341
FXUS65 KCYS 152013
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
213 PM MDT THU OCT 15 2026
KEY MESSAGES
- A WIDESPREAD HARD FREEZE IS EXPECTED ACROSS BOTH SOUTHEAST
WYOMING AND WESTERN NEBRASKA THURSDAY NIGHT INTO FRIDAY
MORNING.
- DRIER AND MILDER WEATHER EXPECTED THIS WEEKEND INTO EARLY NEXT
WEEK.
SHORT TERM /THROUGH SATURDAY NIGHT/
ISSUED AT 137 PM MDT THU OCT 15 2026
PRECIPITATION IS TAPERING OFF ACROSS THE AREA EARLY THIS AFTERNOON
AS THE SYSTEM CONTINUES TO PUSH EASTWARD. WITH CLOUDS CLEARING,
VISIBLE SATELLITE IS REVEALING SNOWFALL IN THE MOUNTAINS AS WELL AS
AROUND THE ARLINGTON AREA AND IN THE LARAMIE VALLEY. TEMPERATURES
OUTSIDE OF THE MOUNTAINS IN THESE AREAS WILL REACH THE LOW 40S THIS
AFTERNOON, SO SOME MELTING IS LIKELY. FOR THE EASTERN HALF OF THE
FORECAST AREA, GUSTY WINDS CONTINUE. OBSERVATIONS SHOW 30 TO 50 MPH
WIND GUSTS ALONG THE INTERSTATE 25 CORRIDOR AND EASTWARD INTO THE
NEBRASKA PANHANDLE. DESPITE TEMPERATURES HERE BEING IN THE 40S AND
50S, THE STRONG NORTH WINDS ARE MAKING FOR A CHILLY DAY. WINDS WILL
GRADUALLY WEAKEN LATER THIS EVENING, BUT THE COLD WILL REMAIN.
MODELS HAVE CLOUDS CLEARING OUT OVERNIGHT, WITH WINDS BECOMING CALM
ACROSS SOUTHEAST WYOMING. WITH CLEAR SKIES AND CALM WINDS, EFFECTIVE
RADIATIONAL COOLING WILL TAKE PLACE, ESPECIALLY IN AREAS WITH SNOW
COVER. FREEZE WARNINGS ARE ALREADY IN PLACE FOR SOUTHEAST WYOMING.
LOWS ARE EXPECTED TO DROP INTO THE 20 TO 25 DEGREE RANGE, WITH THE
POTENTIAL FOR A FEW ISOLATED TEENS IN VALLEYS, SNOW COVERED, OR
SHELTERED LOCATIONS. IT IS WORTH MENTIONING THAT THESE
CONDITIONS COULD PRODUCE SOME AREAS OF PATCHY FOG. THE NEBRASKA
PANHANDLE WAS UPGRADED TO A FREEZE WARNING WITH THIS FORECAST
PACKAGE. DESPITE THE BREEZIER CONDITIONS, A REINFORCING SHOT OF
COLD AIR FROM A CANADIAN TROUGH WILL GRAZE THE NEBRASKA
PANHANDLE, DROPPING TEMPERATURES BELOW 30 DEGREES. IT IS WORTH
MENTIONING THAT MANY MODELS WERE LIKELY NOT CAPTURING THE
COOLING EFFECTIVELY, SO NUDGED OVERNIGHT LOWS TOWARDS THE NBM
25TH PERCENTILE.
LOOKING AT A PRETTY QUIET DAY ON FRIDAY AS UPPER-LEVEL RIDGING
BEGINS TO BUILD OVER THE ROCKIES. IT'LL START OUT COLD AND FROSTY,
BUT TEMPERATURES WILL GRADUALLY WARM UP THROUGHOUT THE DAY AS WARMER
AIR ALOFT IS USHERED IN. HIGHS ON FRIDAY WILL BE ABOUT 10 DEGREES
BELOW AVERAGE, WITH TEMPERATURES GENERALLY IN THE 50S ACROSS THE
FORECAST AREA. AREAS WITH SNOW COVER COULD BE COOLER, NAMELY THE
LARAMIE VALLEY. EVEN THOUGH TEMPERATURES WILL BE ON THE
SEASONABLY COOL SIDE, AMPLE SUNSHINE THROUGHOUT THE DAY WILL
HELP CUT THROUGH SOME OF THE CHILL.
AS THE UPPER-LEVEL RIDGE SHIFTS EASTWARD OVERNIGHT ON FRIDAY, MID-
LEVEL WINDS WILL BECOME MORE WESTERLY. THE WESTERLY WINDS WILL POSE
A POSSIBLE CONCERN FOR HIGH WINDS IN THE TYPICAL SOUTHEAST WYOMING
WIND PRONES OF ARLINGTON AND BORDEAUX DURING THE DAY SATURDAY. MSLP
GRADIENTS WILL STEEPEN ALONG AND WEST OF THE LARAMIE RANGE. CAG TO
CPR 850 MB GRADIENTS ALSO REACH THE 50 METER RANGE, SIGNALING
THE POTENTIAL FOR GRADIENT DRIVEN MARGINAL HIGH WINDS IN THE
WIND PRONES. 700 MB WINDS WILL REACH ABOUT 40 KTS, BUT
SUBSIDENCE IS RATHER WEAK AND WILL LIKELY NOT PLAY A HUGE ROLE
IN THE WINDS SATURDAY INTO SUNDAY MORNING. WIND GUSTS OF AT
LEAST 40 TO 50 MPH WILL BE LIKELY DURING THE DAY SATURDAY AND
INTO THE OVERNIGHT HOURS. WESTERLY WINDS WILL HELP PLAY A ROLE
IN THE WARM, ABOVE AVERAGE TEMPERATURES EXPECTED ON SATURDAY.
