347
FXUS65 KCYS 020601
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1055 PM MST SAT FEB 1 2025
KEY MESSAGES
- ANOTHER ROUND OF HIGH WINDS ARE EXPECTED DURING THE DAY
SUNDAY WITH A HIGH WIND WATCH IN EFFECT.
- WINTER STORM WARNINGS CONTINUE FOR THE SIERRA MADRE AND SNOWY
RANGES SATURDAY MORNING THROUGH SUNDAY FOR HEAVY ACCUMULATING
SNOW AND WINDY CONDITIONS, ALONGSIDE WINTER WEATHER ADVISORIES FOR
RAWLINS AND THE ARLINGTON AREA.
- WIDESPREAD ELEVATED TO STRONG WINDS CONTINUE INTO NEXT WEEK.
- TEMPERATURES WILL REMAIN ABOVE AVERAGE DURING THE EARLY TO
MIDDLE PORTION OF NEXT WEEK.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 240 PM MST SAT FEB 1 2025
WINDS HAVE CONTINUED TO REMAIN HEIGHTENED AS OF THIS AFTERNOON
ACROSS THE CWA. ALTHOUGH MOST LOCATIONS ARE STAYING JUST OUTSIDE
OF WARNING CRITERIA, THE OCCASIONAL GUST TO 60+ MPH HAS
WARRANTED KEEPING HIGHLIGHTS UP UNTIL THEY ARE SET TO EXPIRE
HERE IN A COUPLE OF HOURS. MODEL GUIDANCE IS HONING IN ON THE
JET ENTERING A LULL OVER THE NEXT SEVERAL HOURS INTO THE
OVERNIGHT HOURS, ALLOWING FOR A BREAK FROM THE STRONGEST WINDS.
BUT GUIDANCE HAS FURTHER PICKED UP ON THIS FEATURE RE-
INTENSIFYING OVER THE REGION BEGINNING TOMORROW MORNING AND
REACHING ANOTHER PEAK INTENSITY SUNDAY AFTERNOON/EVENING,
WEAKENING ONCE AGAIN INTO MONDAY MORNING. MODELS ARE SHOWING THE
700 MB JET REACHING AS STRONG AS 70-80 KNOTS FROM A WEST TO
SOUTHWESTERLY DIRECTION, WITH MIXING TO THE SURFACE EXPECTED
ONCE AGAIN. ALONGSIDE THIS AND AGREEMENT FROM IN HOUSE GUIDANCE
WITH PROBABILITIES OF 60-70% AT GUSTS 60+ MPH, NEW HIGH WIND
WATCHES HAVE BEEN ISSUED FOR OUR WIND PRONE AND ADJACENT ZONES,
REACHING AS FAR EAST AS LARAMIE AND GOSHEN COUNTIES. OF NOTE,
THE HIGH WIND WARNING FOR THE SNOWY RANGE FOOTHILLS INCLUDING
ARLINGTON IS SET TO EXPIRE WITH THE WATCH BEGINNING DIRECTLY
AFTER THIS TOMORROW MORNING, AS WINDS MAY REMAIN ELEVATED FOR
THIS AREA FOR THE DURATION OF THIS PERIOD WITH LITTLE TO NO
LULL. FINALLY, THE WATCH IN EXTREME EASTERN LARAMIE COUNTY WAS
EXPIRED AS WINDS HAVE JUST NOT QUITE REACHED FAR ENOUGH INTO
THIS ZONE.
OTHERWISE, WINTER WEATHER IS OVERSPREADING THE WESTERN ZONES OF
THE REGION THIS AFTERNOON, WITH WEBCAMS NEAR ARLINGTON SHOWING
A NICE COVERING OF SNOW, AND OBSERVATIONS OCCASIONALLY
INDICATING REDUCED VISIBILITIES FROM THE BLOWING PRECIPITATION.
SNOTELS IN THE MOUNTAINS ALSO ARE SHOWING SEVERAL INCHES OF
SNOWFALL ALREADY OCCURRING WITH MORE EXPECTED THROUGH THE
EVENING AND NIGHTTIME HOURS INTO SUNDAY MORNING, GIVING GOOD
CONFIDENCE IN THE ONGOING WINTER STORM WARNINGS/WINTER WEATHER
ADVISORIES ALREADY OUT. ANOTHER BURST OF MOISTURE TOMORROW
SHOULD OVERSTRETCH INTO THE PLAINS AND ALLOW FOR SOME SHOWERS
INTO THE NEBRASKA PANHANDLE, BUT WITH TEMPERATURES SEVERAL
DEGREES ABOVE NORMAL EAST OF I-25, ANY PRECIPITATION THAT CAN
MAKE IT PAST THE MOUNTAINS WILL BE RAIN OR RAIN MIXED WITH SNOW.
