266
FXUS65 KCYS 060853
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
253 AM MDT MON APR 6 2026
KEY MESSAGES
- ABOVE-AVERAGE TEMPERATURES AND LOW PRECIPITATION CHANCES
REMAIN IN PLACE ACROSS SOUTHEAST WYOMING AND WESTERN NEBRASKA
ON MONDAY INTO TUESDAY.
- WINDS WILL INCREASE ACROSS SOUTHEAST WYOMING TUESDAY INTO WEDNESDAY,
INCREASING FIRE CONCERNS.
- GREATER PRECIPITATION CHANCES RETURN TO SOUTHERN WYOMING AND
WESTERN NEBRASKA INTO THE WEEKEND, CONFIDENCE ON HOW MUCH
PRECIPITATION WE WILL SEE REMAINS LOW.
SHORT TERM /THROUGH TUESDAY/
ISSUED AT 225 AM MDT MON APR 6 2026
OVERNIGHT CONDITIONS REMAIN MILD AND TRANQUIL AS SOUTHERN WYOMING
AND WESTERN NEBRASKA REMAIN IN A NORTHWESTERLY FLOW REGIME
DOWNSTREAM OF A LONGWAVE RIDGE LOCATED OVER THE WESTERN THIRD OF THE
COUNTRY. AS WE ARE LOCATED AT THE INFLECTION POINT BETWEEN THE
AFOREMENTIONED RIDGE AND A LONGWAVE TROUGH OVER THE EASTERN THIRD OF
THE COUNTRY (A FAVORABLE LOCATION FOR AGEOSTROPHIC CONVERGENCE
ALOFT), WE REMAIN UNDER THE INFLUENCE OF A 1040 MB SURFACE HIGH
LOCATED OVER MONTANA AND NORTH DAKOTA RESULTING IN BROAD, 5-10 KNOT
E/ENE SURFACE WINDS.
LATER IN THE AFTERNOON/EARLY EVENING ON MONDAY, A WEAK BACKDOOR COLD
FRONT WILL MOVE IN FROM THE NORTHEAST, RESULTING IN ESE SURFACE FLOW
ALONG AND EAST OF THE LARAMIE RANGE, RESULTING IN AN INCREASE IN
CLOUD COVER POST FROPA. HOWEVER, GIVEN DRY LOW-LEVELS WITH 50TH
PERCENTILE RH VALUES AROUND 30% ALONG WITH NO PRECIPITATION IS
EXPECTED AT THIS TIME.
THE MID-LEVEL RIDGE WILL BEGIN TO DAMPEN AS WE HEAD INTO TUESDAY AND
FLOW WILL BECOME MORE ZONAL. DUE TO DOWNSLOPING, OUR WIND SPEEDS
WILL ALSO BEGIN TO RAMP UP ON TUESDAY AFTERNOON. WHILE RANDOM FOREST
GUIDANCE GENERALLY KEEPS WINDS BELOW HIGH-WIND CRITERIA, HIGH-
RESOLUTION ENSEMBLE GUIDANCE HAS MEAN GUSTS OF 15-20 MPH EAST OF THE
LARAMIE RANGE IN ADDITION TO RH VALUES < 25%, SO WILL MENTION FIRE
CONCERNS DURING THIS TIME ESPECIALLY WITH ABOVE-AVERAGE HIGH
TEMPERATURES IN THE 60S. SOME WEAK MID-LEVEL INSTABILITY IS ALSO
PROGGED (SBCAPE AROUND 100 J/KG) INTO TUESDAY AFTERNOON WITH
FORECAST SOUNDINGS SHOWING AN INVERTED-V PROFILE WITH SURFACE
DEWPOINT DEPRESSIONS OF 45-50 DEGREES, SO ANY CONVECTION WILL LIKELY
PRODUCE GUSTY WINDS RATHER THAN ANY BENEFICIAL PRECIPITATION. THIS
IS EXACERBATE FIRE CONCERNS IN THE VICINITY OF ANY HIGH-BASED
CONVECTION.
