629
FXUS65 KCYS 071752
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1152 AM MDT TUE APR 7 2026
KEY MESSAGES
- ABOVE-AVERAGE TEMPERATURES AND LOW PRECIPITATION CHANCES
REMAIN IN PLACE ACROSS SOUTHEAST WYOMING AND WESTERN NEBRASKA
THROUGH TUESDAY.
- WINDS WILL INCREASE ACROSS SOUTHEAST WYOMING TUESDAY INTO
WEDNESDAY, INCREASING FIRE CONCERNS AND POTENTIAL FOR STRONG
WINDS IN THE WIND PRONE AREAS.
- A RED FLAG WARNING IS IN EFFECT FOR NORTHERN PORTIONS OF THE
AREA FROM NOON TUESDAY THROUGH 8PM TUESDAY NIGHT.
- A HIGH WIND WATCH IS IN EFFECT FOR THE ARLINGTON/ELK MOUNTAIN
WIND PRONE AREA FROM MIDNIGHT TONIGHT THROUGH 3PM WEDNESDAY.
- GREATER PRECIPITATION CHANCES RETURN TO SOUTHERN WYOMING AND
WESTERN NEBRASKA INTO THE WEEKEND, CONFIDENCE IN PRECIPITATION
AMOUNTS REMAINS LOW.
SHORT TERM /THROUGH WEDNESDAY NIGHT/
ISSUED AT 345 AM MDT TUE APR 7 2026
LOW-LEVEL ANTICYCLONIC UPSLOPE FLOW PREVAILS OVERNIGHT AS WINDS
REMAIN OUT OF THE SE UNDER THE INFLUENCE OF A 1034 MB SURFACE HIGH
CENTERED OVER MN. TUESDAY WILL AGAIN FEATURE MILD, ABOVE-AVERAGE
HIGH TEMPERATURES MAINLY IN THE 60S TO PERHAPS 70 DEGREES EAST OF
THE I-25 CORRIDOR. THE MAIN CONCERN TODAY WILL BE FIRE WEATHER EAST
OF THE LARAMIE RANGE, HENCE THE ISSUANCE FOR A RED FLAG WARNING FOR
PORTIONS OF NIOBRARA, CONVERSE, AND PLATTE COUNTIES DUE TO DRY
FUELS, 30-35 MPH WIND GUSTS, AND LOW PROBABILITIES (~15%) OF DRY
THUNDERSTORMS PRODUCING LIGHTNING, ERRATIC WINDS, AND LITTLE TO NO
PRECIPITATION. FORECAST SOUNDINGS ACROSS SOUTHEASTERN WYOMING
CONTINUE TO INDICATE INVERTED-V PROFILES WITH SURFACE DEWPOINT
DEPRESSIONS GREATER THAN 40 DEGREES WITH MLCAPE AROUND 100 J/KG, SO
HIGH-BASED CONVECTION POSING A DRY MICROBURST THREAT SEEMS
APPROPRIATE LATER THIS AFTERNOON. THIS ACTIVITY SHOULD WANE QUICKLY
AFTER SUNSET AS ANY CONVECTION WILL BE DIURNALLY AND TERRAIN-DRIVEN.
WE REMAIN DOWNSTREAM OF A WEAK MID-LEVEL RIDGE INTO WEDNESDAY, WITH
A ROBUST CLOSED LOW RAPIDLY PROPAGATING ACROSS THE DAKOTAS TO OUR
NORTH, PLACING US IN A NORTHWESTERLY FLOW REGIME. WHILE NOT EXACTLY
AN IMPRESSIVE WIND EVENT AT LEAST FOR WYOMING STANDARDS, ARLINGTON
SHOULD SEE WIND SPEEDS RAMP UP INTO THE EARLY MORNING HOURS. RANDOM
FOREST GUIDANCE SUGGESTS HIGH WIND PROBABILITIES OF 35-40% DURING
THIS TIME, HENCE THE ISSUANCE OF A HIGH WIND WATCH FOR THIS AREA
INTO WEDNESDAY AFTERNOON. THIS IS ALSO SHOWN ON HIGH-RESOLUTION
ENSEMBLE GUIDANCE ESPECIALLY ALONG THE SNOWY RANGE, WITH 75TH
PERCENTILE WIND GUSTS EXCEEDING HIGH WIND CRITERIA. ALTHOUGH NOT AS
IMPRESSIVE AS FURTHER WEST OF LARAMIE, WINDS ALONG AND EAST OF THE I-
25 CORRIDOR WILL REMAIN BREEZY THANKS TO ENHANCED FLOW INDUCED BY A
12 MB CASPER TO RAPID CITY PRESSURE GRADIENT AROUND THE PERIPHERY OF
THE SURFACE HIGH. WHILE NOT AS WARM AS TUESDAY, TEMPERATURES WILL
CONTINUE TO BE ABOVE CLIMATOLOGY AND PRIMARILY IN THE 60S, WITH
MOSTLY DRY CONDITIONS. INSTABILITY IS MUCH LOWER RELATIVE TO
TUESDAY, SO THE THREAT OF DRY LIGHTNING IS MUCH LOWER, MINIMIZING
FIRE CONCERNS AT THIS TIME.
