937
FXUS65 KCYS 151103
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
503 AM MDT WED JUL 15 2026
KEY MESSAGES
- HOT, DRY AND BREEZY CONDITIONS EXPECTED THROUGH THE END OF THE
WEEK.
- MONSOON FLOW IN THE LONG TERM INTENSIFIES, LOWERING OUR
AFTERNOON HIGHS AND INCREASING RAIN CHANCES.
SHORT TERM /THROUGH THURSDAY NIGHT/
ISSUED AT 124 AM MDT WED JUL 15 2026
HOT AND DRY CONDITIONS ARE EXPECTED TO CONTINUE FOR THE FORESEEABLE
FUTURE AS A STOUT, UPPER-LEVEL RIDGE REMAINS FIRMLY IN PLACE ACROSS
THE CONUS. THE 500MB RIDGE REMAINS LARGELY UNCHANGED FOR THE NEXT
COUPLE OF DAYS, THOUGH THE 595DM 500MB HIGH ACROSS THE EAST COAST
ATTEMPTS TO STRETCH NORTHWESTWARD TOWARDS THE REGION. LUCKILY, IF
THAT IS EVEN THE PROPER TERM, THIS HIGH SHOULD REMAIN JUST TO OUR
EAST WITH A "MEASLY" 591DM HIGH ACROSS THE INTERMOUNTAIN WEST.
THERE ARE SOME HINTS AT THE MONSOON ATTEMPTING TO DEVELOP, THOUGH
MUCH OF THE MOISTURE LOOKS TO REMAIN WELL SOUTH OF THE CWA FOR THE
NEXT SEVERAL DAYS. UNSURPRISINGLY, 700MB TEMPERATURES WILL REMAIN IN
THE 12 TO 15C RANGE WEDNESDAY, WITH THURSDAY STARTING TO SEE 15 TO
20C TEMPERATURES RETURNING TO THE REGION. AS A RESULT, SURFACE
TEMPERATURES WILL RISE BACK INTO THE UPPER-80S TO LOW-100S ONCE
AGAIN BOTH WEDNESDAY AND THURSDAY, AND LIKELY MOST DAYS THROUGH THE
WEEKEND AS WELL. MOSTLY CLEAR SKIES WILL PERSIST UNDER THIS STRONG
RIDGE, LEADING TO SUNNY, HOT, AND DRY CONDITIONS. LITTLE TO NO
PRECIPITATION IS EXPECTED OUTSIDE OF THE MOUNTAIN FOR THE NEXT TWO
DAYS, WITH THE MOUNTAINS ONLY SEEING A SLIGHT CHANCE (~15%) FOR
PRECIPITATION THURSDAY AFTERNOON. HOWEVER, LESS THAN 0.01IN OF
PRECIPITATION IS POSSIBLE FOR THE MOUNTAINS THURSDAY. "BETTER"
PRECIPITATION CHANCES RETURN TOWARDS THE END OF THE WEEK INTO THE
WEEKEND, BUT STILL REMAIN RATHER LOW. WINDS WILL REMAIN FAIRLY
BREEZY TODAY AND THURSDAY, LEADING TO SLIGHTLY "COOLER" HIGHS FOR
THE CHEYENNE AREA DUE TO COOLER, SOUTHERLY FLOW FROM UPSLOPE ALONG
THE CHEYENNE RIDGE. HOWEVER, THE HEAT ADVISORY REMAINS IN EFFECT
THROUGH MIDNIGHT TONIGHT, AS OVERNIGHT LOWS ONLY DROP INTO THE MID-
50S TO MID-60S TONIGHT AND MID-50S TO LOW-70S THURSDAY MORNING.
EXTENSIONS MAY BE NEEDED FOR THE HEAT ADVISORY, BUT WILL LET THE
DAYTIME SHIFT TAKE ANOTHER LOOK. WITH HOT, DRY, AND BREEZY
CONDITIONS, THE RED FLAG WARNING REMAINS IN EFFECT THROUGH THE DAY
TODAY. SLIGHT HUMIDITY IMPROVEMENTS ARE POSSIBLE THURSDAY AFTERNOON,
THOUGH ELEVATED FIRE CONDITIONS ARE STILL EXPECTED.
LONG TERM /FRIDAY THROUGH TUESDAY/
ISSUED AT 124 AM MDT WED JUL 15 2026
NO MAJOR CHANCES, PLEASE SEE PREVIOUS FORECAST DISCUSSION...
THE RIDGE IS STILL DOMINATING THE WEATHER AT THE START OF THE LONG
TERM, THOUGH IT APPEARS THAT IT WILL BE WEAKENING SLIGHTLY COMPARED
TO WHAT IT WAS THIS PAST WEEKEND. A RETROGRADING CUT OFF LOW TO OUR
SOUTH WILL LOWER DAM HEIGHTS OVERHEAD AND ELONGATE THE RIDGE AXIS.
