380
FXUS65 KCYS 151800
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1200 PM MDT SUN MAR 15 2026
KEY MESSAGES
- STRONG NORTHWEST TO NORTH WINDS WILL CONTINUE OVER THE HIGH
PLAINS INTO SUNDAY, PRODUCING SUB-ZERO WIND CHILL
TEMPERATURES.
- VERY GUSTY WINDS RETURN EARLY IN THE WEEK, AS WELL AS
INCREASING FIRE WEATHER CONCERNS.
- RECORD BREAKING WARM TEMPERATURES ARE EXPECTED TO RETURN TO
THE FORECAST FOR THE SECOND HALF OF THE WEEK AHEAD.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 248 AM MDT SUN MAR 15 2026
MUCH COLDER TEMPERATURES ARE EXPECTED TODAY AND MONDAY AS COLD AIR
FROM THE UPPER-LEVEL TROUGH CONTINUES TO SPILL INTO THE REGION
BEHIND A COLD FRONT. UPPER-LEVEL NORTHERLY TO NORTHWESTERLY FLOW IS
EXPECTED TO CONTINUE THROUGH AT LEAST TUESDAY, AIDING IN THE COOLER
TEMPERATURES ACROSS THE REGION. 500MB FLOW REMAINS LARGELY
UNIMPRESSIVE AS THE STRONGEST CYCLONIC VORTICITY ADVECTION MOVES OFF
TO THE EAST THROUGHOUT THE DAY. 700MB FLOW SLOWLY BECOMES LESS
ELEVATED AS THE 700MB LOW RESPONSIBLE FOR THE GUSTY WINDS THIS
MORNING CONTINUES OFF TO THE NORTHEAST TOWARDS THE MIDWEST AND GREAT
LAKES REGION. LARGELY NORTHERLY TO NORTHWESTERLY FLOW IS EXPECTED
ACROSS THE REGION. PRECIPITATION HAS ENDED ACROSS MOST OF THE REGION
TONIGHT, BUT LOCATIONS LIKE ARLINGTON, DAWES COUNTY, THE SNOWY
RANGE, AND NORTHERN PORTIONS OF THE CWA WILL CONTINUE TO SEE
PRECIPITATION PERSIST. THESE FINALS ZONES WILL SLOWLY TAPER OFF BY
ABOUT 6PM THIS EVENING, LEAD TO CLEARING SKIES AND VERY COLD
OVERNIGHT TEMPERATURES. DAYTIME HIGHS TODAY UNDER CLOUDY SKIES WILL
STRUGGLE TO REACH THE UPPER-20S FOR MOST AREAS, WITH THE COLDEST
TEMPERATURES EXPECTED IN LOCATIONS WITH THE MOST SNOWPACK. OVERNIGHT
LOWS TONIGHT ARE EXPECTED TO TANK AS SKIES CLEAR AND RADIATION
COOLING TAKES OVER. CURRENT FORECAST OVERNIGHT LOWS AND IN THE
SINGLE DIGITS TO TEENS, BUT SOME LOCATIONS MAY EASILY FALL INTO THE
NEGATIVES, ESPECIALLY LOOKING AT CHADRON AND ALLIANCE. WITH LIGHT
WINDS OVERNIGHT, MANY LOCATIONS WILL SEE SUB-ZERO WIND CHILLS FOR
EARLY MONDAY MORNING.
CLOUD COVER ON MONDAY WILL QUICKLY RETURN AS A REINFORCING BRANCH OF
UPPER-LEVEL NORTHERLY FLOW PUSHES INTO THE REGION. MUCH OF THE CWA
WILL BE WITHIN THE LEFT EXIT REGION OF THE UPPER-LEVEL JET, FAVORING
SYNOPTIC ASCENT ACROSS THE AREA AND, THEREFORE, INCREASING CLOUD
COVER. WITH INCREASING CLOUDS, DAYTIME MAXIMUM TEMPERATURES ARE
EXPECTED TO BE STUNTED IN THE 40S FOR MUCH OF THE AREA, WITH CLOUD
COVER PREVENT ANY ADDITIONAL SIGNIFICANT WARMING THROUGH THE
AFTERNOON AND EVENING HOURS. 700MB FLOW REMAINS LARGELY
NORTHWESTERLY THROUGHOUT THE DAY MONDAY, WITH A DIFFUSE SHORTWAVE
EXPECTED TO PUSH THROUGH THE REGION. SURFACE WINDS WILL BE ABLE THE
ONLY HINT OF THIS SHORTWAVE MOVING THROUGH AS GUSTY CONDITIONS
RETURN TO THE TYPICAL WIND PRONES OF SOUTHEAST WYOMING, NAMELY
ARLINGTON AND THE I-80 SUMMIT.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 248 AM MDT SUN MAR 15 2026
NO MAJOR CHANGES, PLEASE SEE PREVIOUS DISCUSSION...
