360
FXUS65 KCYS 131109
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
509 AM MDT FRI MAR 13 2026
KEY MESSAGES
- HIGH WIND WARNINGS AND RED FLAG WARNINGS REMAIN IN EFFECT
THROUGH SATURDAY EVENING AND INTO THE OVERNIGHT HOURS. GUSTS
BETWEEN 70 AND 85MPH ARE EXPECTED THROUGH THIS PERIOD.
- WIDESPREAD PRECIPITATION EXPECTED TO RETURN SUNDAY AS A POTENT
COLD FRONT RACES THROUGH THE REGION. HIGH TEMPERATURES SUNDAY
WILL BE ABOUT 40F COLDER THAN HIGHS ON SATURDAY.
- RECORD WARM TEMPERATURES MAY BE IN STORE FOR THE REGION BY
MID-WEEK, BUT UNCERTAINTY IS HIGHER AT THIS TIME.
SHORT TERM /THROUGH SUNDAY NIGHT/
ISSUED AT 253 AM MDT FRI MAR 13 2026
VERY STRONG WINDS HAVE CONTINUED TONIGHT ACROSS MUCH OF THE AREA,
BUT ESPECIALLY SOUTHEAST WYOMING. CURRENT GOES19 NIGHTTIME CLOUD
MICROPHYSICS SHOWS AN INTERESTING FEATURE FROM ABOUT DOUGLAS,
SOUTHEAST TO CHUGWATER, AND OVER TOWARDS CARPENTER. LOOKING AT
CURRENT OBSERVATIONS EAST AND WEST OF THE THIS FEATURE, IT WAS
DETERMINED TO BE THE STALLED COLD FRONT ACROSS THE REGION ATTEMPTING
TO PUSH WESTWARD, BUT THE HIGH WINDS COMING OFF THE LARAMIE RANGE
PREVENTING WESTWARD MOVEMENT. AS A RESULT, A CLEAR BOUNDARY HAS SET
UP ON SATELLITE ACROSS SOUTHWEST WYOMING THIS MORNING. WINDS GUSTS
ALONG I-80 HAVE REMAINED IN THE 65-85MPH RANGE, WITH THE WIND PRONE
AREAS SEEING THE HIGHEST GUSTS. AREAS EAST OF THE I-25 CORRIDOR ARE
SEEING RELATIVELY CALMER WINDS THIS EVENT AS THE MOUNTAIN WAVE HAS
RETREATED BACK OVER THE LARAMIE RANGE, RATHER THAN DOWNSTREAM. THIS
LULL IS ONLY EXPECTED FOR A COUPLE MORE HOURS BEFORE HIGH WINDS
RETURN TO MUCH OF SOUTHEAST WYOMING THIS MORNING INTO THE AFTERNOON
HOURS THROUGH LATE SATURDAY NIGHT. WIND GUSTS ON THURSDAY PEAKED
BETWEEN ABOUT 80 TO 95MPH WITH BEAR CREEK SEEING A FEW GUSTS AT
109MPH. SLIGHTLY LOWER WIND GUSTS ARE EXPECTED FOR FRIDAY, BUT
LIKELY BETWEEN ABOUT 75 AND 85MPH.
FOR TODAY, BROADLY NORTHWESTERLY FLOW ALOFT WILL CONTINUE THROUGH
ABOUT 00Z THIS EVENING, WHEN UPPER-LEVEL WINDS SHIFT MORE WESTERLY
DUE TO A WEAK SHORTWAVE RIDGE PUSHING UP FROM THE SOUTHWEST TOWARDS
THE CWA. THIS RIDGE WILL EVENTUALLY BE ABSORBED INTO THE UPPER-LEVEL
ZONAL FLOW, ESPECIALLY AS THE NEXT UPPER-LEVEL TROUGH PUSHES SOUTH
TOWARDS THE REGION LATE SATURDAY NIGHT INTO EARLY SUNDAY MORNING.
THIS TROUGH WILL BE THE NEXT WEATHER MAKER ACROSS CWA, WITH
WIDESPREAD RAIN AND SNOWFALL LOOKING INCREASINGLY LIKELY. FRIDAY AND
SATURDAY, 700MB FLOW WILL REMAIN HIGHLY ELEVATED DUE TO ELEVATED
HEIGHT GRADIENTS ACROSS MUCH OF THE WESTERN CONUS. AS A RESULT, A
700MB JET BETWEEN ABOUT 65 AND 70KTS WILL REMAIN OVER THE LARAMIE
RANGE FRIDAY AND SATURDAY, FAVORING THE CONTINUATION OF HIGH WINDS
ACROSS SOUTHEAST WYOMING. FRIDAY MORNING THROUGH FRIDAY NIGHT WILL
HAVE THE STRONGEST, WIDESPREAD HIGH WINDS BETWEEN FRIDAY AND
SATURDAY AS THE STRONG 700MB JET IS MORE WIDESPREAD WITH IMPRESSIVE
DOWNWARD OMEGA GRADIENTS CONTINUING. SATURDAY THE STRONGEST 700MB
JET IS EXPECTED TO RETREAT FURTHER NORTH, MORESO ACROSS WESTERN
PLATTE COUNTY, THOUGH DOWNWARD OMEGAS ARE PROGGED TO BE MAXED OUT
ALONG THE ENTIRE LARAMIE RANGE. AS A RESULT, EXPECT VERY STRONG WIND
GUSTS BETWEEN 75 AND 85MPH TO CONTINUE BOTH FRIDAY AND SATURDAY,
WITH THE STRONGEST GUSTS LIKELY TO BE MORE WIDESPREAD ON FRIDAY AS
COMPARED TO SATURDAY, THOUGH STILL FAIRLY WIDESPREAD. HIGH WIND
WARNINGS WILL CONTINUE THROUGH LATE SATURDAY NIGHT FOR ALL AREAS.
