886
FXUS65 KCYS 150748
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
148 AM MDT MON JUN 15 2026
KEY MESSAGES
- A RED FLAG WARNING IS IN EFFECT FOR PORTIONS OF SOUTHEAST
WYOMING AND WESTERN NEBRASKA FROM NOON TO 9 PM MONDAY.
- A FIRE WEATHER WATCH IS IN EFFECT FOR ALL AREAS ALONG AND EAST
OF INTERSTATE 25 FROM NOON TUESDAY THROUGH 8 PM WEDNESDAY.
- A HIGH WIND WATCH HAS BEEN ISSUED FOR THE TYPICAL WIND PRONE
REGIONS OF SOUTHEAST WYOMING FROM 6 PM TUESDAY THROUGH 3 PM
WEDNESDAY.
- FIRE WEATHER CONCERNS CONTINUE TUESDAY THROUGH AT LEAST
FRIDAY, WITH DRY, BREEZY CONDITIONS AND VERY WARM
TEMPERATURES. MINIMAL PRECIPITATION EXPECTED DURING THIS TIME.
SHORT TERM /THROUGH WEDNESDAY/
ISSUED AT 147 AM MDT MON JUN 15 2026
UPPER-LEVEL RIDGING WILL BEGIN TO DOMINATE THE REGION STARTING THIS
MORNING AND CONTINUING THROUGH FRIDAY. THE UPPER-LEVEL RIDGE IS
STRENGTHENING OVER THE PACIFIC OCEAN AND WILL MOVE EASTWARD VERY
SLOWLY THROUGH THE FIRST HALF OF THE WEEK. BY WEDNESDAY MORNING, THE
RIDGE AXIS WILL FINALLY MOVE ONSHORE ACROSS THE WEST COAST.
NORTHWESTERLY FLOW WILL CONTINUE MONDAY THROUGHOUT THE WEEK DUE TO
THE UPPER-LEVEL RIDGE PLACEMENT, WHICH FAVORS DRY AIR FROM CANADA TO
SINK INTO THE REGION MOST DAYS THIS WEEK. A 700MB SHORTWAVE WILL
PUSH THROUGH THE NORTHERN PLAINS AND MIDWEST THIS EVENING INTO EARLY
TUESDAY MORNING, LIKELY RESULTING IN INCREASING WINDS ACROSS EASTERN
PORTIONS OF THE REGION AS A 700MB JET KICKS UP IN ASSOCIATION WITH
THE PASSING SHORTWAVE. THIS SHORTWAVE WILL BRING A WEAK COLD FRONT
THROUGH THE REGION EARLY TUESDAY MORNING, BUT 700MB TEMPERATURES
REBOUND QUICKLY AND COOLER TEMPERATURES WILL LIKELY NOT BE FELT
TUESDAY AFTERNOON. 700MB TEMPERATURES MONDAY WILL WARM INTO THE 5 TO
10C RANGE BY THE AFTERNOON HOURS, LEADING TO SURFACE TEMPERATURES IN
THE MID-70S TO LOW-80S. 700MB TEMPERATURES WARM QUICKLY INTO THE 13
TO 16C RANGE BY TUESDAY AFTERNOON LEADING TO SURFACE HIGH
TEMPERATURES IN THE MID-80S TO LOW-90S EVERYWHERE. WITH SUBSIDENCE
ALOFT FROM THE RIDGE, VERY DRY CONDITIONS ARE EXPECTED IN ADDITION
TO THE WARM TEMPERATURES, WITH AFTERNOON HUMIDITY VALUES DROPPING
INTO THE 10 TO 15 PERCENT RANGE EACH AFTERNOON MONDAY THROUGH
WEDNESDAY. AS A RESULT, A RED FLAG WARNING REMAINS IN EFFECT FOR
MONDAY AFTERNOON AND EVENING, WITH A FIRE WEATHER WATCH IN EFFECT
FROM NOON TUESDAY THROUGH 8PM WEDNESDAY EVENING. VERY FAVORABLE
CONDITIONS FOR RAPID FIRE SPREAD ARE EXPECTED BOTH DAYS.
