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FXUS65 KCYS 202010
AFDCYS
AREA FORECAST DISCUSSION
NATIONAL WEATHER SERVICE CHEYENNE WY
110 PM MST WED NOV 20 2024
KEY MESSAGES
- HIGH WIND WARNINGS REMAIN IN EFFECT UNTIL 5 PM THIS AFTERNOON
FOR ARLINGTON, ELK MOUNTAIN AND THE I-80 SUMMIT, INCLUDING
VEDAUWOO AND BUFORD.
- WARMING TREND ANTICIPATED FOR THURSDAY AND FRIDAY WITH LESS WIND.
. A STRONG COLD FRONT IS EXPECTED TO ARRIVE BY THE END OF THIS
WEEKEND WITH A RETURN TO NEAR-NORMAL TEMPERATURES.
SHORT TERM /THROUGH FRIDAY NIGHT/
ISSUED AT 104 PM MST WED NOV 20 2024
TONIGHT...BASED ON RECENT OBSERVATIONS, THE HIGH WIND WARNING LOOKS
GOOD UNTIL 5 PM. GRADIENTS BEGIN TO RELAX LATE THIS AFTERNOON AS
EVIDENCED BY THE CRAIG TO CASPER 850/700 MB HEIGHT DIFFERENCES AND
LOOKING AT OUR LOCAL WIND MODEL, SO WINDS SHOULD DECREASE BELOW HIGH
WIND CRITERIA BY EARLY EVENING. AS RIDGING ALOFT MOVES OVERHEAD, THE
LOW LEVELS WILL MODERATE WITH WARMER OVERNIGHT MINIMUM TEMPERATURES
COMPARED TO LAST NIGHT.
THURSDAY...A RATHER PLEASANT DAY WEATHERWISE WITH RIDGING ALOFT, AND
700 MB TEMPERATURES NEAR 4 CELSIUS YIELDING MAXIMUM TEMPERATURES
FROM THE UPPER 40S TO UPPER 50S. LOW AND MID LEVEL GRADIENTS SUGGEST
BREEZY CONDITIONS ALONG AND WEST OF I-25.
THURSDAY NIGHT/FRIDAY...RIDGING ALOFT FLATTENS, LEADING TO ZONAL
FLOW ALOFT AND THE DEVELOPMENT OF A SURFACE LEE TROUGH, HELPING TO
CONTINUE THE WARMING TREND. 700 MB TEMPERATURES NEAR 4 CELSIUS AND
DOWNSLOPE WINDS WILL HELP YIELD MAXIMUM TEMPERATURES IN THE LOWER
50S WEST OF I-25, WITH MID 50S TO MID 60S FURTHER EAST. TOO DRY FOR
ANY PRECIPITATION AND MINIMAL CLOUD COVER AS WELL.
FRIDAY NIGHT...ZONAL FLOW ALOFT CONTINUES AND WITH DECENT LOW LEVEL
MIXING, LOW TEMPERATURES WILL BE EVEN MORE MILD FOR MOST LOCATIONS,
ESPECIALLY JUST TO THE LEE OF THE LARAMIE RANGE, WHERE ABOVE
FREEZING MINIMUM TEMPERATURES LOOK LIKELY.
LONG TERM /SATURDAY THROUGH TUESDAY/
ISSUED AT 104 PM MST WED NOV 20 2024
LONG TERM FORECAST WILL SEE THE RETURN OF ACTIVE WEATHER, WITH THE
UPPER LEVEL RIDGE BEGINNING TO BREAK DOWN BY THE WEEKEND AS SEVERAL
SHORTWAVE TROUGHS DIG ACROSS THE NORTH CONUS AND ALLOW FOR DAILY
CHANCES FOR PRECIPITATION SUNDAY ONWARD. BEST DAYS FOR WIDESPREAD
RAIN/SNOW ARE CENTERED ON BOTH SUNDAY AND WEDNESDAY WHERE THE
STRONGEST OF THE SERIES OF SHORTWAVES UNDERCUT THE MAIN FLOW AND
PROPAGATE EAST FROM THE INTERMOUNTAIN WEST INTO THE HIGH PLAINS.
