786
FXUS65 KCYS 121131
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
531 AM MDT SUN JUL 12 2026
KEY MESSAGES
- STRONG RIDGING ALOFT WILL PRODUCE A DRY AND HOT PERIOD FOR
TODAY THROUGH TUESDAY, WITH THE PRIMARY CHALLENGES BEING THE
ABOVE NORMAL HEAT AND FIRE WEATHER CONDITIONS.
- ISOLATED HIGH-BASED THUNDERSTORMS POSSIBLE ON WEDNESDAY
THROUGH THE END OF THE WEEK, ALONG WITH A SLOW COOLING TREND.
TEMPERATURES WILL REMAIN ABOVE NORMAL THOUGH.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 233 AM MDT SUN JUL 12 2026
WELCOME READERS TO ANOTHER DAY WHERE WE GET TO PLAY ARE WE GOING TO
REACH CONVECTIVE TEMPERATURE OR NOT! THE UPPER LEVEL RIDGE WILL
REMAIN PARKED OVER THE INTERMOUNTAIN WEST TODAY KEEPING THE SKIES
RELATIVELY CLEAR FOR THE BETTER PART OF THE DAY. THE HIGH
TEMPERATURES WILL ONCE AGAIN BE IN THE 90'S TO 100'S TODAY. RH
VALUES WILL FLOAT BETWEEN 5 TO 15 PERCENT IN SOUTHEAST WYOMING AND
BETWEEN 15 AND 25 FOR THE NEBRASKA PANHANDLE. THIS MEANS WHEN YOU'RE
OUTSIDE IT WILL BE A DRY HEAT AND WONT REALIZE YOU ARE SWEATING
ESPECIALLY IF YOU'RE IN CARBON COUNTY WHERE THE LOWEST RH VALUES ARE
FORECASTED. YOUR BODY WILL CONSTANTLY COOL YOURSELF THROUGH
EVAPORATIVE COOLING LEADING YOU TO DEHYDRATE FASTER. BECAUSE OF
THESE HIGH SUMMER TEMPERATURES THE HEAT ADVISORY WILL REMAIN IN
PLACE ESPECIALLY SINCE LARAMIE, WY WAS PRETTY MUCH THE ONLY PLACE TO
DROP BELOW 70 DEGREES BEFORE MIDNIGHT-1AM. A WEAK SHORTWAVE WILL BE
MOVING THROUGH THE REGION TODAY GIVING US SOME GUSTY WINDS THAT MAY
HELP YOU FEEL LIKE YOU'RE COOLING OFF OR POSSIBLY FEELING LIKE YOUR
IN AN AIR DRYER IN THESE HOT CONDITIONS. THE LOW RH VALUES AND
BREEZY WINDS TODAY ARE THE REASON A RED FLAG GOES INTO EFFECT THIS
AFTERNOON AND ALSO A REASON TO JUST PUT DOWN THE MATCHES AND
LIGHTERS BECAUSE IF THE FUELS AREN'T ALREADY CRITICAL (80 PERCENT OF
OUR FORECAST AREA) THEY PROBABLY WILL BE IN A COUPLE DAYS. THE RED
FLAG EXPIRES MONDAY EVENING AS THESE DRY CONDITIONS ARE EXPECTED TO
PERSIST THROUGH WEDNESDAY, IT WILL PROBABLY BE REISSUED COME MONDAY
NIGHT. NOW WHERE THE CONVECTIVE TEMPERATURE COMES IN, IF THE
SHORTWAVE COMES THROUGH DURING THE TIME WHERE WE HIT THE CONVECTIVE
TEMPERATURE WE WILL GET A FEW CLOUDS AND PROBABLY SOME BRIEF
SHOWERS. HOWEVER WITH THE SOUNDINGS HAVING THE TEMPERATURE AND
DEWPOINT SO FAR APART YOU CAN LAND A C-130 ON IT, THE PRECIP WILL
PROBABLY NOT REACH THE GROUND AND YOU WILL JUST GET VIRGA AND
GUSTIER WINDS UNDERNEATH THEM. SO TODAY, DO EMS A FAVOR AND HYDRATE
AND EAT SOME LIGHT SNACKS SO YOU KEEP NUTRIENTS AND VITAMINS IN YOUR
BODY TO PREVENT WATERLOGGING YOUR BODY AND HEAT RELATED
INJURIES.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 123 PM MDT SAT JUL 11 2026
THE WEATHER OVER THE MEDIUM TO LONG RANGE WILL BE DOMINATED BY
THE QUASI-STATIONARY UPPER LEVEL HIGH, FORECAST TO REMAIN OVER
THE SOUTH-CENTRAL TO CENTRAL UNITED STATES, INCLUDING THE ROCKY
MOUNTAIN REGION. TO PUT IT IN PERSPECTIVE, MODELS SHOW THE
POSITION OF THE UPPER LEVEL HIGH (CENTER) DRIFTING WESTWARD BY A
FEW HUNDRED MILES FROM MONDAY TO NEXT SATURDAY. THEREFORE, NOT
EXPECTING CONDITIONS TO CHANGE TOO MUCH THROUGH NEXT WEEK.
