109
FXUS65 KCYS 060505
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
1105 PM MDT SUN JUL 5 2026
KEY MESSAGES
- THIS AFTERNOON AND MONDAY WILL BE MAINLY DRY AND HOT AS AN
UPPER LEVEL RIDGE BUILDS OVER THE REGION, EXPECT HIGHS TODAY
AND AGAIN MONDAY TO TOP OUT IN THE MID 80S TO MID 90S.
- CONDITIONAL THUNDERSTORM CHANCES RETURN MONDAY THROUGH AT
LEAST THURSDAY IN RESPONSE TO INCREASING MOISTURE.
- A RIDGE BUILDS LATE IN THE LONG TERM, DRYING US OUT AND
PERHAPS BREAKING HEAT RECORDS.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 131 PM MDT SUN JUL 5 2026
AS WE START OFF THE SHORT TERM PERIOD, ENJOY THE BEAUTIFUL
AFTERNOON/EVENING UNDER A DOMINATING RIDGE OF HIGH PRESSURE. WITH
THIS, THERE WILL THERE BE PLENTIFUL SUNSHINE AS TEMPERATURES SOAR
INTO THE UPPER 80S PRIMARILY WEST OF I-25 AND LOWER TO UPPER 90S
EAST OF THE CORRIDOR. A QUICK LOOK AT WINDS FOR THIS AFTERNOON,
EXPECT GENERALLY LIGHT WINDS WEST OF THE LARAMIE RANGE AND A BIT
GUSTY BY THIS EVENING TO THE EAST AS A LOW-LEVEL JET RAMPS UP,
EXPECT WINDS 30 TO 40 MPH IN AND AROUND CHEYENNE AND PINE RIDGES.
NOT ONLY THIS, DUE TO AMPLE SUBSIDENCE AS A RESULT OF THE RIDGE,
CONVECTION WILL HAVE A HARD TIME TO GET STARTED, LET ALONE DEVELOP
THIS AFTERNOON. THIS IS CONFIRMED BY HI-RES GUIDANCE AS THE SUITE
ALL SHOWS, NOTHING, NO CONVECTIVE DEVELOPMENT.
ONTO MONDAY, THE AFOREMENTIONED LOW-LEVEL JET WILL WEAKEN AROUND
SUNRISE AS THE RIDGE PUSHES OFF TO THE EAST. AS THIS DOES THIS,
MOISTURE WILL SURGE BACK INTO PORTIONS OF THE CWA, PRIMARILY EAST OF
THE I-25 CORRIDOR, WITH DEWPOINTS BUMPING BACK UP INTO THE 40S AND
50S. AS THE RIDGE SHIFTS TO THE EAST, A WEAK SHORTWAVE WILL DROP
SOUTH AND CLIP NORTHERN PORTIONS OF THE CWA BY MONDAY AFTERNOON.
THIS ENERGY COUPLED WITH THE ADDED MOISTURE WILL HELP INCREASE
CHANCES OF ISOLATED SHOWERS AND THUNDERSTORMS. DUE TO WEAK
CONVECTIVE PARAMETERS, ANY THUNDERSTORM ACTIVITY SHOULD REMAIN SUB-
SEVERE. EVEN THOUGH, WITH ANY SHOWER AND/OR THUNDERSTORM, GUSTY
OUTFLOWS WILL STILL BE A THREAT. SHIFTING TO TEMPERATURES, EXPECT
ANOTHER HOT DAY AS TEMPS SOAR A FEW DEGREES WARMER THAN SUNDAY WITH
HIGHS TOPPING OUT NEAR 90 FOR MOST AREAS WEST OF I-25 AND LOW TO
UPPER 90S EAST OF I-25, WITH A FEW LOCATIONS ACROSS THE NEBRASKA
PANHANDLE FLIRTING WITH THE CENTURY MARK.
LONG TERM /TUESDAY THROUGH SUNDAY/
ISSUED AT 131 PM MDT SUN JUL 5 2026
THE LONG TERM FEATURES SOME STORM CHANCES TO START OFF THE PERIOD
AND A SLIGHT COOLING TREND AS MONSOONAL MOISTURE ADVECTS IN FROM THE
WEST. BY NEXT WEEKEND THE RIDGE OVER THE FOUR CORNERS REGION MAY
STRENGTHEN PUSHING TEMPERATURES TOWARDS ALL TIME RECORD HIGHS.
