387
FXUS65 KCYS 171133
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
533 AM MDT SAT OCT 17 2026
KEY MESSAGES
- A HIGH WIND WARNING IS IN EFFECT FOR THE USUAL SOUTHEAST
WYOMING WIND PRONE AREA, ARLINGTON AND BORDEAUX. WIND GUSTS OF
55 TO 65 MPH ARE POSSIBLE.
- DRIER AND MILDER WEATHER EXPECTED THIS WEEKEND INTO EARLY NEXT
WEEK.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 237 AM MDT SAT OCT 17 2026
THIS WEEKEND WILL BE RATHER DRY BUT SEASONABLE. AN UPPER LEVEL RIDGE
BEGINS TO BUILD OVER US SUPPRESSING ANY WEATHER CONCERNS THIS
WEEKEND. AN AREA OF HIGH PRESSURE WILL BE SETTING UP NEAR THE
NORTHWEST CORNER OF COLORADO INCREASING THE PRESSURE GRADIENT OVER
THE MOUNTAINS AND HIGHER ELEVATIONS. THERE IS A HIGH WIND WARNING
OUT STARTING AT 6AM AND WILL END AT 7PM TODAY FOR THE WIND PRONE
AREAS NEAR ARLINGTON ALONG I-80 AND BORDEAUX ALONG I-25. LOOKING AT
THE GLOBAL OMEGA FIELDS, THEY STILL RESEMBLE A WEAK MOUNTAIN WAVE
LIKE STRUCTURE WITH DOWNWARD OMEGAS OVER THE WIND PRONES THROUGHOUT
THE DAY. WESTERLY WINDS WILL AIDE IN DRYING OUT THE LAYER NEAR THE
SURFACE ESPECIALLY IN THE SOUTHERN HALF OF THE FORECAST AREA. RH
VALUES WILL PLUMMET INTO THE TEENS DURING THE LATE MORNING AND
AFTERNOON, HOWEVER THE WINDS WON'T NECESSARILY BE THERE IN THE AREAS
WITH CRITICAL FUELS. UPWARD OMEGAS WILL ACT AS SHIELD PRESERVING THE
STRONG INVERSION THAT SET UP OVER THE LOWER ELEVATIONS EAST OF I-25,
LIKELY LEADING TO LIGHTER WINDS THAT DONT MEET OR EXCEED 25 MPH.
DOWNWARD MOTION DOESN'T REALLY SET UP OVER THE LOWER ELEVATIONS
UNTIL 21Z LOOKING AT MODEL GUIDANCE BY WHICH THE AREAS WILL ALREADY
BE STARTING TO RECOVER AND MAY NOT BE IN CRITICAL TERRITORY ANYMORE.
SO A RED FLAG WARNING WAS NOT ISSUED FOR OUR SOUTHERN HALF OF THE
FORECAST AREA. LOOKING AT MID-LEVEL WATER VAPOR A CONSTANT MIX OF
WATER VAPOR AND DRY AIR WILL BE ADVECTING INTO THE INTERMOUNTAIN
WEST KEEPING RH VALUES POSSIBLY OUT OF RED FLAG CRITERIA ESPECIALLY
SINCE THE WINDS WON'T BE AS STRONG SUNDAY. 700MB TEMPERATURES WILL
BE RANGING FROM 6 TO 11C WHICH TRANSLATES TO SURFACE TEMPERATURES IN
THE 60'S AND LOW 70'S THIS WEEKEND GIVING US A NICE FALL LIKE
FEELING WITH THESE CLEAR SKIES. OVERNIGHT TEMPERATURES WON'T CRASH
OUT LIKE THEY DID LAST NIGHT DUE TO OUR WESTERLY DOWNSLOPING WINDS
KEEPING THE TEMPERATURES IN THE CRISP 30'S AND 40'S WITH THE
POSSIBILITY OF REACHING 50 DEGREES IN SOME AREAS.
