LAYER NEAR MOUNTAIN TOP LEVEL TO BE SHORT LIVED AS COLD AIR ADVECTION BEGINS LATER THIS MORNING. LOCAL WIND GUSTS APPROACHING 45-50 KTS ARE STILL POSSIBLE ALONG EXPOSED RIDGES BUT THE WINDS ARE NOT EXPECTED TO BE FORCED DOWN THE LEE- SIDE GIVEN THE NEAR ISOTHERMAL CONDITIONS AT 700MB...BECOMING MORE UNSTABLE THROUGH THE AFTERNOON. GIVEN LOW RH VALUES OBSERVED THIS AFTERNOON AND THE EXPECTED STRONG WINDS...ISSUED A RED FLAG WARNING FOR JOHNSON AND NATRONA COUNTIES FOR THIS AFTERNOON. MINIMUM RH VALUES ARE MARGINAL IN NATRONA COUNTY BUT WITH SUSTAINED WINDS APPROACHING 25 KTS IN A LARGE PORTION OF THE COUNTY AND GUSTS NEAR 40 KTS POSSIBLE...CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY THROUGH THE LATE AFTERNOON. LATEST MODEL DATA SOMEWHAT SLOWER WITH THE PASSAGE OF THE COLD FRONT AND THE ONSET OF SHOWERS TODAY. COLD FRONT WILL MOVE THROUGH FAR WESTERN AREAS THIS AFTERNOON FROM YELLOWSTONE PARK SOUTHWARD THROUGH THE SALT RIVER MOUNTAINS DURING THE AFTERNOON. H7 TEMPS PROGGED TO DECREASE TO NEAR -5C...SO SNOW LEVELS WILL DROP TO ABOUT 6000 FEET THIS EVENING OVER THE WESTERN MOUNTAINS BUT THE FAST MOVEMENT OF THE UPPER TROUGH WILL LIMIT SNOW AMOUNTS FROM A TRACE IN THE LOWER ELEVATIONS UP TO SEVERAL INCHES POSSIBLE ABOVE ABOUT 7500 FEET. RAPID CLEARING STILL ON TRACK FOR TUESDAY MORNING BEHIND THE TROUGH WITH SOME OROGRAPHIC SNOW AS WELL AS WEAK ISENTROPIC LIFT KEEPING LIGHT SNOW SHOWERS OVER THE WESTERN MOUNTAINS. STRONG PACIFIC JET STREAM WILL NOSE INTO NORTHERN IDAHO AND MONTANA TUESDAY NIGHT WITH OROGRAPHIC SNOWS INCREASING FROM ABOUT JACKSON NORTHWARD INTO GRAND TETON AND YELLOWSTONE PARKS EASTWARD INTO THE NORTHERN BIGHORN MOUNTAINS WEDNESDAY INTO WEDNESDAY NIGHT AS THE JET SAGS SLOWLY SOUTHWARD. .LONG TERM...THURSDAY THROUGH MONDAY A PACIFIC LOW PRESSURE TROUGH WILL MOVE INTO WESTERN WYOMING THURSDAY MORNING SPREADING SHOWERS INTO THE WESTERN MOUNTAINS. THE TROUGH WILL MOVE EAST THROUGH THE DAY WITH THE SHOWERS INCREASING AND SPREADING EAST AS WELL. STRONG WINDS WILL DEVELOP OVER THE MOUNTAIN RIDGES AND ALONG THE EAST SLOPES MOVING INTO THE LOWER ELEVATIONS EAST OF THE CONTINENTAL DIVIDE...ESPECIALLY ACROSS SWEETWATER...SOUTHERN FREMONT AND NATRONA COUNTIES AND IN THE CODY AREA OF PARK COUNTY. THURSDAY NIGHT THE PRECIPITATION WILL BECOME MORE WIDESPREAD WITH SNOW LIKELY IN THE MOUNTAINS ABOVE 7500 FEET. TEMPERATURES WILL COOL AS THE TROUGH DEEPENS OVER THE NORTHERN AND CENTRAL ROCKIES. THE PRECIPITATION