PWATS TUESDAY ARE EXPECTED TO ANOMALOUSLY HIGH AT ABOUT +1.0 TO +2.0
SIGMA VALUES ABOVE NORMAL. THIS MONSOONAL MOISTURE AND AN UPPER
LEVEL SHORTWAVE WILL FLATTEN THE RIDGE AND INCREASE OUR THUNDERSTORM
CHANCES IN THE AFTERNOON. THE THERMO PROFILES AT PEAK DAYTIME
HEATING SHOW A SIGNIFICANT DEWPOINT AND AIR TEMPERATURE SPREAD OF
ALMOST 50 DEGREES. BULK WIND SHEAR IS LIKELY TO BE ON THE LOW SIDE
(BELOW 30 KNOTS) WHICH WOULD FAVOR MULTICELLULAR AND PULSE TYPE
STORMS CAPABLE OF DRY MICROBURST WINDS. DESPITE THE HIGH PWAT
VALUES, AND WITH THE SUB CLOUD LAYER BEING SO DRY, THESE STORMS ARE
NOT GOING TO BE EFFICIENT RAINFALL MAKERS. ADDITIONALLY, DRY
LIGHTNING POTENTIAL COULD BE CONCERN. MINIMUM RELATIVE HUMIDITY
VALUES IN THE AFTERNOON WILL DIP INTO THE TEENS AND LOWER 20S
LEADING TO ELEVATED WILDFIRE CONDITIONS.
WEDNESDAY AND THURSDAY FEATURE MUCH THE SAME WEATHER AS TUESDAY. THE
MOISTURE DOES POTENTIALLY INCREASE SOME ALLOWING MORE WIDESPREAD
PRECIPITATION CHANCES. WIND SHEAR DOES INCREASE, SO WE MAY SEE A FEW
MORE ORGANIZED STORMS WITH HAIL AND WIND THREATS. THE INCREASED
CLOUD COVERAGE AND STORMS MAY KEEP MOST OF THE REGION UNDER 90
DEGREES. THIS WILL BE POSSIBLY THE LAST GOOD CHANCE WE GET FOR
RAINFALL FOR SOME TIME AS THE RIDGE BUILDS OVER THE AREA. ENSEMBLE
MEMBERS HAVE THIS RIDGE REACHING SOME 8 TO 10 DECAMETERS ABOVE
CLIMATOLOGICAL AVERAGE. DETERMINISTIC MODELS HAVE UP TO 15 TO 18
DECAMETERS ABOVE AVERAGE. SUCH A STRONG RIDGE WILL CREATE
SIGNIFICANT SUBSIDENCE IN THE LOWER LEVELS, WARMING AND DRYING US
OUT. RELATIVE HUMIDITY VALUES IN THE SINGLE DIGITS AND TEMPERATURES
OVER 100 ARE CERTAINLY POSSIBLE OVER THE WEEKEND EAST OF I-25.
CRITICAL FIRE WEATHER WOULD ARISE FROM THESE CONDITIONS AND
RECEPTIVE FUELS. WHILE A WAYS OUT, THERE IS A POSSIBILITY THAT ALL
TIME RECORD HIGHS ARE BROKEN SUNDAY OR MONDAY AT A FEW LOCATIONS. IF
THE RIDGE CENTER SHIFTS TO OUR EAST WE ALSO HAVE A DOWNSLOPING
EFFECT THAT WOULD NUDGE TEMPERATURES UP A FEW DEGREES. HOPEFULLY THE
RIDGE ENDS UP NOT AS INTENSE AS MODELS ARE SUGGESTING.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1103 PM MDT SUN JUL 5 2026
VFR CONDITIONS ANTICIPATED FOR THE 06Z TAF PERIOD WITH GUSTY
WINDS SLOWLY DECREASING OVERNIGHT. KCDR WILL REMAIN QUITE GUSTY
OVERNIGHT WITH CONTINUING GUSTS BETWEEN 25 AND 30KTS. WINDS WILL
INCREASE AFTER AROUND 15Z FOR MOST TERMINALS. ISOLATED TO
SCATTERED SHOWERS AND STORMS MAY IMPACT TERMINALS IN THE
AFTERNOON. GUSTY AND ERRATIC WINDS ARE EXPECTED IN AND AROUND
ANY SHOWER OR STORM THE DEVELOPS IN THE AFTERNOON.
CYS WATCHES/WARNINGS/ADVISORIES
WY...NONE.
NE...NONE.
SHORT TERM...RZ
LONG TERM...RV
AVIATION...AM
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