Favorable jet dynamics produced high wind across areas of Sweetwater and southern Sublette counties. Gusts of 60 to 66 mph were observed.
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The episode as NWS RIW wrote it up.
Favorable jet dynamics produced high wind across areas of Sweetwater and southern Sublette counties. Gusts of 60 to 66 mph were observed.
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 Nov 16, 3:17 AM MST, 6 hours 55 minutes earlier.
AREA FORECAST DISCUSSION NATIONAL WEATHER SERVICE RIVERTON WY 317 AM MST TUE NOV 16 2010 .SHORT TERM...TODAY THROUGH THURSDAY NIGHT WHAT WAS LEFT OF THE CONVECTIVE SNOW BANDS OVER THE EASTERN PORTION OF THE CWA EARLIER THIS EVENING HAVE DISSIPATED. LOOKING WEST...THE STRONG VORT MAX JUST EAST OF SEATTLE...THAT HAS BEEN PRODUCING LIGHTNING DURING THE LAST HOUR...WILL BE TRACKING RAPIDLY TOWARD WYOMING DURING THE NEXT 9 HOURS WITH THE TROUPHA EXPECTED AROUND 18Z ACROSS CENTRAL WYOMING TODAY. STRONG WESTERLY DIFLUENT UPSLOPE FLOW AND STRONG ISENTROPIC UPGLIDE PERPENDICULAR TO THE ISOBARS HAS ALREADY ENSUED ACROSS WESTERN WYOMING WHERE SNOW IS INCREASING ALONG WITH SOME BLOWING SNOW EVIDENT ON THE TETON PASS WEB CAM AND WIND GUSTS OF OVER 50 MPH HAVE BEEN REPORTED ON RENDEZVOUS PEAK. THE WINTER WEATHER ADVISORY IS IN GOOD SHAPE AS 3 TO 5 INCHES OF SNOWFALL HAVE FALLEN IN THE MTNS SO FAR WITH ANOTHER 12 HOURS TO GO WITH THE HILITE. WEST SOUTHWEST WINDS WILL ALSO PICK UP ACROSS THE SOUTHERN WIND CORRIDOR AHEAD OF THE THIS APPROACHING WEATHER SYSTEM THIS MORNING. THERE IS A HINT OF A WEAK MTN WAVE THIS MORNING OVER THE LND FOOTHILLS WITH RED CANYON DISPLAYING CLOSE TO 40 MPH WINDS. WILL CONTINUE TO MONITOR. THEN EVEN STRONGER WEST WINDS WILL INCREASE ACROSS SWEETWATER COUNTY AFTER THE TROUHPA AS WELL AS DURING AND AFTER THE ASSOCIATED PACIFIC FROPA WHICH WILL OCCUR AROUND MID DAY. HAVE OPTED TO HOIST A HIGH WIND WARNING FOR SWEETWATER COUNTY GIVEN THE 50 KNOT H7 AND BL WIND SPEEDS...THE 5 ISOHYPES OVER WYOMING SPACED EVERY 3 UNITS AND THE PERSISTENT 35 KNOT SUSTAINED WINDS PORTRAYED ON THE MAV MOS FOR RKS FOR TUESDAY AFTERNOON. SOME RAIN/SNOW TURNING TO ALL SNOW SHOWERS WILL ALSO OCCUR ACROSS SWEETWATER MAKING FOR OCCASIONAL REDUCTION IN VSBY. THE HEAVIEST SNOWFALL SHOULD BE ENDING BY MID AFTERNOON TUESDAY IN THE WEST. MEANWHILE NUMEROUS RAIN AND SNOW SHOWERS WILL SPILL OVER THE DIVIDE TUESDAY AFTERNOON WITH THE PACIFIC FRONT ALONG WITH Q VECTOR FORCING AIDING IN LIFT. EVEN THREW IN ISOLATED LTG TO ACCOUNT FOR THE NEGATIVE LIFTED INDICES. THEN THE CANADIAN FRONT WILL PUSH SOUTH ACROSS NORTHERN WYOMING AROUND 22Z AND CENTRAL WYOMING AROUND 00Z WED. 3 HOURLY 8MB SURFACE PRESSURE RISES HAVE BEEN CONSISTENTLY ADVERTISED BY THE MODELS TO OCCUR OVER JOHNSON COUNTY EARLY TUE EVE WITH 7MB OVER THE NORTHERN BIG HORN BASIN. WITH 50 KNOT NORTHERLY BL AND H7 NW WINDS OVER JOHNSON COUNTY TUE EVE AND THE CLOSER PROXIMATELY TO THE H7 CLOSED LOW TRACKING FROM MT TO SD LATE