WEDNESDAY LOOKS TO BE THE MOST INTERESTING DAY FOR THE WEEK AHEAD AS
A STOUT 700MB SHORTWAVE DIGS INTO EASTERN MONTANA SOUTHEASTWARD
THROUGH THE UPPER MIDWEST. THIS SHORTWAVE WILL EVENTUALLY
STRENGTHEN, BECOMING A CLOSED LOW BY WEDNESDAY MORNING. 700MB HEIGHT
GRADIENTS ACROSS THE REGION WILL INCREASE IN RESPONSE TO THE PASSING
AND DEEPENING 700MB SHORTWAVE, LEADING TO A 55 TO 60KT JET TUESDAY
NIGHT INTO THE EARLY MORNING HOURS WEDNESDAY. GFS OMEGA FIELDS
SUGGESTS AMPLE DOWNWARD MOTION ALONG AND EAST OF THE LARAMIE RANGE,
AS WELL AS NEAR THE SNOWY AND SIERRA MADRE RANGES. SURFACE PRESSURE
GRADIENTS WILL INCREASE TUESDAY NIGHT INTO WEDNESDAY MORNING AS THE
ATTENDANT SURFACE LOW STRENGTHENS ACROSS CENTRAL NEBRASKA, LEADING
TO A 3 TO 4MB GRADIENT ACROSS THE LARAMIE RANGE AND 5 TO 6MB
GRADIENT ACROSS THE SNOWY RANGE NEAR ARLINGTON. IN-HOUSE RANDOM
FOREST GUIDANCE SUGGESTS AROUND A 60% CHANCE FOR HIGH WINDS AT
ARLINGTON/ELK MOUNTAIN AND THE I-80 SUMMIT, WITH AROUND A 50% CHANCE
AT BORDEAUX. AS A RESULT, HIGH WINDS IN THE WIND PRONE REGIONS ARE
LOOKING INCREASINGLY LIKELY, SO A HIGH WIND WATCH HAS BEEN ISSUED
FROM 6 PM TUESDAY EVENING THROUGH 3 PM WEDNESDAY AFTERNOON.
LONG TERM /WEDNESDAY NIGHT THROUGH SUNDAY/
ISSUED AT 147 AM MDT MON JUN 15 2026
MORE BENIGN WEATHER RETURNS WEDNESDAY ONWARDS AT NORTHWESTERLY FLOW
CONTINUES ACROSS THE REGION AND THE 700MB LOW RESPONSIBLE FOR HIGH
WINDS TUESDAY INTO WEDNESDAY MOVES WELL OUT OF THE REGION.
TEMPERATURES THURSDAY WILL LIKELY BE THE COOLEST OF THE WEAK AS
COOLER AIR FUNNELS IN BEHIND THE DEPARTING 700MB LOW. DAYTIME HIGH
TEMPERATURES WILL BE IN THE LOW-70S TO LOW-80S, WITH DRY CONDITIONS
CONTINUING. AFTERNOON HUMIDITY VALUES WILL DROP TO THE 20 TO 25
PERCENT RANGE THURSDAY AFTERNOON, SO A BRIEF REPRIEVE FROM CRITICAL
FIRE DANGER IS POSSIBLE THURSDAY AFTERNOON. CRITICAL FIRE DANGER
LOOKS TO RETURN FRIDAY AS AFTERNOON TEMPERATURES WARM BACK INTO THE
MID-80S TO LOW-90S ONCE MORE AND AFTERNOON HUMIDITY VALUES DROP BACK
INTO THE 15 TO 20 PERCENT RANGE ONCE AGAIN. LITTLE TO NO
PRECIPITATION IS EXPECTED THROUGH AT LEAST FRIDAY. HOWEVER, AN UPPER-
LEVEL TROUGH ATTEMPTS TO DEVELOP AND MOVE INTO THE WESTERN CONUS
FRIDAY INTO SATURDAY AFTERNOON, POTENTIALLY BRINGING WIDESPREAD
PRECIPITATION CHANCES TO THE REGION AND LIMITING FIRE DANGER INTO
THE WEEKEND. LONG RANGE MODELS ARE IN GOOD AGREEMENT WITH THIS
TROUGH MOVING THROUGH, SO A COOLER, WETTER WEEKEND IS LIKELY IN
STORE FOR THE CWA.
AVIATION /06Z TAFS THROUGH 06Z TUESDAY/
ISSUED AT 1126 PM MDT SUN JUN 14 2026
VFR CONDITIONS ARE EXPECTED FOR THE FORECAST PERIOD, ALTHOUGH
THERE REMAINS A SLIM (10-20%) CHANCE FOR LOW CIGS MONDAY MORNING
AT CYS AND SNY. OTHERWISE, EXPECT LARGELY LIGHT AND OCCASIONALLY
VARIABLE WINDS OVERNIGHT OVER THE HIGH PLAINS, WHILE LAR AND RWL
MAY SEE OCCASIONAL GUSTS OF 15 TO 20 KNOTS. WINDS WILL SETTLE ON
NORTH-NORTHWEST AT ALL TERMINALS BETWEEN LATE MONDAY MORNING AND
THE MID AFTERNOON. LOOK FOR GUSTS OF 20 TO 30 KNOTS WHICH WILL
TAPER OFF AROUND SUNSET.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
WYZ417-418-432-433.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR WYZ417-418-430>433.
HIGH WIND WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING
FOR WYZ106.
HIGH WIND WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY MORNING
FOR WYZ110.
HIGH WIND WATCH FROM TUESDAY EVENING THROUGH WEDNESDAY
AFTERNOON FOR WYZ116-117.
NE...RED FLAG WARNING FROM NOON TODAY TO 9 PM MDT THIS EVENING FOR
NEZ434>437.
FIRE WEATHER WATCH FROM TUESDAY AFTERNOON THROUGH WEDNESDAY
EVENING FOR NEZ434>437.
SHORT TERM...AM
LONG TERM...AM
AVIATION...MN
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