IT SHOULD BE NOTED THOUGH THAT IF PRECIPITATION FALLS EARLY
ENOUGH, THIS COULD COOL THE REGION AND PERHAPS BRING A POTENTIAL
FOR MORE SNOW MIXED IN BEFORE DAYTIME HEATING SHOULD BRING THE
AREA BACK UP. THE MOST LIKELY REGION FOR THIS TO OCCUR WOULD BE
OUR NORTHEASTERN ZONES WHERE TEMPS SHOULD HIT JUST BELOW
FREEZING OVERNIGHT. THAT BEING SAID, IT'S STILL UNLIKELY WE'LL
SEE ANYTHING MORE THAN A QUICK DUSTING BEFORE RAIN WOULD TAKE
OVER.
LONG TERM /MONDAY THROUGH SATURDAY/
ISSUED AT 219 PM MST SAT FEB 1 2025
A BROAD AND FAST PACIFIC JET WILL DOMINATE THE WEATHER PATTERN OVER
THE WESTERN CONUS THROUGHOUT THE LONG TERM FORECAST PERIOD FROM
MONDAY NIGHT THROUGH THE REMAINDER OF THE WEEK. AN UPPER-LEVEL LOW
PRESSURE SYSTEM WILL REMAIN GENERALLY STATIONARY OVER THE CANADIAN
MARITIME, DIRECTING FAST FLOW ALOFT ACROSS MOST OF THE WEST.
ANOMALOUSLY HIGH MOISTURE TRANSPORT ASSOCIATED WITH THIS
PACIFIC JET/SUBTROPICAL FLOW WILL BRING HEAVY MOISTURE-LADEN
MOUNTAIN SNOWS ACROSS MUCH OF THE NORTHERN ROCKIES. EARLY IN THE
WEEK FROM TUESDAY THROUGH WEDNESDAY, THIS MOISTURE STREAM WILL
REMAIN TO THE NORTH OF THE MOUNTAINS OF SOUTHEAST WYOMING. MILD
TEMPERATURES, GENERALLY RUNNING AROUND 15 TO 20 DEGREES ABOVE
AVERAGE, WILL BE THE RULE THROUGH THIS TIMEFRAME FOR EVERYONE
WITH MID AND UPPER-LEVEL CLOUDS PRESENT ON BOTH DAYS. BY
WEDNESDAY NIGHT INTO THURSDAY MORNING, A SHORTWAVE TROUGH WILL
PIVOT AROUND THE MAIN UPPER-LEVEL LOW AND REDIRECT SOME OF THE
FASTER FLOW AND PACIFIC MOISTURE SOUTHWARD INTO SOUTHEAST
WYOMING AND WESTERN NEBRASKA. AT THE SAME TIME, A SURFACE COLD
FRONT WILL DROP SOUTHWARD ALONG THE HIGH PLAINS WITH
TEMPERATURES DROPPING BACK BY ABOUT 15 DEGREES OR SO FOR
THURSDAY AND FRIDAY. PRECIPITATION CHANCES WITH THIS WIGGLE IN
THE FLOW ALOFT DO COME UPWARD BY WEDNESDAY EVENING THROUGH
THURSDAY. SNOWFALL WILL BE LIMITED TO THE MOUNTAINS WITH THIS
EVENT, GIVEN STRONG WESTERLY FLOW AND DOWNSLOPING EAST OF THE
LARAMIE RANGE.