LONG TERM /MONDAY THROUGH FRIDAY/
ISSUED AT 325 PM MDT FRI OCT 16 2026
MOSTLY BENIGN CONDITIONS TO START THE WORK WEEK IN THE LONG
TERM, BUT THIS PATTERN SHOULD BEGIN TO BE BROKEN UP BY A DEEP
PACIFIC SYSTEM THAT WILL ENCROACH OUR REGION BY THE END OF THE
FORECAST PERIOD. MONDAY STARTS WITH HIGH PRESSURE RIDGING MOSTLY
HOLDING CONTROL OF OUR FORECAST AREA, BUT A WEAKENING UPPER
LEVEL LOW WILL MOVE ACROSS THE FOUR CORNERS REGION AND THEN JUST
TO OUR SOUTHEAST THROUGH TUESDAY AFTERNOON. WHILE MOSTLY NON-
IMPACTFUL, THIS FEATURE WILL AT LEAST BRING A VERY LOW END
CHANCE OF SOME HIGH ELEVATION PRECIPITATION, ALONG WITH A SMALL
BUMP IN MOISTURE. THIS INFLUX OF MOISTURE WILL CONTINUE THROUGH
THE REST OF THE WEEK AS OUR UPPER LEVEL FLOW TURNS SOUTHWESTERLY
WHILE WE SIT BETWEEN HIGH PRESSURE CONTROLLING THE SOUTHEASTERN
US AND A DEEP PACIFIC SYSTEM THAT WILL MOVE INLAND BY LATER
WEDNESDAY INTO THURSDAY. THIS FEATURE WILL BE THE NEXT
NOTEWORTHY SYSTEM TO IMPACT THE FORECAST AREA AS WE SEE
PRECIPITATION BEGIN OVERSPREADING LATE THURSDAY INTO FRIDAY AND
START ANOTHER COOLING TREND THAT SHOULD PERSIST INTO THE
WEEKEND. FOR THIS FORECAST PERIOD, EXPECT MOSTLY SIMILAR
TEMPERATURES DAY TO DAY AS HIGHS WILL BE AROUND 6 TO 12 DEGREES
ABOVE NORMAL, GENERALLY IN THE 60'S TO 70'S, WITH LOWS SIMILARLY
WARM IN THE 40'S. ANY DROP IN TEMPERATURES WOULD OCCUR JUST
BEYOND THE LONG TERM AFTER THE PACIFIC SYSTEM MOVES IN, AND THE
MOST IMPACTFUL PRECIPITATION CHANCES SIMILARLY JUST BEYOND THIS
FORECAST TIME AS WELL. OVERALL IT SHOULD BE A QUIET PERIOD, BUT
THAT WILL BE ENDING BY THE WEEKEND AFTER NEXT.
AVIATION /12Z TAFS THROUGH 12Z SUNDAY/
ISSUED AT 533 AM MDT SAT OCT 17 2026
MAX WIND GUSTS AROUND 30 KNOTS ARE EXPECTED AFTER 15Z FOR KRWL
BUT ARE EXPECTED TO DIE DOWN AFTER 06Z DUE TO THE TIGHT PRESSURE
GRADIENT FROM A SURFACE HIGH DEVELOPING OVER NORTHWEST COLORADO.
AFTER 18Z WINDS ARE EXPECTED TO START GUSTING FOR KCYS AND THE
NEBRASKA TERMINALS. WIND GUSTS OVER 20 KNOTS AREN'T EXPECTED FOR
THESE AREAS. SOME LOW LEVEL WIND SHEAR MAY BE PRESENT NEAR KEAN
AND KTOR AROUND 2,000 FT DUE TO THE HIGH WINDS ALONG I-25 SOUTH
OF KEAN. NO OTHER WEATHER HAZARDS ARE EXPECTED TODAY WITH VFR
CONDITIONS EXPECTED FOR THE NEXT 48 HOURS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING UNTIL 7 PM MDT THIS EVENING FOR WYZ106-110.
NE...NONE.
SHORT TERM...MM
LONG TERM...CG
AVIATION...MM
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