890
FXUS65 KCYS 140809
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
209 AM MDT SUN JUN 14 2026
KEY MESSAGES
- ANOTHER COOL AND BREEZY DAY EXPECTED SUNDAY AS DAYTIME HIGH
TEMPERATURES ONLY REACH THE 60S FOR MOST LOCATIONS.
- A FIRE WEATHER WATCH HAS BEEN ISSUED FOR PORTIONS OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA FROM NOON TO 9 PM ON MONDAY.
- FIRE WEATHER CONCERNS CONTINUE TUESDAY THROUGH AT LEAST
FRIDAY, WITH DRY, BREEZY CONDITIONS AND VERY WARM
TEMPERATURES. MINIMAL PRECIPITATION EXPECTED DURING THIS TIME.
- HIGH WIND EVENT IS LOOKING INCREASINGLY LIKELY FOR TUESDAY
INTO WEDNESDAY FOR THE WIND PRONE REGIONS OF SOUTHEAST
WYOMING.
SHORT TERM /THROUGH MONDAY NIGHT/
ISSUED AT 208 AM MDT SUN JUN 14 2026
A MUCH COOLER DAY IS IN STORE FOR SOUTHEAST WYOMING AND WESTERN
NEBRASKA TODAY, DUE TO TWO SEPARATE COLD FRONT THAT MOVED ACROSS THE
REGION YESTERDAY. UPPER-LEVEL FLOW REMAINS LARGELY ZONAL AS THE BASE
OF THE UPPER-LEVEL SHORTWAVE TRAVERSES NORTHWEST TO SOUTHEAST ACROSS
THE WESTERN DAKOTAS. THIS SHORTWAVE WILL FUNNEL COOLER, CANADIAN AIR
INTO THE CWA WITH 700MB TEMPERATURES IN THE -1 TO 3C RANGE
THROUGHOUT THE DAY TODAY. AS A RESULT, SURFACE TEMPERATURES WILL BE
MUCH COOLER WITH HIGHS ONLY IN THE 60S ACROSS THE ENTIRE REGION,
WITH 50S IN THE HIGHER ELEVATIONS. WITH THE COOLER, MORE DENSE, AIR
ACROSS THE REGION A SURFACE HIGH PRESSURE IS PROGGED TO DEVELOP OVER
NORTHEASTERN PORTIONS OF THE CWA AND ADVECT SOUTHEASTERLY ACROSS THE
CWA. AS A RESULT, INCREASING SURFACE PRESSURE GRADIENTS ARE
ANTICIPATED LEADING TO BREEZY CONDITIONS WEST OF THE LARAMIE RANGE
AND ALONG INTERSTATE 80 THIS MORNING INTO THE AFTERNOON HOURS. AN
ISOLATED SHOWER CANNOT BE COMPLETELY RULED OUT THIS MORNING INTO THE
AFTERNOON HOURS WHERE EASTERLY, MOIST, UPSLOPE FLOW IN ONGOING, BUT
SIGNIFICANT PRECIPITATION IS NOT ANTICIPATED DUE TO THE DRIER LOW-
LEVELS. WITH THE EASTERLY AND NORTHERLY WINDS ANTICIPATED THROUGHOUT
THE DAY TODAY, SOME SMOKE FROM THE WILD FIRE IN NORTHERN SIOUX
COUNTY MAY LEAD TO A SMOKEY SMELL IN THE AREA, BUT SIGNIFICANT
VISIBILITY REDUCTIONS FROM SMOKE ARE NOT EXPECTED.
COOLER WEATHER COMES TO A QUICK END FOR MONDAY, AS VERY DRY
AFTERNOON HUMIDITY VALUES AND GUSTY WINDS RETURN TO THE REGION.