ON TUESDAY, AN UPPER LEVEL RIDGE WILL BE PUSHING INTO THE WESTERN
COAST CENTERED NEAR THE CALIFORNIA\NEVADA BORDER. THE INTERMOUNTAIN
WEST WILL BE IN NORTHWEST FLOW WITH THE STRONGEST PART OF THE
JETSTREAM CENTERED OVER SOUTHEAST MONTANA AND THE DAKOTAS. WITH A
WEAK SHORTWAVE DIVING INTO THE NORTHERN RED RIVER VALLEY OUR HEIGHT
GRADIENT BECOMES COMPRESSED INTENSIFYING THE 700MB JET TO GENERALLY
AROUND 55-60 KNOTS WITH THE GFS HAVING A COUPLE BRIEF INSTANCES OF
ACCELERATIONS GREATER THAN 60. THE CRAIG TO CASPER HEIGHT GRADIENT
DIFFERENCE INCREASES FROM 50METERS TO 85METERS BY THE AFTERNOON
INCREASING OUR CONFIDENCE IN POTENTIAL HIGH WINDS FOR TUESDAY. OUR
IN-HOUSE HIGH WIND ALGORITHM PLACES HIGH CONFIDENCE IN THE WIND
PRONES HITTING HIGH WIND CRITERIA FROM 40 PERCENT TO 80/90 PERCENT
BY NOON ON TUESDAY. AS THIS RIDGE SLOWLY APPROACHES THE FOUR CORNERS
REGION, THE JETSTREAM SHOULD BE SLOWLY PUSHING NORTH AS WELL
TAPERING OFF OUR WINDS THROUGHOUT THE DAY WEDNESDAY. LOOKING AT
CLUSTER ANALYSIS THERE IS SOME UNCERTAINTY IN THE TIMING OF THE
ARRIVAL OF THE RIDGE AS SOME MEMBERS OF THE GRAND ENSEMBLE HAVE IT
ARRIVING LATER AND LESS AMPLIFIED THAN OTHERS. A LATER AND LESS
AMPLIFIED RIDGE EQUATES TO THE EXTENSION OF THE HIGH WINDS THROUGH
THE END OF THE WEEK AS THE JETSTREAM WON'T BE PUSHED NORTH WITHOUT
THE AMPLIFIED RIDGE. IN WARMER NEWS, THIS RIDGE ALSO HAS THE MAKINGS
OF A FUN DEATH RIDGE BY THE MIDDLE TO END OF THE WEEK. MEANING 700MB
TEMPERATURES RISE BETWEEN 10 TO 14C AND SURFACE TEMPERATURES RISE
INTO THE 90 TO 99TH PERCENTILE LATER THIS WEEK DEPICTED BY NAEFS. TO
GIVE EVERYONE AN IDEA OF THE POTENTIAL MAGNITUDE OF THIS RIDGE. THE
HIGH WINDS LOOK TO POTENTIALLY STOP BY WEDNESDAY AFTERNOON/EVENING
AND THE HIGH TEMPERATURES START IN THE 30/40'S AT THE BEGINNING OF
THE WEEK AND END IN THE 70'S TO 80'S UPON THE ARRIVAL OF THIS RIDGE
WITH NO PRECIPITATION CHANCES AS WELL AFTER TUESDAY. SO THIS RIDGE
WILL BE SOMETHING TO KEEP AN EYE ON AS FIRE WEATHER CONCERNS LOOK TO
AMPLIFY AS WELL WITH THIS RIDGE.
AVIATION /18Z TAFS THROUGH 18Z MONDAY/
ISSUED AT 1155 AM MDT SUN MAR 15 2026
A MIX OF FLIGHT CATEGORIES EXPECTED OVER THE NEXT 12 HOURS OR SO
THANKS TO LINGERING LOW LEVEL CLOUDS AND BLOWING SNOW, ALONGSIDE
THE CHANCE OF SOME NEW SNOWFALL. PRIMARY SITES AT RISK OF SEEING
NEW SNOW INCLUDE KCYS AND KCDR, THOUGH PROBABILITIES ARE ON THE
LOWER SIDE, BUT KEPT THE CHANCE IN TAFS. PRIMARILY EXPECTING
MVFR STATUS WITH MOST CLOUDS OR LOWERED VIS, BUT LOCALIZED
LOWER FLIGHT CATEGORIES CAN'T BE RULED OUT DUE TO BLOWING SNOW.
WINDS WILL REMAIN GUSTY FOR ALL SITES THROUGH THIS AFTERNOON,
RELAXING TONIGHT BUT PICKING BACK UP AGAIN TOMORROW FOR KLAR AND
KRWL WITH STRONG WESTERLY GUSTS AGAIN.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...HIGH WIND WARNING UNTIL 3 PM MDT THIS AFTERNOON FOR NEZ002-003-
019>021-054-055-095-096.
SHORT TERM...AM
LONG TERM...MM/AM
AVIATION...CG
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