FOR EARLY IN THE WEEK, BROAD CENTER OF THE 600DM UPPER LEVEL
HIGH WILL BE GENERALLY LOCATED IN THE CENTRAL ROCKY MOUNTAIN
REGION EXTENDING NORTHEAST INTO THE GREAT LAKES REGION. GFS AND
ECMWF STANDARDIZED 500MB ANOMALIES SHOW BETWEEN 1-3 SD'S ABOVE
AVERAGE...WHICH IS PRETTY IMPRESSIVE SINCE WE'RE CURRENTLY
ENTERING THE HOTTEST WEEK OF THE YEAR...CLIMATOLOGICALLY
SPEAKING. FORECAST HIGH TEMPERATURES WILL BE 90S FOR MOST OF
SOUTHEAST WYOMING, INCLUDING THE HIGH VALLEYS WEST OF THE
LARAMIE RANGE. FOR WESTERN NEBRASKA, 95 TO 105 EXPECTED EACH
DAY. THERE MAY BE SOME SILVERING LINING FOR THE SOUTH FACING
RIDGES. DUE TO SOUTH TO SOUTHEASTERLY WINDS, SOME LOCALIZED
UPSLOPE MAY PREVENT TEMPERATURES FROM CLIMBING EVEN HIGHER. KEPT
TEMPERATURES A FEW DEGREES COOLER (COMPARED TO THE SURROUNDING
AREAS) IN THESE LOCATIONS, WHICH INCLUDE CHEYENNE, KIMBALL,
SIDNEY, ALLIANCE, AND LUSK. HOWEVER, ANY WESTERLY WIND SHIFT OR
LIGHT AND VARIABLE WINDS WILL RESULT IN A RAPID WARM-UP.
AS WE HEAD INTO LATER IN THE WEEK, CENTER OF THE UPPER LEVEL
HIGH WILL DRIFT OVERHEAD, AND EVEN RETROGRADE WESTWARD A BIT.
ALTHOUGH WINDS WILL REMAIN OUT OF THE SOUTHEAST, OR SHIFT INTO
THE EAST DURING THIS TIME, WIND SPEEDS WILL DECREASE OR BECOME
LIGHT AND VARIABLE. THIS MAY ACTUALLY LEAD TO THE HOTTEST
TEMPERATURES OVER THE SOUTH FACING RIDGES. OTHERWISE,
TEMPERATURES WILL BE A FEW DEGREES COOLER ACROSS MOST OF THE
AREA...ALTHOUGH IT WILL BE HARDLY NOTICEABLE. ENSEMBLES AND NBM
75TH TO 90TH PERCENTILE SHOW HIGH TEMPERATURES ONLY A FEW
DEGREES HIGHER THAN THE CURRENT FORECAST, SO KEPT HIGH
TEMPERATURES CLOSE TO THE 50TH PERCENTILE OF THE NBM. LOW
CONFIDENCE ON ANY PRECIPITATION DURING THIS TIME. SUBTROPICAL
MONSOON MOISTURE IS EXPECTED TO CREEP NORTH OUT OF MEXICO AND
THE SOUTHWESTERN US. HOWEVER, THE POSITION OF THE UPPER LEVEL
HIGH OVERHEAD MAY RESULT IN THE MONSOON MOISTURE PLUME OVER
IDAHO, UTAH, AND WESTERN WYOMING. THEREFORE, MOST OF THE MENTION
OF POP AND THUNDERSTORMS WILL BE LIMITED TO THE MOUNTAINS AND
ADJACENT VALLEYS FOR NOW THROUGH NEXT SATURDAY.
AVIATION /12Z TAFS THROUGH 12Z MONDAY/
ISSUED AT 531 AM MDT SUN JUL 12 2026
VFR CONDITIONS WILL REMAIN THROUGH THE TAF PERIOD. WIND GUSTS
ARE EXPECTED TO PICK UP AROUND 18Z TODAY AND AFTER 00Z WINDS
WILL RAMP UP WITH GUSTS BETWEEN 25 AND 30 KTS. THE LOW LEVEL
JET IS EXPECTED TO SUSTAIN THESE HIGHER WINDS OVERNIGHT. KBFF IS
LIKELY TO HAVE LOW LEVEL WINDSHEAR AROUND 35KTS AT 08Z AND
CONTINUE UNTIL AROUND 12Z.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HEAT ADVISORY UNTIL MIDNIGHT MDT TUESDAY NIGHT FOR WYZ101-102-
107-108-118-119.
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT MONDAY FOR
WYZ417>420-423-427-430>433.
NE...HEAT ADVISORY UNTIL MIDNIGHT MDT TUESDAY NIGHT FOR NEZ002-003-
019>021-054-055-095-096.
RED FLAG WARNING FROM NOON TODAY TO 8 PM MDT MONDAY FOR NEZ434.
SHORT TERM...MM
LONG TERM...TJT
AVIATION...MM
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