WILL SPREAD INTO THE LOWER ELEVATIONS EAST OF THE CONTINENTAL DIVIDE FRIDAY MORNING AND CONTINUE THROUGH FRIDAY NIGHT AS TEMPERATURES CONTINUE TO FALL. WESTERN AND CENTRAL WYOMING WILL BEGIN TO DRY OUT FROM NORTHWEST TO SOUTHEAST LATE FRIDAY NIGHT WITH CLEARING OCCURRING SATURDAY. SATURDAY NIGHT WILL SEE WIDESPREAD FREEZING TEMPERATURES WITH DECREASING CLOUDS. SUNDAY AND MONDAY WILL BE DRY AND WARMER THROUGH THE PERIOD. THE EXTENDED MODELS START OUT IN FAIR AGREEMENT BUT THE SIGNIFICANT DIFFERENCES DEVELOP WITH THE TROUGH MOVING THROUGH FRIDAY AND SATURDAY. LESS DIFFERENCE OCCURS AS HIGH PRESSURE BUILDS IN THE THE DRY AND STABLE CONDITIONS SUNDAY AND MONDAY. && .AVIATION... DEEPENING TROUGH WILL CONTINUE TO BACK UPPER FLOW TO THE SOUTH-SOUTHWEST EARLY TODAY. STRENGTHENING PRESSURE GRADIENT WILL LEAD TO INCREASING WIND BY AROUND 18Z AT MOST TAF SITES. HAVE TONED DOWN WIND SPEEDS IN THE WIND RIVER BASIN AS MOUNTAIN WAVE EVENT DOES NOT APPEAR AS LIKELY AS IT DID EARLIER. GUSTY NORTHWEST WIND EXPECTED AT FAVORED SITES FOLLOWING TROUGH PASSAGE BETWEEN 00Z AND 06Z TUESDAY. OTHERWISE...VFR CONDITIONS TO PREVAIL AT ALL TAF SITES THROUGH THE PERIOD. MOISTURE PLUME WORKING ITS WAY NORTH THROUGH THE GREAT BASIN MAY PROVIDE AN ISOLATED SHOWER OR TWO OVER SOUTHWEST WYOMING AROUND 00Z/TUESDAY. HOWEVER...HAVE LEFT ALL INDICATIONS OUT OF THIS TAF PACKAGE DUE TO DRY AND WARM SUB-CLOUD LAYER. && .FIRE WEATHER... WINDY AND WARM CONDITIONS EXPECTED FOR MOST AREAS IN THE DISTRICT TODAY AHEAD OF AN APPROACHING UPPER TROUGH AND ASSOCIATED SURFACE COLD FRONT. MINIMUM RELATIVE HUMIDITY VALUES FROM 10-15 PERCENT ARE EXPECTED IN JOHNSON AND NATRONA COUNTIES THIS AFTERNOON AND WITH THE THE EXPECTED STRONG WINDS...A RED FLAG WARNING HAS BEEN ISSUED FOR THESE AREAS FROM 1200 THROUGH 1800 HOURS. MINIMUM RH VALUES WILL BE MARGINAL IN NATRONA COUNTY BUT WITH SUSTAINED WINDS APPROACHING 30 MPH IN A LARGE PORTION OF THE COUNTY AND GUSTS NEAR 40 MPH POSSIBLE...CRITICAL FIRE WEATHER CONDITIONS ARE LIKELY THROUGH THE LATE AFTERNOON IN THESE AREAS. A COLD FRONT WILL MOVE RAPIDLY THROUGH THE AREA THIS EVENING WITH WINDS DECREASING AND BECOMING WEST-NORTHWEST AND RELATIVE HUMIDITY LEVELS RAPIDLY INCREASING ALONG WITH MAINLY MOUNTAIN SHOWERS AND SNOW SHOWERS. A STRONG WESTERLY FLOW IS EXPECTED TO KEEP SCATTERED SNOW SHOWERS OVER THE NORTHWESTERN MOUNTAINS WEDNESDAY AND WEDNESDAY NIGHT. && .RIW WATCHES/WARNINGS/ADVISORIES... RED FLAG WARNING FROM 1 PM TO 6 PM MDT THIS AFTERNOON FOR WYZ280- 281-289. && UPDATE...AEM SHORT TERM...CHURCH LONG TERM...C.BAKER AVIATION...CNJ FIRE WEATHER...CHURCH