SOME CONCERNS WITH HOW MUCH MOISTURE ADVECTION WILL BE ASSOCIATED
WITH THE PREDOMINANTLY WESTERLY FLOW AND PUSHING THE BETTER PWATS
JUST THE SOUTH INTO COLORADO. ULTIMATELY, WILL DEPEND ON WHAT MODEL
IS ABLE TO LOCK ONTO THE EXPECTED FLOW, WITH A DECENT AMOUNT OF
MODEL INCONSISTENCY BETWEEN THE MEDIUM TO LONG RANGE MODELS AND BOTH
THE GFS AND EURO ALTERNATING BETWEEN THE OVERALL FLOW PATTERN. AT
THE TIME OF THIS FORECAST ANALYSIS, THE GFS HAS BEEN KEEPING A MORE
ZONAL FLOW AND THE EURO HAVING SOME ELEMENTS TO A BRIEFLY EMERGING
SOUTHWESTERLY FLOW TO THE SOUTH OF EACH SHORTWAVE, WITH THE EURO
SOLUTION BRINGING IN MUCH BETTER MOISTURE ADVECTION INTO THE REGION.
IN ADDITION TO PRECIPITATION THROUGH THE LATE WEEKEND, SOME CHANCES
FOR STRONGER WINDS ARE POSSIBLE ON SUNDAY, WHICH IS ASSOCIATED WITH
THE STRONG SHORTWAVE. THIS HAS CONTINUED TO GAIN TRACTION WITH THE
NBM V4.2 PROBABILITY OF EXCEEDING 41KTS INDICATING A HIGH LIKELIHOOD
OF GREATER THAN 41 KNOT WINDS ACROSS THE SOUTHERN TO CENTRAL LARAMIE
RANGE, SPILLING OVER INTO THE I-25 CORRIDOR NEAR BORDEAUX, IN
ADDITION TO ALBANY AND CARBON COUNTY. WILL NEED TO CONTINUE TO TRACK
THE REST OF THE WEEK FOR STRONGER WINDS, WITH INCREASED PRESSURE
GRADIENTS IN-BETWEEN EACH SHORTWAVE AS QUASI-ZONAL TO ZONAL FLOW
SETS UP AND INCREASES THE WESTERLY FLOW ACROSS WYOMING AND NEBRASKA.
HOWEVER, CURRENTLY IN-HOUSE MODEL GUIDANCE ONLY INDICATES HIGHER
WIND ON SUNDAY AND DOES NOT HAVE DECENT PROBABILITIES FOR ANY OTHER
DAYS DUE TO THE DIRECTION OF THE FLOW.
AVIATION /18Z TAFS THROUGH 18Z THURSDAY/
ISSUED AT 1016 AM MST WED NOV 20 2024
VFR CONDITIONS LIKELY THROUGH THE FORECAST PERIOD FOR ALL
TERMINALS. UPPER LEVEL RIDGING IS PROGGED TO CONTINUE PUSHING
EAST THROUGHOUT THE DAY WITH THE RIDGE AXIS CENTERING ACROSS THE
INTERMOUNTAIN WEST IN THE AFTERNOON HOURS. MAIN CONCERNS
THROUGH THE FORECAST PERIOD INCLUDE GUSTY TO STRONGER WINDS AS
SHORTWAVE DISTURBANCES PULSE WITHIN THE FLOW ON THE BACKSIDE OF
THE UPPER LEVEL CLOSED LOW CYCLING ACROSS THE GREAT LAKES. ONCE
THIS FEATURE CONTINUES TO MOVE EAST INTO THE EASTERN SEABOARD,
SHOULD SEE THESE WINDS DECREASE THIS EVENING.
CYS WATCHES/WARNINGS/ADVISORIES
WY...HIGH WIND WARNING UNTIL 5 PM MST THIS AFTERNOON FOR WYZ110-116.
NE...NONE.
SHORT TERM...RUBIN
LONG TERM...MRD
AVIATION...MRD/GERHARDT
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