DOWNSLOPING WINDS WILL AID 90TH PERCENTILE 700 MB TEMPERATURES
IN ACHIEVING DAYTIME HIGHS IN THE 70S FOR AREAS EAST OF THE
LARAMIE RANGE. TO THE WEST, HIGHS IN THE 60S CAN BE EXPECTED.
AMPLE SUNSHINE IS ONCE AGAIN EXPECTED FOR SATURDAY.
LONG TERM /SUNDAY THROUGH WEDNESDAY/
ISSUED AT 137 PM MDT THU OCT 15 2026
THE LONG TERM WILL BE MOSTLY CONTROLLED BY HIGH PRESSURE
RIDGING, THOUGH SEVERAL EMBEDDED DISTURBANCES WILL HELP TO
DISRUPT THIS FEATURE FROM GROWING STRONGER AND BRINING MUCH
WARMER CONDITIONS, WHILE MODEST MOISTURE SHOULD BRING AT LEAST A
WEAK CHANCE OF PRECIPITATION THROUGH THIS PERIOD. THE LONG TERM
STARTS WITH UPPER LEVEL HIGH PRESSURE CONTROLLING MUCH OF THE
SOUTHEASTERN US AND EXTENDING UP TOWARDS OUR REGION, WHILE A
WEAK LOW OFF OF THE SOUTHWESTERN CALIFORNIA COASTLINE MOVES
INLAND AND UP TOWARDS THE FOUR CORNERS REGION WHILE CONTINUING
TO WEAKEN. THIS SYSTEM, WHILE WEAK AND MOSTLY NON-IMPACTFUL,
WILL AT LEAST HELP TO STAVE OFF THE RIDGE FROM STRENGTHENING
OVER THE REGION WHILE ALSO BRINGING A QUICK AND WEAK SHOT OF
MOISTURE THAT SHOULD FUEL A FEW WEAK UPPER ELEVATION SHOWERS IN
THE REGION. WE WILL BE CLEARING OUT ON MONDAY AGAIN BEFORE FLOW
TURNS MORE SOUTHERLY TO SOUTHWESTERLY ON TUESDAY AS A DEEP
PACIFIC LOW BEGINS TO APPROACH THE WEST COAST AND THEN MOVES
INLAND THROUGH THE END OF THE FORECAST PERIOD. THIS WILL
CONTINUE TO STREAM MOISTURE IN, ALLOWING FOR FURTHER INCREASING
CHANCES OF UPSLOPE INDUCED PRECIPITATION THAT WILL BE AIDED BY
EMBEDDED WEAK SHORTWAVES WITHIN THE FLOW, THOUGH ONCE AGAIN NOT
EXPECTING SIGNIFICANT ACCUMULATIONS FROM THIS ACTIVITY. UNDER
THIS PATTERN LOOK FOR TEMPERATURES TO REMAIN LARGELY THE SAME
THROUGH THE LONG TERM AS HIGHS SIT GENERALLY 5-10 DEGREES ABOVE
NORMAL (60'S TO UPPER 70'S), WITH PORTIONS OF EASTERN WYOMING
AND THE NEBRASKA PANHANDLE NEARING 80 DEGREES, BUT CURRENTLY NOT
EXPECTED TO REACH THIS WARM. OTHERWISE, WITH NO SIGNIFICANT
FEATURES PRESENT OVER OUR AREA, LOOK FOR LARGELY BENIGN
CONDITIONS UNTIL LIKELY JUST BEYOND THE LONG TERM INTO THE
WEEKEND AFTER NEXT. THERE IS OVERALL MODERATE TO HIGH CONFIDENCE
IN THE FORECAST AS ENSEMBLES AND THEIR CLUSTERS ARE LARGELY
SIMILAR IN THEIR EXPECTATIONS OF THE EVOLUTION OF THIS PATTERN,
THOUGH DISCREPANCIES BEGIN TO ARISE ON HOW QUICKLY THE PACIFIC
LOW AT THE END OF THE FORECAST WILL MOVE INLAND, BUT THIS
SHOULDN'T CREATE DRASTIC CHANGES AT LEAST TO THIS FORECAST
PERIOD.
AVIATION /18Z TAFS THROUGH 18Z FRIDAY/
ISSUED AT 1147 AM MDT THU OCT 15 2026
CONDITIONS ARE EXPECTED TO BECOME WIDESPREAD VFR WITHIN THE NEXT
FEW HOURS AS HEATING AND DRYING CONTINUES TO CLEAR OUT CLOUDS
ACROSS THE REGION. ONCE THIS OCCURS, EXPECT HIGH CIGS TO SKC
THROUGH THE END OF THE FORECAST PERIOD. WINDS ARE VERY BREEZY
TODAY, WITH WIDESPREAD GUSTS 20-40 KNOTS THROUGH THIS EVENING
FROM THE NORTH. WINDS WILL BEGIN TO RELAX THIS EVENING OR THE
EARLY NIGHTTIME HOURS, WITH LIGHT WINDS EXPECTED TOMORROW
MORNING INTO THE AFTERNOON.
CYS WATCHES/WARNINGS/ADVISORIES
WY...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT FRIDAY FOR
WYZ101-102-104>111-113-115>119.
NE...FREEZE WARNING FROM MIDNIGHT TONIGHT TO 9 AM MDT FRIDAY FOR
NEZ002-003-019>021-054-055-095-096.
SHORT TERM...SF
LONG TERM...CG
AVIATION...CG
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