TUE AIDING IN FORCING FOR SNOWFALL...HAVE OPTED TO GO WITH A WINTER WEATHER ADVISORY FOR NORTHERN JOHNSON COUNTY FOR THE COMBINATION OF 1 TO 2 INCHES OF SNOW COMBINING WITH 30 TO 40 MPH WIND WITH GUSTS TO 50 MPH REDUCING THE VSBY TO NEAR ZERO AT TIMES KEEPING INTERSTATES 25 AND 90 IN MIND. EVEN AREAS SUCH AS THE RIW AND THE SURROUNDING WIND RIVER BASIN...WHICH HAVE THE RELATIVELY LOWEST POPS...HAVE A GOOD SHOT AT SEEING AT LEAST A LIGHT SNOW ACCUMULATION AS THIS AREA SEEMS TO HAVE GOOD TRACK RECORD OF SUCH OCCURRENCES WHEN THE NOSE OF THE COLD AIR ADVECTION AT H7 WRAPS AROUND THE BACK SIDE OF THE LOW. STRONG NORTH WINDS SHOULD ALSO OCCUR OVER THE WIND RIVER BASIN AND THE NORTHERN BIG HORN BASIN BUT TO A LESSER DEGREE. THE WINDS SHOULD DECREASE RAPIDLY AFTER 04Z OR SO THIS EVENING. WEDNESDAY WILL BE A RELATIVELY UNEVENTFUL DAY BETWEEN WEATHER SYSTEMS WITH BACKING NW FLOW DELIVERING LIGHT SNOW TO THE NW MTNS. BY WED NT WE WILL SEE A MAJOR PATTERN CHANGE WITH THE DEEP TROUGH THAT HAS BEEN SITTING OVER THE CENTRAL UNITED STATES FOR A WHILE EXITING EAST ALONG WITH A BACKING FLOW PATTERN. LATE WED NT THE CIRCULATION OFF THE EASTERN ALEUTIANS WILL APPROACH THE LOWER 48. AS IT DOES THE GRADIENT WILL CONTINUE TO BACK AND TIGHTEN WED NT WHICH IS A FAVORABLE PATTERN FOR A HIGH WIND EVENT FOR CODY/CLARK. THE CROSS SECTIONS ARE INDICATING SIGNATURES FOR A POTENTIAL MTN WAVE EVENT THERE WITH 50 KNOT INBOUND WINDS INTO THE ABSAROKAS AND 70 KNOT OUT BOUND WINDS ALONG WITH A GOOD LOWER STABLE LAYER IN THE FIRST FEW THOUSAND FEET. THE FROUDE NUMBER WAS CALCULATED TO BE .99. IF ALL ELSE FALES WE STILL HAVE THE RIGHT FRONT QUAD OF THE JET TO GET GOOD GAP FLOW GOING IN THAT REGION. THE COD NAM MOS GUIDANCE GIVES COD 28 SUSTAINED WINDS AT 18Z THU WHICH ONE DOES NOT SEE VERY OFTEN. THEN THE SOUTHERN WIND CORRIDOR GETS INTO THE ACT THURSDAY WITH 60 KNOT H7 WINDS OVER THAT AREA ALONG WITH RIGHT FRONT QUAD DYNAMICS TO SURFACE SOME OF THOSE STRONG WINDS. THE FIRST IN A SERIES OF SHORTWAVES EJECTING FROM THE AFOREMENTIONED ALEUTIAN TROUGH WILL TRACK EAST ACROSS SOUTHERN CANADA THURSDAY NIGHT FOR AN INCREASING CHANCE OF ACCUMULATING SNOW IN NORTHWEST WY. .LONG TERM...FRIDAY THROUGH TUESDAY SIGNIFICANT MODEL DIFFERENCES IN THE MEDIUM RANGE PERIOD... ESPECIALLY WITH RESPECT TO THE SWD PUSH OF THE CANADIAN AIRMASS OVER THE WEEKEND. THE ECMWF HAS THE BEST SWD PUSH FRIDAY NIGHT INTO SATURDAY...WELL INTO CENTRAL WYO...WHILE THE GFS HOLDS THE FRONT IN THE FAR NRN ZONES. THE GEM IS ABOUT HALF WAY IN THE MIDDLE WITH THE FRONT ALONG A THP TO SRN JOHNSON COUNTY LINE SATURDAY. THE PACNW UPPER LOW THAT DEVELOPS OVER THE WEEKEND IS NOT FORECAST TO BE AS FAR SOUTH AS PREVIOUS NIGHTS BUT I AM STILL VERY CONCERNED ABOUT THIS COLD AIRMASS SAGGING SWD EVEN WITH THE SLY FLOW ALOFT. IF THE MODELS ERROR IN THESE SCENARIOS...IT'S USUALLY BECAUSE THEY DON'T PUSH THE COLD AIR FAR ENOUGH SWD. THE GFS IS WEAKER WITH THE SFC HIGH ACROSS MT AND SRN CANADA THAN THE