316
FXUS65 KCYS 210925
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
325 AM MDT SAT JUN 21 2025
KEY MESSAGES
- HOT TEMPERATURES WILL CONTINUE SATURDAY. NEAR RECORD HIGH
TEMPERATURES ARE POSSIBLE.
- COOLER TEMPERATURES EXPECTED FOR MOST OF NEXT WEEK AS A
PACIFIC COLD FRONT MOVES ACROSS THE AREA LATE SUNDAY.
- SHOWERS AND THUNDERSTORMS WILL RETURN TO THE AREA AS EARLY AS
SUNDAY AFTERNOON, WITH MOST OF THE ACTIVITY EXPECTED LATE
MONDAY THROUGH THURSDAY.
SHORT TERM /THROUGH MONDAY/
ISSUED AT 310 AM MDT SAT JUN 21 2025
CURRENT SURFACE OBSERVATIONS ACROSS THE AREA EARLY THIS MORNING
SHOWS MILD TEMPERATURES AND GUSTY WINDS CONTINUING AS THE 500MB
TO 700MB THERMAL RIDGE AXIS LIFTS NORTHEAST ACROSS THE PLAINS.
TEMPERATURES AT 2 AM HAVE BEEN ON THE WARM SIDE, WITH READINGS
IN THE 70S AND EVEN LOW 80S ACROSS SOUTHEAST WYOMING. CHEYENNE
RECORDED A TEMPERATURES OF 80 AN HOUR AGO WITH GUSTY SOUTHWEST
WINDS. THIS IS PRETTY ATYPICAL AROUND HERE LATE AT NIGHT, EVEN
IN THE SUMMER. LIGHT WINDS FURTHER EAST HAVE RESULTED IN GOOD
RADIATIONAL COOLING WITH READINGS AROUND 60 FOR THE WESTERN
NEBRASKA PANHANDLE AND FAR EASTERN WYOMING. CANCELLED THE HIGH
WIND WARNING FOR MOST OF SOUTHERN AND CENTRAL CARBON COUNTY WITH
WINDS IN THESE AREAS GENERALLY UNDER 25 MPH. HOWEVER, KEPT THE
HIGH WIND WARNING GOING FOR THE ARLINGTON/ELK MOUNTAIN AREA AND
THE LARAMIE VALLEY SINCE GUSTS ARE STILL PEAKING AROUND 50 MPH
LATE LAST NIGHT/EARLY THIS MORNING. WITH GOOD MIXING EXPECTED
AROUND SUNRISE, DECIDED TO KEEP THIS WARNING GOING UNTIL 9 AM
SINCE MODELS CONTINUE TO SHOW AN AREA OF 55 KNOT WINDS AT 700MB
UNTIL NOON. OTHERWISE, REMAINING VERY DRY AND MOSTLY SUNNY TODAY
WITH HOT TEMPERATURES IN THE UPPER 80S TO UPPER 90S ACROSS MOST
OF THE AREA. A FEW LOCATIONS MAY END UP BEING A LITTLE WARMER
COMPARED TO YESTERDAY WITH SOME ADDITIONAL RECORD HIGHS
POSSIBLE, BUT WITH SURFACE WINDS SHIFTING INTO THE SOUTH,
DECIDED TO KEEP HIGH TEMPERATURES NEAR OR SLIGHTLY ABOVE
GUIDANCE THIS AFTERNOON. GUSTY WINDS THIS MORNING SHOULD
GRADUALLY DIMINISH BY MID TO LATE AFTERNOON.