TEMPERATURES FRIDAY AND SATURDAY WILL BE QUITE WARM WITH THESE
STRONG DOWNSLOPING WINDS, LIKELY IN THE MID-50S TO LOW-70S BOTH
DAYS.
UNFORTUNATELY WITH CONTINUED STRONG, DOWNSLOPING WINDS AND WARMER
TEMPERATURES, DRY CONDITIONS WILL PERSIST FRIDAY AND SATURDAY BEFORE
THE NEXT SURGE OF MOISTURE RETURNS ON SUNDAY. AFTERNOON RELATIVE
HUMIDITY VALUES ARE ANTICIPATED TO DROP INTO THE 15-22% RANGE FRIDAY
AFTERNOON. OVERNIGHT HUMIDITY RECOVERIES WILL BE QUITE POOR FRIDAY
INTO SATURDAY, LIKELY ONLY IN THE 30-45% RANGE. AS A RESULT, EVEN
DRIER RELATIVE HUMIDITY VALUES ARE EXPECTED SATURDAY, LIKELY IN THE
15-20% RANGE ACROSS A MORE WIDESPREAD AREA. WITH WINDS STILL GUSTING
UP TO 70MPH ACROSS SOUTHEAST WYOMING AND 50MPH ACROSS WESTERN
NEBRASKA, CRITICAL FIRE WEATHER CONDITIONS WILL CONTINUE TODAY AND
SATURDAY. THEREFORE, RED FLAG WARNINGS REMAIN IN EFFECT THROUGH LATE
SATURDAY NIGHT.
A DIFFERENT STORY IS EXPECTED SUNDAY AS THE UPPER-LEVEL TROUGH
STRENGTHENS AND MOVES INTO THE INTERMOUNTAIN WEST EARLY SUNDAY
MORNING THROUGH MUCH OF THE DAY. VERY STRONG 500MB CYCLONIC
VORTICITY ADVECTION IS EXPECTED EARLY SUNDAY MORNING, LEADING TO THE
RAPID DEEPENING OF THE UPPER-LEVEL TROUGH IN THE MID-MORNIGN HOURS
SUNDAY. A DECENTLY STRONG 700MB LOW WILL MOVE SOUTHEAST FROM EASTERN
MONTANA INTO EASTERN SOUTH DAKOTA THROUGHOUT THE LATE NIGHT HOURS
SATURDAY INTO THE VERY EARLY HOURS SUNDAY MORNING. THE ASSOCIATED
SURFACE LOW WILL STRENGTHEN QUICKLY EARLY SUNDAY MORNING, RESULTING
IN STRONG SURFACE PRESSURE GRADIENTS, CONTINUED STRONG WINDS, AND A
POTENT COLD FRONT PUSHING DOWN FROM THE NORTH. THE COLD FRONT IS
EXPECTED TO DROP 700MB TEMPERATURES FROM ABOUT 3 TO 5C LATE SATURDAY
NIGHT TO -22 TO -20C BY NOON SUNDAY. SUNDAY'S DAYTIME TEMPERATURES
WILL STRUGGLED TO REACH THE 30S ACROSS MUCH OF THE AREA, WITH SUNDAY
MORNING LOWS IN THE TEENS AND MONDAY MORNING LOWS IN THE SINGLE
DIGITS TO TEENS. THEREFORE, TEMPERATURES ARE EXPECTED TO BE ABOUT
40F COOLER FROM SATURDAY AFTERNOON TO SUNDAY AFTERNOON, A BRUTAL
REMINDER THAT WINTER HAS NOT YET LEFT SOUTHEAST WYOMING AND WESTERN
NEBRASKA. WITH A COLD FRONT THIS STRONG, VERY GUSTY WINDS ARE
EXPECTED BEHIND THE FRONT, LIKELY LASTING THROUGHOUT MOST OF THE DAY
SUNDAY, ESPECIALLY ALONG I-80 FROM CHEYENNE TO SIDNEY. IN ADDITION
TO THE VERY COLD TEMPERATURES, WIDESPREAD PRECIPITATION IS EXPECTED
WITH THE COLD FRONT DUE TO INCREASED MOISTURE ACROSS THE REGION AND
STRONG LIFTING MECHANISMS. PRECIPITATION IS CURRENTLY EXPECTED TO
FALL INITIALLY AS RAIN ACROSS THE LOWER ELEVATIONS BEFORE QUICKLY
SWITCHING OVER THE SNOW. PRIMARILY SNOW IS EXPECTED IN THE HIGHER
ELEVATIONS. CURRENT FORECAST SNOW ACCUMULATION RANGES FROM ABOUT 0.5
INCHES TO 1.5 INCHES IN THE LOWER ELEVATIONS, AND 6 TO 8 INCHES IN
THE MOUNTAINS.