NORTHWESTERLY TO NORTHERLY FLOW ALOFT DEVELOPS FOR MONDAY LEADING TO
DRY, CONTINENTAL AIR FROM CANADA TO CONTINUE TO MOVE INTO THE
INTERMOUNTAIN WEST AS AN UPPER-LEVEL RIDGE BUILDS OFF THE WESTERN
COAST OF THE CONUS. 700MB FLOW WILL REMAIN LARGELY NORTHWESTERLY
THROUGHOUT THE DAY MONDAY WITH TEMPERATURES WARMING TO THE 8 TO 12C
RANGE ACROSS THE REGION. SURFACE TEMPERATURES ARE EXPECTED TO WARM
INTO THE MID-70S TO LOW-80S ACROSS THE CWA. BREEZY, NORTHWESTERLY
WINDS DEVELOP AT THE SURFACE MONDAY AFTERNOON AS SURFACE PRESSURE
GRADIENTS INCREASE TO A WEAK FRONT PUSHING THROUGH THE REGION. AS A
RESULT, HOT, DRY, AND WINDY CONDITIONS ARE EXPECTED MONDAY AFTERNOON
ALONG AND EAST OF THE LARAMIE RANGE. A FIRE WEATHER WATCH HAS BEEN
ISSUED FROM NOON MONDAY THROUGH 9 PM MONDAY EVENING FOR THE WESTERN
NEBRASKA PANHANDLE AND PORTIONS OF SOUTHEAST WYOMING, MAINLY NORTH
OF THE INTERSTATE-25 CORRIDOR. HUMIDITY WILL BE BORDERLINE CRITICAL
FOR LARAMIE COUNTY, SO DID NOT INCLUDE THIS REGION INTO THE FIRE
WEATHER WATCH. HOWEVER, SHOULD FORECAST HUMIDITY VALUES DECREASE
WITH FUTURE MODEL RUN, THE FIRE WEATHER WATCH MAY NEED TO BE
EXPANDED TO INCLUDE CENTRAL AND EASTERN LARAMIE COUNTY. OVERNIGHT
HUMIDITY RECOVERIES MONDAY INTO TUESDAY WILL BE GOOD, IN THE 50 TO
60 PERCENT RANGE ACROSS FIRE-PRONE AREAS.
LONG TERM /TUESDAY THROUGH SATURDAY/
ISSUED AT 208 AM MDT SUN JUN 14 2026
TUESDAY ONWARDS WILL BE LARGELY DOMINATED BY AN UPPER-LEVEL RIDGE
ACROSS THE WEST COAST AS IT SLOWLY MEANDERS ONSHORE BY WEDNESDAY
MORNING. LARGELY NORTHWESTERLY FLOW IS ANTICIPATED ACROSS THE CWA
WITH MORE ZONAL FLOW POTENTIALLY RETURNING FRIDAY INTO THE WEEKEND
AS LONG RANGE MODELS SUGGEST AN UPPER-LEVEL TROUGH MOVING ONSHORE
INTO THE PACIFIC NORTHWEST LATE FRIDAY INTO SATURDAY MORNING. THIS
PATTERN SHIFT WILL PROMOTE SOME ISOLATED TO SCATTERED PRECIPITATION
CHANCES FRIDAY INTO THE WEEKEND, BUT THE EXACT LOCATION OF THESE
SHOWERS IS UNCERTAIN AS THIS TIME. PRIOR TO THE PATTERN SHIFT FRIDAY
EVENING, WARM AND DRY WEATHER IS ANTICIPATED TUESDAY THROUGH FRIDAY
AFTERNOON. DAILY HIGH TEMPERATURES WILL BE IN THE 80S AND 90S
TUESDAY THROUGH FRIDAY, WITH A WEAK FRONT MOVING THROUGH THURSDAY
DROPPING HIGH TEMPERATURES INTO THE 70S AND 80S. WITH SYNOPTIC-SCALE
RIDGING IN PLACE FOR A MAJORITY OF THE WEEK, VERY DRY CONDITIONS ARE
EXPECTED WITH LITTLE TO NO PRECIPITATION CHANCES UNTIL FRIDAY
EVENING. DAILY AFTERNOON MINIMUM HUMIDITY VALUES WILL TANK INTO THE
10 TO 15 PERCENT RANGE, LEADING TO CRITICAL FIRE CONDITION FOR MUCH
OF THE WORK WEEK. ADDITIONALLY, WINDS WILL BE QUITE BREEZY MOST OF
THE WEEK, BUT ESPECIALLY WEDNESDAY WHEN A HIGH WIND EVENT LOOKS TO
BE TAKING SHAPE. AS A RESULT, CRITICAL FIRE CONDITIONS ARE EXPECTED
FOR MUCH OF THE WEEK AND EXTENSIONS AND EXPANSION OF FIRE WEATHER
HEADLINES IS LIKELY.