A FEW NOTABLE CHANGES ON SUNDAY WITH MODELS TRENDING SLOWER WITH
THE SURFACE COLD FRONT. WITH ALL MODELS DELAYING THE COLD FRONT
UNTIL LATE SUNDAY EVENING (WEST OF I-25) AND LATE SUNDAY FOR
AREAS EAST OF I-25, INCREASED HIGH TEMPERATURES INTO THE 80S AND
LOW 90S AHEAD OF THE FRONT...MAINLY SOUTHEAST OF A LARAMIE TO
LUSK LINE. FURTHER WEST ACROSS CARBON AND CONVERSE COUNTIES,
EXPECT AFTERNOON TEMPERATURES TO GRADUALLY LOWER INTO THE 60S
AND 70S AS THE FRONT NUDGES INTO THE AREA. WITH THIS DELAY,
THERE HAS BEEN A NOTICEABLE INCREASE IN INSTABILITY AND MOISTURE
ADVECTION AHEAD OF THE FRONT ACROSS EAST CENTRAL WYOMING AND
THE NORTHERN NEBRASKA PANHANDLE. AGREE WITH SPC'S MARGINAL RISK
FOR SEVERE THUNDERSTORMS IN THIS REGION WITH HIGH RES CAMS
SHOWING ACTIVITY DEVELOPING BETWEEN 2 PM TO 6 PM SUNDAY
AFTERNOON AND LINGERING THROUGH THE EVENING HOURS. INCREASED POP
AND ADDED A CHANCE OF THUNDERSTORMS EAST OF THE I-25 CORRIDOR.
AGAIN, SOME STRONG TO MARGINALLY SEVERE STORMS ARE POSSIBLE.
MUCH COOLER AIR SPREADS ACROSS THE AREA SUNDAY NIGHT. IN FACT,
MODEL GUIDANCE IS HINTING AT LOW TEMPERATURES A FEW DEGREES
ABOVE FREEZING FOR THE HIGH VALLEYS...INCLUDING RAWLINS,
SARATOGA, AND LARAMIE. WILL HAVE TO KEEP AN EYE ON THESE TRENDS
OVER THE NEXT FEW DAYS FOR FROST OR FREEZE ADVISORIES. AT THIS
TIME, KEPT LOWS TEMPERATURES AROUND 37 TO 39 DEGREES IN THESE
LOCATIONS WITH MID 40S TO LOW 50S FURTHER EAST.
FOR MONDAY, MODELS CONTINUE TO TREND A BIT WARMER DURING THE DAY
WITH THE LACK OF A STRATUS DECK DEVELOPING DURING THE DAY, BUT
STILL EXPECTED MONDAY NIGHT. MOISTURE ADVECTION SEEMS TO BE
DELAYED UNTIL THE AFTERNOON HOURS...PROBABLY DUE TO LESS
PROGRESSIVE NATURE OF THE FRONT ON SUNDAY. INCREASED HIGH
TEMPERATURES A FEW MORE DEGREES WITH HIGHS IN THE LOW TO MID
70S. STILL EXPECT A STRONG TEMPERATURE INVERSION AROUND 700MB,
SO THERE SHOULD BE PLENTY OF CIN THROUGH THE MIDDLE OF THE
AFTERNOON. HOWEVER, SHOWERS AND THUNDERSTORMS ARE POSSIBLE LATER
IN THE DAY WITH INCREASING ELEVATED CAPE AND A WEAK DISTURBANCE
ALOFT LIFTING NORTHEAST ACROSS THE FRONT RANGE. INCREASED POP
UP TO 40 PERCENT FOR THUNDERSTORMS MONDAY EVENING.
LONG TERM /MONDAY NIGHT THROUGH FRIDAY NIGHT/
ISSUED AT 320 AM MDT SAT JUN 21 2025
NO MAJOR CHANGES TO THE LONG TERM PORTION OF THE FORECAST WITH
ALL MODELS IN REASONABLE AGREEMENT. COOLER TEMPERATURES ARE
EXPECTED WITH THE RETURN OF SHOWERS AND THUNDERSTORMS THE
FOR MOST OF NEXT WEEK AS A SLOW MOVING PACIFIC UPPER LEVEL
TROUGH MOVES EASTWARD ACROSS THE GREAT BASIN AND INTO THE
ROCKYS. MODELS ARE TRENDING A LITTLE BIT WARMER EARLY TO MID
NEXT WEEK COMPARED TO THE LAST SEVERAL MODEL RUNS, BUT STILL
EXPECT BELOW AVERAGE TEMPERATURES IN THE UPPER 60S TO MID 70S
THROUGH WEDNESDAY. SURFACE WINDS WILL SHIFT INTO THE EAST OR
SOUTHEAST WITH EXCELLENT MOISTURE ADVECTION NEAR THE SURFACE.
