628
FXUS65 KCYS 071028
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
328 AM MST FRI MAR 7 2025
KEY MESSAGES
- SNOWFALL WILL GRADUALLY END THROUGHOUT THE DAY AS THE SYSTEM
PUSHES EAST AND DEPARTS THE REGION.
- MILD AND DRY CONDITIONS EXPECTED TO START NEXT WEEK WITH A
RETURN OF WINDY CONDITIONS FOR MOST OF SOUTHEAST WYOMING.
- THE NEXT PACIFIC STORM SYSTEM IS FORECAST TO MOVE ACROSS
WYOMING THURSDAY.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED AT 324 AM MST FRI MAR 7 2025
IT IS STILL SNOWING IN MOST AREAS NORTH OF I-80 WITH THE EXCEPTION
OF RAWLINS WHERE IT IS STILL SNOWING. LOOKING AT RADAR THERE IS
STILL A BAND OF F-GEN JUST SOUTH OF CHUGWATER AND FURTHER WEST. AS
WE PROGRESS THROUGH THE DAY, THE SURFACE LOW OVER EASTERN COLORADO
WILL PUSH OFF EAST TAKING MAJORITY OF THE MOISTURE AND STRONGER
FORCING WITH IT. THE WARNING OVER CONVERSE AND NIOBRARA COUNTY WILL
EXPIRE ON TIME AT 12Z THIS MORNING BECAUSE OF THIS. AROUND THE
AFTERNOON THE DRY AIR WILL START TO FILTER IN AS THE UPPER LEVEL LOW
MOVES ACROSS SOUTHERN COLORADO. THIS UPPER LEVEL LOW WILL INJECT
SOME MOISTURE BUT SNOWFALL IS ONLY EXPECTED IN THE SOUTHERN MOUNTAIN
RANGES. AFTER 18Z OR 11 AM ALL THE WARNINGS AND ADVISORIES WILL BE
EXPIRED WITH THE EXCEPTION OF THE SNOWY AND SIERRA MADRE MOUNTAIN
RANGE. THE COMBINATION OF WEAK UPSLOPE AND ISENTROPIC LIFT OF THE
INJECTED MOISTURE SHOULD SUSTAIN LIGHT TO MODERATE SNOWFALL FOR OUR
SOUTHERN MOUNTAIN RANGES. BY 11PM THE SNOWFALL OVER THE MOUNTAINS
SHOULD HAVE STOPPED OR BE LIGHT ENOUGH THAT NO IMPACTS ARE CAUSED
FROM IT. SATURDAY MORNING SHOULD BE MOSTLY CLEAR SKIES AS THE UPPER
LEVEL RIDGE PUSHES INTO OUR REGION. TEMPERATURES ARE EXPECTED TO
REMAIN A LITTLE COOL AS MOST PLACES WILL HAVE A SNOWPACK FROM THIS
SYSTEM. TEMPERATURES WERE DROPPED A FEW DEGREES HOWEVER OUR SOUTHERN
COUNTIES EAST OF I-25 MAY REACH A COUPLE TEMPERATURES WARMER THAN
FORECAST SINCE THEIR SNOWPACK WILL MELT OFF A LIGHTER FASTER THAN
ANTICIPATED. FOR INSTANCE THE 1 INCH SNOW PACK IN CHEYENNE MAY BE
GONE BEFORE LUNCH AND THE TEMPERATURES MAY RAISE HIGHER THAN ALL THE
MODELS ANTICIPATE AND CHEYENNE REACHES A HIGH TEMPERATURE IN THE MID
40'S ON SATURDAY. THE HIGH TEMPERATURES WILL BE A LITTLE TRICKY TO
FORECAST SINCE THEY WILL BE HIGHLY INFLUENCE WITH HOW MUCH REMAINING
SNOW IS ON THE GROUND EACH DAY. ALSO AS A CONSEQUENCE OF THE
SNOWPACK THE OVERNIGHT TEMPERATURES LOOK TO BE INTO THE TEENS AND
20'S THIS WEEKEND.