LOOKING SPECIFICALLY AT THE HIGH WIND POTENTIAL FOR WEDNESDAY, 700MB
FLOW REMAINS LARGELY NORTHWESTERLY, BUT A SHORTWAVE IS ANTICIPATED
TO MOVE ACROSS EASTERN MONTANA AND WESTERN NORTH DAKOTA TUESDAY
EVENING INTO WEDNESDAY MORNING. THIS SHORTWAVE WILL INCREASE HEIGHT
GRADIENTS ACROSS THE CWA, WITH THE 700MB JET INCREASING TO 50 TO 55
KTS IN RESPONSE, WITH SOME MODELS SUGGESTING 60+ KTS ACROSS THE
INTERSTATE-80 SUMMIT. GFS OMEGA FIELDS SUGGEST STRONG DOWNWARD
MOTION ALONG AND EAST OF THE LARAMIE RANGE DURING THIS TIME,
FAVORING A POTENTIAL HIGH WIND EVENT TUESDAY INTO WEDNESDAY,
ESPECIALLY IN THE TYPICAL WIND PRONE REGIONS OF SOUTHEAST WYOMING.
IN-HOUSE, RANDOM FOREST GUIDANCE SUGGESTS AROUND A 60 PERCENT
PROBABILITY OF HIGH WINDS AT ARLINGTON/ELK MOUNTAIN AND NEAR THE
INTERSTATE-80 SUMMIT. THIS SETUP WILL BE MONITORED OVER THE NEXT
SEVERAL DAYS TO DETERMINE WHETHER HIGH WIND HEADLINES ARE NEEDED.
FOR NOW, DANGER FIRE CONDITIONS ARE ANTICIPATED WEDNESDAY.
AVIATION /00Z TAFS THROUGH 00Z MONDAY/
ISSUED AT 1057 PM MDT SAT JUN 13 2026
LOW CLOUDS ARE PUSHING UP AGAINST THE HIGHER TERRAIN IN
NORTHEAST FLOW THIS EVENING. IN NEBRASKA, CIGS SHOULD REMAIN VFR
BUT GENERALLY BETWEEN 4K AND 7K FT. LAR AND CYS HAVE THE HIGHEST
PROBABILITIES (80%) FOR MVFR CONDITIONS. A FEW LIGHT SHOWERS ARE
ANTICIPATED, BUT VIS DROPS ARE NOT EXPECTED. STILL, VCSH WAS
MAINTAINED WITH THIS TAF ISSUANCE.
OVERALL WINDS WILL BE LIGHT NORTH TO NORTHEAST WINDS WITH
OCCASIONAL GUSTS TO AROUND 20 KNOTS POSSIBLE AT CYS AND NEBRASKA
TERMINALS. WINDS WILL BE OCCASIONALLY VARIABLE OVER THE HIGH
PLAINS. WINDS WILL CONTINUE TO GUST 20 TO 30 KNOTS AT RWL AND
LAR, BUT SHOULD DECREASE MID MORNING. EXPECT A GRADUAL DECREASE
IN CLOUD COVER SUNDAY AFTERNOON WITH MOSTLY LIGHT WINDS.
CYS WATCHES/WARNINGS/ADVISORIES
WY...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY
EVENING FOR WYZ417-418-432-433.
NE...FIRE WEATHER WATCH FROM MONDAY AFTERNOON THROUGH MONDAY
EVENING FOR NEZ434>437.
SHORT TERM...AM
LONG TERM...AM
AVIATION...MN
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