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 931 AM MDT MON OCT 1 2007 WYZ001>020-022>030-021100- ABSAROKA MOUNTAINS-BIGHORN MOUNTAINS SOUTHEAST- BIGHORN MOUNTAINS WEST-CASPER MOUNTAIN-CODY FOOTHILLS- EAST SWEETWATER COUNTY-FLAMING GORGE- GREEN MOUNTAINS AND RATTLESNAKE RANGE-JACKSON HOLE-LANDER FOOTHILLS- NATRONA COUNTY LOWER ELEVATIONS-NORTH BIG HORN BASIN- NORTHEAST JOHNSON COUNTY-OWL CREEK AND BRIDGER MOUNTAINS- ROCK SPRINGS AND GREEN RIVER-SALT RIVER AND WYOMING RANGES- SOUTH LINCOLN COUNTY-SOUTHEAST BIG HORN BASIN- SOUTHEAST JOHNSON COUNTY-SOUTHWEST BIG HORN BASIN-STAR VALLEY- TETON AND GROS VENTRE MOUNTAINS-UPPER GREEN RIVER BASIN- UPPER GREEN RIVER BASIN FOOTHILLS-UPPER WIND RIVER BASIN- WIND RIVER BASIN-WIND RIVER MOUNTAINS EAST-WIND RIVER MOUNTAINS WEST- YELLOWSTONE NATIONAL PARK- 931 AM MDT MON OCT 1 2007 ...RED FLAG WARNING FOR NATRONA AND JOHNSON COUNTIES AS WELL AS THE GREEN AND RATTLESNAKE MOUNTAINS THIS AFTERNOON... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT A RED FLAG WARNING HAS BEEN ISSUED FOR NATRONA AND JOHNSON COUNTIES AS WELL AS THE GREEN AND RATTLESNAKE MOUNTAINS THIS AFTERNOON FROM 1 PM THROUGH 6 PM FOR STRONG WIND AND LOW RELATIVE HUMIDITY. MUCH OF THE REST OF WESTERN AND CENTRAL WYOMING WILL HAVE BREEZY TO WINDY CONDITIONS. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY AN ACTIVE WEATHER PATTERN IS THEN EXPECTED TO DEVELOP AROUND MIDWEEK AND CONTINUE INTO THE WEEKEND. A FAVORABLE PATTERN FOR SNOW IN THE NORTHWEST MOUNTAINS IS EXPECTED TO DEVELOP WEDNESDAY NIGHT AND CONTINUE THROUGH THURSDAY. AS THIS NEW STORM SYSTEM GATHERS STRENGTH IN THE GREAT BASIN THURSDAY AND MOVES TOWARDS WESTERN WYOMING...THE CHANCES OF PRECIPITATION WILL BE ON THE INCREASE ACROSS ALL OF WESTERN AND CENTRAL WYOMING BY FRIDAY. COLDER AIR WILL FILTER INTO AREAS EAST OF THE DIVIDE FRIDAY NIGHT WHICH COULD TURN THE EXPECTED RAIN INTO SNOW ABOVE 6000 FEET. STAY TUNED THIS WEEK FOR FREQUENT UPDATES ON THIS WEEKS RAPIDLY CHANGING WEATHER. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT ANY WINDS GREATER THAN 40 MPH. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
1 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2007Every state in 2007This day in weather historyWarnings in Wyoming, October 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: 56161.