LONG TERM /SUNDAY THROUGH THURSDAY/
ISSUED AT 324 AM MST FRI MAR 7 2025
NOT MANY CHANGES TO THE MEDIUM TO LONG RANGE FORECAST AS
MODELS AND ENSEMBLES REMAIN IN GOOD AGREEMENT THROUGH MOST OF
NEXT WEEK. QUIET AND BENIGN WEATHER IS FORECAST THROUGH
WEDNESDAY WITH ONLY WIND AND TEMPERATURE CONCERNS BEFORE THE
NEXT PACIFIC STORM SYSTEM MAKES ITS WAY INLAND WEDNESDAY NIGHT
AND THURSDAY. MAIN CONCERN ON SUNDAY WILL BE HIGH AND LOW
TEMPERATURES. THE FIRST FEW SNOWFALL REPORTS FROM THIS PART
STORM SHOW A GOOD SNOWPACK ALREADY ON THE GROUND FROM DOUGLAS TO
CHADRON WITH 8+ INCHES IN A FEW PLACES. HAVE A HARD TIME
BELIEVING THIS WILL MELT IN 3 DAYS, ESPECIALLY WITH VERY COLD
TEMPERATURES FOR THIS TIME OF THE YEAR EXPECTED FRIDAY AND
FRIDAY NIGHT. THEREFORE TRENDED THE TEMPERATURE FORECAST FOR
NORTH OF I-80 AND ALONG & NORTH OF THE NORTH PLATTE RIVER
VALLEY BELOW GUIDANCE AND TOWARDS THE COLDEST 25TH PERCENTILE OF
THE ENSEMBLE SPREADS FROM DOUGLAS OVER TO LUSK AND CHADRON, AND
AROUND RAWLINS AS WELL. EVEN ON SUNDAY, HIGHS WILL STRUGGLE TO
REACH THE MID TO UPPER 40S. ENSEMBLE SPREAD HAVE BEEN HINTING TO
THIS OUTCOME FOR SEVERAL DAYS, WITH VERY LOW SPREADS FURTHER
SOUTH NEAR THE COLORADO BORDER...WHICH HAD LITTLE SNOW WITH THIS
EVENT. ELSEWHERE, HIGHS IN THE 50S TO LOW 60S ARE EXPECTED
SUNDAY AFTERNOON WITH WINDS INCREASING SLIGHTLY THROUGH THE
AFTERNOON.
WARMING TREND WILL CONTINUE INTO MONDAY WITH HIGHS IN THE 50S
AND 60S, WITH EVEN A FEW PLACES AROUND 70 ACROSS THE SOUTHERN
NEBRASKA PANHANDLE. EVEN UP NORTH, EXPECT MOST LOCATIONS TO LOSE
MOST OF THEIR SNOWPACK BY MID MONDAY AFTERNOON WITH HIGHS
RETURNING TO THE 50S AND LOW 60S. PRIMARY FORECAST CONCERN EARLY
NEXT WEEK IS WINDY CONDITIONS AND THE POTENTIAL FOR LOCALLY
STRONG WINDS ACROSS THE WIND PRONE AREAS. ALL MODELS ARE A
LITTLE MORE FAVORABLE WITH SHOWING THE POTENTIAL FOR HIGH WIND
CRITERIA, AT LEAST ACROSS THE WIND PRONE AREAS. IN-HOUSE
WIND GUIDANCE ALSO SHOWS INCREASING PROBABILITIES FOR ARLINGTON,
BORDEAUX, AND EVEN NORTHERN PLATTE COUNTY NEAR COLEMAN ALONG
I-25. SYNOPTIC MODELS SHOW STRONGER SUBSIDENCE IN THE BOUNDARY
LATER BETWEEN LATE SUNDAY NIGHT THROUGH EARLY TUESDAY MORNING
WITH 700MB OVER 50 KNOTS. LOW LEVEL GRADIENTS ARE MARGINAL, BUT
ENOUGH TO WARRANT INCREASING WINDS OVER THE WIND PRONE AREAS.
NO PRECIPITATION IS EXPECTED FOR THIS TIME PERIOD SINCE MODELS
HAVE TRENDED FURTHER SOUTH WITH THE WEAK UPPER LEVEL TROUGH
MOVING EASTWARD OUT OF SOUTHERN CALIFORNIA.