MONSOONAL MOISTURE STREAMING IN ON THE WESTERN EDGE OF THE RIDGE
WILL REACH THE AREA AND MAY PROMOTE A FEW SHOWERS AND STORMS,
PARTICULARLY FOR HIGHER ELEVATIONS NEAR THE SNOWY AND SIERRA MADRE
RANGES AND POINTS WEST. THE MEAN FLOW WILL CAUSE STORMS TO DRIFT
SOUTHWEST. HIGH TEMPERATURES IN THE 90S TO LOW 100S AND CLEAR SKIES
ARE MOST LIKELY FOR THE MAJORITY OF US. HUMIDITY VALUES WILL BE LOW
FOR MOST OF THE AREA, BUT THANKFULLY WINDS WILL NOT BE VERY STRONG
AND VALUES DON'T STAY BELOW 15 PERCENT LONG ENOUGH TO WARRANT A RED
FLAG WARNING AT THIS TIME. HOWEVER, CONDITIONS WOULD SUGGEST
ELEVATED FIRE CONCERNS.
THIS TYPE OF PATTERN HOLDS FOR THE NEXT FEW DAYS. THE RIDGE BUILDS
SLIGHTLY AS THE UPPER LEVEL LOW SLOWLY DECAYS WELL TO OUR SOUTH.
DAILY AFTERNOON SHOWERS AND STORMS IN THE MOUNTAINS AND WESTERN
COUNTIES OF OUR CWA ARE POSSIBLE. TEMPERATURES CLIMB SLIGHTLY EACH
DAY WITH MORE PLACES HITTING THE 100S EAST OF I-25, WITH SATURDAY
AND SUNDAY APPEARING TO BE THE HOTTEST DAYS. ELEVATED FIRE WEATHER
CONTINUES.
THE MONSOONAL FLOW CONTINUES TO BE ADVECTED NORTH FROM THE PACIFIC
OCEAN DURING THIS TIME. INTERESTINGLY OUR WEATHER COULD BE
INFLUENCED BY TROPICAL CYCLONE ACTIVITY STARTING MONDAY. A
DISTURBANCE IS FORMING IN THE EAST PACIFIC WHICH COULD MATURE AND
MOVE NORTHWEST AHEAD OF UPPER LEVEL TROUGHING OFF THE WEST COAST.
MOISTURE FROM THIS CYCLONE WOULD THEN BE CHANNELED NORTH IN THIS
TROUGHING FLOW AND ADD TO THE MONSOON. THIS IS DEPENDENT ON THE
TRACK OF THE FUTURE SYSTEM AND WOULD ONLY IMPACT THE AVAILABLE
MOISTURE CONTENT OF THE MONSOON AND JET POSITIONS FOR OUR AREA. THE
DETERMINISTIC GFS IS PRODUCING WIDESPREAD PWATS OF ABOVE 1 INCH
STARTING MONDAY. WHILE AN IMPERFECT PROXY TO GAUGING THE MAGNITUDE
OF THIS MOISTURE, WE TURN TO THE RIVERTON PWAT CLIMATE FOR THIS
PERIOD. THE MAXIMUM MEASURED PWAT FOR THIS TIME IS BETWEEN 1.10 AND
1.20 INCHES. THE GFS IS GIVING PWATS OF 1.10 INCHES FOR THE RAWLINS
AREA. SO IN OTHER WORDS THE ATMOSPHERE WILL BE HOLDING AN
ANOMALOUSLY HIGH AMOUNT OF MOISTURE. STORMS AND SHOWERS CHANCES
NATURALLY INCREASE WITH ALL THIS AMBIENT MOISTURE. SOME OF THESE
STORMS COULD PRODUCE HEAVY RAINS. THE WPC HAS MARGINAL EXCESSIVE
RAINFALL OUTLOOKS FOR AREAS WEST WITH THE CURRENT MONSOONAL FLOW, SO
IT WOULD NOT BE THAT FAR OF A STRETCH THAT FUTURE OUTLOOKS COVER OUR
AREA AS WELL FOR THIS PERIOD. WITH INCREASING MOISTURE THE EXTRA
CLOUD COVERAGE WILL KEEP AFTERNOON TEMPERATURES IN CHECK WITH
HOPEFULLY MOST LOCATIONS STAYING BELOW 100. THIS MOISTURE IS
EXPECTED TO LINGER INTO TUESDAY, SO MUCH THE SAME WEATHER CAN BE
EXPECTED THEN.
AVIATION /12Z TAFS THROUGH 12Z THURSDAY/
ISSUED AT 503 AM MDT WED JUL 15 2026
VFR CONDITIONS ANTICIPATED FOR THE 12Z TAF PERIOD WITH CLEAR SKIES
THROUGHOUT MUCH OF THE DAY. A BRIEF PERIOD OF LOW-LEVEL WIND SHEAR
IS POSSIBLE AT KBFF THIS MORNING, BUT BEGINS TO DIMINISH AS STRONGER
SURFACE WINDS RETURN. GUSTY WINDS RETURN FOR THE LATE-MORNING HOURS
WITH MOST TERMINALS SEEING GUSTS 25 TO 30KTS. GUSTY CONDITIONS WILL
TAPER OFF AFTER SUNSET WITH STOUT SUSTAINED WINDS AROUND 15KTS
EXPECTED TO DEVELOP AT MOST TERMINALS FOR THE OVERNIGHT HOURS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR WYZ417>420-
423-427-430>433.
HEAT ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR WYZ101-102-107-
108-118-119.
NE...RED FLAG WARNING UNTIL 8 PM MDT THIS EVENING FOR NEZ434>437.
HEAT ADVISORY UNTIL MIDNIGHT MDT TONIGHT FOR NEZ002-003-
019>021-054-055-095-096.
SHORT TERM...AM
LONG TERM...AM/RV
AVIATION...AM
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