LONG TERM /MONDAY THROUGH THURSDAY/
ISSUED AT 253 AM MDT FRI MAR 13 2026
COOL TEMPERATURES ARE EXPECTED TO CONTINUE ON MONDAY AS THE UPPER-
LEVEL TROUGH SLOWLY PUSHES WEST AND FUNNELS COLD, CANADIAN AIR INTO
THE REGION THROUGHOUT THE DAY. PRECIPITATION OUTSIDE OF THE
MOUNTAINS IS EXPECTED TO END BY MONDAY EVENING, WITH MOUNTAIN
SNOWFALL CHANCES CONTINUING THROUGH TUESDAY MORNING. HOWEVER, A
PATTERN CHANGE IS EXPECTED BY TUESDAY AS A POTENT UPPER-LEVEL RIDGE,
THE LIKES OF WHICH ARE USUALLY SEEN IN JULY, BUILDS OVER THE
SOUTHWESTERN CONUS. 500MB TEMPERATURES ARE CURRENTLY PROGGED TO BE
MAXED OUT PER THE NAEFS MEAN TEMPERATURES CLIMATOLOGY, AND CONTINUE
TO BE SO THROUGH THE END OF NEXT WEEKEND. 700MB TEMPERATURES ARE
CURRENTLY PROGGED TO BE MAXED OUT AS WELL BY THURSDAY EVENING ACROSS
THE AREA, RESULTING IN A VERY STRONG WARMING PATTERN THROUGH THE
UPCOMING WEEK. WITH THE RIDGE ALOFT, MINIMAL PRECIPITATION WILL BE
EXPECTED, ESPECIALLY WEDNESDAY THROUGH FRIDAY WHEN THE RIDGE STARTS
SIGNIFICANTLY IMPACTING THE REGION. WITH NAEFS MEAN TEMPERATURES
CLIMATOLOGY VALUES BEING MAXED OUT, TEMPERATURES MAY SOAR TO NEAR-
RECORD HIGH LEVELS AS EARLY AS WEDNESDAY AND POTENTIALLY CONTINUING
THROUGH FRIDAY. CURRENT FORECAST IS AS FOLLOWS... WEDNESDAY: HIGHS
IN THE UPPER-60S TO MID-80S, THURSDAY: HIGHS IN THE LOW-70S TO UPPER-
80S, FRIDAY: HIGHS IN THE MID-70S TO UPPER-80S. THIS EVENT WILL BE
ONE TO KEEP A CLOSE EYE ON OVER THE NEXT SEVERAL DAYS, ESPECIALLY
WITH DRY CONDITIONS RETURNING UNDER THE RIDGE. NEXT WEEK COULD BE
VERY WARM, VERY DRY, AND POTENTIALLY QUITE WINDY DUE TO ELEVATED
700MB HEIGHT GRADIENTS THROUGH THE WEEK.
AVIATION /12Z TAFS THROUGH 12Z SATURDAY/
ISSUED AT 507 AM MDT FRI MAR 13 2026
VFR CONDITIONS EXPECTED TODAY FOR THE 12Z TAF PERIOD, BUT VERY
GUSTY WINDS ARE EXPECTED TO RETURN TO MOST TERMINALS. KRWL,
KLAR, AND KCYS WILL LIKELY SEE GUSTS IN EXCESS OF 50KTS
THROUGHOUT THE DAY, WHILE KBFF, KCDR, KSNY, AND KAIA WILL SEE
GUSTS IN EXCESS OF 40KTS. EXPECTING HIGH CLOUDS TO CONTINUE TO
DEVELOP THROUGH THE DAY, BUT LIKELY REMAINING AROUND 20,000FT
AGL. WINDS SLOWLY DECREASE AFTER SUNSET.
CYS WATCHES/WARNINGS/ADVISORIES
WY...RED FLAG WARNING UNTIL 6 PM MDT SATURDAY FOR WYZ430>433.
HIGH WIND WARNING UNTIL MIDNIGHT MDT SATURDAY NIGHT FOR WYZ101-
103>107-109-110-113-115>118.
HIGH WIND WARNING UNTIL 6 AM MDT SATURDAY FOR WYZ114.
NE...RED FLAG WARNING UNTIL 6 PM MDT SATURDAY FOR NEZ436-437.
SHORT TERM...AM
LONG TERM...AM
AVIATION...AM
CLICK HERE TO GO TO PREVIOUS BULLETINS.
Main Text Page