A storm system brought rain to northeastern Wyoming, with rain changing to snow over much of the area. The heaviest snow fell across the Bear Lodge Mountains north of Sundance, where around six inches of snow was 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 UNR wrote it up.
A storm system brought rain to northeastern Wyoming, with rain changing to snow over much of the area. The heaviest snow fell across the Bear Lodge Mountains north of Sundance, where around six inches of snow was reported. One to four inches of snow fell across the plains.
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 Rapid City, SD wrote its last area forecast discussion before the first event at Sep 10, 7:26 PM MST, 2 hours 34 minutes earlier.
AREA FORECAST DISCUSSION FOR WESTERN SD AND NORTHEASTERN WY
NATIONAL WEATHER SERVICE RAPID CITY SD
826 PM MDT WED SEP 10 2014
.UPDATE...
ISSUED AT 815 PM MDT WED SEP 10 2014
INITIAL SHORTWAVE TRACKING ACROSS SOUTHERN NORTH DAKOTA...WITH
FIRST ROUND OF PRECIPITATION EXITING EASTERN PORTIONS OF FORECAST
AREA. MUCH STRONGER SHORTWAVE ON NOSE OF JET STREAK TRACKING
ACROSS SOUTHERN MONTANA. CLOUD TOPS CONTINUE TO COOL...WITH SOME
TSRA DEVELOPING ACROSS EAST-CENTRAL WYOMING INTO THE NORTHERN
NEBRASKA PANHANDLE. 00Z MODELS CONTINUE TO SHOW PERIOD OF
DEEP/STRONG LIFT ACROSS THE FORECAST AREA TONIGHT...MAINLY ALONG
THE I-90 CORRIDOR. TEMPERATURE ALREADY BELOW FREEZING ACROSS
HIGHER ELEVATIONS OF BLACK HILLS...WITH TEMPERATURES IN THE MID
30S ACROSS NORTHEAST WYOMING INTO NORTHWEST SOUTH DAKOTA. LITTLE
CHANGE TO SNOWFALL AMOUNTS AT THIS TIME. HOWEVER...POTENTIAL EXISTS
FOR HIGHER SNOWFALL ACCUMULATIONS TO EXTEND ONTO THE PLAINS EAST
OF THE BLACK HILLS...INCLUDING THE RAPID CITY AREA.
&&
.SHORT TERM...THIS EVENING THROUGH THURSDAY NIGHT
ISSUED AT 235 PM MDT WED SEP 10 2014
ANOMALOUSLY DEEP NORTHERN STREAM UPPER TROUGH WILL
SHIFT SE INTO THE REGION...BRINGING UNSEASONABLY COLD TEMPS AND SNOW
ACCUMULATIONS TO THE AREA. IMPRESSIVE SOUTHERN PERIPHERY IMPULSE
WITH AN ASSOCIATED 75+ KNOT MID LEVEL SPEED MAX QUICKLY ADVECTING SE
ACROSS MT THIS AFTERNOON. THIS SYSTEM WILL SUPPORT STRONG DEEP LAYER
ASCENT WITH REFLECTED LL FGEN AND ASSOCIATED LL FORCING...SUPPORTING
INCREASING CHANCES FOR PRECIP ACROSS THE REGION THIS EVENING. VERY
TRICKY FORECAST GIVEN EXPECTED RAIN/SNOW MIX...WITH WARM SFC
CONDITIONS LIKELY HAMPERING SNOW ACCUMS...ESP ON THE PLAINS...MAKING
HEADLINES A TOUGH DECISION. THE OTHER SIGNIFICANT IMPACT FROM THIS
SYSTEM WILL BE THE GROWING POTENTIAL FOR AN EARLY SEASON HARD
FREEZE ACROSS A LARGE PORTION OF THE AREA FRIDAY NIGHT. GIVEN
CLEARING SKIES/LIGHT WINDS/WITH THE SFC HIGH CENTER SHIFTING SOUTH
OF THE AREA...STRONG RADIATIONAL COOLING AND SIG T FALLS ARE
EXPECTED.
TONIGHT...POWERFUL IMPULSE WILL SUPPORT STRONG LSA WITH POTENT LL
FGEN PER REFLECTED SOUTHERLY FLOW. APPRECIABLE COLUMN MOISTURE WITH
PW IN EXCESS OF ONE HALF INCH WILL BE MORE THAN AMPLE TO SUPPORT A
PERIOD OF MODERATE RAIN/SNOW. STEEP MID LEVEL LAPS RATES WILL ALSO
BE IN PLACE THROUGH PORTION OF THE THE DGZ...SUPPORTING CONDITIONAL
INSTABILITY...WITH THE CHANCE FOR SOME THUNDER EARLY THUR
MORNING...GIVEN THE AMOUNT OF CONDITIONAL INSTABILITY PRESENT. THE
DIFFICULT PART THIS FORECAST IS THE DETERMINATION OF SNOW ACCUMS.