ANOTHER SPOKE OF ENERGY WILL EJECT AROUND THE BROAD WEST-COAST LOW
ON FRIDAY INTO SATURDAY OF THIS COMING WEEK. THIS PARTICULAR SYSTEM
MAY ULTIMATELY HELP DRIVE THE CORE OF THE MOIST SUBTROPICAL JET OVER
THE CENTRAL ROCKIES, INCLUDING SOUTHEAST WYOMING AND INTO THE
NEBRASKA PANHANDLE. PRECIPITATION EAST OF THE MOUNTAINS WITH THESE
TYPES OF SYSTEMS IS USUALLY A CHALLENGE AS A SURFACE FRONTAL SYSTEM
IN THE HIGH PLAINS IS TYPICALLY NEEDED TO HELP SATURATE THE LOWER
LEVELS AND ROTATE WINDS TO BETTER UPSLOPE VECTORS. IT DOES APPEAR AS
THOUGH THIS TROUGH EJECTION LATER NEXT WEEK WILL FEATURE SOME SORT
OF SURFACE FRONT EAST OF THE MOUNTAINS. HOWEVER, AS OF THE 12Z
FORECAST CYCLE TODAY, ENSEMBLE GUIDANCE IS QUITE DISPERSIVE WITH THE
TIMING OF THIS FRONT. MANY MEMBERS DO NOT BRING IT THROUGH UNTIL
MOST OF THE MOISTURE IS OUT OF THE REGION, RESULTING IN A MAINLY DRY
END OF THE WEEK EAST OF THE I-25 CORRIDOR. EITHER WAY, TEMPERATURES
WILL DROP BACK ONCE AGAIN BY FRIDAY INTO SATURDAY WITH MOST PLACES
NEAR OR BELOW AVERAGE BY SATURDAY. OVERALL FORECAST CONFIDENCE IS
HIGH EARLY IN THE WEEK WITH COMPACT ENSEMBLE DISTRIBUTIONS IN BOTH
TEMPERATURE AND DRY WEATHER. BY THE END OF THE WEEK, FORECAST
CONFIDENCE IS VERY LOW AS GUIDANCE STRUGGLES TO RESOLVE THE EXACT
TRACK AND LOCATION OF FRONTAL BOUNDARIES AND MOISTURE IN THE LOWER
LEVELS.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1055 PM MST SAT FEB 1 2025
ZONAL WESTERLY FLOW ALOFT IS FORECAST TO CONTINUE LATE THIS WEEKEND
AS A STATIONARY FRONT LIFTS NORTHEAST AS WARM FRONT EARLY SUNDAY
MORNING. EXPECT INTERVALS OF MIDLEVEL CLOUDS WITH RAIN/SNOW SHOWER
ACTIVITY REDEVELOPING AND MOVING EAST THIS MORNING. WINDY CONDITIONS
WILL CONTINUE TONIGHT FOR THE SOUTHEAST WYOMING TERMINALS WITH
BREEZY CONDITIONS AT TIMES FOR THE WESTERN NEBRASKA TERMINALS. SOME
LLWS WILL CONTINUE FOR TERMINALS ALONG THE I-80 CORRIDOR UNTIL 15Z.
HAZARDS/WEATHER TRENDS: VFR CONDITIONS ARE FORECAST TO PREVAIL FOR
MOST TERMINALS TONIGHT THROUGH SUNDAY. KRWL WILL BE TRICKY SINCE
HIGH RES GUIDANCE HAS UNDERPERFORMED THE LAST 12 HOURS WITH SNOW
SHOWER ACTIVITY. EXPECT ANOTHER BAND OF SNOW/RAIN TO IMPACT KRWL
TONIGHT, BUT TIMING IS UNCERTAIN. EXPECT A WINDOW OF IFR CONDITIONS
FOR KCDR AND KAIA AS A WARM FRONT LIFTS NORTHEAST ACROSS THE HIGH
PLAINS. MAY SEE VIS DOWN TO 1 MILE IN LOCALLY HEAVY SNOW BEFORE
PRECIP CHANGES TO RAIN BETWEEN 15Z AND 19Z.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WATCH FROM SUNDAY MORNING THROUGH MONDAY MORNING FOR
WYZ101-106>108-116>118.
HIGH WIND WARNING UNTIL 5 AM MST SUNDAY FOR WYZ104-110.
HIGH WIND WATCH FROM 5 AM MST SUNDAY THROUGH MONDAY MORNING
FOR WYZ104-109-110.
WINTER WEATHER ADVISORY UNTIL 5 PM MST SUNDAY FOR WYZ109-110.
WINTER STORM WARNING UNTIL 5 PM MST SUNDAY FOR WYZ112-114.
NE...NONE.
SHORT TERM...CG
LONG TERM...MAC
AVIATION...TJT
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