THIS WILL LIKELY RESULT IN SOME LOW STRATUS ACROSS THE EASTERN
HIGH PLAINS AND CLOUDY SKIES FOR MONDAY NIGHT THROUGH TUESDAY
NIGHT. HOWEVER, THIS MAY ALSO LIMIT DAYTIME AND EVENING
CONVECTION. CAN'T RULE OUT THE POTENTIAL FOR STRONG OR SEVERE
THUNDERSTORMS, ESPECIALLY TUESDAY AND WEDNESDAY AS THE PACIFIC
TROUGH SLIDES EASTWARD INTO THE CONTINENTAL DIVIDE WITH DECENT
SHEAR AND SBCAPE OF 1000 TO 1500 J/KG ACROSS A GOOD PORTION OF
THE EASTERN PLAINS. HOWEVER, COVERAGE AND CONFIDENCE ARE PRETTY
LOW AT THIS TIME WITH MARGINAL CONVECTIVE PARAMETERS AND 0-6KM
SHEAR TRENDING LOWER AS WE HEAD INTO MID TO LATE WEEK. EXPECT
ANOTHER SLOW WARMING TREND LATE NEXT WEEK BEHIND THE PACIFIC
SYSTEM WITH HIGHS RETURNING TO THE 80S TO AROUND 90 ACROSS THE
LOWER ELEVATIONS OF WESTERN NEBRASKA AND FAR EASTERN WYOMING.
AVIATION /06Z TAFS THROUGH 06Z SUNDAY/
ISSUED AT 1150 PM MDT FRI JUN 20 2025
UPPER LEVEL RIDGE AXIS WILL PUSH NORTHEAST ACROSS THE GREAT
PLAINS AND GREAT LAKES REGION OVER THE NEXT 24 HOURS AS A PACIFIC
COLD FRONT SLOWLY MOVES EASTWARD INTO CENTRAL WYOMING. THIS FRONT IS
NOT EXPECTED TO PUSH INTO EASTERN WYOMING UNTIL SUNDAY MORNING.
HAZARDS/WEATHER TRENDS: VFR CONDITIONS EXPECTED OVER THE NEXT 24
HOURS UNDER MOSTLY CLEAR SKIES. BREEZY CONDITIONS ARE EXPECTED
TONIGHT FOR KLAR AND KRWL WITH SOUTHWEST WINDS OCCASIONALLY GUSTING
UP TO 25 TO 30 KNOTS AT TIMES. DO NOT EXPECT IT TO BE BREEZY ALL
NIGHT WITH PERIODS OF LIGHTER WINDS EXPECTED. OTHERWISE, ANOTHER
ROUND OF WINDY CONDITIONS AFTER 15Z SATURDAY FOR ALL SOUTHEAST
WYOMING TERMINALS WITH SOUTH TO SOUTHWEST WINDS GUSTING UP TO 45
KNOTS, AND UP TO 25 KNOTS FOR THE WESTERN NEBRASKA TERMINALS. WINDS
ARE FORECAST TO EASE MID TO LATE AFTERNOON AFTER 21Z.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 6 PM MDT THIS EVENING FOR WYZ421>423-
425-427.
HIGH WIND WARNING UNTIL 9 AM MDT THIS MORNING FOR WYZ110-115.
NE...NONE.
SHORT TERM...TJT
LONG TERM...TJT/WFO CYS
AVIATION...TJT
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