LONG TERM /THURSDAY THROUGH MONDAY/
ISSUED AT 345 AM MDT TUE APR 7 2026
NO MAJOR CHANGES TO THE FORECAST AT THIS TIME. AN IMPRESSIVE
SYSTEM STILL LOOKS TO IMPACT THE AREA SATURDAY, POTENTIALLY
BRINGING RAIN AND THUNDERSTORMS TO THE REGION, SOME OF WHICH MAY
BE STRONG. PLEASE SEE PREVIOUS DISCUSSION FOR MORE DETAILS...
THE LONG TERM LOOKS MORE ACTIVE WITH A MORE TYPICAL SPRING TIME
PATTERN. AFTER A SERIES OF COLD FRONTS ON WEDNESDAY AND OVERNIGHT
THURSDAY, A RIDGE WILL MOVE EAST OF OUR AREA TO REINFORCE
SOUTHEASTERLY LOW LEVEL FLOW OVER THE PLAINS REGIONS OF WY AND
THE NE PANHANDLE. THIS FLOW WILL INCREASE DEWPOINTS INTO THE 40S
FOR THE NEXT COUPLE OF DAYS. THESE DEWS PAIRED WITH A RATHER
MOIST 700-500MB LEVEL LAYER ARE INCREASING PWAT VALUES DURING
THE FRIDAY AND SATURDAY TIMEFRAME. THE NAEFS MEAN PWAT OVER THE
FRONT RANGE IS BETWEEN THE 90TH AND 95TH PERCENTILE (0.50 TO
0.75 INCHES). THIS INCREASE IN MOISTURE IS LIKELY TO ELEVATE POP
VALUES. UNFORTUNATELY RAINFALL AMOUNTS ARE NOT IMPRESSIVE ON
GUIDANCE, GEFS HAS BETWEEN 25-40% CHANCES OF SEEING 0.1" OF
PRECIPITATION, CONFINED TO MOSTLY THE SOUTHERN AREAS OF WY AND
THE NE PANHANDLE. GIVEN THE LACK OF ANY SIGNIFICANT SOURCES OF
SYNOPTIC LIFT AND THE CONVECTIVE NATURE OF THE PRECIPITATION,
THE CONFIDENCE IN PRECIP AMOUNTS ARE LOW. THIS DOES NOT
COMPLETELY RULE OUT LOCALLY HEAVIER AMOUNTS, BUT THE GENERAL
PICTURE AT THIS TIME IS NOT OF WIDESPREAD RAIN OR SNOWFALL. A
FEW THUNDERSTORMS CANNOT BE RULED OUT EITHER AS MOST AI ENSEMBLE
MODELS SUPPORT IT AND DETERMINISTIC GFS DOES MANIFEST DAYTIME
VALUES OF ABOVE 100 J/KG MUCAPE THURSDAY AND FRIDAY, AND ABOVE
500 MUCAPE FOR THE NE PANHANDLE SATURDAY AFTERNOON. WIDESPREAD
CLOUD COVER MAY DAMPEN COVERAGE AND INTENSITY.
EVEN WITH BRIEF COOL DOWNS WITH THE LATE WEEK AND WEEKEND
DISTURBANCE PASSAGES, WE ARE LIKELY TO STAY 5-10 DEGREES ABOVE
AVERAGE. SATURDAY LOOKS TO BE THE WARMEST WITH GENERALLY MID 60S TO
MID 70S OVER THE REGION. AFTERWARDS A SLIGHT COOLING TREND WITH
CHANCES OF RAIN/SNOW SHOWERS GOING INTO MONDAY. MOST OF THE AREA HAS
A 40-50% CHANCE OF RAINFALL MONDAY, BUT CONFIDENCE IS LOW AT THIS
RANGE AND DEPENDS LARGELY ON THE POSITIONING OF SYNOPTIC
FEATURES.
AVIATION /18Z TAFS THROUGH 18Z WEDNESDAY/
ISSUED AT 1150 AM MDT TUE APR 7 2026
THERE IS A SMALL CHANCE FOR LIGHT SHOWERS THIS AFTERNOON AND
EVENING. SOME MODELS HAVE SHOWERS DEVELOPING AS EARLY AS 20Z
AND ENDING AROUND 04Z. THERE IS A SMALL CUMULUS SECTION
DEVELOPING OVER KLAR RIGHT NOW HOWEVER, LOOKING AT MODEL
SOUNDINGS IT WILL BE MOST LIKELY TO HAVE VIRGA OCCUR. VCSH WAS
PUT IN FOR KLAR, KCYS, AND KBFF TO ACCOUNT FOR THE VIRGA WITH
SOME POSSIBLE ERRATIC WINDS UNDERNEATH THE SHOWERS. BY 04Z THE
SHOWERS ARE EXPECTED TO DISSIPATE ACROSS THE TAF AREA. CEILINGS
ARE EXPECTED TO BE RATHER HIGH THROUGHOUT THE DAY TYPICALLY
10,000FT+ BUT NEAR KLAR THE CLOUDS MAY DROP TO AROUND 4,000FT.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR WYZ417-418-
432-433.
HIGH WIND WATCH FROM LATE TONIGHT THROUGH WEDNESDAY AFTERNOON
FOR WYZ110.
NE...NONE.
SHORT TERM...NB
LONG TERM...AM/RV
AVIATION...MM
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