AS WE HEAD INTO THURSDAY, MODELS ARE IN GOOD AGREEMENT, EVEN
FOR 7 DAYS OUT, AS THE NEXT PACIFIC STORM MOVES ONSHORE AND INTO
THE EASTERN GREAT BASIN REGION. THIS STORM IS FORECAST TO PUSH
INTO THE FRONT RANGE THURSDAY NIGHT AND FRIDAY WITH PRETTY GOOD
AGREEMENT ON TIMING, EVEN THOUGH THE GFS IS A BIT MORE
PROGRESSIVE THAN THE ECMWF AND CANADIAN. ENSEMBLES ARE MAINLY
SUGGESTING RAIN QUICKLY CHANGING TO SNOW LATE THURSDAY NIGHT AND
INTO EARLY FRIDAY MORNING. NBM POP WAS WAY TOO HIGH FOR 7 DAYS
OUT (NEARLY 95% IN SOME AREAS) AS THERE ARE SOME TIMING
DIFFERENCES, SO LOWERED POP BETWEEN 40 TO 60 PERCENT FOR NOW, AND
KEPT THEM SLIGHTLY HIGHER IN THE MOUNTAINS. WILL HAVE TO MONITOR
THIS STORM SINCE IT DOES TRACK OVER THE FOUR CORNERS REGION AND
LIFTS NORTHEAST INTO NORTHEAST COLORADO.
AVIATION /06Z TAFS THROUGH 06Z SATURDAY/
ISSUED AT 1029 PM MST THU MAR 6 2025
A TROUGH ALOFT WILL MOVE ACROSS THE REGION TONIGHT, THEN MOVE TO
THE EAST OF THE AREA ON FRIDAY.
WYOMING TAFS...FOR RAWLINS, CEILINGS WILL BE NEAR 2500 FEET
UNTIL 12Z, WITH OCCASIONAL LIGHT SNOW AND FOG REDUCING
VISIBILITIES TO 1 MILE AND CEILINGS TO 800 FEET UNTIL 09Z, THEN
CEILINGS WILL BE NEAR 5000 FEET AFTER 12Z FRIDAY. EXPECT LOW
LEVEL WIND SHEAR UNTIL 12Z.
FOR LARAMIE AND CHEYENNE, OCCASIONAL LIGHT SNOW AND FOG WILL
OCCUR UNTIL 09Z, REDUCING VISIBILITIES TO 3/4 MILE WITH CEILINGS
FROM 500 TO 2500 FEET, THEN CEILINGS NEAR 2500 FEET WILL OCCUR
UNTIL 18Z, THEN CEILINGS WILL IMPROVE TO 5000 TO 8000 FEET AFTER
18Z.
NEBRASKA TAFS...FOR CHADRON AND ALLIANCE, OCCASIONAL LIGHT SNOW
AND FOG WILL REDUCE VISIBILITIES TO 1/2 MILE UNTIL 15Z, THEN
CEILINGS WILL IMPROVE TO 3500 TO 6000 FEET AFTER 15Z FRIDAY.
WINDS WILL GUST TO 25 KNOTS UNTIL 08Z.
FOR SCOTTSBLUFF AND SIDNEY, OCCASIONAL LIGHT SNOW WILL OCCUR
UNTIL 12Z TO 15Z, REDUCING VISIBILITIES TO 2 TO 4 MILES AND
CEILINGS TO 800 TO 2500 FEET, THEN CEILINGS WILL IMPROVE TO
3500 TO 8000 FEET AFTER 15Z FRIDAY. WINDS WILL GUST TO 25 KNOTS
UNTIL 09Z.
CYS WATCHES/WARNINGS/ADVISORIES
WY...WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR
WYZ108.
WINTER STORM WARNING UNTIL 5 AM MST EARLY THIS MORNING FOR
WYZ101-102.
WINTER STORM WARNING UNTIL 8 AM MST THIS MORNING FOR
WYZ103>107-109.
WINTER WEATHER ADVISORY UNTIL 8 AM MST THIS MORNING FOR WYZ110-
116-117.
WINTER STORM WARNING UNTIL 11 PM MST THIS EVENING FOR WYZ112.
WINTER WEATHER ADVISORY UNTIL 11 PM MST THIS EVENING FOR
WYZ114.
NE...WINTER STORM WARNING UNTIL 11 AM MST THIS MORNING FOR NEZ002-
003-095.
WINTER WEATHER ADVISORY UNTIL 11 AM MST THIS MORNING FOR
NEZ019>021-096.
SHORT TERM...MM
LONG TERM...TJT
AVIATION...RUBIN
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