ECMWF OR GEM WHICH MAKES ALL THE DIFFERENCE. THE CONSENSUS WAS TO KEEP THE COLD FRONT FURTHER NORTH BUT CONFIDENCE IS LOW AT BEST THIS WEEKEND WITH THE FRONTAL POSITION. TEMPERATURES WILL BE AT LEAST 20 DEGREES COLDER BEHIND THIS FRONT. SNOW SHOULD RETURN TO THE WEST FRIDAY INTO SATURDAY WITH SIGNIFICANT ACCUMULATION POSSIBLE AS THE INCREASING SW FLOW COMBINES WITH POTENTIAL RIGHT ENTRANCE REGION OF 130KT JET. IF THE FRONT DROPS FAR ENOUGH SOUTH SATURDAY...A DECENT SHOT OF SNOW MAY FALL EAST OF THE DIVIDE WITH JET STREAK PROVIDING FORCING ON TOP OF THE LOW LEVEL COLD DOME. THE WEST WILL LIKELY SEE PERIODS OF SNOW INTO EARLY NEXT WEEK. THE GFS WANTS TO RELOAD THE UPPER TROUGH EARLY NEXT WEEK WHILE THE ECMWF PUSHES THE TROUGH/UPPER LOW E OVER WYOMING ON MONDAY WITH A COLD...CYLCONIC NW FLOW DEVELOPING MONDAY NIGHT INTO TUESDAY. COLD AIRMASS MORE OF A CERTAINTY BUT PRECIPITATION AMOUNTS AND EXACT TIMEFRAME IS STILL UNCERTAIN EAST OF THE DIVIDE. && .AVIATION... SNOW WILL OCCUR IN WESTERN WY TODAY WITH SNOW SHOWERS CONTINUING AFTER 00Z WED. MVFR TO IFR CONDITIONS WILL BE COMMON IN THE WEST INCLUDING THE KJAC...KBPI AND KPNA AIRPORTS. CONDITIONS WILL SLOWLY IMPROVE IN THE WEST AFTER 00Z WED. ACROSS SOUTHERN WY VERY WINDY CONDITIONS WILL OCCUR TODAY WITH WIND SPEEDS OF 25 TO 35 KNOTS AND GUSTS TO 45 KNOTS. SNOW SHOWERS WILL MOVE THROUGH THIS AREA BETWEEN 20Z AND 00Z WITH LOCAL MVFR CONDITIONS. THE REST OF THE REGION EAST OF THE DIVIDE WILL SEE VFR CONDITIONS TODAY INTO THIS EVENING. HOWEVER SNOW SHOWERS WILL OCCUR AFTER 20Z AS A COLD FRONT PUSHES FROM NORTH TO SOUTH DURING THE AFTERNOON AND EARLY EVENING HOURS. AREAS OF MVFR CONDITIONS WILL BE POSSIBLE EAST OF THE DIVIDE FROM 20Z THROUGH 02Z WED. IFR CONDITIONS ALONG WITH MOUNTAIN OBSCURATIONS ARE EXPECTED EARLYTHIS EVENING IN JOHNSON COUNTY INCLUDING KBYG DUE TO SNOW AND BLOWING SNOW WHERE NORTHWEST WINDS WILL BLOW AT 30 TO 40 MPH WITH GUSTS TO 50 MPH. && .FIRE WEATHER... SNOWFALL WITH ACCUMULATIONS OF 5 TO 10 INCHES IN THE WESTERN MOUNTAINS AND 3 TO 5 INCHES IN THE WESTERN VALLEYS WILL TAPER OFF BY EARLY TO MID AFTERNOON TODAY. STRONG WEST WINDS WILL ENSUE ACROSS SOUTHERN WYOMING TODAY WITH 30 TO 40 MPH WINDS ALONG WITH 60 MPH WIND GUSTS EXPECTED IN ZONE 279 THIS AFTERNOON AS A STRONG COLD FRONT TRACKS SOUTHEAST ACROSS THE REGION. NUMEROUS RAIN AND SNOW SHOWERS WILL SPILL EAST OF THE DIVIDE TODAY. BEHIND THE FRONT WIND GUSTS AS HIGH AS 50 MPH WILL COMBINE WITH SNOWFALL IN ZONE 281 FOR LOWERED VISIBILITY THERE. WEDNESDAY WILL BE RELATIVELY DRY WITH THE EXCEPTION OF ZONES 140 AND 415 WHERE A BACKING NORTHWEST FLOW WILL DELIVER LIGHT SNOW THERE. LATE WEDNESDAY NIGHT WILL FEATURE VERY STRONG WINDS WEST IN ZONES 286 AND 276. THEN ON THURSDAY ZONES 289 AND 280 WILL BE UNDER THE GUN FOR VERY STRONG SOUTHWEST WINDS. SNOWFALL WILL INCREASE ONCE AGAIN IN ZONES 415...140 AND 286 THURSDAY NIGHT. && .RIW WATCHES/WARNINGS/ADVISORIES... WINTER WEATHER ADVISORY UNTIL 3 PM MST THIS AFTERNOON WYZ001-012-013-023-024. HIGH WIND WARNING FROM NOON TODAY TO 6 PM MST THIS EVENING WYZ028>030. WINTER WEATHER ADVISORY FROM 2 PM THIS AFTERNOON TO 8 PM MST THIS EVENING WYZ010. && SHORT TERM...LIPSON LONG TERM...SKRBAC AVIATION...AR FIRE WEATHER...LIPSON