TEMPS ARE ALREADY BEHIND THE CURVE...WITH LOW TO MID 30S IN THE HIGH
ELEVATIONS OF THE HILLS. ONCE PRECIP BEGINS IN THE HIGHER PORTIONS
OF THE BLACK HILLS IT WILL LIKELY BEGIN AS SNOW INSTEAD OF RAIN. QPF
VALUES IN EXCESS OF 0.5 INCHES IN MEAN MODEL SOLUTIONS SHOULD
SUPPORT 5 INCHES OR MORE OF WET HEAVY SNOW IN AREAS ABOVE 5 KFT.
HAVE DECIDED TO ISSUE A WINTER STORM WARNING FOR THE NORTHERN AND
CENTRAL BLACK HILLS...ESP GIVEN THE VERY EARLY NATURE OF THIS SYSTEM
WITH POTENTIAL FOR TREE DAMAGE AND POWER INTERRUPTIONS FROM WET
HEAVY SNOW. OTHERWISE...PRECIP WILL BEGIN AS RAIN ON THE WY
PLAINS...TRANSITIONING TO ALL SNOW BY EARLY THUR MORNING. SNOW
AMOUNTS WILL BE ESP TRICKY THERE AND INTO PORTIONS OF THE WESTERN
SD PLAINS...INCLUDING THE BH FOOTHILLS. WARM SFC CONDITIONS WILL
SUPPORT SIG MELTING AS SNOW FALLS...ESP AT FIRST. HOWEVER...GIVEN
THE STRENGTH OF THE VERTICAL MOTION FIELDS...A PERIOD OF HEAVY SNOW
WILL BE POSSIBLE...WHICH GIVEN TEMPS AROUND FREEZING MAY OVERWHELM
MELTING MAKING FOR ESP SLICK TRAVEL. THIS IS ALSO TRUE IN AND AROUND
THE SPEARFISH AREA. HAVE DECIDED TO EXPAND THE WINTER WEATHER ADV TO
THESE AREAS...ESP GIVEN THE EARLY SEASON NATURE TO THIS SYSTEM.
EXPECTING 1 TO 4 INCHES ON THE WY PLAINS...WITH THE HIGHEST AMOUNTS
ON RIDGES AND IN THE WESTERN BH FOOTHILLS. FURTHER EAST ON THE SD
PLAINS...A LATER CHANGEOVER WITHE SLIGHTLY WARMER TEMPS WHEN
COMPARED TO THE WY PLAINS SHOULD SUPPORT GENERALLY LIGHT SNOW
ACCUMULATIONS IF ANY. THE BEST CHANCE FOR AROUND AN INCH OR SLIGHTLY
MORE WILL BE ON THE EASTERN AND NORTHERN BLACK HILLS FOOTHILLS.
FORECAST MODELS HAVE COME IN COOLER PER TEMPS TONIGHT THROUGH THUR
NIGHT AND ADJUSTED TEMPS FOR THIS. TEMPS WILL BE AN IMPRESSIVE 30 TO
40 DEGREES BELOW SEASONAL NORMS...A TESTAMENT TO HOW COLD THIS
AIRMASS IS. WIDESPREAD FROST IS EXPECTED FRIDAY MORNING MOST PLACES
GIVEN LOWS IN THE MID TO UPPER 20S TO AROUND 30. SFC HIGH SHIFTING
SOUTH OF THE FA/LIGHT WINDS/DRY AIR/AND CLEAR SKIES WILL SUPPORT
EXCELLENT RADIATIONAL COOLING...ESP OVER ANY RESIDUAL SNOW COVER.
TEENS ARE EXPECTED IN THE BLACK HILLS. HAVE ADDED WIDESPREAD FROST
TO THE GRIDS FRIDAY NIGHT.
&&
.LONG TERM...FRIDAY THROUGH WEDNESDAY
ISSUED AT 235 PM MDT WED SEP 10 2014
MAINLY DRY WEATHER AND A WARMING TREND CAN BE EXPECTED
FROM FRIDAY THROUGH EARLY NEXT WEEK AS A RIDGE BUILDS ACROSS THE
WESTERN STATES AND EVENTUALLY MOVES INTO THE PLAINS. TEMPERATURES
WILL RISE BACK TO NEAR AVERAGE LEVELS BY MONDAY. A WEAK SHORTWAVE IS
PROGGED BY A COUPLE OF THE MEDIUM RANGE MODELS TO SLIDE THROUGH THE
AREA ON SUNDAY AND COULD BRING A FEW SHOWERS.
&&
.AVIATION...FOR THE 00Z TAFS THROUGH 00Z THURSDAY EVENING
ISSUED AT 235 PM MDT WED SEP 10 2014
WIDESPREAD IFR CONDITIONS WILL PERSIST ACROSS THE FORECAST AREA
THROUGH THURSDAY AFERNOON...WITH RAIN AND SNOW SPREADING ACROSS
THE AREA TONIGHT. ACCUMULATING SNOW EXPECTED ACROSS NORTHEAST
WYOMING INTO WESTERN SOUTH DAKOTA....WITH LIFR VSBY. CONDITIONS
WILL BE SLOWLY IMPROVE THURSDAY AFTERNOON.