LONG TERM /TUESDAY NIGHT THROUGH MONDAY/
ISSUED AT 250 AM MDT MON APR 6 2026
MODELS IN REASONABLE AGREEMENT THROUGH THE WEEKEND AND CONTINUE
TO SHOW A STRONG UPPER LEVEL LOW PASSING WELL NORTH OF WYOMING
AND WESTERN NEBRASKA TUESDAY NIGHT AND WEDNESDAY. OUTSIDE OF A
FEW SHOWERS ACROSS THE AREA, THE PRIMARY CONCERNS WILL BE STRONG
GUSTY WINDS WEDNESDAY AND FIRE WEATHER CONCERNS. 700MB WINDS
WILL INCREASE TO OVER 50 KNOTS BY MIDMORNING WEDNESDAY WITH
EXCELLENT SUBSIDENCE FOR A FEW OF THE WIND PRONE AREAS. WE'RE
STARTING TO GET OUT OF "GAP WIND SEASON", BUT THE ASSOCIATED
COLD FRONT AND INCREASING 700MB FLOW COULD RESULT IN SOME GUSTS
OVER 58 MPH FOR ARLINGTON, ELK MOUNTAIN, AND THE I-80 SUMMIT
LATE TUESDAY NIGHT THROUGH MID AFTERNOON ON WEDNESDAY. IN-HOUSE
WIND GUIDANCE IS NOT COMPLETELY ON BOARD AND SHOW MAINLY
ELEVATED WIND GUSTS BETWEEN 45 TO 55 MPH, LIKELY DUE TO THE POOR
SURFACE PRESSURE GRADIENTS WITH THIS EVENT. KEPT WIND GUSTS
NEAR CRITERIA, ESPECIALLY AFTER MIDNIGHT EARLY WEDNESDAY MORNING
THROUGH NOON WEDNESDAY. OTHERWISE, THE BEST CHANCE FOR
PRECIPITATION DURING THIS SYSTEM MAY BE LATER ON INTO WEDNESDAY
EVENING ACROSS THE HIGH PLAINS, ONCE THE PRIMARY UPPER LEVEL LOW
MOVES EASTWARD INTO THE GREAT LAKES REGION.
AS WE HEAD INTO LATE WEEK, MODELS ARE STARTING TO SHOW A PATTERN
THAT'S MORE CONSISTENT WITH A TYPICAL SPRING TIME WEATHER
PATTERN ACROSS THE INTERMOUNTAIN WEST, WITH UPPER LEVEL
TROUGHING DIGGING FURTHER SOUTH ACROSS THE CALIFORNIA COASTLINE
AND GREAT BASIN REGION. SOUTHERN BRANCH OF THE POLAR JET LOOKS
TO BECOME A LITTLE MORE ACTIVE LATE IN THE WEEK AS SEVERAL
DISTURBANCES LIFT NORTHEAST ACROSS THE FRONT RANGE. ALTHOUGH NOT
SYNOPTICALLY IMPRESSIVE, SURFACE BASED CONVECTION WILL LIKELY
BE MORE OF A FORECAST TOPIC IN THE COMING DAYS. AGREE WITH THE
PREVIOUS FORECASTS AND CURRENT ENSEMBLE GUIDANCE WITH INCREASING
POP WITH POSSIBLE THUNDERSTORMS BY FRIDAY AND SATURDAY. IN
ADDITION, NAEFS MEAN PWAT OVER THE FRONT RANGE IS BETWEEN THE
90TH AND 95TH PERCENTILE (0.50 TO 0.75 INCHES) FROM FRIDAY
THROUGH SATURDAY. THIS IS LIKELY NOT ONLY DUE TO SURFACE
MOISTURE ADVECTION AS WINDS SHIFT INTO THE EAST, BUT ALSO
MOISTURE ADVECTION ALOFT AHEAD OF THE MAIN PACIFIC SYSTEM NEAR
THE WEST COAST. WIDESPREAD SHOWERS AND THUNDERSTORMS APPEAR
UNLIKELY SINCE THE BULK OF THE MID TO UPPER LEVEL ENERGY STAY TO
OUR SOUTH. REGARDLESS, WILL LIKELY SEE WIDELY SCATTERED TO
SCATTERED CONVECTION AT THE VERY LEAST IN THIS PATTERN. KEPT
THUNDER OUT OF THE FORECAST FOR NOW DUE TO UNKNOWN AMOUNT OF
CLOUD COVER, WHICH MAY LIMIT DEEPER CONVECTION. EVEN WITH BRIEF
COOL DOWNS BEHIND EACH DISTURBANCE, VERY LITTLE IMPACT ON HIGH
TEMPERATURES EXPECTED WITH ABOVE AVERAGE TEMPERATURES THROUGH
THE END OF THE WEEK AND INTO THE WEEKEND...GENERALLY IN THE 60S
TO LOW 70S. SATURDAY LOOKS LIKE THE WARMEST DAY BASED ON THE
GRAND ENSEMBLE WITH HIGHS IN THE UPPER 60S TO MID 70S.
AVIATION /06Z TAFS THROUGH 06Z MONDAY/
ISSUED AT 1145 PM MDT SUN APR 5 2026
MIDLEVEL CLOUDINESS WILL BECOME MORE WIDESPREAD THIS MORNING AS A
SHALLOW COOL FRONT MOVES SOUTHWEST ACROSS THE HIGH PLAINS, SHIFTING
WINDS INTO THE EAST.
HAZARDS/WEATHER TRENDS: VFR CONDITIONS EXPECTED TO CONTINUE OVER THE
REGION FOR THE NEXT 24 HOURS. LIGHT AND VARIABLE WINDS WILL SHIFT
INTO THE EAST OR SOUTHEAST FOR THE HIGH PLAINS TERMINALS, AND REMAIN
OUT OF THE SOUTHEAST FOR KRWL AND KLAR. GUSTS UP TO 25 KNOTS ARE
POSSIBLE. PRECIPITATION LOOKS UNLIKELY AT THIS TIME (LESS THAN 10%
CHANCE).
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...NB
LONG TERM...TJT/MN
AVIATION...TJT
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