HAZARDOUS WEATHER OUTLOOK NATIONAL WEATHER SERVICE RIVERTON WY 333 AM MST TUE NOV 16 2010 WYZ001>020-022>030-171200- 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- 333 AM MST TUE NOV 16 2010 ...WINTER WEATHER ADVISORY FOR THE FAR WESTERN MOUNTAINS AND VALLEYS THROUGH 3 PM THIS AFTERNOON... ...WINTER WEATHER ADVISORY FOR NORTHERN JOHNSON COUNTY FROM 2 PM TO 8 PM TODAY... ...HIGH WIND WARNING IN EFFECT FOR SWEETWATER COUNTY FOR THIS AFTERNOON... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN AND CENTRAL WYOMING. .DAY ONE...TODAY AND TONIGHT A PACIFIC STORM SYSTEM WILL CONTINUE TO IMPACT FAR WESTERN WYOMING THROUGH MID AFTERNOON WITH 5 TO 10 INCHES OF SNOW ACROSS THE WESTERN MOUNTAINS BY MIDDAY TODAY AND 3 TO 5 INCHES IN THE FAR WESTERN VALLEYS. LOWER ELEVATIONS EAST OF THE DIVIDE WILL SEE SNOW MOVE IN DURING THE LATE MORNING. ACCUMULATION WILL BE LIGHT AT LOWER ELEVATIONS BUT MAY CAUSE HAZARDOUS TRAVEL AT TIMES. STRONG WEST WINDS OF 30 TO 45 MPH WITH GUSTS TO 60 MPH WILL IMPACT SWEETWATER COUNTY THIS AFTERNOON CAUSING DANGEROUS CROSS WINDS ON AREA HIGHWAYS INCLUDING SECTIONS OF INTERSTATE 80. OTHERWISE SOUTHWEST WINDS OF 25 TO 35 MPH WITH GUSTS TO 45 MPH ARE EXPECTED FROM THE GREEN MOUNTAINS TO CASPER TODAY. 30 TO 40 MPH NORTHWEST WINDS ALONG WITH 50 MPH WIND GUSTS WILL COMBINE WITH ONE TO TWO INCHES OF SNOWFALL TO PRODUCE HAZARDOUS DRIVING CONDITIONS ALONG WITH REDUCED VISIBILITY BETWEEN ZERO AND ONE QUARTER OF A MILE IN SNOW AND BLOWING SNOW ON AREA HIGHWAYS THROUGHOUT NORTHERN JOHNSON COUNTY INCLUDING INTERSTATES 25 AND 90 THIS EVENING. .DAYS TWO THROUGH SEVEN...TUESDAY THROUGH SUNDAY VERY STRONG WINDS ARE POSSIBLE LATE WEDNESDAY NIGHT AND THURSDAY ALONG THE EAST SLOPE OF THE ABSAROKA MOUNTAINS INCLUDING THE CODY FOOTHILLS. STRONG WINDS ARE ALSO QUITE POSSIBLE FROM THE RED DESERT OVER TO THE CASPER AREA THURSDAY AND POSSIBLY IN THE LANDER FOOTHILLS. ANOTHER STORM SYSTEM MAY MOVE INTO THE NORTHWEST MOUNTAINS FRIDAY INTO FRIDAY NIGHT AND THEN MOVE INTO NORTH-CENTRAL WYOMING ON SATURDAY. SIGNIFICANT SNOWFALL IS POSSIBLE IN THE NORTHWEST MOUNTAINS WITH ACCUMULATING SNOW ALSO POSSIBLE ACROSS THE LOWER ELEVATIONS OF THE NORTHWEST FRIDAY THROUGH SATURDAY AND ACROSS NORTH-CENTRAL WYOMING ON SATURDAY. .SPOTTER INFORMATION STATEMENT... SPOTTERS ARE ENCOURAGED TO REPORT SNOWFALL AND ANY WIND GUSTS OVER 40 MPH. THANK YOU. TEAM RIVERTON
The national radar mosaic for the moment the first event began.
3 high wind. Local standard time, as filed.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2010Every state in 2010This day in weather historyWarnings in Wyoming, November 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: 264581, 264580, 264579.