&&
.UNR WATCHES/WARNINGS/ADVISORIES...
SD...WINTER STORM WARNING UNTIL NOON MDT THURSDAY FOR SDZ024-028.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT
THURSDAY FOR SDZ025-029.
WY...WINTER STORM WARNING UNTIL NOON MDT THURSDAY FOR WYZ057.
WINTER WEATHER ADVISORY FROM MIDNIGHT TONIGHT TO NOON MDT
THURSDAY FOR WYZ054>056-071.
&&
UPDATE...7
SHORT TERM...JC
LONG TERM...13
AVIATION...7HAZARDOUS WEATHER OUTLOOK...UPDATED NATIONAL WEATHER SERVICE RAPID CITY SD 243 PM MDT WED SEP 10 2014 SDZ001-002-012>014-024>032-041>044-046-047-049-072>074-WYZ054>058- 071-111300- HARDING-PERKINS-BUTTE-NORTHERN MEADE CO PLAINS-ZIEBACH- NORTHERN BLACK HILLS-NORTHERN FOOT HILLS-RAPID CITY- SOUTHERN FOOT HILLS-CENTRAL BLACK HILLS-SOUTHERN BLACK HILLS- CUSTER CO PLAINS-PENNINGTON CO PLAINS-HAAKON-FALL RIVER-SHANNON- JACKSON-BENNETT-MELLETTE-TODD-TRIPP-STURGIS/PIEDMONT FOOT HILLS- SOUTHERN MEADE CO PLAINS-HERMOSA FOOT HILLS-NORTHERN CAMPBELL- SOUTHERN CAMPBELL-WESTERN CROOK-WYOMING BLACK HILLS-WESTON- NORTHEASTERN CROOK- 243 PM MDT WED SEP 10 2014 /343 PM CDT WED SEP 10 2014/ ...WINTER STORM WARNING FROM LATE THIS EVENING THROUGH THURSDAY MORNING NORTHERN AND CENTRAL BLACK HILLS... ...WINTER WEATHER ADVISORY FROM LATE TONIGHT THROUGH THURSDAY MORNING NORTHEAST WYOMING AND THE SOUTHERN BLACK HILLS... THIS HAZARDOUS WEATHER OUTLOOK IS FOR WESTERN SOUTH DAKOTA AND NORTHEASTERN WYOMING. .DAY ONE...THIS AFTERNOON AND TONIGHT RAIN WILL MIX WITH OR CHANGE TO SNOW LATE TONIGHT OVER NORTHEAST WYOMING AND THE BLACK HILLS. UP TO 4 INCHES OF ACCUMULATION IS EXPECTED IN THE BLACK HILLS...WITH UP TO TWO INCHES POSSIBLE ON THE WYOMING PLAINS. LITTLE OR NO ACCUMULATION IS EXPECTED ON MOST OF THE SOUTH DAKOTA PLAINS. .DAYS TWO THROUGH SEVEN...THURSDAY THROUGH TUESDAY SNOW WILL CONTINUE ACROSS PARTS OF NORTHEAST WYOMING AND THE BLACK HILLS THURSDAY...WITH RAIN OR SNOW ON THE PLAINS OF WESTERN SOUTH DAKOTA. PRECIPITATION WILL TAPER OFF THURSDAY NIGHT. 4 TO 7 INCHES OF TOTAL SNOW ACCUMULATION...WITH LOCALLY HIGHER AMOUNTS...ARE EXPECTED IN THE BLACK HILLS...WITH GENERALLY 2 INCHES OR LESS ON THE PLAINS OF NORTHEAST WYOMING AND FAR WESTERN SOUTH DAKOTA. A HARD FREEZE IS EXPECTED FRIDAY MORNING ACROSS NORTHEAST WYOMING AND MOST OF WESTERN SOUTH DAKOTA. .SPOTTER INFORMATION STATEMENT... SPOTTER ACTIVATION WILL NOT BE NEEDED TODAY. && STAY TUNED TO NOAA WEATHER RADIO FOR FURTHER DETAILS OR UPDATES... OR CHECK OUR WEB SITE AT WEATHER.GOV/RAPIDCITY JC
The national radar mosaic for the moment the first event began.
3 winter weather, 1 heavy snow. Local standard time, as filed.
The Sundance observer received 4.2 inches of snow, which broke the record for earliest measurable snowfall on record. The previous record was 1.0 inch on September 13, 1970.
Upton received 3 inches of snow, which was the earliest measurable snowfall on record. The previous record was on September 12, 1949.
After NWS Directive 10-1605, the rules offices file Storm Data by.
Every storm in Wyoming in 2014Every state in 2014This day in weather historyWarnings in Wyoming, September 2014
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: 540303, 541407, 541408, 541409.